Chapter 6 The Human Body

abdomen

The body cavity that contains many of the major organs of digestion and excretion. It is located below the diaphragm and above the pelvis

acetabulum

The depression on the lateral pelvis where its three component bones join, in which the femoral head fits snugly

adenosine triphosphate (ATP)

The nucleotide involved in energy metabolism; used to store energy

adrenal glands

Endocrine glands located on top of the kidneys that release adrenaline when stimulated by the sympathetic nervous system

adrenergic

Pertaining to nerves that release the neurotransmitted norepinephrine, or noradrenaline (eg, adrenergic nerves, adrenergic respone); also pertains to the receptors acted on by norepinephrine

aerobic metabolism

Metabolism that can proceed only on the presence of oxygen

agonal gasps

Abnormal breathing pattern characterized by slow, gasping breaths, sometimes seen in patients in cardiac arrest

alpha-adrenergic receptors

Portions of the nervous system that, when stimulated, can cause constriction of blood vessels

alveoli

The air sacs of the lungs in which the exchange of oxygen and carbon dioxide takes place

anaerobic metabolism

Metabolism that takes place in the absence of oxygen; the main by-product is lactic acid

anatomic position

The position of reference in which the patient stands facing forward, arms at the side, with the palms of the hands forward

anatomy

The study of the physical structure of the body and its components

aorta

The main artery leaving the left side of the heart and carrying freshly oxygenated blood to the body

appendicular skeleton

The portion of the skeletal system that comprises the arms, legs, pelvis, and shoulder girdle

appendix

A small, tubular structure that is attached to the lower border of the cecum in the lower right quadrant of the abdomen

arterioles

The smallest brance of arteries leading to the vast network of capillaries

articular cartilage

A pearly layer or specialized cartilage covering the articular surfaces (contact surfaces on the ends) of bones in synovial joints

atrium

One of the two upper chambers of the heart

autonomic nervous system

The part of the nervous system that regulates functions, such as digestion and sweating, that are not controlled voluntarily

axial skeleton

The part of the skeleton comprising the skull, vertebral column, and rib cage

axons

Extensions of a neuron that carry impulses away from the nerve cell body to the dendrites (receivers) of another neuron

ball-and-socket joint

A joint that allows internal and external rotation, as well as bending

beta-adrenergic receptors

Portions of the nervous system that, when stimulated, can cause an increase in the force of contraction of the heart, an increased heart rate, and bronchial dilation

biceps

The large muscle that covers the front of the humerus

bile ducts

The ducts that convey bile between the liver and the intestine

blood pressure (BP)

The pressure that the blood exerts against the walls of the arteries as it passes through them

brachial artery

The major vessel in the upper extremities that supplies blood to the arm

brain

The controlling organ of the body and center of consciousness; functions include perception, control of reactions to the environment, emotional responses, and judgement

brainstem

The area of the brain between the spinal cord and cerebrum, surrounded by the cerebellum; controls functions that are necessary for life, such as respiration

calcaneus

The heel bone

capillary vessels

The tiny blood vessels between the arterioles and venules that permit transfer of oxygen, carbon dioxide, nutrients, and waste between body tissues and the blood

cardiac muscle

The heart muscle

cardiac output (CO)

A measure of the volume of blood circulated by the heart in 1 minute, calculated by multiplying the stroke volume by the heart rate

carotid artery

The major artery that supplies blood to the head and brain

carpals

Small bones that compose the wrist

cartilage

The smooth connective tissue that forms the support structure of the skeletal system and provides cushioning between bones; also forms the nasal septum and portions of the outer ear

cecum

The first part of the large intestine, into which the ileum opens

cellular metabolism

A set of chemical reactions that supplies cells with energy. Includes both anaerobic and aerobic metabolism

central nervous system (CNS)

The brain and spinal cord

cerebellum

One of the three major subdivisions of the brain, sometimes called the little brain; coordinates the various activities of the brain, particularly fine body movements

cerebrospinal fluid (CSF)

Fluid produced in the ventricles of the brain that flows in the subarachnoid space and bathes the meninges

cerebrum

The largest part of the three subdivisions of the brain, sometimes called the gray matter; made up of several lobes that control movement, hearing, balance, speech, visual perception, emotions, and personality

cervical spine

The portion of the vertebral column consisting of the first seven vertebrae that lie in the neck

chordae tendineae

Thin bands of fibrous tissue that attach to the valves in the heart and prevent them from inverting

chyme

The substance that leaves the stomach. It is a combination of all of the eaten foods with added stomach acids

circulatory system

The complex arrangement of connected tubes, including the arteries, arterioles, capillaries, venules, and veins, that moves blood, oxygen, nutrients, carbon dioxide, and cellular waste throughout the body.

