Spinal Cord

Question 1

Somite subdivisions

Answer 1

From Superficial to Deep

1. Dermatome
2. Myotome
3. Sclerotome

Question 2

Somite Cells that migrate ANTERIORLY give rise to what?

Answer 2

• Muscles
• Limbs
• Trunk (hypaxial muscles)
• Associated Dermis

Question 3

Somite Cells that migrate POSTERIORLY give rise to what?

Answer 3

• Intrinsic muscles of the BACK

- Associated Dermis

Question 4

Part of each somite gives rise to what?

Answer 4

• Skeletal muscle

- Dermis of the skin

Question 5

Upper Limb bud vertebral segments

Answer 5

C5 - T1

Question 6

Lower Limb bud vertebral segments

Answer 6

L2 - S2

Question 7

Dermatome

Answer 7

The area of the skin supplied with AFFERENT nerve fibers (Towards the CNS) by a Single POSTERIOR spinal Root.

Question 8

Myotome

Answer 8

• All the muscles that are innervated by a Single EFFERENT Anterior Root.

Question 9

T/F: Most muscles are composed of only one myotome.

Answer 9

False

Most are composed of MORE than one myotome

Question 10

Somatic Innervation

Answer 10

Arises SEGMENTALLY along the Developing CNS in association with Somites

Question 11

Spinal cord enlargements occur where?

Answer 11

• Cervical region

&

• Lumbar region

Question 12

How many spinal nerves in total

Answer 12

31

Question 13

How many CERVICAL nerves?

Answer 13

8

• But 7 vertebrae

Question 14

How many THORACIC nerves?

Answer 14

12

• The most of any nerve subset

Question 15

How many LUMBAR nerves?

Answer 15

5

Same as Sacral

Question 16

How many SACRAL nerves?

Answer 16

5

• Same as Lumbar

Question 17

How many COCCYGEAL nerves?

Answer 17

1

Lowest number

Question 18

How many Plexuses are there?

Answer 18

3 total

1. Cervical
2. Brachial
3. Lumbo-sacral

“LBC”

Question 19

What nerve is the location where the nerves switch from being ABOVE the bone to being BELOW?

Answer 19

C8

Question 20

Cauda Equina is Latin for what?

Answer 20

Horse’s Tail

Question 21

What is the Cauda Equina?

Answer 21

A bundle of nerves at the end of the spinal cord

Question 22

What shape does the gray matter have in the spinal cord?

Answer 22

An ‘H’ shape

Question 23

The Post. Horns have a ____ shape and the Ant. Horns have a ____ shape.

Answer 23

• Pointed/Triangular

- Blunt/Square

Question 24

Which matter is Myelinated?

Answer 24

White matter

• It contains the axons

Question 25

What region of the Spinal Cord are the LATERAL horns located?

Answer 25

- Thoracic & - Upper Lumbar

Question 26

Characteristics of the ANTERIOR horns?

Answer 26

Aka VENTRAL Horns - Site of of the CELL BODIES of the Alpha Motor Neurons to the Skeletal Muscle fiber

Question 27

How many types of columns exist in the White matter?

Answer 27

3 Total 1. Posterior (Dorsal) 2. Anterior (Ventral) 3. Lateral

Question 28

Which Root type also has associations with a Root GANGLION?

Answer 28

Dorsal root - Carries Cell bodies from the AFFERENT neurons

Question 29

White Ramus Communications

Answer 29

Carries PRE-ganglionic fibers from LATERAL horns (Gray matter)

Question 30

Gray Ramus Communications

Answer 30

Carries POST-ganglionic fibers from Paravertebral ganglia

Question 31

Dura Mater

Answer 31

Tough Outer layer of the Spinal Cord

Question 32

Arachnoid Mater

Answer 32

Web-like MIDDLE layer of the spinal cord

Question 33

Pia Mater

Answer 33

Delicate Innermost Layer of the Spinal cord

Question 34

Outer Layers of the spinal chord from Sup to Deep

Answer 34

1. Dura Mater 2. Arachnoid Mater 3. Pia mater “DAP”

Question 35

What is contained in the Subarachnoid space?

Answer 35

CSF

Question 36

The nerves exit the spinal cords through what opening?

Answer 36

The MENINGES