Lec 15

Front 1

How do dihydropyridine and ryanodine receptors interact to enable interaction of sliding filaments?

Back 1

calcium channel in t-tubule interacts with calcium channel in sarcoplasmic reticulum for calcium release

Front 2

How localized, to spinal segments, would you expect to find the alpha motor neurons for a muscle like the gastrocnemius or the soleus?

Back 2

might be spread over 5 segments

Front 3

Say something about mototopic organization of motor neurons in the ventral horn.

Back 3

proximal muscles are medial, flexors are dorsal

Front 4

You withdraw one supporting leg because you stepped on something painful. What happens to the opposite leg's flexor?

Back 4

it is inhibited via interneurons

Front 5

Binding to troponin, helping with the release of vesicles at the "presynaptic" membrane of the neuromuscular junction, release from sarcoplasmic reticulum. Name a yet one additional location or channel for the action of calcium ions in excitation ­p; contraction coupling.

Back 5

T-tubules carry action potentials into cell with DHP calcium channels

Front 6

The numbers 13 vs 1730 were given for extraocular vs gastrocnemius muscles respectively (and explained in terms of muscles for fine vs gross movement respectively). 13 and 1730 what?

Back 6

Number of muscle cells (fibers) per motor unit (one spinal motor neuron)

Front 7

For a Golgi tendon organ in the tendon of the biceps, answer either (1) How would the muscle react from stimulation? Or (2) What is the sensory afferent axon?

Back 7

Muscle is inhibited from contracting (via inhibitory interneuron); Ib

Front 8

How is it that, in the knee-jerk reflex, the flexor is inhibited from contracting?

Back 8

Through an inhibitory interneuron

Front 9

I have located a spinal motor neuron for the triceps in the ventral horn. Where should I look, relative to that cell, for neurons that would mediate making a fist?

Back 9

(using that diagram of making a muscle superimposed on the ventral gray matter) lateral to that neuron

Front 10

What do dihydropyridine and ryanodine receptors have to do with each other?

Back 10

dihydropyridine in t tubules interact with ryanodine in sarcoplasmic reticulum, calcium channels

Front 11

Make a statement about how many different metabolic muscle types connect to one motor unit.

Back 11

each motor unit has only one metabolic type

Front 12

How would you go about visualizing the cell bodies of all the spinal motor neurons that connect to one muscle?

Back 12

backfill from the nerve

Front 13

Pick one: (1) What is the source of the signal that comes up the Ib afferent? (2) What is the function of the signal that comes up the Ib afferent?

Back 13

Golgi tendon organ, let go (as opposed to contract

Front 14

What is the function of the enzyme deficient in familial amyotropic lateral sclerosis?

Back 14

get rid of superoxide

Front 15

What cells degenerate in ALS (amyotrophic lateral sclerosis, Lou Gehrig's disease)?

Back 15

spinal motor neurons

Front 16

Relative to adjacent areas, what would be more plentiful in the cervical enlargement?

Back 16

spinal motor neurons

Front 17

In the ventral horn of the spinal cord, where are motor neurons controlling the hand relative to those controlling the shoulders?

Back 17

lateral

Front 18

Where is the cell body for the stretch receptor involved in the monosynaptic reflex?

Back 18

dorsal root ganglion

Front 19

What are gamma motor neurons used for?

Back 19

to preset stretch in intrafusal muscle fibers

Front 20

The sensitivity for the reflex can be preset by the fusimotor system. What type of nerve and what type of muscle are used in this efferent system?

Back 20

gamma motor neuron to intrafusal system

Front 21

What muscles are excited and inhibited in the crossed-extensor reflex?

Back 21

ipsi + flexor to withdraw, - extensor, contra + extensor to support and - flexor

Front 22

Consecutive muscle twitches that come close enough together in time fuse to a steady and stronger contraction. What is this called?

Back 22

tetanus

Front 23

One motor neuron connects to quite a few muscle cells. What is this called?

Back 23

motor unit

Front 24

There's a muscle protein called "dystrophin." Why did they give it that name?

Back 24

it is the product of a gene that, if mutant, leads to Duchenne (or Becker) muscular dystrophy

Front 25

Name a Ca2+ channel relevant to excitation-contraction coupling.

Back 25

dihydropyridine receptor and ryanodine receptor (also synaptic calcium channel)

Front 26

I compared 13 for extraocular muscle and 1730 for gastrocnemius. 13 and 1730 what?

Back 26

muscle cells per neuron in a motor unit

Front 27

In the knee-jerk reflex, the flexor is inhibited. How?

Back 27

there is an inhibitory interneuron