anatomy and physiology terms. intro. to anatomy and physiology

Anatomy and Physiology Terms

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Anatomy and Physiology Terms

Intro. to Anatomy and Physiology

Anatomy• Branch of science dealing with

the form and structure of body parts.

Physiology • Branch of science that studies

body functions.

Appendicular• Upper and lower limbs

Axial• Head, neck, and trunk

Homeostasis • State of equilibrium in which

the internal environment of the body remains at a normal range.

Cellular Metabolism

Anabolism • Synthesis of larger molecules

from smaller molecules.

Synthesis • Building large molecules from

smaller ones.

Catabolism • Breakdown of larger molecules

into smaller ones.

Decomposition • The breakdown of molecules

into simpler compounds.

Oxidation • Process by which oxygen is

combined with another chemical.

Enzyme • Protein that catalyzes a

specific biochemical reaction.

Substrate • Target of enzyme action.

Organic • Carbon-containing molecules.

Inorganic • Chemical substances that lack

carbon and hydrogen.

Ion • Atom or molecule with an

electric charge.

Lipid • Fat, oil, or fatlike compound

that usually has fatty acids in its molecular structure.

Nucleic Acid • Substance composed of

boded nucleotides; RNA or DNA.


Cytoplasm • The contents of a cell

excluding the nucleus and cell membrane.

Organelle • Part of a cell that performs a

specialized function.

Nucleus • Cellular organelle enclosed by

a double-layer, porous membrane and containing DNA.

Differentiation • Cell specialization

Diffusion • Random movement of

molecules from a region of higher concentration toward one of lower concentration.

Facilitated Diffusion • Diffusion in which a carrier

molecule transports a substance across a cell membrane from a region of higher concentration to a region of lower concentration.

Active Transport • Process that requires energy

to move a substance across a cell membrane, usually against the concentration gradient.

Osmosis • Diffusion of water through a

selectively permeable membrane in response to a concentration gradient.

Equilibrium • State of balance between two

opposing forces.

Endocytosis • Physiological process by

which a cell membrane envelopes a substance and draws it into the cell in a vesicle.

Exocytosis • Transport of a substance out

of a cell in a membrane-bound vesicle.

Phagocytosis • Process by which a cell

engulfs and digests solids.

Pinocytosis • Process by which a cell

engulfs droplets of fluid from its surroundings.

Mitosis • Division of a somatic cell (body

cell) to form two genetically identical cells.

Meiosis • Cell division that halves the

genetic material, resulting in egg and sperm cells (gametes).


Epithelial Tissue • One of the basic types of

tissue that covers all free body surfaces.

Connective Tissue • Basic type of tissue that

consists of cells within an extracellular matrix, including bone, cartilage, blood, loose and fibrous connective tissue.

Adipose Tissue • Fat storing tissue.

Cartilage • Type of connective tissue in

which cells are located in the lacunae and are separated by a semisolid extracellular matrix.

Nervous Tissue • Neurons and neuroglial cells

composing the brain, spinal cord, and nerves.


Integumentary • Pertaining to the skin and its

accessory organs.

Epidermis • Outer epithelial layer of skin.

Dermis • The thick layer of skin beneath

the epidermis.

Subcutaneous Layer • Layer of tissue that is mostly

fat and beneath the skin; hypodermis.

Sebaceous Gland • Skin gland that secretes

sebum (oil).

Sweat Gland • Exocrine gland in skin that

secretes a mixture of water, salt, urea, and other bodily fluids.

Melanin • Dark pigment found in the skin

and hair.

Keratinization • Process by which cells form

fibrils of keratin and harden.

Arrector Pili Muscle • Smooth muscle in the skin

associated with a hair follicle (goose bumps).

Skeletal System

Spongy Bone • Bone that consists of bars and

plates separated by irregular spaces; cancellous bone.

Compact Bone • Dense tissue in which cells are

arranged in osteons with no apparent spaces.

Diaphysis • Shaft of the long bone.

Epiphysis • End of a long bone.

Periosteum • Fibrous connective tissue

covering the surface of the bone.

Medullary Cavity • Cavity containing marrow

within the diaphysis of a long bone.

Marrow • Connective tissue that

occupies space within bones that includes stem cells.

Articular Cartilage • Hyaline cartilage that covers

the ends of bones in synovial joints.

Intramembraneous Bone

• Bone that forms from membrane-like layers of primitive connective tissue.

Endochondral Bone • Bone that begins as hyaline

cartilage that is subsequently replaced by bone tissue.

Osteocyte • Mature bone cell.

