f

Overview of the Human Body

Note: The circulatory system is covered in depth in the following chapter, so it is not included here.

1. Describe body systams

and define key

anatomical terms

Bodies are organized into body systems. Each system in the body has a condition under which it works best. Homeostasis is the name for the condition in which all of the body's systems are balanced and are working together to maintain internal stability. To be in homeostasis, the body's metabolism, or physical and chemical processes, must be working at a steady level.

When disease or injury occurs, the body's metabolism is disturbed, and homeostasis is lost.

Changes in metabolic processes are called signs (objective information) and symptoms (subjec-tive information). For instance, changes in the amounts of certain substances in the blood might be signs of liver damage in a patient. Fa-tigue, or feeling tired even when rested, might be a symptom of a condition like heart disease.

A blood test conducted as part of a routine examination may be the first indication that the body's homeostasis is disturbed. Testing may also help a provider whose patient is experiencing symptoms to determine what changes are happening in the body's systems. This information can aid diagnosis and treatment. Blood tests can also be helpful in measuring progress back toward homeostasis and improved health. The PBT makes this process possible by drawing high-quality specimens.

Each system in the body has its own unique structure and function. The body's systerns can be organized in different ways. In this book, the human body is divided into 10 systems:

Integumentary (skin)

Musculoskeletal

Nervous

Circulatory (covered in the next chapter)

Respiratory

Urinary

Gastrointestinal
Endocrine

Reproductive

Immune and Lymphatic

Body systems are made up of organs. An organ has a specific function. Organs are made up of tissues. Tissues are made up of groups of cells that perform a similar task. For example, in the gastrointestinal system, the stomach is one of the organs. It is made up of tissues and cells.

Cells are the building blocks of the body. Living cells divide, grow, and die, renewing the tissues and organs of the body.

Anatomical terms of location are descriptive terms to help identify positions or directions the body. Here are some anatomical terms used to describe location in the human body (Fig. 6-1):

Anterior or ventral: the front of the body or body part

Posterior or dorsal: the back of the body or body part
Superior: toward the head
Inferior: away from the head

• Medial: toward the midline of the body

• Lateral: to the side, away from the midline of the body

Proximal: closer to the torso

Distal: farther away from the torso

Right side

Left side

Superior:

toward the head

Proximal: closer to the torso

or ventral: + the front of the body or body part

Posterior

→ or dorsal: the back of the body or body part

Distal: farther away from the torso

Inferior: away from the head

Lateral: to the +-side, away from the midline of the body

Medial: toward the midline of the body

Fig. 6-1. PBTs should understand the terms used to indicate location or direction on the human body.

2. Describe the integumentary system

The largest organ and system in the body is the skin, a natural protective covering, or integu-ment. Skin prevents injury to internal organs, and it protects the body against entry of bacteria.

Skin also prevents the loss of too much water, which is essential to life. Skin is made up of layers of tissues. Within these layers are sweat glands, which secrete sweat to help cool the body when needed, and sebaceous glands, which secrete oil (sebum) to keep the skin lubricated.

There are also hair follicles, many tiny blood vessels (capillaries), and tiny nerve endings

(Fig. 6-2).

Openings of sweat ducts

Hair

shaft

Epidermis

Dermis

Sebaceous gland

Subcutaneo&

tissue

Sweat gland

Hair follicle

Fig. 6-2. Cross-section showing details of the integumen. tary system.

The skin is also a sense organ that feels heat, cold, pain, touch, and pressure. It then tells the brain what it is feeling. Body temperature is regulated in the skin. Blood vessels dilate, or widen, when the outside temperature is too high. This brings more blood to the body's surface to cool it off. The same blood vessels con• strict, or narrow, when the outside temperature is too cold. By restricting the amount of blood reaching the skin, the blood vessels help the body retain heat.

Capillaries, the smallest blood vessels in the body, are located in the dermis, which is the inner layer of skin. (Because of this, the speci men collection procedure called capillary pune-ture is also known as dermal puncture.) The dermis also contains nerves, sweat glands, sebr ceous (oil) glands, and hair roots. Sweat glands help control body temperature by secreting sweat. Sweat is made up of mostly water, but it also contains salt and a small amount of waste products. Sweat comes to the body's surface through pores, or tiny openings in the skin. l! cools the body as it evaporates. Sebaceous glands in the dermis secrete sebum (oil). Sebum comes to the skin surface through hair follicles, or roots. Sebum keeps the skin and hair lubricated.

No blood vessels and only a few nerve endings are located in the epidermis, which is the outer layer of skin. Thinner than the dermis, the epidermis contains both dead and living cells. The dead cells begin deeper in the epidermis. They are pushed to the surface as other cells divide and are eventually worn off. The epidermis also contains pigment cells that give skin its color.

Hair grows from roots located in the dermis. It grows through hair follicles that extend through the epidermis to the outside of the body. Hair protects the body from heat and cold. Hair inside the nose and ears keeps out particles and bacteria trying to enter the body.

The functions of the integumentary system are to protect internal organs from injury, protect the body against bacteria, and prevent the loss of too much water. It also responds to heat, cold, pain, touch, and pressure, and it regulates body temperature.

PBT Connection

Allergies occur due to an overactive response by the immune system, but they often produce symptoms in the integumentary system. Hives and rashes may be caused by allergies. Blood testing can help determine whether allergy plays a role in integumentary system problems. Blood tests for IgE, a type of antibody (protein made by the body to protect against foreign substances), may be ordered. IgE is produced as part of an allergic reaction. A complete blood count (CBC) may also be ordered, as allergies can increase the number of a particular type of white blood cell in a person's blood.

move, bones also protect organs. For example, the skull protects the brain and the vertebrae protect the spinal cord. Bones are hard and rigid, but are made up of living cells. Blood vessels supply oxygen and nutrients to the bones, as well as to other tissues of the body.

To the
body

Obi
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(V)

Overview of the Human Body

3. Describe the musculoskeletal system

Muscles, bones, ligaments, tendons, and cartilage give the body shape and structure. They work together to move the body. The skeleton, or framework, of the human body has 206 bones (Fig. 6-3). In addition to allowing the body to

Fig. 6-3. The skeleton is composed of 206 bones that aid movement and protect organs.

Two bones meet at a joint. Some joints, such as the ball-and-socket joint, make movement possible in all directions. This joint is a type of synovial joint. In this joint, the round end of one bone fits into the hollow end of the other bone, which allows it to move in all directions. The hip and shoulder joints are examples.

Other joints permit movement in one direction only. The hinge joint is another example of a synovial joint. Like the hinge of a door, a hinge joint permits movement in one direction only.

