AEMT Chapter 7 The Human Body

anatomy

The study of the structure of an organism and its parts.

antagonist

A molecule that blocks the ability of a given chemical to bind to its receptor, preventing a biologic response

antibodies

Proteins within plasma that react with antigens

Aorta

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

antigens

Substances on the surface of red blood cells that are recongized by the immune system

Aortic Arch

One of the three described portions of the aorta, the section of the aorta between the ascending and descending portions that gives rise to the right brachiocephalic, left common cartoid, and left subclavian arteries

aortic valve

The semilunar valve that regulates blood flow from teh eft ventricle to the aorta

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.

cecum

first part of the large intestine

arachnoid

the middle membrane of the three meninges that enclose the brain and spinal cord

areolar glands

the glands that produce secretions that protect the nipple and areola during nursing

arteries

the blood vessels that carry blood away from the heart

aterioles

the smallest branches of arteries leading to the vast network of capillaries

Capillaries

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

ascending aorta

the first of three portions of the aorta; orginates from the left ventricle and gives rise to two branches, the right and left main coronary arteries.

atlanto-occipital joint

The location where the atlas articulates with the occipital condyles

Condyle

A smooth, rounded articular process

atlas

the first cervical vertebra (C1), which provides support for the head

atrioventricular (AV) node

the site located in the right atrium adjacent to the septum that is responsible for transiently slowing electrical conduction

Atrium

One of the two upper chambers of the heart

Atrophy

(n.) the wasting away of a body organ or tissue; any progressive decline or failure; (v.) to waste away

auditory ossicles

The bones that function in hearing and are located deep within cavities of the temporal bone.

temporal bone

bone that forms parts of the side of the skull and floor of the cranial activity. There is a right and left temporal bone.

autonomic nervous system

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

axial skeleton

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

axillary vein

The vein that is formed from the combination of the basilic and cephalic veins; it drains into the subclavian vein.

axis

the second cervical vertebra (C2); the point that allows the head to turn

ball and socket joint

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

baroreceptors

Receptors in the blood vessels, kidneys, brain, and heart that respond to changes in pressure in the heart or main arteries to help maintain homeostasis.

base

A substance that decreases the concentration of hydrogen ions

basilic vein

One of the two major veins of the arm; it combines with the cephalic vein to form the axillary vein.

basophils

White blood cells that work to produce chemical mediators during an immune response.

beta cells

Cells located in the islets of Langerhans that secrete insulin.

Islets of Langerhans

cell clusters in the pancreas that form the endocrine part of that organ

beta effects

Stimulation of beta receptors that results in inotropic, dromotropic, and chronotropic states.

Inotropic

strength of contraction

Dromotropic

conductivity of heart

chronotropic

rate of contraction

biceps

The large muscle that covers the front of the humerus.

bile ducts

The ducts that convey bile between the liver and the intestine.

bilirubin

A waste product of red blood cell destruction that undergoes further metabolism in the liver.

blood

The fluid that is pumped by the heart through the arteries, veins, and capillaries and consists of plasma and formed elements or cells, such as red blood cells, white blood cells, and platelets

blood pressure

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

bone marrow

a substance that manufactures most red bloo cells

brachial artery

the major vessel in the upper extremity 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 judgment.

brainstem

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

bronchioles

Fine subdivisions of the bronchi that give rise to the alveolar ducts.

bronchospasm

Constriction of the airway passages of the lungs that accompanies muscle spasms.

bruit

An abnormal blowing or swishing sound heard on auscultation of an artery or an organ. (indicates tubrulent blood flow within a blood vessel)

buffer

Any substance that can reversibily bind (Hydrogen +)

buffer system

Fast-acting defenses for acid-base changes, providing almost immediate protection against changes in the hydrogen ion concentration of extracellular fluid.

bundle of his

Part of the conduction of the heart, a continuation of the atrioventricular node

bursa

A small fluid-filled sac located between a tendon and a bone that cushions and protects the joint.

calcitonin

A hormone produced by the parafollicular cells of the thyroid gland that is important in the regulation of calcium levels in the body

cancellous bone

A type of bone that consists of a lacy network of bony rods called trabeculae.

Capilliaries

tiny blood vessels that deliver supplies to individual cells and takes away waste materials

cardiac cycle

The repetitive pumping process that begins with the onset of cardiac muscle contraction and ends with just prior to the beginning of the next contraction

cardiac muscle

The heart muscle

cardiac output

The amount of blood pumped through the circulatory system in one minute

carotid artery

The major artery that supplies blood to the head and brain.

carpometacarpal joint

The joint between the wrist and the metacarpal bones; the thumb joint.

cartilage

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

Catecholamines

Hormones produced by the adrenal medulla (epinephrine and norepinephrine) that assist the body in coping with physical and emotional stress by increasing the heart and respiratory rates and the blood pressure.

cell membrane

the cell wall; the cell membrane is selectively permable

selectively permeable

some substances can pass across them and others cannot

cellular respiration

A biochemical process resulting in the production of energy in the form of ATP.

central nervous system

the brain and spinal cord

central vision

The visualization of objects directly in front of you.

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 spinal column consisting of the first seven vertebrae that lie in the neck.

cervix

the lower one third, or neck of the uterus

Chemoreceptors

Receptors in the blood vessels, kidneys, brain, and heart that respond to changes in chemical composition of the blood to help maintain homeostasis.

chordae tendinae

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

choroid plexus

Specialized cells within hollow areas in the ventricles of the brain that produce cerebrospinal fluid

chromosones

structures formed from condensed fibers and protein of deoxyribonucleic acid they are threadlike and are contained within the nucleus of the cells

chronic obstructive pulmonary disease (COPD)

A progressive and irreversible disease of the airway marked by decreased inspiratory and expiratory capacity of the lungs

chronotropic state

related to the control of the hearts rate of contraction

chyme

The name of 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.

circumflex coronary arteries

The two branches of the left main coronary artery.

clavicle

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

clitoris

located in the anterior margin of the vestibule, it contains erectile tissue that becomes engorged with blood as a result of sexual excitement

vestibule

opening, entrance

coccyx

the last three to five vertebrae of the spine, the tailbone

concentration gradient

the difference in concentration of a substance on either side of a selectively permeable membrane

conduction system

A group of complex electrical tissues within the heart that initiate and transmit stimuli that result in contractions of myocardial tissue.

conjunctiva

Membranous covering on the anterior surface of the eye

Contractility

the strength of the heart muscle contration

cornea

The transparent tissue layer in front of the pupil and iris of the eye.

coronary arteries

Arteries that arise from the aorta shortly after it leaves the left ventricle and supply the heart with oxygen and nutrients.

coronary sinus

Veins that collect blood that is returning from the walls of the heart

corpus luteum

the remantans of unfertilized ovum that are shedded during menstration

corticosterioids

any of the several steroids secerted by the adrenal gland

cortisol

the most important corticosteroid secreted by the zona fasciculata

zona fasciculata

the middle of the three layers of the adrenal cortex that consists of radially arranged columnar epithelial cells.

cranial nerves

the 12 pairs of nerves that arise from the base of the brain