Systems Lectures (Spinal cord)

Question 1

Stucture

Answer 1

16-18 inches in length
two longitudinal depressions ( posterior median sulcus and anterior median fissure)

Question 2

Regions

Answer 2

Cerical region- continueous with medulla oblongata contains neourons whose axons form the cervical spinal nerves (8 pairs)
Thoracic region (12 pairs of nerves)
Lumbar region (5 pairs of nerves)
Sacral region (5 pairs of nerves)
Coccygeal region (1 pair of nerves)

Question 3

Structure continued

Answer 3

Spinal cord is shorter than the vertebral cnal
Conus medullaris: physical end of spinal cord between L1-L2
After this nerve roots are collectively called cauda equina
filum terminale is a thin strand of pia matter that ancors the conus medularis to the coccyx

Question 4

Spinal Meninges Layers

Answer 4

Vetebra
Epidural space
dura matter
subdural space
arachnoid matter
subarachnoid space
pia matter

Question 5

Afferent/Efferent fibers

Answer 5

Dorsal horns house afferent (sensory) fibers
Ventral horns house efferent (motor) fibers

Question 6

Monosynaptic reflex

Answer 6

direct communication between sensory and motor neuron

Question 7

Polysnyaptic reflex

Answer 7

interneourn facilitates sensory-motor communication

Question 8

Golgitendon reflex

Answer 8

prevents skeletal muscles from tensing excessively