2. Spinal Cord

Question 1

Name the major function of the different sections of the funiculus?

Answer 1

Anterior : mostly motor
Posterior: mostly sensory
Lateral: mostly motor, some sensory

Question 2

Where do the lateral funiculus (white matter) synapse? And what is their function?

Answer 2

On the lateral portion of the ventral horn to control the movement of the extremities

Question 3

Where do the medial funiculus (white matter) synapse? And what is their function?

Answer 3

Synapse on medial ventral horn and of roll movement of trunk and axial musculature

Question 4

Where does the cervical enlargement happen?

Answer 4

C5-T1

Question 5

Where is the lumbosacral enlargement?

Answer 5

L2-S2

Question 6

Where do lateral gray horn send their nucleus to? And for what function?

Answer 6

They send their axons to neurons that control gland, hearts, etc

Question 7

What innervates extrafusal fibers?

Answer 7

Alpha motor neurons

Question 8

What innervates intrafusal fibers?

Answer 8

Gamma motor neurons

Question 9

Explain the patellar reflex?

Answer 9

1. Hit the ligament to stretch muscle
2. The spindle fiber and GTO are activate
3. Message sent to motor neuron to contract quads(effector muscle)
4. Sensory neuron relay message to interneuron which then inhibit motor neuron from hamstring (antagonist) contraction

Question 10

Explain the withdrawal reflex

Answer 10

1. You step in a tack that cause pain receptors to fire
2. Sensory neurons send message to excitatory neurons which excite motor neurons to excite the flexor on the side that got hurt and the extensor on the other one
3. At the same time inhibitory interneurons inhibit the extensors on the hurt side and the flexor on the opposite side