Spinal Nerves and Reflexes

Question 1

Caudal vs Rostral Direction

Answer 1

• Caudal is towards the tail of the spine
• Rostral is towards the head of the spine

Question 2

Vertebrae Where the Spinal Cord Ends

Answer 2

• L2

Question 3

General Structures of the Spinal Cord

Answer 3

• Conus Medullaris: Inferior end
• Filum Terminale: Long filament of connective tissue that attaches to the coccyx
• Cauda Equina: Collection of spinal nerve roots
• Cervical and lumbar enlargements: The areas where the limb nerves meet up with the spinal cord

Question 4

Grooves in the Spinal Cord

Answer 4

• Posterior Median Sulcus
• Anterior Median Fissure

Question 5

Functions of the Spinal Cord

Answer 5

• Process reflexes
• Integrate IPSPs and EPSPs
• Conduct sensory impulses to brain
• Conduct motor impulses to effectors
• Integration occurs in grey matter, conduction occurs in white matter

Question 6

3 Types of Spinal Cord Protection

Answer 6

• Vertebrae
• Meninges
• Cerebrospinal fluid

Question 7

Dura Matter

Answer 7

• Tough outer layer of meninges
• Between epidural space (fat layer) and vertebra

Question 8

Arachnoid Matter

Answer 8

• Cerebrospinal fluid space between dura and pia matter

Question 9

Pia Matter

Answer 9

• Blood vessel space
• Directly touches spinal cord

Question 10

Cerebrospinal Fluid

Answer 10

• Fills hollow cavities in brain and spinal cord
• Acts as a liquid cushion
• Nourishes brain and spinal cord
• Removes wastes
• Carries chemical signals between parts of the CNS

Question 11

Grey Matter

Answer 11

• Unmyelinated
• H shaped
• Grey commissure in the center, which contains the central canal
• Anterior and posterior (dorsal/ventral) dorsal/grey horns contain cell bodies of motor neurons
• Interneurons

Question 12

Dorsal Root

Answer 12

• Sensory input from spinal nerves
• Contains the dorsal root ganglion
• Connects to posterior grey horn

Question 13

Ventral Root

Answer 13

• Motor output through spinal nerves
• Handles somatic and autonomic motor output
• Connects to the anterior grey horn

Question 14

Dermatome

Answer 14

• Areas of the skin that correlate with each spinal nerve

Question 15

Spinal Nerve Connective Tissue Covering

Answer 15

• Epineurium surrounds spinal nerve
• Perineurium surrounds one fascicle
• Endoneurium surrounds each axon

Question 16

Cervical Plexus

Answer 16

• Major nerve is the phrenic nerve
• Innervates the diaphragm
• C1- 4

Question 17

Brachial Plexus

Answer 17

• C 5-8
• Main nerves of the upper limb
• Divided into medial, lateral, and posterior cords

Question 18

Brachial Plexus Lateral Cord

Answer 18

• Musculocutaneous nerve
• Median nerve (connects to 2 cords)

Question 19

Brachial Plexus Medial Cord

Answer 19

• Median Nerve
• Ulnar nerve

Question 20

Brachial Plexus Posterior Cord

Answer 20

• Radial nerve
• Axillary nerve

Question 21

Musculocutaneous Nerve

Answer 21

• Connects to lateral cord
• innervates biceps brachii and brachialis muscles

Question 22

Median Nerve

Answer 22

• Connects to medial and lateral cords
• Innervates anterior forearm and lateral palm, as well as digits 1-4.5

Question 23

Ulnar Nerve

Answer 23

• Connects to the medial cord
• Innervates medial palm, and digits 4.5-5

Question 24

Radial Nerve

Answer 24

• Largest nerve branch of the brachial plexus
• Innervates muscles of the posterior limb

Question 25

Axillary Nerve

Answer 25

• Innervates deltoid and teres minor muscles