CNS: The Brain & Spinal Cord

Question 1

Protection of CNS is called? What does it contain? location?

Answer 1

Meninges

• 3 connective tissue layers
• btwn skull/vertebrae & brain/spinal cord

Question 2

3 protective connective tissue layers are?

Answer 2

Dura Mater
Arachnoid Mater
Pia Mater

Question 3

Dura Mater
description?
function?
contains?

Answer 3

superficial (outside) layer, strongest
connects to periosteum of bones
contains Dural Sineses

Question 4

what are dural sinuses?

function?

Answer 4

spaces within the dura mater

drains blood from brain to neck veins

Question 5

Arachnoid Mater

Answer 5

Avascular (no blood circulation), middle layer

Question 6

Protection- Cerebrospinal Fluid

description? functions? movement? formed?

Answer 6

clear, colorless liquid
protects against chemical & physical injuries
carries 02, glucose, & chemicals from blood to neurons & neuroglia
continuously circulates through subarachnoid space
formed in the ventricles (4) of the brain

Question 7

whats the subarachnoid space?

Answer 7

its the space btwn arachnoid & pia mater

Question 8

Where is Cerebrospinal fluid formed?

Answer 8

formed in the ventricles of the brain

• substances filtered from blood plasma & secreted through ependymal cells
  
  • (mostly water)

Question 9

Pia Mater

description? location? function?

Answer 9

thin, transparent
adheres tightly to brain & spinal cord surfaces
vascular (blood circulation) - nutrient supply

Question 10

CSF stands for ?

Answer 10

Cerebrospinal Fluid

Question 11

CSF Functions (3)

Answer 11

Mechanical protection
Chemical protection
Circulation

Question 12

Mechanical Protection of CSF involves? (function)

Answer 12

shock absorber

Question 13

Chemical Protectionof CSF involves? (function)

Answer 13

Maintains optimal chemical environment w/ ions

Question 14

Circulation of CSF involves? (function)

Answer 14

Provides exchange of nutrients & wastes btwn blood & nervous tissue

Question 15

White Matter of CNS

Answer 15

bundles of mylinated & unmyelinated axons

Question 16

Gray Matter of CNS

Answer 16

contains dendrites, unmyelinated axons, axon temirnals, & neuroglia

Question 17

Gray vs White Matter of CNS ?

Answer 17

White matter- has MYELINATED (& unmyelinated) axons

Gray matter- only has UNMYELINATED axons

Question 18

Spinal cord consists of : (3)

Answer 18

1) bony vertebral column (bones & vertebrae, 31 spinal nerves)
2) Meninges
3) Epidural space

Question 19

What’s the epidural space?

location? function?

Answer 19

(gap) spinal cord consists of this
- space btwn dura mater & vertebral column
- consists of fat & connective tissue for protection

Question 20

spinal cord anatomy, how is it divided?

Answer 20

divided into right & left halves

Question 21

what are the 2 divisions of the spinal cord?

Answer 21

Anterior (ventral) median fissure

Posterior (dorsal) median fissure

Question 22

fissure

Answer 22

groove, fold or slit

Question 23

sulcus

Answer 23

groove or depression btwn 2 parts

Question 24

difference btwn fissure & sulcus

Answer 24

fissure- shallow cut

sulcus- deeper cut

Question 25

spinal cord anatomy, white & gray matter

Answer 25

white matter surrounds 'H shaped' gray matter | central canal in center of gray matter, contains CSF!

Question 26

Gray matter | how is it divided?

Answer 26

divided into regions called: horns

Question 27

what are the 3 divisions (horns) of gray matter?

Answer 27

posterior (dorsal) gray horn anterior (ventral) horn lateral gray horn

Question 28

Posterior (dorsal) gray horn

Answer 28

- cell bodies & axons of INTERNEURONS - send impulses to other parts of spinal cord & brain - axons of incoming sensory neurons

Question 29

Anterior (ventral) gray horn

Answer 29

cell bodies & axons of SOMATIC MOTOR (movement) neurons (MUSCLE CONTRACTION)

Question 30

Lateral gray horn

Answer 30

-cell bodies of AUTONOMIC MOTOR neurons that regulate cardiac, smooth muscle, & gland activities -only in thoracic & upper lumbar spinal region (EX: heart beat, breathing, digestion)

Question 31

Function of gray matter in spinal cord

Answer 31

receives & integrates incoming & out going information

Question 32

White matter how is it organized?