Synovial Joint • Feely movable joint.

Synovial Fluid • Fluid that they synovial

membrane secretes.

Synovial Membrane • Membrane that forms the inner

lining of a freely moveable joint.

Muscular System

Actin • A protein in a muscle fiber that

forms filaments that slide between filaments of the protein myosin, contracting muscle fibers.

Myosin • A protein that, with actin,

contracts and relaxes muscle fibers.

Sarcomere • Structural and functional unit

of a myofibril.

Neurotransmitter • Chemical that an axon end

secretes to stimulate a muscle fiber to contract or a neuron to fire an impluse.

Nervous System

Neuron • Nerve cell

Neuroglial Cell • Specialized cell of the nervous

system that produces myelin, communicates between cells, and maintains the ionic environment, as well as provides other functions.

Soma • Body of the neuron that

contains the nucleus.

Axon • A nerve fiber; conducts a

nerve impulse away from a neuron.

Dendrite • Process of a neuron that

receives input from other neurons.

Meninges • Membrane that covers the

brain and spinal cord.

Synapse • Functional connection

between the axon of one neuron and the dendrite or cell body of another neuron or the membrane of another cell type.

Reflex • Rapid, automatic response to

a stimulus.

Action Potential • Sequence of electrical

changes that occurs in a portion of a nerve cell membrane that is exposed to a stimulus that exceeds the membrane’s threshold.

Sclera • White fibrous outer layer of the


Cornea • Transparent anterior portion of

the outer layer of the eye wall.

Retina • Inner layer of the eye wall that

contains the visual receptors.

Rods • Type of light receptor that

provides colorless vision.

Cones • Color receptor in the retina of

the eye.

Cochlea • Portion of the inner ear that

has hearing receptors.

Endocrine System

Hormone • Substance secreted by an

endocrine gland and transported in the blood.

Target Cell • Cell with specific receptors on

which a hormone exerts its effect.

Cardiovascular System and Blood

Atrium • Chamber of the heart that

receives blood from veins.

Ventricle • Cavity, such as brain

ventricles filled with cerebrospinal fluid, or heart ventricles that contain blood.

Arteriole • Small branch of an artery that

communicates with a capillary network.

Capillary • A small blood vessel that

connects an arteriole and a venule.

Venule • Vessel that carries blood from

capillaries to a vein.

Plasma • Fluid portion of circulating


Erythrocyte • Red blood cell

Leukocyte • White blood cell

Platelet • Cytoplasmic fragment formed

in the bone marrow that helps blood clot.

Antigen • Chemical that stimulates B

lymphocytes to produce antibodies.

Antibody • Protein that B cells of the

immune system produce in response to the presence of a nonself antigen; it reacts with the antigen.

Respiratory System

Inspiration • Breathing in.

Expiration • Expulsion of air from the lungs.

Bronchi • Branches of the trachea that

lead to the lungs.

Alveoli • Air sac of a lung.

Digestive System

Alimentary Canal • Tubular portion of the digestive

tract that leads from the mouth to the anus.

Peristalisis • Rhythmic waves of muscular

contraction in the walls of certain tubular organs (digestion).

Bile • Fluid secreted by the liver and

stored in the gallbladder (emulsifies fats).

Villi • Tiny, finger-like projection that

extends outward from the inner lining of the small intestines.

Urinary System

Nephron • Functional unit of the kidney.

Reproductive System

Puberty • Stage of development in which

the reproductive organs become functional.

Ovulation • Release of an egg cell from a

mature ovarian follicle.

Progesterone • Female hormone secreted by

the corpus luteum of the ovary and the placenta.

Estrogen • Hormones that stimulate the

development of female secondary sex characteristics and produces an environment suitable for fertilization, implantation, and growth of an embryo.

Testosterone • Male sex hormone secreted by

the interstitial cells of the testes.

Zygote • Cell produced by the fusion of

an egg and sperm; a fertilized egg.

Placenta • Structure that attaches the

fetus to the uterine wall, providing for delivery of nutrients to and removal of wastes from the fetus.

Amniotic Fluid • Fluid within the amniotic cavity

that surrounds the developing fetus.

Diseases to Know

Jaundice • A yellowish skin tone, which

can indicate live malfunction.

Diabetes • High blood glucose level and

glucose in the urine due to a deficiency of insulin.

Goiter • Enlarged thyroid gland due to

an iodine deficiency.

Fetal Alcohol Syndrome

• A group of conditions that can occur in a person whose mother drank alcohol during pregnancy.

Diagrams to Know

Divisions of the Body