CNS: The Brain & Spinal Cord Flashcards Preview

Honors Anatomy & Physiology > CNS: The Brain & Spinal Cord > Flashcards

Flashcards in CNS: The Brain & Spinal Cord Deck (73):
1

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

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

2

3 protective connective tissue layers are?

Dura Mater
Arachnoid Mater
Pia Mater

3

Dura Mater
description?
function?
contains?

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

4

what are dural sinuses?
function?

spaces within the dura mater
drains blood from brain to neck veins

5

Arachnoid Mater

Avascular (no blood circulation), middle layer

6

Protection- Cerebrospinal Fluid
description? functions? movement? formed?

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

7

whats the subarachnoid space?

its the space btwn arachnoid & pia mater

8

Where is Cerebrospinal fluid formed?

formed in the ventricles of the brain
-substances filtered from blood plasma & secreted through ependymal cells
-(mostly water)

9

Pia Mater
description? location? function?

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

10

CSF stands for ?

Cerebrospinal Fluid

11

CSF Functions (3)

Mechanical protection
Chemical protection
Circulation

12

Mechanical Protection of CSF involves? (function)

shock absorber

13

Chemical Protectionof CSF involves? (function)

Maintains optimal chemical environment w/ ions

14

Circulation of CSF involves? (function)

Provides exchange of nutrients & wastes btwn blood & nervous tissue

15

White Matter of CNS

bundles of mylinated & unmyelinated axons

16

Gray Matter of CNS

contains dendrites, unmyelinated axons, axon temirnals, & neuroglia

17

Gray vs White Matter of CNS ?

White matter- has MYELINATED (& unmyelinated) axons
Gray matter- only has UNMYELINATED axons

18

Spinal cord consists of : (3)

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

19

What's the epidural space?
location? function?

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

20

spinal cord anatomy, how is it divided?

divided into right & left halves

21

what are the 2 divisions of the spinal cord?

Anterior (ventral) median fissure
Posterior (dorsal) median fissure

22

fissure

groove, fold or slit

23

sulcus

groove or depression btwn 2 parts

24

difference btwn fissure & sulcus

fissure- shallow cut
sulcus- deeper cut

25

spinal cord anatomy, white & gray matter

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

26

Gray matter
how is it divided?

divided into regions called: horns

27

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

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

28

Posterior (dorsal) gray horn

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

29

Anterior (ventral) gray horn

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

30

Lateral gray horn

-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)

31

Function of gray matter in spinal cord

receives & integrates incoming & out going information

32

White matter how is it organized?

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

33

white matter, what does each column contain?

each column contains 1 or more tracts

34

tract

bundles of axons carrying same info to same destination

35

what are the 2 tracts of white matter?

Sensory (Afferent) Tracts
Motor (Descending) Tracts

36

Sensory (Ascending) Tracts

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

37

Motor (Descending) Tracts

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

38

Function of White Matter in spinal cord

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

39

Spinal Roots
location? purpose?

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

40

What are the 2 spinal roots?

Anterior or Ventral Roots
Posterior or Dorsal Roots

41

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

motor neurons
conduct impulses from CNS to effectors

42

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

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

43

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

when they meet, they form spinal nerves

44

what are the spinal roots function?

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

45

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

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

46

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

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

47

Spinal Reflexes
description? help do what?

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

48

type of reflexes? (4)

spinal reflex
cranial reflex
somatic reflex
autonomic (viseral) reflex

49

spinal reflex
description & example

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

50

cranial reflex
description & example

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

51

somatic reflex
example

EX: muscle contraction

52

autonomic (viseral) reflex
description

responses of smooth muscle, heart, & glands
(AUTOMATIC)

53

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

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

54

reflex arcs allow for what?

fast, involuntary processing & responses to stimuli

55

spinal vs cranial reflexes

spinal occur in the spinal cord
cranial occur in the brain

56

are reflexes internal or external?

both internal & external

57

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

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

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

spinal tap

59

how many pairs of spinal nerves arise form the cord?

31

60

of the 31, how many pairs are cervical?

8

61

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

12

62

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

5

63

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

5

64

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

Cervical
Thoracic
Lumbar
Sacral

65

afferent means?
efferent mean?
association neurons mean?

afferent- sensory
efferent-motor
association-interneurons

66

neuron type found in dorsal horn?

association neurons

67

neuron type found in ventral horn

efferent, motor

68

neuron type found in dorsal root ganglion

afferent, sensory

69

fiber type in ventral root

efferent, motor

70

fiber type in dorsal root

afferent, sensory

71

fiber type in spinal nerve

both efferent & afferent

72

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

afferent

73

damage to this fiber type would result in motor function loss

efferent