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Flashcards in PNS Deck (46):
1

I Olfacory Nerve

Transmitting Foramen: cribriform foramina of ethmoid bone

Function: VA neurons - sense of smell (olfaction)

Neuron Type and Location of Cell Bodies:
Bipolar neurons in nasal mucosa (olfaction)

2

II Optic Nerve

Transmitting Foramen: optic canal of sphenoid bone

Function: SA neurons - vision

Neuron Type and Location of Cell Bodies:
Bipolar neurons in retina

3

III Oculomotor nerve

Transmitting Foramen: superior orbital fissure

Function:

. SA/SE neurons - motor to superior, medial, and inferior rectus mm., inferior oblique m., levator palpebrae superioris m. of the eye

. VE neurons - motor to ciliary m. of eye and pupillary sphincter m. of the iris


Neuron Type and Location of Cell Bodies:

SA/SE - Multipolar neurons in nucleus of oculomotor nerve in mesencephalon

VE - Multipolar neurons in accessory oculomotor nucleus within mesencephalon (pre-ganglionics), and within ciliary ganglion (post-ganglionics)


4

IV Trochlear Nerve

Transmitting Foramen: superior orbital fissure

Function: SA/ SE neurons - motor to superior oblique m. of the eye

Neuron Type and Location of Cell Bodies:

Multipolar neurons in motor nucleus of trochlear n. within mesencephalon

5

V Trigeminal Nerve

1. Ophthalmic nerve

Transmitting Foramen: superior orbital fissure

Function: SA neurons - sensory from and around the eye

Neuron Type and Location of Cell Bodies:

Pseudounipolar neurons in the trigeminal ganglion of the trigeminal nerve


2. Maxillary Nerve

Transmitting Foramen: foramen rotundum of the sphenoid bone

Function: SA neurons - sensory from upper lip and surrounding skin, upper teeth and gums, and palate

Neuron Type and Location of Cell bodies:


Pseudounipolar neurons in the trigeminal ganglion of the trigeminal nerve


3. Mandibular Nerve

Transmitting Foramen: foramen ovale of sphenoid bone

Function:
SA neurons: sensory from lower lip and surrounding skin, lower teeth and gums, tongue, and floor of oral cavity

SA/SE neurons: motor to mm. of mastication

Neuron Type and Location of Cell Bodies:

(SA) - Pseudounipolar neurons in the trigeminal ganglion of the trigeminal nerve

(SA/SE) - Multipolar neurons in the motor nucleus of the trigeminal nerve within the pons

6

Indicate which cranial nerves are sensory only.

Six Sailors Made Merry But My Brothers Said

Bad Business My Man

SA (vision, audition, and general sensation from skin, muscles, bones, and joints)

- CN II, V, VIII, IX, and X

VA (olfaction, gustation, and sensation from deep body systems)

- CN I, VII, IX, and X

Overall: 1, 2, 5, 7, 8, 9, 10

7

Indicate which cranial nerves supply skeletal muscles. (carry SE fibers)

Six Sailors Made Merry But My Brothers Said
Bad Business My Man

All except 1, 2, 8

8

Indicate which cranial nerves carry gustatory fibers. (gustation)

7,9,10

9

Indicate which cranial nerves do not emerge from the skull.

8

10

Indicate which cranial nerves supply involuntary effectors.

3,7,9,10

11

Indicate which cranial nerves supply muscles that move the eyeball.

3,4,6

12

Indicate which cranial nerves originate from the superior (posterior) aspect of the brain.

4

13

Sketch the origin of a spinal nerve from the spinal cord and label the rootlets, roots, branches, and sensory ganglion.

(pg. 306)

14

List the general kinds of information (sensory from and motor to) carried by: anterior branches of spinal nerves, posterior branches of spinal nerves, anterior roots of spinal nerves, posterior roots of spinal nerves.

Anterior roots: sends motor impulses from spinal cord

Posterior roots: sends sensory impulses into spinal cord

Anterior branches of spinal nerves: motor to and sensory to hypaxial muscles

Posterior branches of spinal nerves: motor and sensory to epaxial muscles

15

Explain why severance of a nerve at a given location does not disrupt the functions of the nerve proximal to the site of injury.

Nerves have many axons that branch off from it. It a nerve is severed, the axons distal to the nerve will be disrupted. The axons proximal to where the nerve was severed will not be disrupted.

16

Explain why nerve damage may be permanent.

Nerve damage may be permanent if the myelin and the nerve can't be reconnected due to c.t. blocking

- c.t. can scar over so that the nerve and myelin can't join together

17

Explain why severance of a nerve at a given location does not disrupt the functions of the nerve proximal to the site of injury.

Nerves have many axons that branch off from it. It a nerve is severed, the axons distal to the nerve will be disrupted. The axons peripheral to where the nerve was severed will not be disrupted.

18

Explain why nerve damage may be permanent.

nerves have slow regenerative capacity

19

Define the brachial plexus and state the sensory and motor functions of its four most significant derivatives.

Brachial Plexus: supply nerves to the superior limb

Musculocutaneous Nerve:

-motor to: biceps brachii m. , corocobrachialis m., brachialis m.

- sensory from: skin of the anterior antebrachium and skin on the lateral half of the posterior antebrachium

Ulnar Nerve:

- motor to: anterior antebrachial muscle and the m. of the manus

-sensory from: skin of the manus
( lateral 2/3 of manus)

Medial Nerve:

- motor to: anterior antebrachial m. and the m. of the manus

- sensory from: skin of the manus
(medial 1/3 of manus)

Radial Nerve:

- motor to: posterior m. of brachium and antebrachium (the extensors of elbow, carpal, and digital joints)

20

Define lumbosacral plexus and state the sensory and motor functions of its largest derivatives. Include the two named branches of the latter.

