Nervous System Study Guide

central nervous system, peripheral nervous system

what are the two major divisions of the nervous system?

neuroglia, neurons

what are the types of nervous tissue?

sensory receptors, afferent nerves, efferent nerves

what does the PNS contain?

central nervous system (CNS)

brain and spinal cord

peripheral nervous system (PNS)

parts of the nervous system other than brain and spinal cord

autonomic nervous system, somatic nervous system

what are the two parts of the peripheral nervous system?

autonomic nervous system

to cardiac and smooth muscles and glands

somatic nervous system

to skeletal muscles

parasympathetic nervous system, sympathetic nervous system

what are the two divisions of the autonomic nervous system?

parasympathetic nervous system

routine involuntary functions

sympathetic nervous system

high alert

voluntary

is the somatic nervous system in/voluntary?

involuntary

is the autonomic nervous system in/voluntary?

neuroglia (glial cells)

support and protect the neurons

neurons

transmit nerve impulses

astrocytes, microglia, ependymal, oligodendrocytes

which glial cells are in the CNS?

schwann cells, satellite cells

which glial cells are in the PNS?

dendrites

which neuron sends information to the cell body?

axons

which neurons send information away from the cell body?

dendrites, axons, cell body

what is a neuron made up of?

sensory neurons, motor neurons, interneurons

what are the three neuron types?

sensory neurons

send impulses toward the CNS

motor neurons

send impulses away from the CNS

interneurons

bridges between neurons

bipolar, unipolar, multipolar

what are the three neuron structures?

bipolar

one axon and one dendrite

unipolar

one axon

multipolar

one axon and many dendrites

action potentials

change in cell membrane charge

impulse transmission

charge change travels along the axon

reflexes

involuntary programmed responses to stimuli

polarized, depolarized, repolarized, refractory period

what are the types of action potentials?

polarized

when the inside of a cell membrane is more negatively charged than the outside

depolarized

when the inside of a cell membrane is more positively charged than the outside

repolarized

the reestablishment of a polarized state in a cell; happens after depolarization

refractory period

the time between the completion of the action potential and repolarization

conductivity, nerve impulse

what are the types of impulse transmission?

conductivity

the ability to transmit nerve impulses

nerve impulse (action potential)

electrical charge that travels along a nerve fiber when stimulated

all-or-none rule

electrical charge of the action potential is always the same size, and once initiated, always travels the full length of the axon

presence or absence of myelin sheath, diameter of axon, body temperature

what 3 factors can affect the speed of transmission?

higher diffusion rates

warmer temperatures cause...

lower diffusion rates

lower temperatures cause...

myelin sheath

made of fat; acts as an insulator

nodes of ranvier (where the axon is exposed)

where does depolarization occur?

saltatory conduction

the rapid skipping of an action potential from node to node on a myelinated neuron

excitatory and inhibitory effects

neurotransmitters cause...

gap junctions

where does transmission in synapses occur?

somatic and autonomic

what are the two types of reflexes?

somatic reflex

stimulation of voluntary muscles

autonomic reflex

stimulation of involuntary muscles

endoneurium

covers axons (nerve fibers)

perineurium

bundles fascicles (bundle of nerve fibers)

epineurium

tough outer coating of nerves

spinal nerves

31 pairs of neural transmitters that branch from left and right of the spinal cord

dorsal ramus

posterior spinal nerves that transmit motor impulses to the posterior trunk muscles/relay sensory impulses from skin on the back

ventral ramus

anterior division of spinal nerves; communicates with muscle and skin of anterior/lateral trunk

plexus

complex interconnections of nerves

ganglion, preganglionic neurons, postganglionic neurons, sympathetic nerves, parasympathetic nerves

what is included in the autonomic nervous system?

ganglion

mass of nerve tissue made mainly of nerve-cell bodies

preganglionic neurons

first neuron in series; transmits impulses from the CNS

postganglionic neurons

second neuron in series; transmits impulses from CNS

sympathetic nerves

what causes the fight-or-flight reaction?

parasympathetic nerves

what causes the resting or digesting action?

thoracolumbar division, paravertebral ganglia, norepinephrine

what is associated with the sympathetic nerves?

thoracolumbar division

lies near thoracic and lumbar region of the spine

paravertebral ganglia

nerve cell bodies close to the spinal cord

norepinephrine

neurotransmitter released by postganglionic neurons in the sympathetic nervous system

craniosacral divison

what is associated with the parasympathetic nerves?

craniosacral divison

nerves that originate in the brain stem or sacral region of the spinal cord

acetylcholine

if both preganglionic and postganglionic nerves are triggered, what is released?

acetylcholine

stimulates skeletal muscle, inhibits cardia and smooth muscle

mild traumatic brain injury (TBI)

caused by violent impact to the head; may lose consciousness; headache, confusion, dizziness, disturbed vision, ringing in ears, bad taste in mouth, fatigue, abnormal sleep, behavioral changes, trouble with intellectual functions

moderate-severe traumatic brain injury

prolonged headaches, repeated nausea/vomiting, convulsions/seizures, not able to wake from sleeping, dilation in one or more pupils, slurred speech, weakness/numbness in extremities, loss of coordination, confusion, agitation

cerebral palsy

caused by damage to the brain; occurs before or during birth/infancy; commonly includes motor function impairment, but can include hearing, seeing, and cognitive impairments

C1-C3 spinal cord injury

usually fatal

C1-C4 spinal cord injury

quadriplegia-loss of function below the neck

C5-C7 spinal cord injury

paralysis of the lower extremities

T1-L5 spinal cord injury

paraplegia-loss of function in legs/trunk

meningitis

inflammation of the meninges caused by fungal infection

multiple sclerosis

autoimmune disease where the immune system causes inflammation that destroys the myelin sheath of nerve axons

epilepsy

repeated seizures over time

Parkinson's disease

characterized by tremors, difficulty with initiating movements - especially walking - and deficits in coordination

dementia

loss of function in 2 or more areas of godnition including memory, thinking, judgement, behavior, perception, and language

Alzheimer's disease

progressive loss of brain function with major consequences for memory, thinking, and behavior

gyri

raised area on the brain

sulci

shallow grooves in between each gyrus

fissures

uniform, deep grooves in the brain

cerebrum

largest part of the brain, divided into right and left hemispheres

diencephalon (interbrain)

contains the epithalamus, thalamus, metathalamus, and hypothalamus

cerebellum

coordinates body movements (balance)

meninges

3 protective membranes surrounding the brain and spinal cord

pia mater, arachnoid mater, dura mater

what are the three meninges? (inner to outer)

blood-brain barrier

protects the brain from surges of ions and hormones

frontal lobe

located behind the forehead

parietal and occipital lobe

integrate sensory info from the skin, internal organs, muscles, and joints

temporal lobe

responsible for speech, hearing, vision, memory, and emotion

primary motor cortex

outer region of the brain in the frontal lobes that sends neural impulses to the skeletal muscles

primary somatic sensory cortex

outer region of the brain in the parietal lobes that interprets sensory impulses received from the skin, internal organs, muscles, and joints

thalamus

communicates sensory and motor info between the body and cerebral cortex