Abeka Biology Ch. 8

poliomyelitis

(polio) serious disease that attacks the spinal cord. I scared by a virus that enters the motor neurons of the spinal cord and destroys some of them.

pain receptors

a bare dendrite that reacts to a certain type of strong stimulus.

neurobiologist

a biologist who studies the nervous system.

neurotransmitter

a chemical released into a synapse any a neuron to cause an action in the receiving cell.

cerebrospinal fluid

a clear fluid that circulates through the fibers of thee arachnoid mater, serving to cushion the brain when you bump your head.

cochlea

a coiled tube resembling a snail's shell.

Sciatica

a condition characterized by pain in the lower back and the back of the thigh is caused by a pinching of sciatic verve of the lower spinal cord.

nerve center

a group of cell bodies in the brain or spinal cord.

axon

a long extension that relays nerve impulses from the cell body to other neurons.

amnesia

a loss of memory.

corpus callosum

a mass of nerve fibers through located at the base of the cerebrum through which the two hemispheres of the cerebrum communicate with each other.

limbic system

a number of complex brain structures that lie clustered around the brain stem at the core of the brain, surrounded by the cerebrum.

concussion

a period of paralysis of the central nervous system accompanied by a short period of unconsciousness.

neurologist

a physician who specializes in disorders of the nervous system.

reflex

a quick automatic response

dendrite

a short branched extension of the cell that receives nerve impulses from other neurons and conducts them toward the cell body.

coma

a state of prolonged unconsciousness

eardrum

a taut membrane stretched across the canal like the surface of a drum.

meninges

a triple layer of protective tissues that protects th spinal cord and brain.

parasympathetic division

acts as a balance to counteract the actions of the sympathetic division.

synapse

an enclosed junction between two neurons or a neuron and another cell.

reticular formation

an intricate network of neurons. Its most important function is serving as the "master switch" of the cerebrum.

lobes

any of the main regions into which the hemispheres of the cerebrum are divided.

special senses

any of the senses that are provided by neurons in sense organs.

somatic senses

any of the senses that detect touch, temperature, pain, etc.

chemical senses

any of the senses that result from chemical stimuli.

occipital lobes

are located at the back of the brain. it interprets the sense of vision.

temporal lobes

are located on either side of the brain, are associated with the senses of hearing, taste, and smell.

inner ear

as the vibrations pass through the stapes they enter this portion of the ear, the actual organ of hearing.

thalamus

at the uppermost end of the brain stem. Which acts like a switch-board, routing activation signals from the reticular formation and sensory impulses from various parts of the body to the appropriate areas of the cerebral cortex.

action potential

brief pulse of positive charge that travels down the axon of a neuron that has been triggered to fire.

nerves

bundles of nerve fibers (axons) branching from the brain and spinal cord and connecting the central nervous system to the extremities of the body.

auditory nerve

carries electrical messages to the brain, where they are translated into meaningful sounds.

motor nerve fibers

carry impulses from the brain and spinal cord to produce action in muscles and organs.

Arteriosclerotic dementia

caused by the death of brain cells; however, the cells die because blockage in the arteries restricts their blood supply.

sensorineural deafness

complete hearing loss.

peripheral nervous system

consists of nerves that branch off from the brain and spinal cord.

cell body

contains a nucleus and most of the nerve cells' cytoplasm.

cerebral palsy

damage to the cerebral motor are is known as what?

neuritis

degeneration and inflammation of nerves.

tetanus

disease caused by the soil bacterium Clostridium tetani, whose toxin damages motor nerves, resulting in death if untreated; also called lockjaw.

Multiple Sclerosis

disease that occurs when the body's immune system attacks the glial cells that provide myelin sheaths for central-nervous-system axons.

epilepsy

disorder in which neurons malfunction and begin to fire together over and over, disrupting ordinary cerebral processing and causing unconsciousness.

gray matter

found within the brain and spinal cord consists largely of the cell bodies of neurons and is gray because the cell bodies lack myelin.

sympathetic division

generally responds to your needs during increased activity and in emergency situations by causing heartbeat and breathing rates to increase thus suppling more blood to your body so that you can respond quickly.

sensory nerve fibers

have only sensory fibers or only motor fibers. Carry impulses from light, taste, sound, touch, and pain from other parts of the body to the spinal cord and brain for analysis.

amygdala

helps generate emotions and processes emotional memories.

central nervous system

includes the brain and the spinal cord, which are both encased in bone for protection.

sense organs

intricately designed organ for a special sense

white matter

is composed of axons and glial cells that are white because of their myelin content.