The elbow and knee are hinge joints. They bend in one direction only (Fig. 6-4). Ball-and-socket

joint

Tendon

Bone

Muscle

Hinge joint

Fig. 6-4. Muscles are connected to bones by tendons.

Bones meet at different types of joints. The ball-and-socket joint and the hinge joint are shown here.

Muscles provide movement of body parts to maintain posture and to produce heat. Muscles can be voluntary or involuntary. Voluntary muscles are also called skeletal muscles. They are attached to bones and can be moved when a person wants them to move. Examples of voluntary muscles are the arm and leg muscles, which are consciously controlled. Involuntary muscles cannot be consciously controlled. They automatically regulate the movement of organs and blood vessels. An example of an involuntary muscle is the heart.

The functions of the musculoskeletal system are to give the body shape and structure, to allow the body to move, to protect body organs, to maintain posture, and to produce heat.

PBT Connection

There are several different blood tests associated with the musculoskeletal system. One test, the erythrocyte sedimentation rate (ESR), measures the rate at which red blood cells settle to the bottom of a test tube. When the cells settle quickly, this can indicate

inflammation, though the test does not reveal the cause. Tests for certain antibodies may help diagnose arthritis. Levels of muscle enzymes may be measured to find out if muscle tissue is being dam. aged or destroyed by a disease process. These same tests can also help monitor progress in the treatment of musculoskeletal disorders.

4. Describe the nervous system

The nervous system is the control and message center of the body. It controls and coordinates all body functions. The nervous system also senses and interprets information from outside the human body.

The neuron, or nerve cell, is the basic unit of the nervous system. Neurons send messages or sensations from the receptors in different parts of the body, through the spinal cord, to the brain.

The nervous system has two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system is composed of the brain and spinal cord. The peripheral nervous system deals with the periphery, or outer part, of the body via the nerves that extend throughout the body (Fig. 6-5).

Brain

Spinal cord_

Central Nervous System

The C

The

cord

spin trut

COI up

Peripheral

Nervous System

Nerves

Fig. 6-5. The nervous system includes the brain, spinal cord, and nerves throughout the body. The Central Nervous System

The brain is housed within the skull. The spinal awd is housed within the spinal column. The spinal column extends from the brain into the trunk of the body. Both the brain and the spinal cord are covered by a protective membrane made up of three layers. Between two of these layers is the cerebrospinal fluid. This fluid circulates around the brain and spinal cord. It provides a cushion against injuries.

The brain has three main sections: the cere-brum, the cerebellum, and the brainstem (Fig.

6-6). The largest section of the human brain is the cerebrum. The outside layer of the cerebrum is the cerebral cortex. The cerebral cortex is the part of the brain in which thinking, analysis, association of ideas, judgment, emotions, and memory occur. The cerebral cortex also

Directs speech and emotions

Interprets messages from the eyes, ears, nose, tongue, and skin

Controls voluntary muscle movement
Cerebrum

Cerebral cortex.

and function in the right side of the body (Hig 6-7). Any illness in or injury to the right hemisphere affects functions on the left side of the body. Illness or injury in the left hemisphere dis. rupts function on the right side.

The right hemisphere controls movement and function in the left side of the body,

The left hemisphere controls movement and function in the right side of the bary.

Overview of the Human Body

Controlled by the left hemisphere of the brain

Controlled by the right hemisphere of the brain

Cerebellum

Brainstem

Fig. 6-6. The three main sections of the brain are the ce-rebrum, cerebellum, and brainstem.

The cerebrum is divided into right and left hemispheres. The right hemisphere controls movement and function in the left side of the body. The left hemisphere controls movement

Fig. 6-7. The right hemisphere controls movement and function in the left side of the body. The left hemisphere controls movement and function in the right side of the body.

The cerebellum controls balance and regulates the body's voluntary muscles. It produces and coordinates smooth movements. Someone who has a problem in the cerebellum will be uncoordinated and have jerky movements and muscle weakness.

The cerebrum and cerebellum are connected to the spinal cord by the brainstem. The brainstem contains a kind of regulatory center called the medulla oblongata. It controls heart rate, breath-ing, swallowing, coughing, vomiting, and clos. ing/opening of blood vessels.

The spinal cord is connected to the brain. It is protected by the bones of the spinal column.

Nerve pathways run through the spinal cord.

They conduct messages between the brain and the body, Cranial nerves attach to the brain and brainstem. Some of these nerves bring information from the sense organs to the brain. Some

Overview of the Human Body

control muscles, and others are connected to glands or organs, such as the lungs. There are 12 pairs of cranial nerves. Nerves that are attached to the spinal cord and connect the spinal cord to other parts of the body are called spinal Nerves. The brain communicates with most of the body through the spinal nerves. There are 31 pairs of spinal nerves.

The functions of the nervous system are to control and coordinate all body functions and to sense, interpret, and respond to changes occurring both inside and outside the human body.

The Nervous System: Sense Organs

The eyes, ears, nose, tongue, and skin are the body's major sense organs. They are considered part of the central nervous system because they contain receptors that receive impulses from the environment. They relay these impulses to the nerves.

The eye, which is about an inch in diameter, is located in a bony socket in the skull (Fig. 6-8).

The bony socket protects the eye, which is surrounded by muscles that control its movements.

Sclera

Cornea

Retina

Pupil

Iris

Fig. 6-8. The parts of the eye.

The outer part of the eye is called the sclera. The sclera appears white, except in front, where it is

called the cornea. The cornea is actually clear, but it appears colored because it lies over the iris, or the colored part of the eye. The pupil, or black circle in the center of the iris, widens or narrows to adjust the amount of light that enters the eye. Inside the back of the eye is the retina.

The retina contains cells that respond to light and send a message to the brain, where the picture is interpreted so a person can see.

The ear is a sense organ that provides balance and hearing. It is divided into three parts: the outer, middle, and inner ear (Fig. 6-9). The outer ear is the funnel-shaped outer part, sometimes called the auricle or pinna. It guides sound waves into the auditory canal. This canal is about 1 inch long and contains many glands that secrete ear-wax. Earwax and hair in the ear protect the ear from foreign objects. The eardrum, or tympanic membrane, separates the outer ear from the middle ear.

transi ear al taini

PBl

cer

con

per

wi te

Outer ear

Middle ear Inner ear

Ossicles

Eardrum

Internal auditory canal

Auricle or pinna

Cochlea

Ossicle

Auditory canal Eustachian tube

Fig. 6-9. The outer ear, middle ear, and inner ear are the three main divisions of the ear.

