Motor physiology

Question 1

Type II muscles: glycolytic or oxidative?

Answer 1

Glycolytic

Question 2

Soleus and antigravity muscles of the back are examples of type __ muscle fibers.

Answer 2

Type I

Question 3

What kind of smooth muscles have gap junctions?

Answer 3

Unitary or syncytial or visceral smooth muscles

Question 4

There is no true AP propagation in this type of smooth muscle

Answer 4

Multi unit smooth muscle

Question 5

Examples of unitary smooth muscles

Answer 5

Intestines
Bile ducts
Ureters
Uterus

Question 6

Thick filaments are composed of

Answer 6

Myosin

Question 7

Area between two z lines

Answer 7

Sarcomere

Question 8

Stabilizes sarcolemma and prevents contraction-induced rupture

Answer 8

Dystrophin

Question 9

The H zone contains: myosin only, actin only, both myosin and actin

Answer 9

Myosin only!

Question 10

Which does not shorten during skeletal muscle contraction?

Answer 10

A band which represents entire length of myosin

Question 11

Binds z lines to sarcolemma

Answer 11

Desmin

Question 12

Depolarization of T tubules causes

Answer 12

Activation of dihydropyridine receptor in T tubules

Question 13

DHPR causes activation of _______ receptor which releases ______ ions

Answer 13

Ryanodine

Calcium

Question 14

Calcium binds to what troponin?

Answer 14

Troponin C

Question 15

When ATP binds to cleft on myosin head, there is conformational change which causes _______ affinity of myosin for actin

Answer 15

Decreased affinity

Question 16

ATP hydrolysis causes recocking of Myosin head. True or False?

Answer 16

True!

Question 17

Distance achieved in a single power stroke

Answer 17

10 nm

Question 18

Basis for Treppe effect

Answer 18

Calcium accumulation
Ph changes
Increased temperature

Question 19

Pushing against the wall is isometric or isotonic contraction?

Answer 19

Isometric

Question 20

Load is held constant in _______ contraction

Answer 20

Isotonic

Question 21

Protective mechanism to prevent muscle injury or death

Answer 21

Muscle fatigue

Question 22

Phase 2 of cardiac muscle contraction is the _______ and is due to _____ of _________

Answer 22

Plateau

Calcium influx

Question 23

Phase 0 of cardiac AP is due to

Answer 23

Na influx

Question 24

Why is there no tetany in cardiac muscles?

Answer 24

Long phase 2 ( long refractory period)

Question 25

Phase 3 or final repolarization is due to

Answer 25

Decrease Ca influx

Increased K efflux

Question 26

In the smooth muscle, calcium binds to ________ which is similar to troponin C of skeletal muscle

Answer 26

Calmodulin

Question 27

________ phosphorylates myosin

Answer 27

Activated myosin light chain kinase

Question 28

Alpha motor neuron is for _______ fibers

Answer 28

Extrafusal

Question 29

Intrafusal fibers is associated with

Answer 29

Gamma motor neurons

Question 30

Muscle spindle detect changes in muscle

Answer 30

Length and rate of change of muscle length

Question 31

Golgi tendons are arranged in a ______ manner and detect changes in muscle _____

Answer 31

Parallel

Tension

Question 32

Sense of awareness of the position of body in space

Answer 32

Proprioception

Question 33

Proteins in smooth muscle that are equivalent to troponin I

Answer 33

Caldesmon

Calponin

Question 34

_______ motor neurons are the final common pathway

Answer 34

Alpha motor neurons

Question 35

Purkinje layer of the cerebellum is always __________

Answer 35

Inhibitory

Question 36

Symptoms of cerebellar dysfunction

Answer 36

Ataxia dysmetria dysdiadochokinesia

Question 37

Function of Renshaw cells

Answer 37

Inhibitory cells in the ventral horns of the spinal cord

Question 38

Flexor withdrawal reflex is an example of a ______ synaptic reflex

Answer 38

Polysynaptic

Question 39

Opposite of stretch reflex

Answer 39

Golgi tendon reflex

Question 40

Functional unit of the muscle

Answer 40

Sarcomere