nervous system

Question 1

cranial nerve #1

Answer 1

Olfactory. sensory only

Question 2

cranial nerve #2

Answer 2

Optic. sensory only

Question 3

cranial nerve #3

Answer 3

Oculomotor. motor only.

Question 4

cranial nerve #4

Answer 4

Trochlear. eye muscles. motor only.

Question 5

cranial nerve #5

Answer 5

Trigeminal. motor AND sensory. general sensation and chewing musces.

Question 6

cranial nerve #6

Answer 6

Abducens. motor only. moves eye laterally.

Question 7

cranial nerve #7

Answer 7

Facial. motor AND sensry. taste and muscles of facial expression

Question 8

cranial nerve #8

Answer 8

Acoustic/Vestibulocochlear. sensory and some motor. hearing and balance.

Question 9

cranial nerve #9

Answer 9

Glossopharyngeal. motor AND sensory. taste and muscles of pharynx and tongue.

Question 10

cranial nerve #10

Answer 10

Vagus. Extends to thorax and abdomen. Sensory AND motor. taste.

Question 11

cranial nerve #11

Answer 11

Accessory. motor only. back of the neck muscles.

Question 12

cranial nerve #12

Answer 12

Hypoglossal. motor only. under the tongue and in tongue muscles.

Question 13

list all cranial nerves in order

Answer 13

I. Olfactory
II. Optic
III. Oculomotor
IV. Trochlear
V. Trigeminal
VI. Abducens
VII. Facial
VIII. Acoustic/Vestibulochochlear
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal

Question 14

How many pairs of cranial nerves?

Answer 14

12

Question 15

How many pairs of spinal nerves?

Answer 15

31

Question 16

dorsal roots

Answer 16

contain sensory fibers

Question 17

ventral roots

Answer 17

contain motor (efferent) fibers

Question 18

dorsal rami

Answer 18

smaller of the two, supply the posterior body trunk only. contain both sensory and motor fibers.

Question 19

ventral rami

Answer 19

larger of the two. supply all of the body except the head and the posterior part of the trunk. Contain both sensory and motor fibers.

Question 20

plexus

Answer 20

a network formed by ventral rami. they primarily supply the limbs. Occur in cervical, brachial, lumbar, and sacra regions (NOT thoracic)

Question 21

phrenic nerve

Answer 21

nerve in the cervical plexus. supplies the diaphragm.

Question 22

median nerve

Answer 22

allows grabbing. damaged in carpal tunnel.

Question 23

wrist drop

Answer 23

result of trauma to the radial nerve. will also interfere with forearm extension.

Question 24

mechanoreceptors

Answer 24

respond to mechanical force such as touch, pressure (including blood pressure), vibration, and stretch.

Question 25

thermoreceptors

Answer 25

respond to temperature changes.

Question 26

photoreceptors

Answer 26

such as those of the retina of the eye, respond to light.

Question 27

chemoreceptors

Answer 27

respond to chemicals in solution (molecules smelled or tasted, or changes in blood or interstitial fluid chemistry).

Question 28

Nociceptors

Answer 28

respond to potentially damaging stimuli that result in pain. For example, searing heat, extreme cold, excessive pressure, and inflammatory chemicals are all interpreted as painful. These signals stimulate subtypes of thermoreceptors, mechanoreceptors, and chemoreceptors.

Question 29

exteroceptors

Answer 29

are sensitive to stimuli arising outside the body (extero = outside), so most exteroceptors are near or at the body surface. They include touch, pressure, pain, and temperature receptors in the skin and most receptors of the special senses (vision, hearing, equilibrium, smell, and taste).

Question 30

interoceptors

Answer 30

also called visceroceptors, respond to stimuli within the body (intero = inside), such as from the internal viscera and blood vessels. Interoceptors monitor a variety of stimuli, including chemical changes, tissue stretch, and temperature. Sometimes their activity causes us to feel pain, discomfort, hunger, or thirst. However, we are usually unaware of their workings.

Question 31

proprioceptors

Answer 31

ike interoceptors, respond to internal stimuli. However, their location is much more restricted. Proprioceptors occur in skeletal muscles, tendons, joints, and ligaments and in connective tissue coverings of bones and muscles. (Some authorities include the equilibrium receptors of the inner ear in this class.) Proprioceptors constantly advise the brain of our body movements by monitoring how much the organs containing these receptors are stretched.

Question 32

Nonencapsulated (Free) Nerve Endings

Answer 32

mostly small and nonmyelinated. respond to pain, heat, and cold, and itch.

Question 33

merkel cells and discs

Answer 33

AKA Epithelial tactile complexes. light pressure receptors between the dermis and epidermis. a type of free nerve ending.

Question 34

encapsulated nerve endings

Answer 34

consist of one or more fiber terminals of sensory neurons enclosed in a connective tissue capsule. Most are mechanoreceptors but a few are proprioceptors; they vary greatly in shape, size, and distribution in the body. They include tactile corpuscles, lamellar corpuscles, bulbous corpuscles, muscle spindles, tendon organs, and joint kinesthetic receptors

Question 35

tonic receptors

Answer 35

provide a sustained response with little or no adaptation. Nociceptors and most proprioceptors are tonic receptors because of the protective importance of their information.

Question 36

phase receptors

Answer 36

fast adapting, often giving bursts of impulses at the beginning and the end of the stimulus. Phasic receptors report changes in the internal or external environment. Examples are lamellar and tactile corpuscles.

Question 37

origin of parasympathetic fibers

Answer 37

the brain or sacral spinal cord

Question 38

origin of sympathetic fibers

Answer 38

the lumbar or thoracic spinal cord

Question 39

which are longer: postganglionic or preganglionic fibers?

Answer 39

In the parasympathetic system, preganglionic fibers are longer. in the sympathetic system, postganglionic fibers are longer

Question 40

are preganglionic and postganglionic fibers myelinated?

Answer 40

Preganglionic fibers are lightly myelinated. Postganglionic fibers are not myelinated.