The middle ear consists of the eustachian tube and three ossicles, small bones that amplify sound. The ossicles transmit sound to the inner ear. The eustachian tube connects the middle ear to the throat. It functions to allow air into the middle ear to equalize pressure on the tympanic membrane. The inner ear contains fluid that carries sound waves from the middle ear to the auditory nerve. The auditory nerve then tranemite the immpulse to the brain. The inner ear also contains structures that help in maintaining balance.

PBT Connection

Cerebrovascular accident, or stroke, is one of the most common disorders of the nervous system. It happens when the blood supply to a part of the brain is blocked, or when a blood vessel leaks or ruptures within the brain. There is no blood test that can detect or confirm a stroke. When a stroke is suspected however, blood tests will be ordered to rule out other possible causes of the patient's symptoms. Blood tests might also provide clues to possible causes of stroke, such as abnormal blood clotting. Nervous system disorders like Parkinson's disease and multiple sclerosis cannot be diagnosed by blood test, but blood tests are likely to be ordered for patients in whom these illnesses are suspected. They can help the doctor determine if other problems might be causing the patient's symptoms. Researchers are working to develop blood tests that can diagnose these and other nervous system illnesses. Most of this research centers on testing the patient's blood for biological markers associated with certain diseases.

5. Describe the respiratory system

Respiration is the body taking in oxygen and removing carbon dioxide. It involves breathing in, or inspiration, and breathing out, or expiration.

The lungs accomplish this process (Fig. 6-10).

Pharynx

Trachea

Larynx

Bronchus

Lungs

Bronchus

Bronchioles

Fig. 6-10. The respiratory process begins with inspiration through the nose or mouth. The air travels through the trachea and into the lungs via the bronchi, which then branch into bronchioles.

As the lungs inhale, the air is pulled in through

the nose and into the pharynx, a tubular passageway for both food and air. From the phar-ynx, air passes into the larynx, or voice box.

The larynx is located at the beginning of the trachea, or windpipe. The trachea divides into two branches at its lower portion, the right and left bronchus, or bronchi. Each bronchus leads into a lung and then subdivides into bronchioles.

These smaller airways subdivide further. They end in alveoli: tiny, one-cell sacs that appear in grape-like clusters. Blood is supplied to the alve-

Overview of the Human Body

oli by capillaries. Oxygen and carbon dioxide are exchanged between the alveoli and capillaries.

Oxygen-saturated blood then circulates through the capillaries and venules (small veins) of the lungs into the pulmonary vein and left side of the heart. The carbon dioxide is exhaled through the alveoli into the bronchioles and bronchi of the lungs, through the trachea, through the larynx and the pharynx, and out the nose and mouth.

Each lung is covered by the pleura, a membrane with two layers. One is attached to the chest wall. The other is attached to the surface of the lung. The space between the layers is filled with a thin fluid that lubricates the layers, preventing them from rubbing together during breathing The functions of the respiratory system are to bring oxygen into the body and to eliminate carbon dioxide produced as the body uses oxygen.

PBT Connection

Blood gas testing is commonly used to evaluate the function of the respiratory system. Blood is usually drawn from an artery (arterial blood gas test), but in some cases may be drawn from a vein or from the capillaries (especially in infants). The pH (acid/base balance), oxygen level, and carbon dioxide level of the blood is tested, showing providers how well the lungs are working. Entry-level PBTs do not generally collect arterial blood specimens, but they may draw other specimens for blood gas testing. Blood tests are also important in the diagnosis of cystic fibrosis, a genetic disorder (passed down through families) that, among other symptoms, causes recurring respiratory illnesses. Newborn infants are screened, through blood tests, for a number of illnesses, including cystic fibrosis.

6. Describe the urinary system

The urinary system is composed of two kidneys, two ureters, one urinary bladder, a single ure-thra, and a meatus (Figs. 6-11 and 6-12).

Kidney

Ureter

Urinary bladder

-Urethra

Meatus

Fig. 6-11. The urinary system consists of two kidneys and two ureters, the bladder, the urethra, and the meatus.

This is an illustration of the male urinary system.

- Kidney

Ureter

Urinary

bladder

Urethra

Meatus

Fig. 6-12. The female urethra is shorter than the male urethra. This is one reason why the female bladder is more likely to become infected by bacteria.

The kidneys are located in the upper part of the abdominal cavity on each side of the spine.

These two bean-shaped organs are protected by

the muscles of the back and the lower part of the rib cage. When blood flows through the kidneys, waste products and excess water are filtered out.

Necessary water and substances are reabsorbed into the bloodstream. Waste and the remaining fluid form urine. The body must maintain a proper balance between water absorbed in the body and waste fluids that are released from the body.

Each kidney has a ureter, which is attached to the bladder. Urine flows through the ureters to the bladder, a muscular sac in the lower part of the abdomen. Urine flows from the bladder through the urethra. It then passes out of the body through the meatis, the opening at the end of the urethra. In the female, the meatus is located in the genital area just in front of the opening of the vagina. In the male, the meatus is located at the end of the penis.

The urinary system has two important func-tions. Through urine, the urinary system eliminates waste products created by the cells. The urinary system also maintains the water balance in the body.

PBT Connection

Urinary tract infections are among the most common disorders of the urinary system. They are usually detected through urinalysis, or the examination of a patient's urine. Many PBTs are trained to collect urine specimens. Urinalysis and blood tests are both used in the diagnosis of kidney disorders. When a doctor is assessing a patient for possible kidney disease, she will test the patient's blood for the presence of certain waste products. The presence of these wastes shows that the kidneys are not filtering the blood as effectively as they should be. The series of tests ordered to evaluate kidney health is known as a renal panel.

7. Describe the gastrointestinal system

The gastrointestinal (GI) system, also called the digestive system, is made up of the gastrointestinal tract and the accessory digestive organs (Fig. 6-13). The gastrointestinal tract is a long passageway extending from the mouth to the anus, the opening of the rectum. Food passes from the mouth through the pharynx, esopha-gus, stomach, small intestine, and large intes-tine, then out of the body as solid waste (feces or stool. The teeth, tongue, salivary glands, liver, gallbladder, and pancreas are the accessory organs to digestion. They help prepare the food so that it can be absorbed.

Mouth

Tongue

Pharynx (throat)

- Salivary glands

Esophagus

Liver-

Gallbladder-

Pancreas

-Stomach

Appendix-

Small intestine

- Large intestine

Rectum

Anal canal

Fig. 6-13. The Gl system consists of all the organs needed to digest food and process waste.

