Psl #4 Part 2

Front 1

Two type I muscle fibers have the same diameter, but one is much longer than the other.
That is, they differ in the number of sarcomeres in each myofibril. Compared to short
myofiber, the longer myofiber would:

Back 1

be able to undergo greater total shortening (when lifting the same load)

Front 2

What types of voltage gated channels do t-tubules have?

Back 2

voltage gated Na+ and K+ channels

Front 3

True or False: each motorneuron innervates more than one muscle fiber in a skeletal muscle?

Back 3

True

Front 4

What accounts for the decline in cytosolic [Ca++] following a
twitch contraction in normal skeletal muscle fiber?

Back 4

Active transport of Ca2+ into the SR

Front 5

In skeletal muscle, cytosolic [Ca++ ] is increased primarily by

Back 5

coupling between t-tubule depolarization and the ryanodine receptors on the SR

Front 6

The total force that can be developed by a skeletal muscle contracting isometrically is:

Back 6

equal to the sum of the active force generated by cross bridge cycling and the passive
tension

Front 7

Decreased ALDOSTERONE has what effect?

Back 7

Increased natriuresis (Na+ excretion through urine)

Front 8

Endogenous cellular precursor of NO

Back 8

Arginine

Front 9

Pharmacologic precursors of NO

Back 9

nitroglycerin

nitroprusside

Front 10

Source cells of NO

Back 10

endothelial cells

nerve terminals

Front 11

target cells for NO

Back 11

smooth muscle (intracellular NO receptors with GUANYLATE CYCLASE)

Front 12

NO binding to intracellular receptor initiates what signaling cascade?

Back 12

GTP --> cGMP --> PKG --> phophorylation of effector proteins, e.g.: MLCK

Front 13

Chemical component of soluble, cytosolic GC that binds NO

Back 13

HEME

Front 14

Inhibitor of platelet activation, via cGMP pathway =

Back 14

NO

Front 15

Two chemicals that ENCOURAGE platelet activation and their source

Back 15

thrombin and TxA2 (from platelets)

Front 16

two chemicals that INHIBIT platelet aggregation

Back 16

NO and PGI2 (from endothelial cells0

Front 17

Three classes of EICOSINOIDS

Back 17

prostaglandins

thromboxanes

leukotrienes

Front 18

thromboxanes

-stimulus
-target
-response

Back 18

THROMBOXANES

stimulus: thrombin
target: platelets
response: aggregation

Front 19

leukotrienes

-stimulus
-target
-response

Back 19

LEUKOTRIENES

stimulus: antigen-IgE
target: mast cells
response: anaphylactic reaction

Front 20

prostaglandins

-stimulus
-target
-response

Back 20

PROSTAGLANDINS

stimulus: pyrogens
target: hypothalamus cells
response: fever

Front 21

Which of the following describe the action of eicosinoids?

autocrine
paracrine
juxtacrine
endocrine

Back 21

autocrine

paracrine

Front 22

What enzyme cleaves FA to become arachodonate?

Back 22

PLA2

Front 23

PLA2

negative regulation
positive regulation

Back 23

PLA2

neg reg: anti-inflamm corticosteroids
pos reg: thrombin

Front 24

Two eicosinoid synthesis pathways deriving from arachodonate

Back 24

lipoxygenase pathway

cyclooxygenase pathway

Front 25

Which eicosinoid family/ies derive from the lipoxygenase pathway?

Back 25

leukotrienes

Front 26

Which eicosinoid family/ies derive from teh cyclooxygenase pathway?

Back 26

PG

TX

Front 27

PGH Synthase (COX) is inhibited by what OTC?

Back 27

aspirin

Front 28

How many carbons in an eiconsinoid?

Back 28

20 C

Front 29

Functionally, LTs are...

Back 29

muscle contractants

Front 30

systemic allergic response involves...

Back 30

Slow Reacting Substances of Anaphylaxis (SRS-A) = LTC4, LTD4, LTE4

Front 31

PGI2 and TxA2 - which vasodilates and which vasoconstricts?

Back 31

PGI2 vasodilates

TxA2 vasoconstricts

Front 32

anti-inflammatory corticosteroids inhibit _____ via ____

NSAIDS inhibit _____ via _____

Back 32

anti-inflammatory corticosteroids inhibit TOTAL EICOSINOID PRODUCTION via PLA2 inhibition

NSAIDS inhibit PG and TX proudction via PGH synthase (COX) inhibition

Front 33

Which COX protein is constitutive and found in the GI tract

Back 33

COX-1

Front 34

Which COX protein is inducible and released by macrophages?

Back 34

COX-2

Front 35

What was the problem with VIOXX?

Back 35

Vioxx inhibits COX-2 much more than COX-1. Endothelial cells express COX-2. Therefore, the inhibition of COX-2 lead to an increase in platelet aggregation, causing MIs.

Front 36

What propery is shared by the v-erb B2 oncoprotein (gp65v-erb B2) and
the receptor for epidermal growth factor (EGFR)?

Back 36

phosphorylating tyrosine residues of target proteins

Front 37

What protein found in skeletal muscle is ABSENT from smooth muscle?

Back 37

Troponin C

Front 38

In what type of muscle are cholinergic receptors ion channels?

Back 38

Skeletal muscle

Front 39

Which muscle types have actin-regulated contraction?

Back 39

Cardiac and skeletal muscle

Front 40

Alpha OR beta adrenergic receptors are found on what muscle type?

Back 40

Smooth muscle

Front 41

Stress relaxation is defined as the FALL in FORCE that occurs...

Back 41

following the initial increase in force associated with stretch

Front 42

What does SERCA (sarcoplasmic reticulum Ca2+ ATPase) do?

Back 42

transfers Ca2+
FROM CYTOSOL
TO SARCOPLASMIC RETICULRUM

during MUSCLE RELAXATION.

Front 43

Response of skeletal muscle arteriolar endothelium to acetylcholine

Back 43

Non-innervated receptors

Front 44

Innervation of skin blood vessels

Back 44

Adrenergic neuroeffector junction only

Front 45

Adrenergic control of fat cells

Back 45

Non-innervated receptors

Front 46

Vasoconstrictor response of skeletal muscle arterioles

Back 46

Non-innervated receptors

Front 47

Main autonomic NTs

Back 47

ACh

NE