A&P test 5 chapters 12 and 13 review

functions of the central nervous system (CNS)

process and coordinate sensory data, motor commands, and higher brain functions

functions of the peripheral nervous system (PNS)

deliver sensory information to the CNS, and carry motor commands to peripheral tissues and systems

components of the CNS

spinal cord, brain, blood vessels, and neural and connective tissues

components of the PNS

all neural tissue that isn't part of the CNS

Which nervous system controls skeletal muscles?

central nervous system (CNS)

function of neuroglia (glial cells)

support and protect neurons

oligodendrocytes

1 of 4 types of neuroglia. small cell bodies with few processes that contact the other neuron cell bodies

ependymal cells

1 of 4 types of neuroglia. form epithelium called ependyma, and line central canal of spinal cord and ventricles of brain (these do a lot with cerebrospinal fluid)

microglia

1 of 4 types of neuroglia. smallest and least numerous, with many fine-branched processes. migrate through neural tissue and clean up cellular debris, etc

What are the most abundant class of neuron in the CNS?

interneurons (located between sensory and motor neurons) (distribute sensory information and coordinate motor activity, also involved in higher functions)

telodendria

fine extensions of distal axon

passive channels

AKA leak channels. they are always open and their permeability changes with conditions

active channels

AKA gated channels. most are closed at resting potential, but all open and close in response to stimuli

all-or-none principle

the initiation of action potential (if a stimulus exceeds the threshold amount, the action potential is the same, no matter how large the stimulus is) (the action potential is either triggered or it isn't)

action potential

electrical signals that transport information through the nervous system

type A fibers

a classification of axon. myelinated, large diameter, HIGH speed (140 meters per second), carry rapid information to and from the CNS (ex. position, balance, touch, and motor impulses)

type of neurotransmitter released from Cholinergic synapses

acetylcholine (ACh)

cholinergic synapses

any synapse that releases ACh

type of neurotransmitter released from Adrenergic synapses

norepinephrine (NE)

the effect that a neurotransmitter has on the postsynaptic membrane depends on what?

the receptor of the neurotransmitter (not the neurotransmitter itself)

Excitatory Postsynaptic Potentials (EPSPs) occur when:

sodium channels open in response to a stimulus, depolarizing the postsynaptic membrane and making its charge more positive

Inhibitory Postsynaptic Potentials (IPSPs)

hyperpolarization of postsynaptic membrane (when its charge becomes more negative)

neuroglia

glial cells, support and protect neurons, account for about half of the volume of the nervous system

In the spinal cord, white matter is separated into ascending and descending tracts organized as what?

columns (anterior, posterior, lateral)

ascending tracts

carry information to the brain

descending tracts

carry information to the spinal cord

spinal meninges

specialized membranes that isolate the spinal cord from its surroundings, protect the spinal cord, and carry blood supply

What is the name for the outward projections from the central gray matter of the spinal cord?

gray horns

Ventral spinal nerves are: motor, sensory, both, or neither?

motor

Dorsal spinal nerves are: motor, sensory, both, or neither?

sensory

Which muscle areas does the cervical plexus innervate?

neck, thoracic cavity, diaphragmatic

Which muscle areas does the sacral plexus innervate?

posterior thigh, lower leg, foot

plexus

network of nerves

Ways to classify reflexes

by early development, by type of motor response, by complexity of neural circuit, and by site of information processing

functions of tendon reflexes

prevent skeletal muscles from developing too much tension and tearing or breaking tendons

flexor reflex

type of withdrawal reflex (moves body part away from pain or pressure stimulus) (ex. pulling your hand away from a hot stove)

reciprocal inhibition

allows the flexor reflex to work by inhibiting the stretch reflex of the antagonistic (extensor) muscle

dura mater

outer layer of spinal cord, touch and fibrous

arachnoid mater

middle meningeal layer of the spinal cord, covered by arachnoid membrane

pia mater

innermost meningeal layer of the spinal cord, mesh of collagen and elastic fibers, bound to underlying neural tissue

meningitis

viral or bacterial infection of the meninges

epineurium

outer connective tissue layer of spinal nerves, dense network of collagen fibers

perineurium

middle connective tissue layer of spinal nerves, divides nerve into fasicles (axon bundles)

endoneurium

inner connective tissue layer of spinal nerves, surrounds individual axons