Food is first placed in the mouth. The teeth chew it by cutting it, then chopping and grinding it into smaller pieces that can be swallowed Saliva moistens the food and begins chemical digestion. The tongue helps with chewing and swallowing by pushing the food around between the teeth and then into the pharynx. The pharynx is a muscular structure located at the back of the mouth. It extends into the throat. It contracts with swallowing and pushes food into the esophagus. The muscles of the esophagus then move food into the stomach through involuntary contractions called peristalsis.

The stomach is a muscular pouch located in the upper left part of the abdominal cavity.

Overview of the

ems an

It provides physical digestion by stirring and churning the food to break it down into smaller particles. The glands in the stomach lining aid in digestion. They secrete gastric juices that

chemically break down food. This process turns food into a semiliquid substance called chyme.

Peristalsis continues in the stomach, pushing the chyme into the small intestine.

The small intestine is about 20 feet long. Here enzymes secreted by the liver and the pancreas finish digesting the chyme. Bile, a green liquid produced by the liver, is stored in the gallblad-

Overview of the Human Body

der and released into the small intestine. Bile helps break down dietary fat. The liver converts fats and sugars into glucose, a natural sugar that can be carried to cells by the blood. The liver also stores glucose. The pancreas produces insulin, a hormone that works to move glucose from the blood into the cells for energy for the body.

The chyme is moved by peristalsis through the small intestine. There villi, tiny projections lining the small intestine, absorb the digested food into the capillaries.

Peristalsis moves the chyme that has not already been digested through the large intestine. In the large intestine, most of the water in the chyme is absorbed. What remains is feces, a semisolid material of water, solid waste material, bacteria, and mucus. Feces passes by peristalsis through the rectum, the lower end of the colon. It moves out of the body through the anus, the rectal opening.

The gastrointestinal system has the following functions: digestion, absorption, and elimina-tion. Digestion is the process of preparing food physically and chemically so that it can be absorbed into the cells. Absorption is the transfer of nutrients from the intestines to the cells. Elimination is the process of expelling wastes (made up of the waste products of food and fluids) that are not absorbed into the cells. PBT Connection

Common blood tests associated with gastrointestinal diseases and disorders include tests for antibodies often present in patients with digestive illnesses such as Crohn's disease or ulcerative colitis. There are also many blood tests related to the health of the liver. These tests, known as a hepatic function panel or liver function tests, check the levels of certain substances and enzymes in the blood. The results can help a provider determine if a patient's liver is functioning properly. PBTs may also assist in collecting stool samples or in conducting CLIA-waived tests such as checking stool for the presence of hidden (occult) blood, which can be an indicator of colon or rectal cancer.

8. Describe the endocrine system

The endocrine system is made up of glands in different areas of the body (Fig. 6-14). Glands are organs that produce and secrete chemicals called hormones. Hormones are chemical substances created by the body that control numerous body functions. Hormones are carried in the blood to various organs.

Pituitary

Thyroid-

Parathyroids

Thymus

Adrenals.

-Pancreas

Ovaries (in female)

Testes (in male)

Fig. 6-14. The endocrine system includes organs that produce hormones that regulate essential body processes.

The pituitary gland, often called the master gland, is located behind the eyes at the base of the brain. It secretes key hormones that cause other glands to produce other hormones. The following are some hormones secreted by the pituitary gland:

•

Growth hormone, which regulates growth and development

Antidiuretic hormone (ADH), which controls the balance of fluids in the body

Oxytocin, which causes the uterus to contract during and after childbirth The pituitary gland also produces hormones that regulate the thyroid gland and the adrenal glands. The thyroid gland is located in the neck in front of the larynx. It produces thyroid hor-mone, which regulates metabolism, the burning of food for heat and energy.

The parathyroid glands secrete a hormone that regulates the body's use of calcium. Nerves and muscles require calcium to function smoothly.

A deficiency of this hormone can cause severe muscle contractions and spasms. It can be fatal if untreated.

The pancreas, a gland located in the upper midsection of the abdomen, secretes insulin. Insulin is a hormone that works to move glucose (natu-ral sugar) from the blood and into the cells for energy for the body.

The body has two adrenal glands. One is at the top of each kidney. They produce hormones that are essential to life. These hormones are important because they help the body regulate carbohydrate metabolism. They also control the body's reaction to stress and regulate salt and water absorption in the kidneys. Adrenal glands also produce the hormone adrenaline, which regulates muscle power, heart rate, blood pressure, and energy levels during stressful situations or emergencies.

Gonads, or sex glands, produce hormones that regulate the body's ability to reproduce. The testes in the male secrete testosterone. The ovaries in the female secrete estrogen and progesterone.

The functions of the endocrine system are to maintain homeostasis through hormone se-cretion, influence growth and development, maintain blood sugar levels, and regulate levels of calcium and phosphate in the body. The endocrine system also regulates the body's ability to reproduce and determines how fast cells burn food for energy.

PBT Connection

Many blood tests are associated with diseases and disorders of the endocrine system. Diabetes is an illness in which the pancreas does not produce enough insulin or does not produce any insulin.

Blood tests to check how much glucose is present in the blood help to diagnose and manage diabetes.

Patients with diagnosed diabetes may test their own blood regularly, and PBTs may also be trained to perform CLIA-waived tests for blood glucose levels.

PBTs may also assist in performing glucose challenge or glucose tolerance tests. In these tests, a patient drinks a very sweet liquid and then has her blood drawn for testing at certain intervals. These tests are commonly performed to check for gestational diabetes, a form of diabetes associated with pregnancy. Blood tests are also commonly used to diagnose and monitor treatment for other endocrine system disorders such as hyperthyroidism and hypo-thyroidism. In these disorders the levels of thyroid hormone, which controls many body processes, are either too high (hyper) or too low (hypo).

9. Describe the reproductive system

The reproductive system is made up of the reproductive organs, which are different in men and women. The reproductive system allows human beings to reproduce, or create new human life.

Reproduction begins when a male's and female's sex cells (sperm and ovum) join. These sex cells are formed in the male and female sex glands.

These sex glands are called the gonads.

In the male, the gonads are the testes, also called testicles. The two oval glands are located outside the body in the scrotum. The scrotum is

a sac made of skin and muscle that is suspended between the thighs. The testes produce the male sex cells, called sperm, and testosterone (Fig. 6-15). Testosterone is the hormone needed for the male reproductive organs to function properly. Testosterone also promotes development of male secondary sex characteristics, such as growth of facial and body hair and deepening of the voice.

Bladder

Ureter

Seminal vesicle

Urethra

Rectum

Erectile tissue

Penis -

Ejaculatory duct

Testes

Scrotum

Vas deferens

Prostate gland

Epididymis

Fig. 6-15. The male reproductive system.

