SAAT Biology - Chapter 6: Human Body Systems Flashcards

Flashcards about the human body systems, including the musculoskeletal, nervous, cardiovascular, respiratory, excretory, digestive, endocrine, reproductive, and immune systems.

Functions of the Skeletal System

Supports & shapes the body, protects internal organs, stores calcium & phosphorus, and produces blood cells (RBC, WBC, platelets in red bone marrow).

Axial Skeleton

Skull, vertebral column, & sternum (rib cage).

Appendicular Skeleton

Upper & lower extremities, shoulder girdle, clavicle, & pelvis.

Structure of Bones

Periosteum, cortical (compact) bone, cancellous (spongy) bone, osteocytes, red marrow, & yellow marrow.

Long Bones

Bones of the arms (Radius), & legs (Femur)

Short Bones

Bones that make up the wrist

Flat bones

Skull bones

Irregular Bones

Vertebrae

Osteoblasts

Responsible for building bones (in the presence of adequate nutrition).

Osteoclasts

Responsible for the breakdown of old bone tissue.

Red Marrow

Responsible for the formation of blood cells such as RBC, WBC & Platelets.

Yellow Marrow

Aids in the storage of fat

Ligament

Fibrous connective tissue that connects bones to other bones.

Tendon

Tough dense fibrous connective tissue that connects muscles to bones.

Joints

A point where two or more bones meet, that allow mobility (except for skull).

Ball & Socket Joint

Allows movement in all directions. Example - Shoulder & Hip.

Pivot Joint

Allows rotation around a single axis. Example - Radius & Ulna

Hinge Joint

Allows movement in a single direction (back & forth). Example - Elbow & Knee

Gliding Joint

Allows limited motion (sliding or gliding) –Example Vertebrae, Wrist & Ankle

Immovable Joint

No movement. Example –Skull

Osteoarthritis

A painful condition that affects the joints & results in the breakdown of cartilage, mostly due to wear and tear.

Osteoporosis

When bones become very weak, to a point where they break easily. It is seen in people who are deficient in calcium.

Rheumatoid Arthritis

It affects the joints, results in both loss of strength & function.

Skeletal Muscle

Connected to bones by tendons allowing movements, Example: Arm, leg, Face& tongue muscles. Voluntary, Striated, Multiple nuclei peripherally located, Made up of Actin & Myosin

Smooth Muscle

Found in the walls of hollow organs Example - Stomach, Small & Large Intestines, Bladder, & Uterus. Involuntary, Non striated, One nucleus centrally located

Cardiac Muscle

Cardiac muscle (Heart). Involuntary, Striated, One nucleus centrally located

Neurons

Specialized cells that transfer impulses from one area to another.

Cell Body (Neuron)

Contains both the cytoplasm and nucleus

Myelin Sheath

Covers Axon and it increases speed of nerve impulse conduction.

Action Potential

Influx of Na+ & efflux K+.

Resting Potential

Na+/K+ Pump moves 3 Na+ out & 2 K+ in.

Threshold (Neuron)

It is the level that a depolarization must reach for an action potential to occur. The minimum level of a stimulus that is required to cause an impulse in a neuron.

Synapse

The point at which a neuron transfers an impulse to another cell.

Neurotransmitters

Chemicals that transmit an impulse across a synapse to another cell.

Central Nervous System (CNS)

Made up of the Brain and the Spinal Cord.

Cerebrum

Enables thinking, reasoning, learning, speech & memory; largest part of the brain (made and up of two hemispheres).

Cerebellum

Coordination of movements, as well as maintaining balance.

Brain Stem

Connects the brain and spinal cord.

Pons

Relays signals from the cerebellum to the Cerebrum. (Part of Brain Stem)

Medulla Oblongata

Connects both the brain & spinal cord. It helps control vital processes like heart rate, & breathing. (Part of Brain Stem)

Hypothalamus

Regulates food and fluid intake, sleep, body temperature & sexual arousal, also helps to coordinate the nervous and endocrine systems.

Thalamus

Receives messages from sensory receptors throughout the body.

Spinal Cord

Coordinates involuntary reflexes.

Reflex Arc

Nerve pathway of a reflex.

Somatic Nervous System

Transmits nerve impulses from the skin & muscles to the brain & vice versa. (Voluntary)

Autonomic Nervous System

Transmits nerve impulses from the CNS to the internal organs. (Involuntary)

Sympathetic Nervous System

Controls the body's fight-or-flight response (responds to dangerous stressful situations), increases heart rate & respiratory rate, dilatation of the bronchi, decreases appetite & dilates the pupil.

Parasympathetic Nervous System

Regulates body’s function at rest. It also returns the body to its resting state after a stressful encounter.

Drug

A natural or synthetic substance that may alter the body’s function.

Stimulants

Performance enhancing drugs, making an individual more alert, such as Caffeine (found in tea coffee, & fizzy drinks), & Nicotine.

Depressants

Drugs that reduce arousal & stimulation (decrease activity), such as alcohol & inhalants.

Tolerance (Drugs)

An increased dose of a drug has to be taken in order to achieve the desired effect.

Addiction

Psychological & Physiological dependence on a certain drug.

