Central Nervous System Exam 1 Study Guide - Pathophysiology 1

initial segment

The _______ of an axon lies between the axon hillock & the axon; this is where the AP begins.

Schwann cells

Myelin sheaths are made up of a series of ________ & are not a continuous sheath.

Nodes of Ranvier

segments between adjacent Schwann cells of an axon

endoplasmic reticulum

Since there is so much ________ in a neuronal cell body, lots of protein production occurs within.

types of neurons:

- multipolar

- bipolar

- unipolar/pseudounipolar

multipolar

neurons with star-shaped cell bodies; have multiple dendrites branching from the cell body

Multipolar

________ neurons make up the majority of the neurons in the body.

bipolar

neuron with spindle-shaped cell body with only 1 dendrite branching from it

bipolar

neurons found only in specific areas of the body including the retina, nasal olfactory epithelium, & vestibular & cochlear ganglia (associated with cranial nerve 8)

(pseudo)unipolar

neuron with round cell body that has 1 functional unit extending; this functional unit branches to dendrites at one end and axon on the other

axon

conductive process of neuron

(pseudo)unipolar

all sensory neurons in the body have this structure

neuroglia

neurons' supporting cells

10

There are _____ times more neuroglia in the body than there are neurons.

astrocytes

microglia

oligodendrocytes

ependymal cells

types of neuroglial cells:

astrocytes

neuroglia that come in contact with both neurons & blood vessels; provide mechanical & molecular support (like nutrients) to neurons while also providing protection

astrocytes

type of neuroglial cell that makes up part of the BBB

astrocytes

supportive cell that send nutrients to the brain

microglia

type of neuroglial cell that is involved with phagocytosis

oligodendrocytes

type of neuroglial cell involved with myelin sheath formation in the CNS

F: attach to multiple axons & produce myelin sheaths simultaneously

T/F: Oligodendrocytes produce myelin sheaths on only 1 axon.

Schwann cells, oligodendrocytes

_______ produce myelin sheaths of axons in the PNS while _________ produce myelin sheaths in the CNS.

ependymal cells

type of neuroglial cells that line fluid filled cavities in the brain (like the cerebral ventricles) & the central canal of the spinal cord

plasma membrane

Myelin ensheathment consists of compacted _________ of a Schwann cell.

F: have Schwann cells that protect axons, but no myeline sheaths produced

T/F: Unmyelinated axons do not contain Schwann cells.

A

B

C

There are 3 classes of axons based on diameter:

A & B

Myelinated classes of axons:

alpha

beta

gama

delta

Class A axons are divided into 4 categories:

faster

The larger the diameter of the axon, the ________ (faster, slower) the conduction of an AP.

somatic efferent

skeletal muscle

motor

Class A alpha axon fibers

type:

location:

function:

somatic afferent

skin & joints

tactile, proprioception

Class A beta axon fibers

type:

location:

function:

efferent

muscle spindles

muscle tone

Class A gama axon fibers

type:

location:

function:

somatic afferent

sensory nerves

pain, cold temp, & touch

Class A delta axon fibers

type:

location:

function:

visceral efferent

preganglionic

cardiac muscle, smooth muscle, exocrine glands, adipocytes

Class B axon fibers

type:

location:

function:

small, unmyelinated

Class C axon fibers have ______ diameter & are _________ (myelinated, unmyelinated).

visceral efferent

postganglionic

cardiac muscle, smooth muscle, exocrine glands, adipocytes

Class C sC axons

type:

location:

function:

somatic afferent

sensory nerves

pain, warm temp.

Class C dC axons:

type:

location:

function:

C

Class ______ axons have the slowest conductivity.

CNS

nervous system made up of the brain, spinal cord, & bony encasements that protect them

T

T/F: There is direct communication between the CNS & PNS because neither system can operate independently.

PNS

nervous system made up of everything outside of the CNS like paired nerves, ganglia, & sensory receptors

CNS, nuclei

Collections of neuronal cell bodies are most commonly found in the _______ & they are referred to as ________.

ganglia

collections of neuronal cell bodies in the PNS

sensory, motor

Ganglia can be ______ or _______.

