textbook W3D1

Question 1

dorsal side of spinal chord has BLANK nerves

Answer 1

efferent/motor

Question 2

ventral side of spinal chord has BLANK nerves

Answer 2

afferent/sensory

Question 3

what do the efferent and afferent nerves combine to form

Answer 3

spinal nerves

Question 4

name the four spinal regions (including numbers)

Answer 4

cervicle (C1-C7), thoracic (T1-T12), lumbar (L1-L5), sacral (S1-S5)

Question 5

sensory neurons carry info BLANK CNS

Answer 5

TO the CNS

Question 6

motor neurons carry info BLANK CNS

Answer 6

AWAY FROM the CNS

Question 7

mixed neurons have BLANK

Answer 7

both sensory and motor fibers

Question 8

most neurons in the body are BLANK neurons

Answer 8

mixed

Question 9

what columns/horns are white matter

Answer 9

dorsal column, ventral horn, lateral column

Question 10

dorsal column (location)

Answer 10

posterior side of spinal chord

Question 11

ventral horn (location)

Answer 11

anterior side of spinal chord

Question 12

lateral column (location)

Answer 12

lies between dorsal column and ventral horn

Question 13

what horns/columns are made of gray matter

Answer 13

dorsal horn, ventral horn, lateral horn

Question 14

dorsal horn

Answer 14

loaction of sensory synapses

Question 15

ventral horn

Answer 15

location of motor neurons

Question 16

lateral horn

Answer 16

location of cell bodies in autonomic nervous system

Question 17

where are the cell bodies of ALL somatosensary receptor neurons located

Answer 17

DORSAL ROOT GANGLION

Question 18

where are the cell bodies of alpha motor neurons located

Answer 18

ventral horn of spinal chord

Question 19

where do the axons of alpha motor neurons go

Answer 19

leave spinal chord via ventral roots and travel to the muscle via EFFERENT spinal nerves

Question 20

what is myasthenia gravis (MG)

Answer 20

autoimune disorder characterized by weak facial muscles (droopy eyes, double vision, etc).

results from disctruction of nicitinic ACh receptors at neuromuscular junctions causing weak or no contractions of facial muscles

Question 21

motor unit (def)

Answer 21

alpha motor neuron + all the muscle fibers that it innervates

Question 22

motor pool (def)

Answer 22

group of motor neurons that innervate all the fibers of one muscle

Question 23

slow motor unit (def)

Answer 23

slow to contract, generate less force but can work for a long time. used during endurance work (ex running)

Question 24

fast fatigue-resistant motor units (def)

Answer 24

quick to contract, generate more force than slow motor units and are more resistant to fatigue than fast fatiguable

Question 25

fast fatigable motor units (def)

Answer 25

quickest to contract and generate the most force. prone to fatigue due to fewer mitochondria within muscles. used in high-intensity exercise (ex. weighlifting, sprinting)

Question 26

unfused tetanus (def)

Answer 26

short time between stimuli, but far enough apart that the muscle fiber has a partial relaxation period

Question 27

fused tetanus (def)

Answer 27

if action potentials are close enough together, they will summate and cause one large contraction

Question 28

muscle recruitment

Answer 28

smallest motor units are activated first and ‘recruit’ larger ones as necessary (lifting pencil vs 20 lbs)

Question 29

sensory cells from dorsal root ganglion (function)

Answer 29

provide sensory info from muscles through propreoception

Question 30

upper motor neurons from motor cortex in brain + brainstem (function)

Answer 30

are responsible for innitiating voluntary movement

Question 31

interneurons in spinal chord (function)

Answer 31

largest input to alpha neurons, can provide excitation or inhibition to alpha motor neurons

Question 32

proprioceptors (function)

Answer 32

inform us about body position + movement in space

Question 33

muscle spindles (function)

Answer 33

measure muscle stretch (length) + transmit this info via 1a sensory fibers. nested within and arranged parallel to the extrafusal muscle fibers

Question 34

golgi tendon organs (function)

Answer 34

measure muscle tension + transmit this sensory info via 1b sensory fibers. located between extrafusal muscle fibers and their points of attachement to bone

Question 35

extrafusal + intrafusal muscle fibers (def)

Answer 35

fiberous cpsuls located within muscles (muscle spindle)

Question 36

intrafusal muscle fiber (def)

Answer 36

located within fiberous capsul of muscle spindle. innervated by gamma motor neurons that cause them to contract

Question 37

extrafusal muscle fiber (def)

Answer 37

make up bulk of muscle, located outside muscle spindle. stimulated to contract by alpha motor neurons

Question 38

golgi tendon organ (def)

Answer 38

propreoceptor that measure muscle tention/force of contraction

Question 39

golgi tendon organ (location)

Answer 39

inside tendon that connects muscle to bone

Question 40

reflex (def)

Answer 40

involuntary motor response performed automatically and independantly of brain signals

Question 41

myotatic reflex (def)

Answer 41

knee jerk reflex

stretch reflex that occurs in response to activation of the muscle spindle stretch receptors

Question 42

monosynaptic communication (def)

Answer 42

only one synapse between the sensory input and motor output