Week 1 Wednesday - Severson - Peripheral Nervous System & Spinal Column

Question 1

Meninges layers from outer to inner

Answer 1

Dura mater, Arachnoid mater, Pia mater

Question 2

Afferent and efferent nerves

Answer 2

Afferent nerves take sensory messages from the PNS and convey them to the CNS. (Often These are pseudounipolar neurons.)

Efferent nerves take sensory messages from the CNS to effector organs like muscle. (Often these are multipolar.)

Question 3

This neuron cell type is often sensory (afferent)

Answer 3

Pseudounipolar

Question 4

This neuron cell type is often efferent

Answer 4

Multipolar

Question 5

Where is the epidural space and what is in it?

Answer 5

Epidural space is located between the dura mater of the spinal chord and the surrounding vertebral column. It contains the epidural adipose.

Question 6

Differentiate between somatic motor, somatic sensory, visceral motor, and visceral sensory neurons. Where are the cell bodies of each? What is their function?

Answer 6

Somatic motor - Transmit efferent impulses to skeletal muscle. Cell bodies are multipolar, in the grey matter of the CNS.

Somatic sensory - Afferent receptors of the body (muscles, skin, etc.) that transmit signals to the CNS. Cell bodies: Pseudounipolar, PNS.

Visceral motor - Transmit efferent impulses to smooth muscle. Cell bodies of the presynaptic neurons are multipolar, in the grey matter of the CNS. Postsynaptic neuron bodies are outside the CNS in autonomic ganglia (same as somatic motor).

Visceral sensory - Afferent receptors that transmit signals from hollow organs and blood vessels to the CNA. Cell bodies: Pseudounipolar, PNS.

Question 7

Which two types of ganglia contain sensory nerve cells bodies?

Answer 7

Cranial nerve ganglia and dorsal root ganglia.

Question 8

What is the name for the end of the spinal chord?

Answer 8

Conus Medullaris

Question 9

This bundle of nerves is inferior to the end of the spinal chord.

Answer 9

Cauda Equina

Question 10

Alpha motor neurons innervate:

Gamma motor neurons innervate:

They are located:

Answer 10

Alpha: extrafusal skeletal muscle

Gamma: intrafusal muscle

Located in the anterior horn of the grey matter. (he also said that we will be tested on this in a different class, may not be important yet)

Question 11

What is in the dorsal spinal column (funiculus)

Answer 11

Ascending nerve cell fibers originating from dorsal root ganglion cells.

Question 12

What is in the lateral column (funiculus)

Answer 12

Ascending sensory nerve fibers that originated in the grey matter of the dorsal horn. ALSO Descending motor nerve fibers that originate in the neuraxis (brain stem or cerebrum)

Question 13

Where are the preganglionic cell bodies of the autonomic nervous system?

Answer 13

Lateral horn (also known as the intermediolateral cell column)

Question 14

What type of ganglia do cranial nerves have?

Answer 14

Sensory and parasympathetic. NOT sympathetic.

*Parasympathetic ganglion have a star shaped morphology

Question 15

Describe: First order neuron

Answer 15

a sensory neuron (dorsal ganglion houses nucleus)

Question 16

Describe: second order neurons

Answer 16

Reach from the spinal CNS to the the thalmus

Question 17

Describe: third order neurons

Answer 17

Reach from the thalmus to the cerebral cortex

Question 18

Atrophy is typically a degeneration of which category of neuron?

Answer 18

Lower motor neuron.

Question 19

Autonomic nerve ganglia

Answer 19

Where the nuclii of the postsynaptic visceral nerves are.