Lumbosacral plexus: nerves that supply the inferior limbs (consists of lumbar plexus combined with sacral plexus)

Femoral Nerve:
- motor to: the pectineus and sartorius muscles, and the quadriceps femoris muscle
(also goes to medial crus)

Obturator Nerve:
- motor to: the medial muscles of the thigh and external obturator muscle
- sensory to: skin on medial aspect of thigh

Sciatic Nerve: (largest nerve in the body)
- motor to: posterior thigh muscles

1. Tibial Nerve (posterior muscles of crus and few muscles of the pes)

2. Common Fibular Nerve (anterior muscles of crus and few muscles of pes)

(also motor to skin of the foot and most skin on the anterior, lateral, and posterior aspects of the crus)


21

Compare sensory and autonomic ganglia in regard to the presence of synapses, the functional types of neurons present, and the cranial nerves which have them.

Sensory Ganglia:
- no synapses
- Pseudounipolar and Bipolar neurons
- on posterior roots of spinal cord and found in most of the cranial nerves (5,7,8,9,10)

Autonomic Ganglia:
- synapses

- Sympathetic Trunk Ganglia: occur along sympathetic trunk and are synaptic sites for pre and post ganglionic sympathetic neurons

- Named peripheral ganglia: cranial nerves 3,7,9,10 (as well as named ganglia within the thoracic and abdominal cavities)

- Terminal (intramural ganglia): in the walls of the organs innervated

22

Divide the senses into general and special categories.

General Categories: pain, pressure, heat, cold, touch

Special Categories: audition, vision, olfaction, gustation, equilibrium

23

Classify Sensory Receptors based on type of energy transduced.

Mechanoreceptors: pressure, vibration, touch, stretch, hair movement

Chemoreceptors: activated by specific chemicals (taste buds and olfactory cells)

Photoreceptors: light

Thermoreceptors: heat, cold

Nociceptors: pain receptors, respond to chemicals released during tissue damage

24

Classify sensory receptors based on locus of sensory information.

Exteroreceptors: external environment
- ex) skin, taste, hearing, vision, smell)

Visceroreceptors (interoceptors) : in deep body organs (visceral organs)
- ex) hunger, thirst, nausea

Proprioceptors: joints, tendons, muscles bellies, internal ear
- ex) balance, body position, and movement

25

Classify cutaneous receptors.

Those located in the skin

26

Classify Kinesthetic receptors.

Proprioceptors whose impulses are consciously perceived.

27

Classify Encapsulated receptors.

Those which are surrounded by supporting cells.

28

Classify Free Nerve Endings.

Simplest receptors. Extend superficially into the deep layers of cells in the epidermis and respond to touch and pain.

29

Classify Tonic Receptors.

Send impulses as long as a stimulus is received.

30

Classify Phasic Receptors.

Reduce firing rate of impulses with time. (when continuously stimulated)

31

Given a named sensory receptor, state its location and the type of stimulus to which it responds.

pg. 358

32

Define dermatome and explain its clinical value.

the specific area of skin whose sensory neurons are carried by a particular spinal nerve. dermatome maps can be helpful when evaluating nerve injuries.

33

List the components of a spinal reflex and differentiate monosynaptic and disynaptic reflexes.

1. sensory info. is carried by pseudounipolar neurons to the spinal cord
2. neurons synapse directly on motor neurons in anterior column of gray matter
3. axons of these motor neurons course out of spinal cord to supply the skeletal muscles

- One synapse between 2 neurons = monosynaptic
- Two synapse 3 neurons = disynaptic

34

Differentiate referred pain and phantom pain.

Referred pain - pain that is perceived in certain areas or organs of the body but is actually caused in another location
(usually the area of referred pain is supplied by the same spinal nerve component as the actual site of pain)

Phantom pain - amputees experience pain in body parts they no longer have; sensory neurons that supplies amputated portions of the body sometimes continue to send impulses

35

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Olfactory Nerve

loss of sense of smell = anosmia caused by fractures of the ethmoid bone or neoplasia

36

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Optic Nerve

total loss of vision = blindness caused by retinal or optic nerve dysfunction

- partial losses are a result of other eye problems

37

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Oculomotor Nerve

prevents upward, downward, or medial movement of visual axis

38

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Trochlear Nerve

medial and downward deflection of visual axis causes diplopia (double vision) when looking straight downward

39

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Trigeminal Nerve

Ophthalmic Nerve: perceive touch to upper forehead, nose, or cornea

Maxillary Nerve: Perceive touch to superior gums, superior lip, or palate

Mandibular Nerve: perceive touch to inferior gums, inferior lip, or tongue

40

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Abducens Nerve

dysfunction prevents abduction of visual axis and causes convergent strabismus (cross-eyed)

41

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Facial Nerve

flaccid paralysis of facial muscles on affected side

(facial paralysis)

42

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Vestibulocochlear Nerve

loss of equilibrium and cochlear nerve dysfunction results in loss of hearing

43

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Glossopharyngeal Nerve

dysphagia = difficult swallowing

xerostomia = dry mouth

44

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Vagus Nerve

dysphagia and partial or complete loss of voice

45

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Accessory Nerve

flaccid paralysis and atrophy of ipsilateral trapezius and sternocleidomastoidus muscles

46

Explain the functional losses related to dysfunction of each one of the cranial nerves.

Hypoglossal Nerve

flaccid paralysis of tongue on affected side