exam review - quiz 5

Question 1

question: how are the cran. nerves distributed across the cerebrum, diencephalon, brainstem, and spinal cord?

Answer 1

• cerebrum: 1 pair
• diencephalon: 1 pair
• brainstem: 9 pairs
• spinal cord: 1 pair

Question 2

name: all cranial nerves in order

Answer 2

I - Olfactory
II - Optic
III - Oculomotor
IV - Trochlear
V - Trigeminal
VI - Abducens
VII - Facial
VIII - Vestibularcochlear
IX - Glossopharyngeal
X - Vagus
XI - Accessory
XII - Hypoglossal

Question 3

explain: function of cran. nerve I (name of nerve, sensory or motor)

Answer 3

OLFACTORY
- sensory
- smell
- 2 neuron sys.
- goes through nerve fibers -> through cribriform bone -> olfactory bulb -> temporal lobe

Question 4

explain: function of cran. nerve II (name of nerve, sensory or motor)

Answer 4

OPTIC
- sensory
- vision
- collect info from retina -> optic nerve -> optic chiasm -> optic tract -> occipital lobe

Question 5

explain: function of cran. nerve III (name of nerve, sensory or motor)

Answer 5

OCULOMOTOR
- motor
- somatic motor = mvts. of eyeball and upper eyelid
- parasympathetic motor = pupil contraction and focusing lens

Question 6

explain: function of cran. nerve IV (name of nerve, sensory or motor)

Answer 6

TROCHLEAR
- motor
- mvt. of eyeball through 1 muscle (trochlea)

Question 7

explain: function of cran. nerve V (name of nerve, sensory or motor)

Answer 7

TRIGEMINAL
- motor and sensory
- 3 branches
1. ophthalmic = sensory (upper facial struc.)
2. maxillary = sensory (middle facial struc.)
3. mandibular = sensory (lower face struc. + anterior to ear)
⤷ motor = mastication

Question 8

explain: function of cran. nerve VI (name of nerve, sensory or motor)

Answer 8

ABDUCENS
- motor
- mvt. of eyeball

Question 9

explain: function of cran. nerve VII (name of nerve, sensory or motor)

Answer 9

FACIAL
- motor and sensory
- taste = sensory
⤷ covers anterior part of tongue
- facial exp. = motor
- salivary glands + lacrimal glands (tears) = parasympathetic motor

Question 10

explain: function of cran. nerve VIII (name of nerve, sensory or motor)

Answer 10

VESTIBULARCOCHLEAR
- sensory
- hearing and balance
- 2 nerves come together
⤷ vestibular = balance
⤷ cochlear = hearing

Question 11

explain: function of cran. nerve IX (name of nerve, sensory or motor)

Answer 11

GLOSSOPHARYNGEAL
- motor and sensory
- taste = sensory
⤷ covers posterior part of tongue
⤷ monitors swallowing musc., bp, blood gases
- swallowing = motor
- parotid gland (saliva) = parasympathetic

Question 12

explain: function of cran. nerve X (name of nerve, sensory or motor)

Answer 12

VAGUS
- motor and sensory
- voice production + swallowing = motor
- bp, blood gases, taste = sensory
- GI control, respira., decreases heart rate = parasympathetic motor
- very broad reaching
⤷ extends down to abdominal and thorasic cavities

Question 13

explain: function of cran. nerve XI (name of nerve, sensory or motor)

Answer 13

ACCESSORY
- motor
- head mvts/ and swallowing
⤷ neck musc.
- roots in brainstem

Question 14

explain: function of cran. nerve XII (name of nerve, sensory or motor)

Answer 14

HYPOGLOSSAL
- motor
- speech and swallowing

Question 15

question: what atoms are on the inside and outside of membrane?

Answer 15

OUT
Cl-, Na+, Ca2+

IN
K+, A-

Question 16

question: what is the overall charge outside and inside of the mem?

Answer 16

OUT = +ive
IN = -ive

Question 17

question: what is the movement for sodium-potassium pump?

Answer 17

• 2 K+ in, 3 Na+ out

Question 18

explain: types of ion channels (2)

Answer 18

1. leak
   - always open
   - more K leak and Na leak
2. gated
   - open and close
   - can be ligand gated, mechanically gated, voltage gated

Question 19

question: do ions follow chemical gradient or electrical gradient?

Answer 19

• ions follow chemical gradient before following electrical gradient

Question 20

explain: how resting potential is determined

Answer 20

• K+ moves from high -> low bc of conc. gradients
  ⤷ makes outside +ive, inside -ive
• K+ on outside starts to get attracted ot new -ive charge on inside bc electrical gradient
• in/out mvt. of K+ eventually becomes equal making it resting potential

**flow will be equal but conc. of K+ will be higher inside

Question 21

explain: leak channel (description + location)

Answer 21

• always open
• in all cells
• dendrites, cell bodies, and axons of neurons

Question 22

explain: ligand gated channels (description + location)

Answer 22

• gated channels that open in resp. to binding of a ligand
• dendrites of some neurons (pain)
• dendrites and cell bodies of some neurons (interneurons and motor neurons)

Question 23

explain: mechanically gated channels (description + location)

Answer 23

• gated channels that open in resp. to mechanical stim.
• dendrites of some sensory neurons
  ⤷ ex. pain, touch, pressure

Question 24

explain: voltage gated channels (description + location)

Answer 24

• gated channels that open in resp. to voltage stim.
• in axons of all types of neurons
• a lot in trigger region

Question 25

explain: types of electrical signals (2)

Answer 25

1. graded potentials (local) - use ligand and mechanically gated - only for comm. over short distances ⤷ bc it only changes mem. potential in+around region of channel - dep. on amount of stim. - more graded potentials add together -> larger amp. (summation) 2. action potential - use voltage gated - allow comm. over short and long distances ⤷ domino effect when 1 channel opens makes it go a long dist.

Question 26

explain: hyperpolarization and depolarization

Answer 26

- hyperpol. = more polar ⤷ more difference between inside and outside - depol. = less polar ⤷ less difference between inside and outside

Question 27

explain: which channels are open and closed at various parts of action potential

Answer 27

resting - inactivation gate Na+ = open - activation gate Na+ = closed - voltage gated K+ = closed depolarization - voltage gated Na+ opens ⤷ lets Na+ into cell repolarization - Na+ inactivation closes - K+ opens ⤷ helps mem. return to -70mV - Na+ activation closes - Na+ inactivation opens afterpotential (hyper overshoot) - too much K+ -> hyper - K+ needs to close - sodium potassium pump restores resting

Question 28

explain: types of refractory periods (2)

Answer 28

1. absolute - another AP CANNOT happen - Na+ activation channel already open during repol. and depol. so it can't be activated to open again 2. relative - needs larger stim. to reach threshold - during afterpotential