spinal cord

Question 1

Where does the spinal cord arise cranially?

Answer 1

It arises cranially as a continuation of the brainstem at the medulla oblongata

Question 2

Where does the spinal cord terminate?

Answer 2

L1/L2 vertebrae where it terminates as the conus medullary (medullary cone)

Question 3

What anchors the spinal cord in place?

Answer 3

a thin thread called the filum terminale which extends from the tip of the conus medullaris to the first coccygeal vertebra

Question 4

What does the medulla oblongata control?

Answer 4

autonomic functions

Question 5

What does the medulla oblongata connect?

Answer 5

brain and spinal cord

Question 6

What is the name of the collection of spinal nerve roots distal to the conus medullaris?

Answer 6

Cauda equina

Question 7

What does the cauda equina consist of?

Answer 7

sacral and coccygeal spinal cord segments

Question 8

What is the cauda equina vital for?

Answer 8

bladder control, urethral and anal sphincters and overall maintenance of continence

Question 9

What is the filum terminale made up of?

Answer 9

made up of a delicate band of fibrous tissue

Question 10

What is the spinal cord surrounded by?

Answer 10

spinal meninges containing cerebrospinal fluid

Question 11

How many spinal nerves are there?

Answer 11

31 bilatterally paired spinal nerves

Question 12

where is the cervical enlargement of the spinal cord?

Answer 12

located approximately at C4-T1 level

Question 13

What does the cervical enlargement of the spinal cord represent?

Answer 13

The origin of the brachial plexus

Question 14

Where is the lumbar enlargement of the spinal cord located?

Answer 14

between T11-L1 level

Question 15

What does the lumbar enlargement of the spinal cord represent?

Answer 15

The origin of the lumbar and sacral plexi

Question 16

What are spinal meninges?

Answer 16

a layered unit of membranous connective tissue that surrounds the spinal cord and cauda equina

Question 17

What do spinal meninges provide?

Answer 17

protection

Question 18

What are the 3 layers of meninges and where are they?

Answer 18

superficially starts with dura mater then the arachnoid mater and Pia mater is the deepest layer

Question 19

Where does the dura mater extend from and go to?

Answer 19

extends from the foramen magnum to the filum terminale

Question 20

What is the space between the vertebra and dura mater called?

Answer 20

epidural space

Question 21

What does the epidural space contain?

Answer 21

the internal vertebral venous plexus

Question 22

What happens with the dura mater as spinal nerves exit the vertebral canal?

Answer 22

They pierce the dura mater passing through the epidural space, the dura mater surrounds the nerve root and fuses with the outer connective tissue covering the nerve

Question 23

What is the outer connective tissue covering the nerve called?

Answer 23

epineurium

Question 24

What is the dura mater composed of?

Answer 24

tough and fibrous collagen fibres

Question 25

What type of membrane is the arachnoid mater?

Answer 25

a delicate membrane

Question 26

What separates the pia mater and arachnoid mater?

Answer 26

subarachnoid space

Question 27

What does the subarachnoid space contain?

Answer 27

Cerebrospinal fluid

Question 28

What does the subarachnoid space expand to form distal to the conus medullaris?

Answer 28

the lumbar cistern

Question 29

Where is the lumbar cistern located?

Answer 29

between the end of the spinal cord and the end of the vertebral column

Question 30

Describe the pia mater

Answer 30

thin membrane that covers the spinal cord, nerve root and their blood vessels

Question 31

Inferiorly what does the pia mater fuse with?

Answer 31

filum terminale

Question 32

What does the pia mater do between the nerve roots?

Answer 32

thickens to form the denticulate ligaments

Question 33

What do the denticulate ligaments attach to?

Answer 33

dura mater

Question 34

What do the denticulate ligaments prevent?

Answer 34

lateral movement

Question 35

What divides the spinal cord into two symmetrical halves?

Answer 35

dorsal median sulcus and ventral median fissure

Question 36

What do afferent spinal nerves enter the cord via?

Answer 36

dorsal/posterior root

Question 37

What do efferent spinal nerves exit the cord via?

Answer 37

the ventral/anterior root

Question 38

What is the white matter divided into?

Answer 38

structures called columns or funiculus

Question 39

Name the 3 columns that the white matter has?

Answer 39

dorsal (posterior), lateral and ventral (anterior)

Question 40

What is the grey matter divided into?

Answer 40

horns

Question 41

Name the horns of the grey matter

Answer 41

dorsal (posterior), lateral and ventral (anterior)

Question 42

What does grey matter consist of?

Answer 42

Grey matter mainly consist of neuron cell bodies, dendrites and synaptic contact

Question 43

here do most synapses occur?

Answer 43

in the grey matter

Question 44

What does the dorsal horn of the grey matter contain and do?

Answer 44

cell bodies of sensory neurons and relays sensory information

Question 45

What do the ventral and lateral horns of the grey matter contain ad do?

Answer 45

cell bodies of motor neurons relaying information either descending from the brain or from the dorsal horn to motor and autonomic nerves respectively

Question 46

What does grey commissure contain?

Answer 46

contains axons that cross to the opposite of the cord

Question 47

What does white matter consist mainly of?

