Ch. 14 Spinal Cord And Spinal Nerves

Question 1

Describe the structure of the spinal cord what are cervical and lumbar enlargements?

Answer 1

The spinal cord goes from the foramen magnum to the first lumbar vertebrae
The conus medullaris is where it ends

The lumbar enlargement supplies nerves to the pelvis and lower limbs

The cervical enlargement supplies nerves to the upper extremities

Question 2

What is the cauda equina?

Answer 2

just below L one and it’s where many along ventral and dorsal roots extend out looking like a horses tail

Question 3

What is the difference in length between the spinal cord and the vertebral column? Where, at what level, does the continuous spinal cord and in the vertebral column

Answer 3

The spinal cord ends at the Conus medullaris at L4 total length 45 cm

vertebral column goes to the coccygeal and is 71 cm

Question 4

What is the organization of white and gray matter in the spinal cord

Answer 4

Gray matter looks like a butterfly are cell bodies of neurons organized into groups called nuclei

White matter is myelinated and unmyelinated axons organized in tracks and columns
-Each column contains tracks

Question 5

What are the structures that originate from the spinal cord to form spinal nerves

Answer 5

Each spinal nerve forms through fusion of dorsal and ventral nerve roots that pass-through intervertebral foramen

The spinal nerve then divides into several branches two branches that are formed are the dorsal and ventral ramus

Question 6

Defined the relationship between a Root, Ramus and a plexus

Answer 6

Root- Neurons directly going into or out of spinal cord Made of axons

Ramus- Branch off of spinal nerve

Plexus- Network of ventral rami of spinal nerves that form a network of nerves

Question 7

What is the difference between the dorsal and ventral roots of the spinal nerve

Answer 7

Dorsal root - contains axons of sensory neurons

Ventral root - contains axons of somatic motor neurons

Dorsal root ganglion - contains cell bodies

Question 8

What are the names numbers of the spinal nerves?

Answer 8

Cervical 8
thoracic 12 
lumbar 5
sacral 5
coccygeal 1

Question 9

Which reminisce of a spinal nerve participate in the formation of a nerve plexus

Answer 9

Ventral ram I have a Jason spinal nerves blend together to produce nerve trunks called nerve plexus

Question 10

Distinguish between epineurium Perineurium and endoneurium

Answer 10

Each peripheral nerve has three layers of connective tissue

Outer layer epineurium
middle layer perineurium (contains fascicles)
Inner layer endoneurium

Question 11

Name the four nerve plexus

Answer 11

Cervical plexus
brachial plexus
lumbar plexus
sacral plexus

Question 12

From what region of the core do the plexus originate? What structures do the plexus innervate?

Answer 12

Cervical plexus C1 to c5 Head neck and chest

Brachial plexus C-5 to T1 entire upper limbs

Lumbar plexus T 12 to L4 Abdominals thighs genitalia

Sacral plexus L4 to S4 Thighs lower limbs feet groin

Question 13

Name some important nerves that arise from the various nerve plexus

Answer 13

Cervical plexus phrenic nerve
brachial plexus axillary nerve
lumbar plexus femoral nerve
sacral plexus sciatic nerve

Question 14

What is the pathway for the somatic sensory fibers

Answer 14

Come in to the ventral and dorsal Ramus through dorsal root ganglia into the somatic sensory fibers

Come in through interocepters of back exteroceptors and proprioceptors of back interceptors a visceral organs and body

Question 15

What is the pathway for the somatic motor fibers

Answer 15

They come from the somatic motor fibers through the ventral root and out through the dorsal and ventral ramus

The exit to skeletal muscles of the back body cleanse and also post ganglionic fibers of the smooth muscles and glands

Question 16

What is the components of spinal reflex

Answer 16

1. arrival of stimulus
2. activation of a sensory neuron
3. Info processing in CNS
4. activation of motor neuron
5. response by effectors

Question 17

Defined the term tract as it relates to white columns of the spinal cord

Answer 17

Tracks are groups of axons

columns are groups of tracks

Question 18

What type of somebody’s are found in dorsal root ganglion

Answer 18

Cell bodies of somatic sensory neurons are found in the dorsal root ganglion

Question 19

What’s cell bodies are found in the anterior gray horn of the spinal cord

Answer 19

Cell bodies found in the anterior gray horn are somatic motor neurons