Cardiovascular System

Heart, Blood vessels, Blood, Lymphatic system

Chambers of the Heart

2 Atria, & 2 Ventricles

Valves of the Heart

Tricuspid valve, Mitral valve, Pulmonary valve, Aortic valve

Right Atrium

Receives deoxygenated blood from the body. It also possesses the Sinoatrial Node which is responsible for setting the rate of contraction of the heart (pacemaker).

Left Atrium

Receives oxygenated blood from the lungs via the Pulmonary Vein.

Right Ventricle

Pumps deoxygenated blood to the lungs via the Pulmonary Artery

Left Ventricle

Pumps oxygenated blood around the body via the Aorta.

Arteries

Carry oxygenated blood away from the heart (except the Pulmonary Artery which carries deoxygenated blood). Can withstand high pressure blood flow. No valves

Veins

Carry deoxygenated blood to the heart (except the Pulmonary vein which carries oxygenated blood). It can withstand low pressure blood flow. Contain valves

Capillaries

Site of gas exchange. Made up of a single layer of cells ( 1 cell thick)

Plasma

Liquid component (90% water, & 10% Salts). Acts as a transport medium.

Red Blood Cells (RBC)

Absent nucleus, contains hemoglobin that transport oxygen.

White Blood Cells (WBC)

Nucleus present blood. Its function is to protect the body against invasion from pathogens. High number of WBC might indicate the presence of infection.

Platelets

Play a vital role in coagulation of blood (Blood clotting). They release chemicals that result in the formation of fibrin.

Antigens

Protein molecules that are present on the surface of red blood cells, they allow identification of the blood group that an individual has.

Rh Factor

If maternal Rh- blood mixes with fetal Rh+ blood, maternal antibodies are formed against it. If she becomes pregnant with another fetus with Rh+ blood, this will result in the maternal antibodies crossing the placenta & destroying the fetal red blood cells.

Respiratory System

Nose, Pharynx, Larynx, Tongue , Epiglottis, Trachea, Lungs (largest organ), & Diaphragm.

Epiglottis

Leaf shaped flap, that closes the larynx while a person is eating, it prevents the passage of food into the trachea. It only allows the passage of air into the trachea.

Passage of Air

Nose→Pharynx→Larynx→Trachea→Bronchus→Bronchioles→Alveoli

Inhalation

Diaphragm contracts and flattens. Volume of the thoracic cavity increases.

Exhalation

Diaphragm relaxes, and becomes dome-shaped Volume of the thoracic cavity decreases.

Lungs (Excretory System)

Removes water vapor and carbon dioxide from the body.

Skin (Excretory System)

Removes water & salts from the body via sweat.

Kidneys

Filters water, salts, & waste products from the blood and it maintains the pH of the blood. Main excretory organ.

Nephron

Functional unit of the kidney. Glomerulus & Bowmans Capsule-Filtration, Proximal & Distal tubules-Reabsorption, Loop of Henle-Reabsorption of sodium ions, Collecting Duct- Transports urine (end product of filtration) from the nephron to the ureter.

Digestive System

Food is broken down by mechanical (chewing) and chemical digestion (enzymes).

Mouth (Digestion)

Salivary Amylase breaks down the starch, into simple sugars. It has a neutral pH

Pharynx

A common pathway between both the respiratory & digestive systems. It provides an inlet to both the esophagus, & the trachea.

Esophagus

Connects the mouth to the stomach and pushes food downwards into the stomach via peristalsis.

Cardiac Sphincter

Prevents the contents of the stomach from flowing back.

Chyme

Food present within the stomach.

Stomach

Proteins are broken down by the enzyme Pepsin, the acidic pH present within the stomach is essential for the activity of Pepsin.

Small Intestine

Most of the nutrients are absorbed into the blood through Villi. It has an alkaline pH. Site of lipid digestion. Both proteins and carbohydrates are also broken down.

Liver

Produces bile that aids in the digestion of fats and store it in the gall bladder.

Pancreas

Secretes Sodium Bicarbonate NaHCO3 alkaline into the small intestine, increasing the pH above 7 providing the enzymes with the optimum pH. Pancreatic amylase that break down carbohydrates.

Large Intestine

Water and minerals are reabsorbed back into the blood from chyme. The normal flora present within the large intestine is responsible for the production of Vitamin K.

Nutrition

Taking in food, converting it into energy & other vital nutrients for life.

Carbohydrates

Made up of simple sugars, 1g=4 Calories.

Proteins

Made up of amino acids, 1g=4 Calories

Lipids

Made up of fatty acids & glycerol. Largest source of energy, 1g=9 Calories.

Steroids

Form Sex Hormones & some vitamins. part of Lipids

Vitamins

Organic compounds required by the body in small quantities, in order to carry out a range of normal functions.

Fat-Soluble Vitamins

Stored in the body in small amounts, such as Vitamins ADEK

Water-Soluble Vitamins

Cannot be stored in the body, such as Vitamin B, & C

Minerals

Inorganic compounds required by the body, some in small amounts, & some in large amounts. They play an essential role within the human body.

Hormones

Chemicals that affect target cells, tissues,& organs. There are 2 types of hormones: Steroid Hormones & Non steroid Hormones.

Steroid Hormones

Fat soluble molecules,& can freely cross the plasma membrane Example-Testosterone,Progesterone & Estrogen