Pbd Quiz 4

Front 1

T/F?
Fast muscle fibers have a more extensive blood vessel supply than slow muscle fibers.

Back 1

False!

Front 2

T/F?
Binding of calcium to the myosin head causes it to detach from the actin active site.

Back 2

False!

Front 3

Increasing the number of motor units contracting simultaneously is referred to as _________ summation.

Back 3

SPATIAL or MULTIPLE MOTOR UNIT

Front 4

Reciprocal inhibition results from the firing of ___________ cells synapsing on a-motor neurons of antagonistic muscles

Back 4

RENSHAW

Front 5

The central portion of intrafusal muscle fibers is directly innervated by:
a. 1a-sensory nerve fibers
b. gamma-motor nerve fibers.
c. a-motor nerves
d. motor fibers from higher CNS centers

Back 5

a) 1a-sensory nerve

Front 6

Which of the following is FALSE concerning Clostridia botulinum:
a. multiply in anaerobic conditions
b. releases a neurotoxin
c. neurotoxin blocks release of inhibitory neurotransmitters
d. results in flaccid paralysis
e. all of the above are TRUE

Back 6

c) neurotoxin blocks release
of inhibitory neurotranmitters

Front 7

Which of the cardinal signs of inflammation results from an increased blood flow in the affected area?
a. swelling
b. fever
c. pain
d. redness
e. loss of function

Back 7

d. redness

Front 8

T/F?
Stimulation of the mast cell allows for an influx of calcium into the cell that raises the intracellular levels of cAMP and results in degranulation of the cell.

Back 8

false!

Front 9

T/F?
Aryl sulfatase B is an enzyme that is released from the mast cell and will degrade interleukins, thus acting to inhibit aspects of inflammation.

Back 9

false!

Front 10

T/F?
Prostaglandin E2 (PGE2) can inhibit the release of histamine from the mast cell.

Back 10

true!

Front 11

T/F?
Tumor necrosis factor is a cytokine that can enhance angiogenesis.

Back 11

true!

Front 12

T/F?
The Hageman Factor is a blood protein, which is activated upon exposure to collagen and can stimulate the production of plasmin and the eventual breakdown of a clot.

Back 12

true!

Front 13

___________are a class of cytokine that is important in the development of fever.

Back 13

Interleukins or interferons

Front 14

a. ____________ and b. ____________ are common events at the site of a chronic inflammation.

Back 14

a. Necrosis
b. fibrosis

Front 15

T/F?
The troponin strands physically cover the actin active sites when not binding a calcium ion.

Back 15

false

Front 16

T/F?
Fast muscle fibers have a more extensive sarcoplasmic reticulum.

Back 16

true

Front 17

T/F?
The "I" band of skeletal muscle contains both actin and myosin filaments.

Back 17

false
(the A strand does)

Front 18

T/F?
Gamma fibers associated with muscle spindles are afferent fibers.

Back 18

false

Front 19

. Concerning the contraction of skeletal muscle, which of the following is FALSE:
a. action potentials cause the release of calcium ions into the sarcoplasm
b. the binding of calcium to troponin causes the actin active sites to be
uncovered
c. conformational changes in the myosin cross bridges pulls actin and myosin filaments past each other (power stroke)
d. binding of ATP causes the myosin heads to detach from the actin active sites
e. all of the above are true

Back 19

e. all of the above are true

Front 20

List the four cardinal signs of inflammation: a._____ b. _____ c. _____ d. ______.

Back 20

a. redness, b. swelling, c. heat, d. pain

Front 21

What substance is released from the eosinophil that degrades leukotreines: ____________________.

Back 21

aryl sulfatase B

Front 22

T/F?
The binding of calcium to troponin allows ATP to bind to the myosin heads.

Back 22

false

Front 23

Active sites on actin filaments are covered by __________ before contraction.

Back 23

tropomycin

Front 24

T/F?
Before contraction, myosin heads bind ATP.

Back 24

true

Front 25

Before contraction, (a)_______ cleaves ATP leaving (b)________ bound to head

Back 25

(a) ATPase
(b) ADP+Pi

Front 26

Action potential causes increase in sarcoplasmic ____ concentration.

Back 26

Ca++

Front 27

Ca++ bind to (a)_________ causing (b)________ active sites to be uncovered.

Back 27

(a) troponin
(b) actin

Front 28

T/F?
After uncovered, myosin heads bind to actin active sites, and once bound there's a conformation chance in cross bridge

Back 28

true

Front 29

During a "power stroke" the bending of _______ pulls the actin and myosin filaments past each other.

Back 29

myosin

Front 30

During "recocking," when the myosin head is tilting, it releases ______ from the binding site. (now a new ATP can bind)

Back 30

ADP-Pi

Front 31

The binding of ATP causes myosin head to ______ from actin active site.

Back 31

detach

Front 32

Detachment of myosin head cause _____ to be cleaved, causing energy to be stored in the myosin head.

Back 32

ATP

Front 33

The idea that ATP required to cause separation of myosin head from actin filament is called what?

Back 33

rigor mortis

Front 34

What is located in the middle of a muscle fiber and generates action potential in the sarcolemma adjacent to endplate?

Back 34

motor endplates

Front 35

What is an invagination of the sarcolemma that communicates with extracellular space, located directly over Z-line?

Back 35

transverse tubule system (t-tubules)

Front 36

What are the 2 parts of the sarcoplastic reticulum called?

Back 36

longitudinal tubules and terminal cisternae

Front 37

T/F?
The SR contains a very high concentration of Ca++?

Back 37

true

Front 38

What is the protein called that's located in the lumen of the reticulum?

Back 38

calsequestrin

Front 39

What are the 2 main things req'd for contraction?

Back 39

1) stimulus (AP w/ release of Ca++)
2) energy

Front 40

An AP produces excitation of the _________ and ___________

Back 40

sarcolemma
T-tubule system

Front 41

Depolarization triggers _______________ on the SR, releasing a pulse of Ca++ into the sarcoplasm.

Back 41

voltage-gated channels

Front 42

T/F?
Calcium ATP-ase pumps depletes Ca++ from sarcoplasm.

Back 42

true

Front 43

What is the average time it takes an "average" muscle fiber to have a calcium pulse?

Back 43

33 msec