Answer 47

myelinated axons

Question 48

Why do axons appear white?

Answer 48

due to the myelin sheath covering them

Question 49

What are the two types of nerve fibres?

Answer 49

ascending (sensory) and descending (motor)

Question 50

what do ascending tracts do?

Answer 50

carry afferent/sensory information to the brain in the posterior columns

Question 51

What do descending tracts do?

Answer 51

Carry efferent/motor information from the brain to the spinal cord in the anterior and lateral columns

Question 52

What does the anterior white commissure do?

Answer 52

interconnects anterior white columns where axons cross to the other side

Question 53

Where are the dorsal and ventral horns larger in the spinal cord?

Answer 53

at the lumbar and cervical regions due to the number of tracts and output in the arms and legs

Question 54

Where do spinal nerves originate from?

Answer 54

spinal cord

Question 55

What do rootlets attach to?

Answer 55

the dorsolateral and ventrolateral aspects of the spinal cord

Question 56

What does the posterior rami supply?

Answer 56

nerve fibres to the synovial joints of the vertebra, motor and sensory input to deep muscles of the back and overlying skin

Question 57

What does the anterior rami supply?

Answer 57

nerve fibres to the majority of the body's sesnorimotor innervation all major neural plexus cervical, brachial and lumbrosacral

Question 58

describe a spinal stretch reflex

Answer 58

extensor muscle is stretched muscle spindle is stimulated primary afferent neuron is excited primary afferent neuron stimulates alpha motor neuron to the extensor muscle alpha motor neuron stimulates extensor muscle to contract primary afferent neuron also stimulates the inhibitory interneuron at the same time interneuron inhibits alpha motor neuron to the flexor muscle flexor muscle (antagonist) relaxes allowing the extensor muscle to contract without

Question 59

what is a neural pathway?

Answer 59

a neural pathway is a bundle of axons that connects two or more different neurons

Question 60

Where are neural pathways located?

Answer 60

Either soley in the brain, providing connections between several of its structures or link link the brain and spinal cord together

Question 61

How many order neurons do ascending pathways have?

Answer 61

3

Question 62

How many order neurons do descending pathways have?

Answer 62

2

Question 63

What do ascending tracts carry?

Answer 63

sensory information to the periphery

Question 64

Name the conscious ascending tracts

Answer 64

anterior spinothalamic tract lateral spinothalamic tract dorsal column medial lemniscus tract

Question 65

name the unconscious ascending tracts

Answer 65

dorsal spinocerebellar ventral spinocerebellar cuneo-cerebellar rostal spinocerebellar

Question 66

What delicate sensations does the dorsal column transmit?

Answer 66

Vibration proprioception two point discrimination

Question 67

What does the anterior spinothalamic tract?

Answer 67

crude touch and pressure

Question 68

What does the lateral spinothalamic tract?

Answer 68

pain and temperature

Question 69

What does the spinocerebellar tract transmit?

Answer 69

It transmits information ipsilaterally between the cerebellum and the body Involved in coordination and posture maintenance

Question 70

Where are the first order neurons of the ascending tracts found?

Answer 70

the dorsal root ganglia

Question 71

Where are the second order neurons of the ascending tracts found?

Answer 71

usually found in the spinal cord or brainstem

Question 72

Where are the third order neurons of the ascending tracts found?

Answer 72

usually found in the thalamus

Question 73

What are the two types of descending tracts?

Answer 73

pyramidal and extra pyramidal motor tracts

Question 74

Where do descending tracts originate from?

Answer 74

originate from the cortex or the brainstem

Question 75

What are descending tracts involved in?

Answer 75

voluntary motion, involuntary motion, reflexes and regulation of muscle tone

Question 76

Why is pyramidal named that?

Answer 76

because it forms a pyramid as it passes through the medulla oblongata

Question 77

Name the pyramidal tracts

Answer 77

corticospinal corticobulbar

Question 78

Name the extra pyramidal tracts

Answer 78

reticulospinal vestibulospinal tectospinal rubrospinal

Question 79

Name the major neural pathway providing voluntary motor function

Answer 79

corticospinal tract

Question 80

What tract is involved with speed and agility of voluntary movements?

Answer 80

corticospinal tract

Question 81

What does the corticospinal tract do?

Answer 81

connects the cortex to the spinal cord to enable movement of distal extremities

Question 82

Where does the lateral corticospinal tract decussate?

Answer 82

in the medulla

Question 83

Where does the anterior corticospinal tract decussate?

Answer 83

spinal cord

Question 84

What type of innervation does the corticospinal tract have?

Answer 84

contralateral

Question 85

What type of innervation of anterior corticospinal tract have?

Answer 85

ipsilateral and contralateral control therefore the trunk muscles bilaterally cortically innervates

Question 86

What do intrafusal fibres detect?

Answer 86

changes in length and velocity of the muscle

Question 87

What do intrafusal fibres send?

Answer 87

sensory information tot he spinal cord

Question 88

What are extrafusal fibres innervated by?

Answer 88

alpha motor neuron

Question 89

What are intrafusal muscle fibres innervated by?

Answer 89

gamma motor neuron

Question 90

What modulates the stretch reflex?

Answer 90

descending pathways from CNS