clavicle

The collarbone; it is lateral to the sternum and anterior to the scapula

coccyx

The last three or four vertebrae of the spine; the tail bone

coronal (frontal) plane

An imaginary plane where the body is divided into front and back parts

coxae

The hip bones (singular: coxa)

cranium

The part of the skull that encloses the brain and is composed of eight bones

cricoid cartilage

A firm ridge of cartilage that forms the lower part of the larynx

cricothyroid membrane

A thin sheet of fascia that connects the thyroid and cricoid cartilages that make up the larynx

dead space

Any portion of the airway that does contain air and cannot participate in gas exchange, such as the trachea and bronchi.

dermis

The inner layer of the skin, containing hair follicles, sweat glands, nerve endings, and blood vessels

diaphragm

A muscular dome that forms the undersurface of the thorax, separating the chest from the abdominal cavity. Contraction of this (and the chest wall muscles) brings air into the lungs. Relaxation allows air to be expelled from the lungs.

diastole

The relaxation, or period of relaxation, of the heart, especially of the ventricles

diffusion

Movement of a gas from an area of higher concentration to an area of lower concentration

digestion

The processing of food that nourishes the individual cells of the body

dorsalis pedis artery

The artery on the anterior surface of the foot between the first and second metatarsals

endocrine system

The complex message and control system that integrates many body functions, including the release of hormones

enzymes

Substances designed to speed up the rate of specific biochemical reactions

epidermis

The outer layer of the skin, which is made up of cells that are sealed together to form a watertight protective covering for the body

epiglottis

A thin, leaf-shaped valve that allows air to pass into the trachea but prevents food and liquid from entering

epinephrine

A substance produced by the body (commonly called adrenaline), and a drug produced by pharmaceutical companies that increase pulse rate and blood pressure; the drug of choice for an anaphylactic reaction

esophagus

A collapsible tube that extends from the pharynx to the stomach; muscle contractions propel food and liquids through it to the stomach

expiratory reserve volume

The amount of air that can be exhaled following a normal exhalation; average volume is about 1,200 mL in the average adult male

extension

The straightening of a joint

fallopian tubes

The tubes that connect each ovary with the uterus and are the primary location for fertilization of the ovum

femoral artery

The major artery of the thigh, a continuation of the external iliac artery. It supplies blood to the lower abdominal wall, external genitalia, and legs. It can be palpated in the groin area.

femoral head

The proximal end of the femur, articulating with the acetabulum to form the hip joint.

femur

The thighbone; the longest and one of the strongest bones in the body

fibula

the smaller of the two bones that form the lower leg, located on the lateral side

flexion

The bending of a joint

foramen magnum

A large opening at the base of the skull through which the brain connects to the spinal cord

frontal bones

The bones of the cranium that form the forehead

gallbladder

A sac on the undersurface of the liver that collects bile from the liver and discharges it into the duodenum through the common bile duct

genital system

The reproductive system in men and women

germinal layer

The deepest layer of the epidermis where new skin cells are formed

greater trochanter

A bony prominence on the proximal lateral side of the thigh, just below the hip joint

hair follicles

The small organs that produce hair

heart

A hollow muscular organ that pumps blood throughout the body

heart rate (HR)

The number of heartbeats during a specific time (usually 1 minute)

hemoglobin

An oxygen-carrying protein found in red blood cells

hinge joints

Joints that can bend and straighten but cannot rotate; they restrict motion to one plane

hormones

Substances formed in specialized organs or glands and carried to another organ or group of cells in the same organism; they regulate many body functions, including metabolism, growth, and body temperature

humerus

The supporting bone of the upper arm

hydrostatic pressure

The pressure of water against the walls of its container

hypercapnia

An abnormally high level of carbon dioxide in the bloodstream; also called hypercarbia

hypoperfusion

A condition in which the circulatory system fails to provide sufficient circulation to maintain a normal cellular function; also called shock

hypoxia

Deficient oxygen concentration in the tissues

hypoxic drive

A “backup system” to control respiration; senses drops in the oxygen level in the blood

ilium

One of three bones that fuse to form the pelvic ring

inferior vena cava

One of the two largest veins in the body; carries blood from the lower extremities and the pelvis and the abdominal organs to the heart

inspiratory reserve volume

The amount of air that can be inhaled after a normal inhalation; the amount of air that can be inhaled in addition to the normal tidal volume

interstitial space

The space in between the cells

intervertebral disks

Tough, elastic structures between adjoining vertebrae that act as shock absorbers

intracellular space

The space within a cell or cells

involuntary muscle

The muscle over which a person has no conscious control. It is found in many automatic regulating systems of the body

ischium

One of three bones that fuse to form the pelvic ring