In the female, the gonads are two oval glands called the ovaries. There is one ovary on each side of the uterus (Fig. 6-16). The ovaries make the female sex cells, or eggs (ova). They release the hormones estrogen and progesterone. Each month, from puberty to menopause, an egg is released from an ovary. This cycle is maintained by estrogen and progesterone. These hormones control development of female secondary sex characteristics, such as increased breast size and growth of pubic and underarm hair.

Fundus

Fallopian tube

Ovary

Cervix

Uterus

Vagina

Overview of the Human Body

Fig. 6-16. The female reproductive system. For males, the function of the reproductive system is to manufacture sperm and the hormone testosterone. For females, the reproductive system manufactures ova (eggs) and the hormones estrogen and progesterone. It also provides an environment for the development of a fetus and produces milk for the nourishment of a baby after birth.

PBT Connection

Blood tests are used to confirm pregnancy by measuring the level of hCG, a pregnancy-related hor-mone, in a patient's blood. Throughout pregnancy, blood tests are ordered at various times to screen for potential problems or defects in the fetus. They may also be used during the course of infertility treatment.

A blood test for prostate-specific antigen (PSA) iS one way to check for prostate cancer, a cancer of the male reproductive system. This screening test is often ordered for men 55 and older. If levels are high, other kinds of tests (e.g., an MRI of the pros-tate) are needed to make a diagnosis.

10. Describe the immune and lymphatic systems

The immune system protects the body from disease-causing bacteria, viruses, and microorganisms in two ways. Nonspecific immunity protects the body from disease in general. Specific immunity protects against a particular disease that is invading the body at a given time.

Nonspecific Immunity

To protect itself against disease in general, the body has several defenses:

Anatomic barriers include the skin and the mucous membranes. They provide a physical barrier to keep foreign materials- bac-teria, viruses, or microorganisms-from invading the body. Saliva, tears, and mucous secretions also help protect the body by washing away substances.

Physiologic barriers include body temperature and acidity of certain organs. Most

organisms that cause disease cannot survive high temperatures or high acidity. When the body senses foreign organisms, it can raise its temperature (by running a fever) to kill off the invaders. The acidity of organs like the stomach keeps harmful bacteria from growing there.

•

Inflammatory response refers to the body's ability to fight infection through inflammation or swelling of an infected area. When inflammation occurs, it indicates that the body has sent extra disease-fighting cells and extra blood to the infected area to fight the infection.

Specific Immunity

To protect itself against specific diseases, the body makes different types of cells that will fight a range of different invaders. Once it has successfully eliminated an invader, the immune system records the invasion in the form of anti-bodies. Antibodies are carried within cells. They prevent a disease from threatening the body a second time.

Acquired immunity is a kind of specific immu-nity. The body acquires it either by fighting an infection or by vaccination. For example, a person can acquire immunity to a disease like the measles in two ways:

The person gets measles. His body forms antibodies to the disease to make sure he will not get it again; or

The person gets a vaccine for the measles.
This causes his body to produce the same antibodies to protect him from the disease.

The lymphatic system removes excess fluids and waste products from the body's tissues. It also helps the immune system fight infection.

It is closely related to both the immune and the circulatory systems. The lymphatic system consists of lymph vessels and lymph capillaries in which a fluid called lymph circulates (Fig. Lymph How does the nervous system send messages to the brain?

Through the blood that flows to the head

Through a network of vessels carrying neuron-filled fluid

Through neurons, from receptors throughout the body and then through the spinal cord

From the right hemisphere of the cerebrum to the left hemisphere

6. Which of the following is part of the peripheral nervous system?

The brainstem

The spinal cord

The cerebral cortex

The nerves

7. Peristalsis is the process that

Transmits information from the sense organs to the brain

Moves food through the gastrointestinal system

Causes blood to clot

Secretes hormones that regulate body processes

8. This gland is also known as the master gland:

The pituitary gland

The parathyroid gland

The adrenal gland

The pancreas

9. Progesterone is a hormone associated with

The male reproductive system

Regulation of calcium levels in the blood

The female reproductive system

Movement of glucose from the blood into the cells of the body

10. Which of the following describes a type of acquired immunity?

A person is exposed to influenza, but does not get sick because he had a flu shot 3 weeks before.

A person is exposed to influenza, but does not get sick because he is always very careful about washing hands.

An infant does not get sick with influ-enza, despite being too young to have a flu shot, because everyone around him has had a flu shot.

A person is exposed to influenza, but does not get sick because he was wearing a mask at the time.

11. Lymph is a fluid that circulates

With the pumping of the heart

Through the spinal column

Through muscle activity, massage, and breathing

Only when a strong immune system response is triggered The Circulatory System in Depth

The Circulatory System in Depth

1. Describe the circulatory system and the structure and function of the heart The circulatory, or cardiovascular, system is made up of the heart, blood vessels, and blood (Fig. 7-1). A healthy circulatory system is essential for life. Phlebotomists are responsible for drawing blood from patients, so it is important that they understand basic facts about how the circulatory system works.

Heart

Veins

Arteries

Fig. 7-1. The heart, blood vessels, and blood are the main parts of the circulatory system.

The heart is located between the lungs, and its center is just left of the midline of the body.

The top of the heart, called the base, points toward the right shoulder. The bottom of the heart, called the apex, points toward the left hip.

The heart can be described as a double pump, pumping deoxygenated blood into the lungs and pumping oxygenated blood to the body.

The right side of the heart receives deoxygenated blood from the body through the veins and pumps it to the lungs. In the lungs, the blood receives oxygen again. The left side of the heart receives the oxygenated blood from the lungs and pumps it out to the body through the arteries.

The right and left sides of the heart are separated by a wall called a septum. The heart has two upper chambers called atria (singular: atrium) and two lower chambers called ven-tricles. The chambers contract and relax in a rhythmic pattern to produce blood flow.

The atria contract while the ventricles relax, and then the atria relax while the ventricles contract.

This back-and-forth action between the upper and lower chambers allows the chambers to fill with blood before they contract to pump the blood.

Blood flows through the heart in a distinct path. First, the right atrium receives deoxygenated blood from the body and pumps it to the right ventricle. The right ventricle pumps the deoxygenated blood to the lungs through the pulmonary arteries. The lungs oxygenate the blood, which then returns to the heart through the pulmonary veins.

The left atrium receives blood from the pulmonary veins and pumps it to the left ventricie. The left ventricle pumps oxygenated blood out of the heart via the aorta, the largest artery in the body.