PNS

Sensory receptors are located in the _______, & there are specific sensory receptors to pick up different signals (baroreceptors, mechanical receptors, touch receptors, etc.)

sensory division

motor division

The PNS is divided into 2 parts:

efferent

Sensory information is what _______ (afferent, efferent) neurons act on.

somatic sensory

visceral sensory

The sensory division of the PNS is divided into:

somatic

the ______ division of the sensory division is involved with senses coming from the surface of the body (touch, pain, pressure, vibration, temp, & proprioception in skin, body wall, & limbs)

hearing

vision

equilibrium

Somatic sensory division's special senses:

visceral

The ______ division of the Sensory division is involved with senses derived from organs (stretch, pain, temp, chemical changes, & irritation is viscera; nausea & hunger)

proprioception

position of the body in space; includes info from joints & allows us to move, stand, etc.

taste

smell

special senses of the visceral division:

somatic NS

autonomic NS

The motor division of the PNS is divided into:

motor

The ______ division of the PNS sends commands to target tissues.

somatic NS

deals with motor innervation of all skeletal muscle (voluntary movement)

autonomic NS

deals with motor innervation of cardiac muscle, smooth muscle, & exocrine glands

T

T/F: Most target structures of the autonomic NS receive information from both the sympathetic & parasympathetic divisions.

brainstem, spinal cord

Axons that exit the CNS & travel to target tissue exit at the ______ or ________.

lower

Motor neurons that exit the brain stem & spinal cord to go to target tissue are _______ (upper, lower) motor neurons.

primary motor cortex

Upper motor neurons are located in the __________.

Upper motor neurons

_________ send axons down from the primary motor cortex that regulate the function of lower motor neurons.

T

T/F: While axons in the somatic NS travel directly to the tissue they affect after exiting the CNS, axons in the autonomic NS must terminate at ganglia before traveling to target tissue (2 neuron systems).

hypothalamus

While somatic neurons are regulated by upper motor neurons in the primary motor cortex, preganglionic neurons in the autonomic NS are regulated by the _________.

cervical

thoracic

lumbar

sacral

regions of the vertebral column:

T

T/F: The curvature of the vertebral column is specific to the different vertebral regions.

7

12

5

5

There are:

______ cervical vertebrae

_______ thoracic vertebrae

_______ lumbar vertebrae

_______ sacral vertebrae

sacrum

The 5 sacral vertebrae are fused to the ________.

atlas

C1 called ______

axis

C2 called ______

C1, C2

Vertebrae _____ & ______ are important for the rotation of the head around an axis.

nerves

Vertebral ___________ extend from the vertebrae.

8, 7

There are ______ cervical spinal nerves but only ______ cervical vertebrae.

above, below

Cervical nerves exit the the spinal column ______ (above, below) their respective vertebrae with C8 exiting ______ (above, below) vertebrae C7.

below

Other than cervical nerves, all other spinal nerves exit the spinal column _______ (above, below) their respective vertebrae.

cervical, lumbar

The spinal cord thickens near the ______ & ______ regions because there is a dense concentration of nerve cells that function as somatic efferent neurons located in these areas.

arm, legs

Nerves that exit the spinal column at the thickened areas of the spinal cord innervate extremities, mainly _____ & _____.

shorter

The spinal cord is _______ (longer, shorter) than the spinal column because the spinal column continues to grow as humans grow.

conus medullaris

The pointed end of the spinal cord that indicates the termination of the spinal cord in the vertebral column is called the _______.

L1, L2

The conus medularis terminates between vertebral column bones _____ & ______.

L2

Paired spinal nerves below vertebral bone ______ travel down the vertebral column to exit at their respective sites.

couda equinas

collection of the spinal nerves that extends down the vertebral column from the conus medullaris

horse tail

Couda equines means ________.

sacral, coccygeal

_______ & _______ spinal nerves make up the couda equines.

cervical, lumbar, sacral, coccygeal

The _______, _________, _________, & ________ regions of spinal nerves exit the spinal column & make contact to from a network of integrated fibers called a plexus.

plexus

branching network of nerves composed of afferent & efferent fibers arising from the merging of ventral rami of spinal nerves

Thoracic

_________ spinal nerves branch into dorsal & ventral rami when exiting the spinal column.

dorsal

The ______ ramus of thoracic spinal nerves heads to the back of the body to innervate vertebral muscles that extend the trunk & aid in posture.

ventral

The ______ ramus of thoracic spinal nerves travel along the body wall to innervate thoracic wall muscles & provide sensory info from those muscles & the skin to the CNS.

ventral rami

In other regions of the spinal nerves other than thoracic, ________ make contact with one another to form complex plexuses.

cervical

spinal nerves that innervate muscles of the head, neck, & shoulders

brachial

nerves that innervate muscles that deal with the chest, shoulders, arms, & hands

lumbar

spinal nerves that innervate muscles of the back, abdomen, groin, thighs, knees, & calves

sacral

spinal nerves that innervate muscles of the pelvis, butt, genitals, thighs, calves, & feet

coccygeal

spinal nerves that innervate a small area over the coccyx

musculocutaneous

axillary

radial

ulnar

nerves that arise from the brachial plexus

T

T/F: All nerves have a name.

F: innervated by a single named nerve

T/F: All somatic efferent muscles have a name & are innervated by multiple somatic efferent nerves.

biceps brachii

coraco-brachialis

muscles of anterior side of upper arm

musculocutaneous, flex

The biceps brachii & coraco-brachialis are innervated by the _______ nerve. These muscles cause ______ of the forearm.