Neuro-Exam 2 Vestibular + Spinal Control + Proprioception

Front 1

Importance of Vestibular System

Back 1

-Balance
-Equilibrium
-Posture
-head/body/eye movement

Front 2

Components of Vestibular Labyrinth

Back 2

-Otolith organs : gravity and tilt
-Semicircular canals: head
rotation
-Hair cells: like auditory
system, to detect changes

Front 3

Otolith organs

Back 3

gravity and tilt (head angle and linear acceleration)

Front 4

Semicircular canals

Back 4

Head rotation

Front 5

Hair cells

Back 5

Detect changes

Front 6

What cells respond to tilt and where in the vestibular system are they located?

Back 6

Macular hair cells and are in the Otolith organs

Front 7

what is the function of kinocilium in otolith organ?

Back 7

Macular cells are usually upright, when direction of the head changes the otoliths move the hair cells either to or away from kinocilia.
Away=depolarization
Toward=hyperpolarization

Front 8

what kind of movement do the semicircular canal detect?

Back 8

-Angular movement
-turning movement

Front 9

what is different between the kinocilia in the semicircular canal vs the ones on the otolith organs?

Back 9

In the semicircular canal they are all in the same direction, therefore get excited or inhibited together

Front 10

how is movement detected in semicircular canal?

Back 10

force moves endolymph ‐>
moves cupula ‐> bends cilia

Front 11

Push-Pull activation of semicircular canal

Back 11

Head rotation-->excitation of one horizontal semicircular canal in one side and inhibition on the other. Adaptation when rotation goes on for too long (dizziness when stopping)

Front 12

Function of the vestibulo-ocular reflex

Back 12

Line of sight fixed on visual
target

Front 13

Mechanism of the vestibulo-ocular reflex

Back 13

Senses rotations of head,
commands compensatory movement of
eyes in opposite direction

Front 14

Pathway for VOR

Back 14

Semicircular canal-->vestibular nucleus-->cranial nerves-->extraocular muscles

Front 15

Push-Pull activation of semicircular canal

Back 15

Head rotation-->excitation of one horizontal semicircular canal in one side and inhibition on the other. Adaptation when rotation goes on for too long (dizziness when stopping)

Front 16

The motor system is mede up of ______ and _____

Back 16

muscles and neuron that innervate them

Front 17

Function of the vestibulo-ocular reflex

Back 17

Line of sight fixed on visual
target

Front 18

Mechanism of the vestibulo-ocular reflex

Back 18

Senses rotations of head,
commands compensatory movement of
eyes in opposite direction

Front 19

Pathway for VOR

Back 19

Semicircular canal-->vestibular nucleus-->cranial nerves-->extraocular muscles

Front 20

The motor system is mede up of ______ and _____

Back 20

muscles and neuron that innervate them

Front 21

Role of the motor system

Back 21

generation of coordinated movement

Front 22

Location of lower motor neurons

Back 22

ventral horn of spinal cord

Front 23

Somatic Musculature and distribution of
lower motor neurons in spinal cord

Back 23

– Axial muscles: Trunk movement
– Proximal muscles: Shoulder,
elbow, pelvis, knee movement
– Distal muscles: Hands, feet, digits
(fingers and toes) movement

Front 24

What are the categories of lower motor neurons in the spinal cord?

Back 24

alpha and gamma

Front 25

1 alpha motor neuron + all the fibers that innervate it

Back 25

motor unit

Front 26

all motor neurons that innervate a single muscle

Back 26

motor neuron pool

Front 27

Size Relationship in alpha motor neurons

Back 27

large motor units have large AMNs

Front 28

Control of fine movement

Back 28

Smaller motor units have smaller AMN's, smaller AMNs are recruited first, then large ones. Smaller ones can be finely controlled by the CNS

Front 29

Differences between red and white muscle fibers

Back 29

RED (SLOW): Lots of mitochondria and enzymes
-Slow to contract
-Can sustain contraction

WHITE (FAST): Few mitochondria
-anaerobic metabolism
-Fast contraction
-Fast fatigue

Front 30

Sliding filament model of muscle contraction (CONTRACTION PHASE)

Back 30

Ca2+binds troponing--->troponin allows binding of myosin to actin--> myosin head dissociates from actin when ATP binds

Front 31

Sliding filament model of muscle contraction (EXCITATION)

Back 31

Excita'on
1. an action potential occurs in AMN
2. ACh is released by AMN at NMJ
3. Sarcolemma depolarizes (EPSP)
4. AP is generated which sweeps down the sacrolemma and
into the T tubules
5. T tubule depolarization leads to Ca++ release from SR

Front 32

Sliding filament model of muscle contraction (RELAXATION)

Back 32

Relaxa'on
1. EPSPs end, sarcolemma and T tubules return to res'ng
poten'al
2. Ca++ sequestered by SR
3. Troponin binds to myosin binding sites

Front 33

Muscle spindle

Back 33

are sensory receptors within the belly of a muscle, which primarily detect changes in the length of this muscle. They convey length information to the central nervous system via sensory neurons. This information can be processed by the brain to determine the position of body parts. The responses of muscle spindles to changes in length also play an important role in regulating the contraction of muscles, by activating motoneurons via the stretch reflex to resist muscle stretch. (GMN)

Front 34

Myotactic reflex

Back 34

Tendon stretched--> activaton of sensory neuron--> synapses with interneurons and motor neuron in spinal cord--> motor neuron inhibits flexor (via interneuron) and stimulates extensor muscle contraction---> leg extends

Front 35

Types of muscle fiber in spinal control of movement

Back 35

-Extrasufal: AMN
-Intrafusal: GMN

Front 36

Gamma Loop (Ia axon)

Back 36

Encodes muscle length info

Front 37

Golgi tendon organ (Ib axon)

Back 37

muscle tension info