A series of valves ensures that blood flows in the correct direction as it is pumped through the heart. The four major valves of the heart are the tricuspid valve, the pulmonary valve, the bicuspid valve, and the aortic valve (Fig. 7-2).

During a normal heart cycle, the tricuspid and bicuspid valves will be closed, and the pulmonary and aortic valves open, when the ventricles

contract.

Pulmonary valve

Tricuspid valve

Left atrium

Aortic valve

Bicuspid valve

Pulmonary valve (open)

Aortic valve (open)

Pulmonary valve (closed)

Aortic valve (closed)

Bicuspid valve (closed)

Tricuspid valve (closed)

Bicuspid valve (open)

Tricuspid valve (open)

Fig. 7-2. The valves of the heart work to ensure proper blood flow.

2. Explain the cardiac conduction system

The pumping of the heart is triggered by a system of special cardiac tissue that is able to generate electrical signals. This tissue begins, or initiates, electrical impulses, then conducts, or carries, them through the heart. These impulses are the "spark" that triggers the contractions of the heart muscle. This network of signal-con-ducting tissue is known as the cardiac conduction system (Fig. 7-3). Fig. 7-3. Electrical impulses are conducted through the heart, causing the heart muscles to contract in a regular rhythm to pump blood.

The cardiac conduction system begins in the upper part of the right atrium. It continues through the heart to the walls of the ventricles.

The sinoatrial node, sometimes called the SA node or sinus node, is in the upper part of the right atrium and is the main pacemaker of the heart. This means it sets the timing of the heart's contractions.

From the SA node, the electrical impulse travels to the atrioventricular node, also called the AV node. The AV node is at the bottom of the right atrium, behind the tricuspid valve. As the impulse enters the AV node it is slowed down slightly. Without this delay the atria and ventricles would contract at the same time. Instead, the atria can empty and the ventricles can fill before they contract.

The electrical impulse then travels through an area known as the atrioventricular (AV) junction to the bundle of His, or AV bundle. The bundle of His is located in the upper part of the wall between the left and right ventricles.

The bundle of His divides into the right and left bundle branches. These branches carry the electrical impulse to the walls of the ventricles.

The bundle branches continue to divide into smaller branches and then form the Purkinje fibers.

3. Describe Bood vessels

There are three main types of blood vessels: arteries, capillaries, and veins. Arteries carry oxygenated blood away from the heart to all cells in the body (Fig. 7-4). The aorta, the largest artery in the body, receives blood from the left ventricle when the heart contracts. Arteries become smaller and connect with arterioles, or small arteries, before connecting with capillaries.

The capillaries are very small blood vessels where exchanges are made. Exchanges of oxygen and carbon dioxide, and of nutrients and waste products, take place between the blood and the cells in areas called capillary beds (Fig. -5).

The capillaries connect to venules, or small veins, which then connect to larger veins. The veins carry blood containing waste products and carbon dioxide back to the heart (Fig. 7-6).

The inferior vena cava carries blood from the legs and trunk. The superior vena cava carries blood from the arms, head, and neck. They both empty into the right atrium of the heart.

Subclavian

Aorta

Brachial

Internal iliac

Radial

Ulnar

Carotid

Brachiocephalic

Renal

Common iliac

External iliac

Femoral

The Circulatory System in Depth

Popliteal

Posterior tibial

Anterior tibial

Peroneal

Fig. 7-4. These are the major arteries of the body.

Vein

Venule

Capillaries

Arteriole Artery

Fig. 7-5. Networks of capillaries allow for the exchange of gases, nutrients, and wastes. Subclavian

Superior vana cava

Inferior vena cava

Median cubital

Internal liac

Radial.

Uinar

lugular

Brachiocephalic

Basilic

Cephalic

Renal

Common iliac

External iliac

Femoral

Great saphenous

Popliteal

Posterior tibial

Anterior tibial

Peroneal

Fig. 7-6. These are the major veins of the body.

The structure of veins and arteries is similar.

However, arteries have thicker walls to withstand the pressure of the beating heart. When felt through the skin (palpated), arteries feel stiff and firm. It is also possible to feel the pulsing of blood through the arteries when the heart beats. Veins have thinner walls, and many veins also have internal valves that help to keep blood moving back toward the heart. When palpated, healthy veins feel more springy or bouncy than arteries, and there is no pulse present.

The walls of veins and arteries have three layers: an outer layer, called the tunica adventitia; a middle layer, called the tunica media; and an inner layer, called the tunica intima (Fig. 7-7).

The middle layer is composed of muscle tissue and elastic fibers. It is much thinner in veins than it is in arteries. The thinner walls of the veins increase their capacity to hold blood. At any given time about 70% of the body's blood is found in the veins.

the the

tual

SuF

- Valve

Tunica intima

Tunica media

Tunica. adventitia

Fig. 7-7. Vein walls are made up of three layers. Valves may be present to help direct the flow of blood.

The blood vessels of the body circulate blood between the heart and the lungs (called the pul. monary circuit) and between the heart and the rest of the body (called the systemic circuit).

After the venae cavae (plural for vena cava) deliver deoxygenated blood to the right atrium, the blood flows to the right ventricle. There it is pumped to the lungs through the pulmonary arteries the only arteries in the body that carry deoxygenated blood). At the end of the respiratory tract are tiny, elastic sacs called alveoli that are surrounded by capillaries. Oxygen and carbon dioxide are exchanged between the alveoli and capillaries. Oxygenated blood goes from the pulmonary capillaries to venules. Then it travels to the pulmonary veins (the only veins in the body that carry oxygenated blood before arriving at the left atrium (Fig. 7-8).

The systemic circuit is the constant, closed circuit that delivers substances needed by the cells and removes waste products at exchange sites throughout the body. It begins when the left ven-trice pumps blood to the aorta. The aorta cat-ries the blood to other major arteries that supply the heart muscle, other organs, and the rest of the body, including the limbs. The blood is eventually returned to the right atrium through the superior and inferior venae cavae.

Fig. 7.8. The pulmonary circuit is the path blood follows from the heart to the lungs and back to the heart.

4. Describe the camponents of blood

The average healthy adult has 5 to 6 liters of blood, consisting of a liquid component called plasma and solid components called formed elements (Fig. 7-9). Blood transports gases, nu-trients, wastes, and hormones throughout the body. It also protects against infections, forms clots to stop blood loss in the case of injury, regulates body temperature, and helps the body maintain homeostasis.

Plasma

Formed elements

Erythrocytes

(red blood cells)

Leukocytes

(white blood cells)

91% Water

Thrombocytes (platelets)

9% Dissolved substances (proteins, gases, hormones, clotting factors, and nutrients)

Fig. 7-9. Blood is made up of liquid and solid components.

