Lecture 7-Spinal Cord 1

Question 1

Where does the spinal cord end?

Answer 1

appx L1

Question 2

How many cervical spinal segments are there?

Answer 2

8

Question 3

How many thoracic nerves are there? lumbar? Sacral? Coccygeal?

Answer 3

12 thoracic
5 lumber
5 Sacral
1 Coccygeal

Question 4

What is the termination of the dura mater that attaches to the coccyx called?

Answer 4

coccygeal ligament

Question 5

What is the end of the spinal cord called?

Answer 5

Conus Medullaris

Question 6

What are the three arteries that supply the spinal cord?

Answer 6

1 anterior spinal artery (supplies 2/3)

2 posterior spinal arteries (suppies 1/3)

Question 7

Where do the anterior and posterior spinal arteries arise from?

Answer 7

vertebral and radiculospinal arterties

Question 8

Describe the venous drainage of the spinal cord.

Answer 8

radicular veins drain into the epidural venous peluxus

Question 9

List the three laters of meninges covering the spinal cord from superficial to deep.

Answer 9

Dura mater
Arachnoid mater
Pia mater

Question 10

What is the extension of the pia mater past the end of the spinal cord called?

Answer 10

filium terminale

Question 11

What is the function of the denticulate ligaments?

Answer 11

anchor the spinal cord to the dural sheath

Question 12

Where are spinal taps usually done?

Answer 12

between L3 and L4

Question 13

What is the term for the collection of spinal rootlets that travel below L1?

Answer 13

cauda equina

Question 14

Where is the lateral horn present in the spinal cord?

Answer 14

T1-L2

Question 15

What are the fibers crossing the spinal cord from side to side known as?

Answer 15

anterior white commissure

Question 16

How many total spinal segments are there?

Answer 16

31

Question 17

Where do spinal nerves arise for segments C1-C7?

Answer 17

above the vertebral body holding the same name

Question 18

Where do spinal nerves arise for segments C8-S5?

Answer 18

below the vertebral body holding the same name

Question 19

Where is the dorsal root ganglion found?

Answer 19

intervertebral foramina

Question 20

What would a spinal transection at C4 result in?

Answer 20

tetrapeligia- no sensation or motor control below neck

Question 21

What would a spinal transection at C6 result in?

Answer 21

tetrapeligia- no sensation or motor control below shoulders

Question 22

What would a spinal transection at T6 result in?

Answer 22

parapeliga- use of arms but no motor or sensation in torso and lower limbs

Question 23

What would a spinal transection at L1 result in?

Answer 23

parapeligia- use of arms and torso no sensation or motor activity in legs

Question 24

What nuclei is found in lamina I?

Answer 24

Nucleus Posteriomarginalis

Question 25

What nuclei is found in lamina II?

Answer 25

Substantia Gelatinosa

Question 26

What lamina contains the nuclues proprius?

Answer 26

Lamina III-VI

Question 27

What spinal segments contain the Nucleus Dorsalis of Clarke?

Answer 27

C8-L3

Question 28

What type of information does the Nucleus Dorsalis of Clarke receive?

Answer 28

Muscle sense/proprioceptive information that it projects to the cerebellum

Question 29

What is unique about the gray matter of thoracic levels?

Answer 29

contains a lateral horn

Question 30

What type of cells are contained in the lateral horn?

Answer 30

Intermediolateral cell column- preganglionic sympathetic autonomic cell bodies that project to the sympathetic chain or prevertebral ganglion via the ventral root

Question 31

What lamina contains the lateral horn at thoracic levels?

Answer 31

Lamina VII

Question 32

Where are cells of the Intermediolateral cell column found?

Answer 32

Thoracic level-Lateral Horn-Lamina VII

Question 33

What levels contain preganglionic parasympathetic cell bodies?

Answer 33

S2-S4

Question 34

What type of sensation is Lissauer’s tract associated with?

Answer 34

pain and temperature

Question 35

What tract do cells from Nucleus of Dorsalis of Clarke project to?

Answer 35

Dorsal Spinocerebellar Tract

Question 36

What lamina surrounds the central canal and is referred to as the “central gray matter”?

Answer 36

Lamina X

Question 37

List the 3 lamina found in the ventral horn

Answer 37

Lamina VIII, IX and X

Question 38

What type of neurons are found in lamina VIII?

Answer 38

interneurons- involved in reflex activity and motor coordination

Question 39

What type of neurons are found in lamina IX?

Answer 39

alpha motor neurons- lg. innervate voluntary muscles

gamma motor neurons- small, innervate muscle spindles

Question 40

Where in the ventral horn are cells found that innervate extensors?

Answer 40

Most ventrally

Question 41

Where in the ventral horn are cells found that innervate flexors?

Answer 41

Most dorsally

Question 42

Where in the ventral horn are cells found that innervate the upper limb?

Answer 42

most laterally

Question 43

Where in the ventral horn are cells found that innervate the lower limb muscles?

Answer 43

most medially

Question 44

What are the two main groups of intraspinal reflex circuits?

Answer 44

paucisynaptic

multisynaptic

Question 45

What types of receptors trigger the stretch reflex (ex. patellar tendon)?

Answer 45

muscle spindles with cell bodies in DRG then activate alpha motor neurons (lamina IX) that contract muscle

Question 46

What is reciprocal activation in a reflex pathway?

Answer 46

an inhibitory interneuron also is activated to inhibit antagonist muscle

Question 47

What is the clasp knife reflex?

Answer 47

When considerable tension activates a tendon and Golgi tendon organ that inhibits the muscle and cause it to relax to prevent damage

Question 48

What is the purpose of the flexion crossed extension reflex?

Answer 48

allows for maintenance of balance but withdrawing the limb that is in contact with the painful stimulus and extending the opposite limb