Subdivions Of Nervous System

Question 1

Afferent

Answer 1

Sensory, toward CNS

Question 2

Efferent

Answer 2

Motor, away from CNS

Question 3

Somatic

Answer 3

Sensory and motor with outside, voluntary

Question 4

Visceral

Answer 4

Sensory and motor with internal viscera, motor is ANS

Question 5

General somatic afferent

Answer 5

• Originate in receptors within the skin and deeper somatic tissues of body and limbs
• Exteroceptive- touch temp pain
• Proprioceptive- deeper, stretch and tension of joints

Question 6

Where are GSA fibers present?

Answer 6

All spinal nerves and in cranial nerve V (trigeminal)

Question 7

General visceral afferent

Answer 7

• Originate in receptors of vessels and glands and viscera of the head and trunk
• Respond largely to stretch and chemical stimuli

Question 8

Where are the GVA fibers present?

Answer 8

All spinal nerves and cranial nerves III, V, VII, IX, X

Question 9

Special somatic afferent

Answer 9

• Retina of eye
• Cochlear and vestibular component of the inner ear

Question 10

Where are SSA fibers present?

Answer 10

• Optic
• Vestibulocochlear

Question 11

Somatic efferent

Answer 11

• Innervate striated muscles
• Body and limbs- arise from somites
• Head- arise from pharyngeal or branchial arches

Question 12

Where are somatic efferent fibers present?

Answer 12

All spinal nerve and in all cranial nerves except those that are sensory (I, II, VIII)

Question 13

Visceral efferent

Answer 13

• ANS
• Innervate the smooth muscle of blood vessels, viscera, heart muscle and glands
• Symp and parasymp

Question 14

Visceral efferent of sympathetic

Answer 14

• Leave CNS via the spinal nerves in the TL region of spinal cord

Question 15

Visceral efferent of parasympathetic

Answer 15

• Found in a small group of cranial nerves (3, 7, 9, 10) and in spinal nerves in the sacral region of the spinal cord

Question 16

Multipolar neurons

Answer 16

• Possess a number of branching dendrites that join the perikaryon at scattered points
• Convergence

Question 17

Bipolar neurons

Answer 17

• Possess dendrites that are joined in a common trunk before reaching the perikaryon at a site remote from the origin of the axon
• In retina and in olfactory epithelium
• Divergence

Question 18

Unipolar neuron

Answer 18

• Directly contiguous along a single process and the perikaryon is attached to taxon by short process
• All sensory neurons in PNS

Question 19

What is neuromodulation?

Answer 19

Postsynaptic receptors neither directly contribute nor inhibit the generation of the AP but instead make the post-synaptic cell more or less responsive to other transmitters at nearby synapses

Question 20

What are the two main types of neuroglia?

Answer 20

• Astrocytes - assist in nutrition of neurons, maint of ECF environment and neurotransmission
• Oligodendrocytes - provide axons in brain and SC with cell membrane sheaths that insulate axons - myelin

Question 21

White matter

Answer 21

• Groups of myelinated axons in brain and SC
• Axons of common origin, destination and function are together in fasciculi or tracts

Question 22

Gray matter

Answer 22

• Group of perikaryon (cell bodies) are termed nuclei and are in the gray matter

Question 23

Ganglia

Answer 23

• Neuronal perikarya in PNS limited to those of sensory afferent and visceral efferent and found in these aggregations

Question 24

Monosynaptic reflex arc

Answer 24

• Only two neurons
• Patellar - quadriceps femoris - know that goes to SC gray
• Important reflex for the limb to remain extended against gravity when standing

Question 25

Interneurons

Answer 25

- Neurons that are interposed in the circuit between afferent and efferent neurons