brain stem

is located between the cerebrum and the spinal cord. It controls the involuntary muscle and activities of the autonomic nervous system.

hypothalamus

just below the thalamus. Which is the control unit for your body's autonomic systems. controls the autonomic nervous system and the endocrine system.

plexus

large mass of ganglia grouped together.

midbrain

located above the pons. Nerve centers in this help coordinate the movements of both eyes, adjust the size of the pupils in response to light, and operate the lens muscles to focus the eyes on the object of your attention.

parietal lobes

located behind the frontal lobe. They analyze the senses on their sides of the body to allow us to feel sensations such as temperature, pressure, and pain and to make judgment about such things as shape and texture.

pons

located just above the medulla oblongata which links the cerebrum with the cerebellum. It assists the medusa oblongata in regulating breathing.

middle ear

malleus, incus, and stapes form this portion of the ear.

ganglia

masses of cell bodies.

stroke

most common serious injury of the nervous system. A leading cause of death throughout the world.

olfactory nerve

nerve connecting the nose's sensory receptors to the brain.

reflex arc

nerve pathway controlling a reflex, which allows nerve impulses to bypass the brain for a speedy response.

mixed nerves

nerves that contain both sensory and motor fibers.

motor neurons

neurons that relay signals from the central nervous system to the other parts of the body.

sensory neurons

neurons that transmit information to the central nervous system from the senses of sight, hearing, taste, tough, and smell, as well as those that transmit pain signals.

sciatic nerve

one of the longest nerves in the body.

acute confusion

one of the most common mental disorders in the elderly. A disturbance of the brain caused by physical illness elsewhere in the body.

alcohol

one of the most commonly abused drugs in the world today.

cerebral cortex

outer layer of the cerebrum, which contains much of the brain's gray matter.

REM sleep

period of sleep in which the eyes move rapidly as if they were watching the events of a dream.

outer ear

portion of the ear consisting of the visible sound-collecting structure and the ear canal.

hippocampus

processes factual memories for storage

chemoreceptors

receptor for a chemical sense, senses of taste and smell.

thermoreceptors

respond to temperature changes.

hemispheres

right or left halves of the cerebrum or cerebellum

semicircular canals

serve as balance sensors....

sensory receptors

specialized neurons that obtain information from the senses to the central nervous system.

neurons

the actual nerve cells

behaviorism

the belief that the behavior of a person is determined by his environment, not by his mind.

spinal cord

the brain communicates with most of the body through this thick bundles of nerve fibers located within the spinal cavity.

Parkinson's disease

the disease that affects the patient's control of posture and movement; it is characterized by tremors and stiffness of the limbs.

meningitis

the disease when bacteria and viruses slip through the blood-brain barrier and infect the meninges.

senile dementia

the disorder that results from the slow process of natural nerve cell loss.

frontal lobes

the forward portion of this lobe is associated with personality, judgment , and self-control.

paralysis

the inability of the muscles to move.

cerebrum

the largest part of the brain and is the physical organ that helps you in the areas of consciousness, memory, voluntary actions, thinking, and intelligence.

medulla oblongata

the lowest part of the brain stem. It contains nerve centers that monitor and regulate breathing, heartbeat, blood pressure, and other vital body functions such as swallowing.

taste buds

the organs responsible for taste. Are chemoreceptors on the back, sides, and front of the tongue that detect dissolved chemicals in the mouth.

autonomic nervous system

the part of the peripheral nervous system that controls the heart and other internal organs.

brain

the principal organ of the nervous system.

motor area

the rear portion of the frontal lobes. Controls voluntary movement of the skeletal muscles.

cerebellum

the second-largest brain region. It lies behind the brain stem and just below the occipital lobe of the cerebrum. Its function is to coordinate skeletal muscle activity.

mechanoreceptors

the sensory receptors responsible for sensations of touch and pressure.

spinal nerves

these thirty-one pairs of nerves transmit nerve signals to and from the rest of the body.

blood-brain barrier

these tightly sealed capillary walls protect the central nervous system from being permanently damaged every time you get sick.

cranial nerves

these twelve pair of nerves branch directly from the brain stem and transmit nerve signals to and from the eyes, ears, mouth, face, and scalp.

Interneurons

which are found only in the central nervous system, relay signals between neurons to groups of neurons and are responsible for the processing of information by the brain, like the logic circuits of a computer.

Alzheimer's disease

which has symptoms similar to dementia but more sever, may occur much earlier in life.

Schwann cells

which produce layers of myelin sheathing that acts much like the insulation on an electrical wire.

glial cells

which support and insulate nerve tissue.

myelin

white, specialized covering.