About 55% of the total blood volume is made up of plasma, which is a clear, straw-colored fluid.

Plasma is about 91% water and 9% dissolved substances, including proteins, gases, hormones, and nutrients. Some of the proteins in the plasma are important for proper blood clotting.

Formed elements make up about 45% of the blood volume and include red blood cells (RBCs), also called erythrocytes, several types of white blood cells (WBCs), also called leuko-cytes, and platelets, also called thrombocytes (Fig. 7-10). Erythrocytes contain hemoglobin, a protein that transports oxygen and carbon diox-ide. Leukocytes protect the body against foreign substances such as bacteria and viruses. Thrombocytes play a role in blood clotting. (Learning Objective 7 has more information.)

Leukocytes (white blood cells)

The Circulatory System in Depth

Monocyte

Eosinophil

Lymphocyte

Neutrophil

Thrombocytes (platelets)

Basophil

Erythrocytes (red blood cells)

Fig. 7-10. Each solid component of blood has its own unique form and appearance.

Erythrocytes are the most common of the blood cells. They make up about 40% of total blood volume. They are generated from stem cells in the bone marrow. Stem cells are cells that can become any type of cell. Erythrocytes mature BLOOD TYPE (ABO AND RHI

A, Rh positive (A+) A, Rh negative (A.) B, Rh positive (B•+) B, Rh negative (B-) AB, Rh positive (AB+)

APPROXIMATE PERCENTAGE OF PEOPLE WITH THIS TYPE

36%

CAN DONATE TO

A+, A-, O+, O

A+, AB+

A+, A-, AB+, AB-B+, AB+

B+, B., AB+, AB-AB+

A-, 0-

B+, B-, O+, O-

B-, O-

All ABO and Rh types/ everyone

AB, Rh negative (AB.)

Less than 1%

AB+, AB.

A-, B-, AB-, O

O, Rh positive (O+)

37%

A+, B+, AB+, O+-

0+, 0-

O, Rh negative (O-)

All ABO and Rh types/

O-

everyone

Table 7-1. Blood type determines the type(s) of blood people can receive and to whom they can donate,

Quality Counts

Patients must always be identified before providing care. In the case of blood typing and blood transfu-sions, the risks of failing to identify patients and/ or label specimens properly can be deadly. Even a small amount of the wrong type of blood transfused into a patient can cause a series of effects that can lead to serious damage or death. PBTs must always remember that following policies about patient identification and specimen labeling can be a life-or-

Although blood in the veins, or venous blood, is usually colored blue in illustrations and may appear blue under the skin, it is not blue at all.

Veins return blood to the heart. In all cases other than the pulmonary veins, they carry deoxygenated blood. The color of this blood is a dark, deep red. The blue color of veins under the skin is a trick of light. When venous blood flows into a collection tube its deep, nearly maroon color is visible (Fig. 7-12).

6. Describe the qualities of arterial, venous, and capillary blood

All blood in the body has the same basic composition of plasma and formed elements. Blood in different types of blood vessels, however, has different qualities.

Blood in the arteries, or arterial blood, has been pumped out from the heart to be carried throughout the body. With the exception of blood in the pulmonary arteries, arterial blood is oxygenated. Oxygen is transported by the protein hemoglobin, which is present in red blood cells. Hemoglobin contains iron and gives blood its red color. Oxygenated arterial blood is bright red. Arterial wounds can bleed forcefully, possibly spurting or spraying due to the pressure created by the beating heart.

Fig. 7-12. Venous blood is very dark red in color.

Venous blood does not flow with the same amount of pressure as arterial blood. Wounds in veins do not spurt or pulse blood. In fact, taking venous blood from a patient requires some amount of force to pull, or draw, the blood from the veins. Venous blood is usually collected in draws in the blood. It mav also be drawn with a syringe, a tube-shaped device with a plunger that draws blood from the veins when pulled.

The capillaries are the smallest blood vessels in the body. They are the exchange sites between veins and arteries. Capillary blood contains a mixture of arterial and venous blood. Nutrients and wastes are also exchanged in capillary beds, so capillary blood also contains these substances. Its color is somewhere between the bright red of arterial blood and the deep red of venous blood.

7. Discuss hemostasis, coagulation, and related conditions

An anticoagulant is a substance that prevents blood from clotting. The inside lining of blood vessels releases natural anticoagulants to keep blood moving within the body. This also prevents thrombosis, or the formation of a clot within the blood vessel. When this lining is disturbed by an injury, the body is able to repair the injury while maintaining the flow of blood in the rest of the circulatory system. This is called hemostasis.

When tissue outside the inner lining of the blood vessels is exposed to blood, this triggers a series of reactions. First, the muscular tissue in the tunica media constricts, or narrows, at the site of the injury. This vasoconstriction limits the amount of blood flowing to the area around the injury (Fig. 7-13). Second, nearby platelets are activated, or made to stick to the site of the injury and to each other. Enzymes are substances in the body that speed up specific reactions. An enzyme in the plasma called thrombin controls the platelet response. Thrombin activates only the platelets in the area immediately around the wound (Fig. 7-14). The formation of this platelet plug is known as primary hemostasis.

Name:

Blood vessel constrict;

Fig. 7-13. After an injury to a blood vessel, such as one caused by a needle during a blood draw, the blood vessel constricts to reduce the flow of blood.

Platelet plug

The Circulatory System in Depth

Fig. 7-14. Platelets are quickly activated to start plugging the wound.

Thrombin is also key in changing a protein called fibrinogen, which is present in the plasma, to fibrin, a protein that cannot be dis-solved. Together, fibrin and the activated platelets form a mesh at the injury site to create a hemostatic plug, stopping blood loss (Fig

7-15). This phase is known as secondary hemo-stasis. When an injury heals, a process called fibrinolysis breaks down the clot. An enzyme called plasmin is key to breaking apart the fibrin in the clot. Fibrinolysis is a complementary process to hemostasis, preserving the balance between blood flow and clotting

Platelet and fibrin mesh

Fig. 7-15. The hemostatic plug is made up of platelets and fibrin.

Hemostasis and blood clotting are very complicated processes, involving a large number of blood proteins (called clotting factors) and enzymes. The term coagulation cascade describes this series of changes that prevent blood loss while also avoiding unnecessary and dangerous excessive clotting. Certain disorders can cause either too much clotting or too much bleeding. Hemophilia is a disorder that can cause excessive bleeding. Thrombophilia is a disorder that can cause excessive clotting. A clot formed inside a blood vessel is called a throm-bus. This is especially dangerous when it occurs in deep veins; these clots can come loose, move, and cause pulmonary embolism, a potentially deadly disorder involving blood clots in the lungs.

