Nervous System Vocab

Acetylcholine

Acetylcholine

neurotransmitter secreted at the ends of many neurons; responsible for the transmission of a nerve impulse across a synaptic cleft.

Acetylcholinesterase

an enzyme that breaks down Acetylcholine

Action potential

change in the potential propagated along the membrane of a neuron; the nerve impulse

Arachnoid membrane

a thin, transparent membrane that surrounds the spinal cord; weblike middle covering of the CNS

Association area

region of the cerebral cortex related to memory, reasoning, judgement, and emotional feeling

Autonomic system

sympathetic and parasympathetic portions of the nervous system that function to control the actions of the visceral organs and skin; regulates the activity of cardiac and smooth muscles and glands

Axon

conducts nerve impulses away from the cell body

Basal nuclei

mass of gray matter located deep within a cerebral hemisphere of the brain

Cell body

portion of a nerve cell that includes a cytoplasmic mass and a nucleus, and from which the nerve fibers extend

Central nervous system

brain and spinal cord

Cerebellum

part of the brain that controls muscular coordination

Cerebral cortex

outer layer of the cerebellum

Cerebral hemisphere

two parts (halves) of the cerebrum (left and right)

Cerebrum

largest portion of the brain in humans; main portion of the vertebrate brain that is responsible for consciousness

Cerebrospinal fluid

a clear tissue fluid that forms a protective cushion around and within the CNS

Cranial nerve

a set of 12 paired nerves in the back of your brain; sends electrical signals between your brain, face, neck and torso.

Dendrite

many short extensions that receive signals from sensory receptors or other neurons (receive info and push it out)

Diencephalon

portion of the brain in the region of the third ventricle that includes the thalamus and the hypothalamus

Ganglion

collection of neuron cell bodies outside the CNS

Gray matter

nonmyelinated nerve fibers in the central nervous system

Hypothalamus

region of the brain; the floor of the third ventricle that helps maintain homeostasis

Interneuron

neuron found withing the CNS system that takes nerve impluses from one portion of the system to another

Limbic system

the part of the brain involved in our behavioral and emotional responses

Meninges

protective membranes that cover the brain and spinal cord

Midbrain

small region of the brain stem located between the forebrain and the hindbrain; contains tracts that conduct impulses to and from the higher parts if the brain

Nerve

bundles of long nerve fibers that run to and from the CNS

Nerve impulse

change in polarity that flows along the membrane of a nerve fiber

Neuron

(nerve cells) that transmits nerve impulses; three parts- dendrite, cell body, and axon

Neurotransmitter

responsible for transmission across a synapse

Norepinephrine

hormone secreted by the adrenal medulla to help initiate the “fight or flight” reaction

Parasympathetic division

the part of the nervous system that slows the heart, dilates blood vessels, decreases pupil size, increases digestive juices, and relaxes muscles in the gastrointestinal tract

Peripheral nervous system

nerves and ganglia of the nervous system that lie outside the brain and spinal cord

Pons

contains bundles of axons traveling between the cerebellum and the rest of the CNS

Posterior-root ganglion

mass of sensory neuron cell bodies located in the dorsal root of a spinal nerve .

Primary motor area

area in the frontal lobe where voluntary commands begin; each section controls a part of the body

Primary somatosensory area

area posterior to the central sulcus where sensory information arrives from the skin and skeletal muscles

Reflex

automatic involuntary responses to changes that occur inside or outside the body

Somatic system

portion of the PNS containing motor neuron motor neurons that control skeletal muscles

Spinal cord

a cylinder of nervous tissue that starts at the base of the brain through the large opening in the skull

Spinal nerve

31 pairs in humans; nerve that arises from the spinal cord

Sympathetic division

part of the autonomic nervous system whose effects are generally associated with emergency situations

Synapse

region between two nerve cells where the nerve impulse is transmitted from one to the other, usually from axon to dendrite

Synaptic cleft

the small gap between the presynaptic membrane and postsynaptic membrane

Thalamus

two masses of gray matter located at the base of the cerebrum in the wall of third ventricle; receives sensory information and selectively passe it to the cerebrum

Tract

a bundle of fibers in the nervous system that connects one area to another and usually consists mostly of white matter.

Ventricle

cavity in an organ, interconnecting chambers that also produce cerebrospinal fluid

White matter

myelinated nerve fibers in the CNS

Alzheimer disease

a brain disorder that slowly destroys memory and thinking skills

Ankle-jerk reflex

happens when the Achilles tendon is tapped while the foot is dorsi flexed

Cerebral palsy

A group of disorders that affect a person’s ability to move and maintain balance and posture

Electroencephalogram

A recording of electrical activity in the brain

Hydrocephalus

A neurological disorder caused by abnormal buildup of cerebrospinal fluid in the ventricles deep within the brain

Epidural hematoma

bleeding into the space between the dura matter and bone

Knee-jerk reflex

sudden kicking movement of the lower leg in response to a sharp tap on the patellar tendon

Paraplegia

paralysis of the lower body and legs occurs

Parkinson disease

a brain disorder that causes unintended or uncontrollable movements and difficulty with coordination

Quadriplegia

entire body, all 4 limbs are effected (paralysis)

Stroke

Called a brain attack, happens when blood flow to the brain is blocked

Subdural hematoma

the presence of blood between the dura matter and the next menix, the arachnoid.

Major functions of the nervous system

Sensory input, Motor output, Integration

Frontal

motor speech area , talking, facial expressions

Parietal

taste area, somatosensory area; sensory area

Temporal

hearing, auditory area

Occipital

vision, visual area; retina

Optic

sense of sight

Olfactory

sense of smell

The brain is divided by the central hemisphere and broken down into

lobes

fissures are also known as

sulcus or sulci

internal/ external changes are

stimulus

stimulus receives from

receptor