Topic 6 DEVELOPMENT OF THE PERIPHERAL NERVOUS SYSTEM

Question 1

is derived from neural crest cells. It consists of cranial and spinal nerves and their ganglia.

Answer 1

Peripheral Nervous System (PNS)

Question 2

has only one process, the axon. All afferent neurons are unipolar and have their cell bodies in sensory ganglia (spinal or dorsal root ganglia and cranial ganglia).

Answer 2

Unipolar Neuron

Question 3

has two (2) processes that arise separately from the cell body, fuse for a while to form 1 process and divide shortly thereafter into axon and dendrite.

Answer 3

Pseudounipolar Neuron

Question 4

has two (2) processes, 1 axon and 1 dendrite.

Answer 4

Bipolar Neuron

Question 5

has three (3) or more processes: one (1) axon and 2 or more dendrites.

Answer 5

Multipolar Neuron

Question 6

conduct impulses from the receptor organs to the CNS.

Answer 6

Sensory or afferent neurons

Question 6

conduct impulses from the receptor organs to the CNS.

Answer 6

Sensory or afferent neurons

Question 7

conduct impulses from the CNS to target organs.

Answer 7

Motor or efferent neurons

Question 8

transfer sensory impulses from sensory neurons to efferent neurons.

Answer 8

Association neurons or interneurons

Question 9

innervate voluntary muscles and structures w/ epithelia derived from ectoderm like skin.

Answer 9

Somatic neurons

Question 10

innervate involuntary muscles and structures derived
from splanchnopleure like blood vessels and visceral organs.

Answer 10

Visceral neurons

Question 11

located entirely in the PNS (cell body is in the autonomic ganglion) at positions w/in the head, or
beside vertebrae, or near the aorta or in the gut wall
(parasympathetic and come from sacral and hindbrain

Answer 11

postganglionic neuron

Question 12

is an axon of neuron and its sheath that connects peripheral structures w/ the brain or spinal cord.

Answer 12

nerve fiber

Question 13

are myelinated nerves segmentally arranged along the spinal cord.

Answer 13

Spinal nerves

Question 14

Arise from olfactory hair cells and terminate in the rhinencephalon.

Answer 14

Olfactory Nerve (1)

Question 15

Arise from sensory neurons in retina and terminate in the superior colliculus of corpora quadrigemina in the brainstem.

Answer 15

Optic Nerve (II)

Question 16

Arise from the basal plate of mesencephalon and terminate in the inferioroblique and the superior, inferior and internal rectus muscles of the eyeball.

Answer 16

Oculomotor Nerve (III)

Question 17

Arise from the basal plate of mesencephalon and terminate in the superior blique muscle of the eye.

Answer 17

Trochlear Nerve (IV)

Question 18

Three main divisions that arise from the semilunar ganglion: a. Opthalmic, b. Maxillary, and c. Mandibular divisions.

Answer 18

Trigeminal Nerve (V)

Question 19

Arise from the basal plate of myelencephalon and terminate in the external rectus muscle of the eyeball.

Answer 19

Abducens Nerve (VI)

Question 20

arise from the taste buds and terminate in the brain.

Answer 20

Sensory fibers

Question 21

Spiral ganglion gives off short afferent nerve fibers that supply the cochlear duct and receive stimuli for the sense of hearing.

Answer 21

Acoustic ganglion

Question 22

sensory; presents an acoustic ganglion beneath the auditory
vesicle, caudal to the geniculate ganglion of CN VII.

Answer 22

Auditory Nerve (VIII)

Question 23

gives off short afferent nerve fibers that supply the semicircular canal, utricule and saccule and receive stimuli for the sense of
equilibrium.

Answer 23

Vestibular ganglion

Question 24

Sensory fibers arise from the superior ganglion and extend to the skin of externalear; and from the inferior or petrosal ganglion to the tongue for sense of taste.

Answer 24

Glossopharyngeal Nerve (IX)

Question 25

Sensory fibers extend from the skin of external ear via the superior (jugular) ganglion and from the pharynx, larynx, trachea, esophagus and thoracic abdominal viscera via the inferior (nodose) ganglion, to the myelencephalon.

Answer 25

Vagus Nerve (x)

Question 26

motor nerve. It has a commissural ganglion, which is a continuation of the jugular ganglion.

Answer 26

Accessory Nerve (XI)

Question 27

predominantly motor nerve fibers that arise separately from the posteriornmyelencephalon and form a single trunk to supply the skeletal muscles of tongue.

Answer 27

Hypoglossal Nerve (XII)

Question 27

The GSA cranial nerves are similar to the GSA spinal nerves except that the point of termination is the alar plate of the brain.

Answer 27

General Somatic Afferent (GSA)

Question 28

similar to the GVA spinal nerves except that the point of termination is the alar plate of the brain.

Answer 28

General Visceral Afferent (GVA)

Question 29

The GSE cranial nerves are similar to the GSE spinal nerves except that the point of origin is the basal plate of the brain.

Answer 29

General Somatic Efferent (GSE)

Question 30

The GVE cranial nerves are similar to the GVE spinal nerves except that the point of origin is the basal plate of the brain.

Answer 30

General Visceral Efferent (GVE)

Question 31

The SSA cranial nerves carry impulses from the eye and ear (involved in the relationship of the animal to external environment) to the alar plate of the brain.

Answer 31

Special Somatic Afferent (SSA)

Question 32

The SVA cranial nerves carry impulses from the chemoreceptors in the olfactory epithelium and taste buds to the alar plate of brain.

Answer 32

Special Visceral Afferent (SVA)

Question 33

The SVE cranial nerves conduct impulses from the basal plate of the brain to skeletal muscles w/ visceral functions.

Answer 33

Special Visceral Efferent (SVE) -

Question 34

the pathway for sensory (afferent) nerve fibers

Answer 34

dorsal root

Question 35

for motor (efferent) nerve fibers.

Answer 35

ventral root