test 3 vocab

Acquired Immune Deficient Syndrome (AIDS)

disease caused by human immunodeficiency virus (HIV). symptoms include serve weight loss, night sweats, swollen lymph nodes, and opportunistic infections

active immunization

the process of activation of the immune system in advance of the presence of a disease. generally, this is accomplished by a vaccine

antibiotics

a substance that interferes with bacterial metabolis. Administered to cure bacterial diseases

antibody

a protein molecule released by a B cell or a plasma cell that binds to a specific antigen

antibody-mediated immunity

these components of the body’s adaptive defenses that result in activation of B cells and the production of antibodies

antigen

a substance or part of a substance that the immune system recognizes as foreign. it activates the immune system and reacts with immune cells or their products

bacteria

one of the three domains of life, these are prokaryotic microorganisms responsible for many human diseases

cell-mediated immunity

the components of the body’s adaptive defenses that are dependent on the activation and action of T cells and the cells they recruit

inflammation

a nonspecific defense response of the body to tissue injury characterized by dilation of blood vessels and an increase in vessel permeability, symptoms are redness, heat, swelling, and pain

interferons

chemical that is able to provide some protection against virus invasion of the body. this habits viral reproduction

passive immunization

the process of fighting an existing or anticipated infection by administration of specific antibodies against the infective agent. the antibodies usually are isolated from a human or animal with immunity to the infective agent

pathogen

disease-causing microorganism, such as bacteria or a virus

phagocytosis

process by which phagocytes, surround, engulf, and destroy foreign cells

Prion

an infectious disease misfolded protein that replicates by causing a normal protein in the infected animal to misfold, producing another prion. they’re technically are not alive since they cannot reproduce on their own.

T Cell

Lymphocytes responsible for cell-mediated immunity, which depends on the actions of several types of this cells.

vaccine

Antigens prepared in such a way that when injected or taken orally they induce active immunity without causing disease.

viruses

A noncellular infectious agent that can replicate only within a host cell. these consist only of one or more pieces of genetic material (DNA or RNA) surrounded by a protein coat.

alveolus

One of the microscopic air sacs of the lungs.

accommodation

The adjustment of lens curvature in the eye so we can focus on either near or far objects.

action potential

A brief change in membrane potential of a nerve or muscle cell due to the movement of ions across the plasma membrane.

Also called a nerve impulse.

autonomic division

Division of the peripheral nervous system composed of the sympathetic and parasympathetic divisions. The this carries signals from the central nervous system that control automatic functions of the body's internal organs. Sometimes referred to as the autonomic nervous system (ANS).

axon

An extension of a neuron that carries nerve impulses away from the nerve cell body. The conducting portion of a nerve cell.

bronchitis

Inflammation of the bronchi.

bronchus

Any one of the larger branching airways of the lungs. The walls of bronchi are reinforced with cartilage.

blood-brain barrier

A functional barrier between the blood and the brain that inhibits passage of certain substances from the blood into brain tissues.

central nervous system (CNS)

The brain and spinal cord.

cerebellum

Brain region most involved in producing smooth, coordinated skeletal muscle activity.

cerebral cortex

The outer gray matter region of the cerebral hemispheres.

Some regions of the this receive sensory information; others control motor responses.

cerebral hemispheres

The large paired structures that together form most of the cerebrum of the brain.

cerebrospinal fluid

Plas-malike fluid that fills the cavities of the CNS and surrounds the CNS externally. Protects the brain and spinal cord.

cerebrum

The cerebral hemispheres and nerve tracts that join them together.

Involves higher mental functions.

chemoreceptor

Type of receptor sensitive to various chemicals.

cone cell

One of the two types of photoreceptor cells in the retina of the eye. Cone cells provide for color vision.

cornea

The transparent anterior portion of the eyeball.

dendrite

Branching neuron extension that serves as a receptive or input region. these conduct graded potentials toward the cell body.

interneuron

A neuron within the central nervous system located between two other neurons. these receive input from one or more neurons and influence the functioning of other neurons.

iris

A colored disk-shaped muscle that determines how much light enters the eye.

lens

A transparent, flexible, curved structure that focuses incoming light on the retina at the back of the eye.

macula

The central region of the retina, where photoreceptor density is the highest.

medulla oblongata

Portion of the brain stem. Contains reflex centers for vital functions such as respiration and blood circulation.

meninges

Protective coverings of the central nervous system.

motor neuron

A neuron in the peripheral nervous system that conducts nerve impulses from the central nervous system to body tissues and organs.

myelin sheath

Fatty insulating sheath that surrounds the neuron axons of some types of neurons.

neuroglial cells

Cells that provide physical support and protection to neurons and help maintain healthy concentrations of important chemicals in the fluid surrounding them.

neurotransmitter

A chemical released by a neuron that may stimulate or inhibit other neurons or effector cells.

olfactory receptor cell

A modified sensory neuron, located in the upper part of the nasal pas-sages, that detects odors.

optic disk

The area of the retina where the axons of the optic nerve exit the eye. this has no photoreceptors, so its presence creates a "blind spot" in each eye.

parasympathetic division

The division of the autonomic nervous system that generally promotes activities associated with the resting state, such as digestion and elimination.

pharynx

The region of the digestive and respiratory systems that extends from behind the nasal cavities to the esophagus, also called the throat. Both air and food pass through the pharynx.

pleural membranes

Membranes that line the thoracic cavity and cover the external surface of the lungs.

photoreceptor

A specialized receptor cell that responds to light energy.

peripheral nervous system (PNS)

Portion of the nervous system that lies outside the brain and spinal cord.

rod cells

One of the two types of photo-sensitive cells in the retina.

resting potential

The slight difference in voltage (electrical potential) between the inside and outside of a cell.

retina

Layers of tissue at the back and sides of the eye. The retina is composed primarily of photoreceptor cells, neurons, and a few blood vessels.

sensory neuron

A neuron of the peripheral nervous system that is specialized to respond to a certain type of sensory stimulus, such as pressure or light. these neurons conduct information about a stimulus to the central nervous system in the form of nerve impulses.

somatic division

The division of the peripheral nervous system that controls voluntary and involuntary skeletal muscles.

sympathetic divison

The division of the autonomic nervous system that helps the body cope with stressors (danger, excitement, etc.) and with situations requiring high mental or physical activity.

synapse

Functional junction or point of close contact between two neurons or between a neuron and an effector cell.

threshold

In an excitable cell such as a nerve or muscle, the membrane voltage that must be reached to trigger an action potential, or nerve impulse.

thermoreceptor

Receptor sensitive to temperature changes.

taste bud

A cluster of taste receptor cells and supporting cells that respond to dissolved food chemicals in the mouth. The human tongue has about 10,000 taste buds.

tidal volume

Volume of air inhaled and exhaled in a single breath. Normal tidal volume is approximately 500 milliliters, or about a pint.

trachea

Tube extending from the larynx to the bronchi that is the passageway for air to the lungs. Also called the windpipe.

vital capacity

The maximum volume of air that can be expelled from the lungs by forcible expiration after the deepest inspiration.

ventilation

The process of breathing, moving air into and out of the lungs.

sympathetic division

The division of the autonomic nervous system that helps the body cope with stressors (danger, excitement, etc.) and with situations requiring high mental or physical activity.

neuron

Cell of the nervous system specialized to generate and transmit nerve impulses.

somatic sensation

Sensations that arise from receptors located at many points throughout the body. These sensations include temperature, touch, vibration, pressure, pain, and awareness of body movements and position.