Answer 32

``` organized into: anterior columns lateral columns posterior columns (COLUMNS NOT HORNS) (white matter- cheese strings=columns (made up of tracts)) ```

Question 33

white matter, what does each column contain?

Answer 33

each column contains 1 or more tracts

Question 34

tract

Answer 34

bundles of axons carrying same info to same destination

Question 35

what are the 2 tracts of white matter?

Answer 35

Sensory (Afferent) Tracts | Motor (Descending) Tracts

Question 36

Sensory (Ascending) Tracts

Answer 36

sends impulses toward brain (touch, pain, pressure, sound, etc)

Question 37

Motor (Descending) Tracts

Answer 37

sends impulses down the spinal cord (in response to stimuli)

Question 38

Function of White Matter in spinal cord

Answer 38

propagates sensory impulses from receptors to brain | sends motor impulses from brain to effectors (muscles, glands)

Question 39

Spinal Roots | location? purpose?

Answer 39

axons of neurons extend from spinal cord to converge to form 'roots' connect each spinal nerve to a segment of the cord

Question 40

What are the 2 spinal roots?

Answer 40

Anterior or Ventral Roots | Posterior or Dorsal Roots

Question 41

Anterior or Ventral Roots | what neurons are involved? what do they do?

Answer 41

motor neurons | conduct impulses from CNS to effectors

Question 42

Posterior or Dorsal Roots | what neurons are involved? what do they do?

Answer 42

Sensory neurons conduct impulses from sensory receptors into CNS Dorsal root ganglion- cell bodies of sensory neurons

Question 43

what is it called when the Anterior or Ventral Roots & the Posterior or Dorsal Roots form?

Answer 43

when they meet, they form spinal nerves

Question 44

what are the spinal roots function?

Answer 44

2 bundles of axon (called roots) connect each spinal nerve to spinal cord

Question 45

Posterior or Dorsal Roots contain? impulses from...?

Answer 45

contain ONLY sensory axons | -impulses from sense receptor in skin, muscles, and internal organs

Question 46

Anterior or Ventral Roots contain? impulses from...?

Answer 46

contain axons of motor neurons | -conduct impulses from CNS to muscles & glands

Question 47

Spinal Reflexes | description? help do what?

Answer 47

fast, involuntary response to a stimulus -can be inborn or learned behavior help maintain homeostasis by controlling involuntary processes

Question 48

type of reflexes? (4)

Answer 48

spinal reflex cranial reflex somatic reflex autonomic (viseral) reflex

Question 49

spinal reflex | description & example

Answer 49

integration in spinal cord gray matter | EX: knee jerk reflex (patellar reflex)

Question 50

cranial reflex | description & example

Answer 50

integration in brain stem | EX: eye movement (like blinking)

Question 51

somatic reflex | example

Answer 51

EX: muscle contraction

Question 52

autonomic (viseral) reflex | description

Answer 52

responses of smooth muscle, heart, & glands | AUTOMATIC

Question 53

pathway followed by nerve impulses that produce a reflex (5 steps)

Answer 53

1) stretching stimulates sensory receptor (muscle spindle) (dendrites recept, stimulus produces graded potential) 2) sensory neuron excited (relay neurons to send impulse to area of brain for conscious awareness, axon to gray matter of spinal cord or brain stem (afferent neurons)) 3) within integrating center (gray matter of spinal cord), sensory neuron activates motor neuron (processes impulse) 4) motor neuron excited (transmit impulse from CNS to part of body) 5) effector (muscle or gland) contracts & relieves the stretching

Question 54

reflex arcs allow for what?

Answer 54

fast, involuntary processing & responses to stimuli

Question 55

spinal vs cranial reflexes

Answer 55

spinal occur in the spinal cord | cranial occur in the brain

Question 56

are reflexes internal or external?

Answer 56

both internal & external

Question 57

spinal cord extends from _______ of the skull to the ______ region of the vertebral column.

Answer 57

``` brain stem (foramen magnum or base of the skull) lumbar region ```

Question 58

meninges cover spinal cord, extend more inferiorly to form a sac from which CSF can be withdrawn without damage to the spinal cord. this procedure is called a

Answer 58

spinal tap

Question 59

how many pairs of spinal nerves arise form the cord?

Answer 59

31

Question 60

of the 31, how many pairs are cervical?

Answer 60

8

Question 61

of the 31 spinal nerves, how many pairs are thoracic?

Answer 61

12

Question 62

of the 31 spinal nerves, how many pairs are lumbar?

Answer 62

5

Question 63

of the 31 spinal nerves, how many pairs are sacral?

Answer 63

5

Question 64

what the order from medulla oblongata to coccygeal for spinal nerves?

Answer 64

Cervical Thoracic Lumbar Sacral

Question 65

afferent means? efferent mean? association neurons mean?

Answer 65

afferent- sensory efferent-motor association-interneurons

Question 66

neuron type found in dorsal horn?

Answer 66

association neurons

Question 67

neuron type found in ventral horn

Answer 67

efferent, motor

Question 68

neuron type found in dorsal root ganglion

Answer 68

afferent, sensory

Question 69

fiber type in ventral root

Answer 69

efferent, motor

Question 70

fiber type in dorsal root

Answer 70

afferent, sensory

Question 71

fiber type in spinal nerve

Answer 71

both efferent & afferent

Question 72

damage to this fiber type would lead to loss of sensory function

Answer 72

afferent

Question 73

damage to this fiber type would result in motor function loss

Answer 73

efferent