People with hemophilia are treated with infusions of the clotting factors they lack. People with thrombophilia may be treated with anticoagulant medications. These medications are also used in other situations. The risk of abnormal clotting goes up when a person has an artificial heart valve or some types of abnormal heart rhythms. Anticoagulants are often prescribed for people with these conditions.

Quality Counts

When a PBT performs venipuncture or capillary puncture, the process of hemostasis repairs the wound. Applying pressure to the puncture site speeds the process along. Bleeding from a capillary puncture site is likely to stop more quickly than bleeding from a venipuncture site. It is important for the PBT to ensure bleeding has stopped before allowing a patient to leave. In patients taking anticoagulant medications this process can take longer.

Blood does not just clot in or on the body. Blood specimens that are not treated with an anticoagulant will clot after a certain amount of time (usually 30-60 minutes). When processing blood specimens, some tests require that the blood be allowed to clot in the collection tube. Some require that the blood remain uncoagulated. Collection tubes contain a variety of additives, or

chemical agents that affect how the blood can be processed and tested. The tubes are color coded to indicate the tupe of additive contained. (More detail about the tubes and the color-coding sys. tem is found in Chapter 8.)

After a specimen is collected, it may need to be processed for testing. Often this involves allow. ing the tube(s) to sit for a specific amount of time and then spinning them in a centrifuge.

The centrifuge separates liquid and solid com-ponents. Blood specimens spun in a centrifuge after coagulation are different from blood specimens collected in a tube with an anticoagulant additive.

After centrifuging, a coagulated specimen contains blood cells in a fibrin clot at the bottom.

At the top, the specimen contains a liquid portion known as serum. Serum is not the same as plasma. Serum lacks fibrinogen, which is present in plasma. Some collection tubes for serum samples will contain a gel that separates the serum from the solid blood components.

Before an anticoagulated specimen is spun, it is known as a whole blood specimen. Because the anticoagulant prevents clotting, the tube contains all components of the blood, similar to how they exist in the body. When an antico-agulated specimen is spun, it divides into three layers. The bottom layer includes red blood cells.

The thin middle layer contains white blood cells and platelets, and is known as the buffy coat.

The top layer contains plasma, including fibrinogen (Fig. 7-16).

Some diagnostic tests, such as tests related to immunology, require serum specimens. Some, such as tests related to hematology, require anti-coagulated specimens. These specimens may be either in whole blood form or centrifuged into solid and liquid components. It is important for PBTs to know the difference between the composition of these specimens. Blood specimen without anticoagulant, pre-centrifuge

Blood specimen with anticoagulant, pre-centrifuge

Serum separator gel

Centrifuged serum specimen

Centrifuged plasma specimen

Serum

(no fibrinogen)

Serum

separator gel

Blood cells in fibrin clot

Plasma (includes fibrinogen)

Buffy coat: white blood cells and platelets

Red blood cells

Fig. 7-16. Blood specimens that have been allowed to coagulate are different from blood specimens collected in tubes with an anticoagulant additive.

Chapter Review

Multiple Choice

1. The circulatory system is also known as the

Cardiovascular system

Vein system

Oxygen exchange system

Arterial system

2. The heart pumps deoxygenated blood to the _

-and oxygenated blood

to the -

Entire body, lungs

Limbs, brain

Extremities, heart muscle

Lungs, entire body

101

3. The valves of the heart

Keep blood flowing in the correct direction through the heart

Protect the arteries from extreme pressure

Send electrical signals that cause the heart to contract

Measure the amount of blood flowing through the heart

4. Which of the following is the main pacemaker of the heart?

The aorta

The semilunar valve

The sinoatrial node

The atrioventricular node

5. The smallest blood vessels are called

Capillaries

Venules

Arterioles

Erythrocytes

6. These blood vessels almost always carry oxygenated blood:

Veins

Arteries

Pulmonary arteries

Venules

7. The layer in blood vessels made up mostly of muscle tissue and elastic fibers is known as the

Tunica intima

Tunica media

Tunica adventitia

Tunica variegata

Which type of blood vessel typically holds about 70% of the body's blood?

The veins

The arteries

The chambers of the heart

The capillaries 9. Which of these sets of words best describes how a healthy vein feels when palpated?

Firm, rope-like

Dense, tight

Soft, spongy

Springy, bouncy

10. The formed elements make up

About one-third of blood volume

A bit less than one-half of blood volume

A bit more than one-half of blood volume

About two-thirds of blood volume

11. The liquid portion of blood is

Entirely made of water

Entirely made of oxygen in oxygenated blood and carbon dioxide in deoxygenated blood

What gives blood its red color

A combination of water and dissolved substances

12. Which type of blood cell contains hemoglobin?

Granulocytes

Erythrocytes

Lymphocytes

Monocytes

13. Which of these parts of the body is associated with the creation of blood cells?

The heart

The kidneys

The tendons

The bone marrow

14. What can be said about a person with blood type A negative?

She has type A antigens, anti-B antibod-ies, and no Rh factor.

She has type B antigens, anti-A antibod-ies, and no Rh factor.

She has type A antigens, anti-B antibod-ies, and Rh factor.

She will naturally possess anti-Rh antibodies,

15. Who could safely donate blood for a patien with the blood type AB negative?

Someone with AB positive blood

Someone with O negative blood

Someone with A positive blood

Someone with B positive blood

16. Venous blood is

Deep, dark red

Blue

Bright red

Bluish purple

is a term describing the

17. process that keeps blood flowing normally through the rest of the body while clotting al the site of an injury.

Homeostasis

Hematology

Coagulation

Hemostasis

18. This is the body's first line of defense when a blood vessel is injured:

The heart rate slows to reduce blood loss.

Platelets and fibrin form a plug at the site of the injury.

The blood vessel constricts to reduce blood loss.

The blood vessel expands to allow clotting materials to flow out.

19. Which of these terms describes the complex series of events within the body related to blood clotting?

The coagulation cascade

The anticoagulative factor

The clotting stream

The antibody response

20. What does blood plasma contain that bloo serum does not?

Red blood cells

Water

White blood cells

Fibrinogen 21. A specimen containing an anticoagulant additive and not spun in a centrifuge is called a (n)

(A) Whole blood

— specimen.

Representative

Undifferentiated

Routine

22. The buffy coat in a centrifuged specimen contains

Red and white blood cells

White blood cells and platelets

Fibrinogen and platelets

White blood cells and fibrinogen