Cv1 Heller 7

Front 1

Vascular adjustments are made by changes in the tone of vascular _____ _____

Back 1

smooth muscle

Front 2

Vascular smooth muscle has many unique properties that make it sensitive to a wide array of local and reflex stimuli and capable of maintaining ____ for long periods of time

Back 2

tone

Front 3

The tone of arterioles, but not veins can be strongly influenced by local _____ factors produced by local tissue metabolism

Back 3

vasodilator

Front 4

In abnromal situations, certain local factors like h_______ and b_______, and hormonal factors like v_______ and a_______ have significant vascular influences

Back 4

histamine
bradykinin
vaspressin
angiotensin

Front 5

__________ vasoconstrictor nerves provide the primary relex mechanisms for regulating both arteriolar and venous tone

Back 5

Sympathetic

Front 6

Sympathetic vasoconstrictor nerves release ________ which interacts with _-______ receptors on vascular smooth muscle to induce ________

Back 6

norepinephrine
alpha1-adrenergic
vasoconstriction

Front 7

The relative importance of local ______ control versus reflex ________ control of arteriolar tone (and blood flow) varies from organ to organ

Back 7

metabolic
sympathetic

Front 8

Which of the following would increase blood flow through a skeletal muscle?
a) increase in tissue Pco2
b) Increase in tissue adenosine
c) presence of alpha-receptor blocking drugs
d) sympathetic activation

Back 8

a, b, and c

Front 9

Autoregulation of blood flow implies that arterial pressure is adjusted by local mechanisms to ensure constant flow through an organ - true or false?

Back 9

false - vascular resistance is adjusted to maintain constant flow in spite of changes in arteriolar pressure

Front 10

Coronary blood flow will normally increase when:
a) arterial pressure increases
b) heart rate increases
c) sympathetic activity increases
d) heart is dilated

Back 10

All because they all increase myocardial oxygen consumption and flow is based on metabolic needs

Front 11

The arterioles of skeletal muscle would have little or no tone in the absence of normal sympathetic vasoconstrictor fiber activity - true or false?

Back 11

False - they have inherent tone

Front 12

Compared to other muscle types, smooth muscle...
Contracts and relaxes much _____
Develops active tension over a _____ range of muscle lengths
Changes contractile activity as the result of action potentials or changes in ____ _____ _____
May change their contractile activity in the absence of changes in _____ potential
Maintain tension for prolonged periods at low _____ cost
Can be activated by _____

Back 12

slower
greater
resting membrane potential
membrane
energy
stretch

Front 13

Because of long ____ filaments and the lack of ______ arrangement, smooth muscle can develop tension over longer lengths than other muscle types

Back 13

actin
sarcomere

Front 14

In smooth muscle, Ca first forms a complex with ______ which activates myosin ____ chain kinase. This uses ATP to phosphorylate a portion of the cross-bridge head of _____. This enables cross-bridge formation.

Back 14

calmodulin
light
myosin

Front 15

Smooth muscle cells have resting membrane potentials that are higher/lower than striated muscle. This is due to what ion being more permeable?

Back 15

lower
range from -40 to -65 mV

potassium

Front 16

Smooth muscle action potentials are initiated primarily by inward ___ current and develop slowly. Repolarization is from what type of channels?

Back 16

Ca2+ through a voltage operated calcium channel

potassium

Front 17

_________ coupling occurs because smooth muscle surface membrane contains VOCs for calcium that are more open during depolarization
________ coupling is when chemical agents can induce smooth muscle contraction without need for change in membrane potential

Back 17

Electromechanical

Pharmacomechanical

Front 18

Pharacomechanical coupling uses chemicals to increase Ca 2 ways:
1) _____-______ channels are opened from an activated g-protein receptor
2) Activated receptor may induce the formation of an intracellular ____ _______ (IP3) that opens SR stores of Ca

Back 18

receptor-operated
second messanger

Front 19

Norepinephrine works on __-_____ receptors to vaso_____

Epinephrine works on __-_____ receptors to vaso_____

Back 19

NE -> alpha-1-adrenergic receptors -> IP3 -> vasoconstrict

E -> beta-2-adrenergic receptor -> cAMP -> protein kinase A -> Ca efflux -> hyperpolarize -> vasodilation

Front 20

What do epinephrine, histamine, and vasoactive intestinal peptide all have in common?

Back 20

Vasodilator substances that act through the cAMP pathway

Front 21

what intracellular second messanger does NO (from nitrates and endothelial cells) activate?
What is its effect?

Back 21

cGMP
Vasodilation

Front 22

Usually exposure to low oxygen reduces arteriolar tone and causes ________; whereas high oxygen levels cause arteriolar _________

Back 22

vasodilation
vasoconstriction

Front 23

CO2, H+, K+, and increased tissue osmolarity causes arteriolar _____

Back 23

dilation - this happens during exercise

Adenosine also released at high metabolic rates or low O2

Front 24

When factors are present that cause vasodilation, blood flow ______

Back 24

increases => therefore those factors do not accumulate

Front 25

Local _______ mechanisms are by far the most important means of local flow control

Back 25

metabolic

Front 26

Acetylcholine causes _______ of intact vessels but ________ of vessels stripped of their endothelial lining

Back 26

vasodilation
vasoconstriction

Front 27

NO is activated by a rise in intracellular __. This can be a result of ____ stress. It causes vasodilation by stimulating ____ production

Back 27

Ca
shear
cGMP

Front 28

Histamine produces arteriolar visodilation via the ___ pathway andi ncreases vascular permeability which leads to ____ formation

Back 28

cAMP

edema

Front 29

_______ is a small polypeptide that has about 10x the vasodilator potential of histamine. It opens junctions between endothelial cells.

Back 29

Bradykinin

Front 30

Skeletal muscle blood flow increases within seconds of the onset of muscle exercise and returns to control values shortly after - follows medibolic rate. What is this called?

Back 30

Active hyperemia

Front 31

______ hyperemia is a higher than normal blood flow that occurs transiently after the removal of any restriction that had caused lower blood flow

Back 31

Reactive or postocclusion

Front 32

The body maintains steady blood flow in the _______ range through metabolites and myogenic changes

Back 32

autoregulatory

Front 33

These neural fibers innervate arterioles in all systemic organs and provide by far the most important means of reflex control of the vasculature

Back 33

Sympathetic vasoconstrictor nerves

Front 34

Parasympathetic vasodilator nerves release ______ and are present in what organs?

Back 34

acetylcholine
brain
heart
salivary glands
pancreas
gastric mucosa
external genitalia

Front 35

Both epinephrine and norepinephrine moderate levels can activate cardiac _-_____ receptors to increase heart rate and myocardial contractility and higher levels can activate vascular _-_____ receptors to cause vasocontriction

Back 35

beta2-adrenergic

alpha1-adrenergic

Front 36

Vasopressin, also known as _____ _____ acts on collecting ducts in the kidneys to decrease renal excretion of water

Back 36

antidiuretic hormone

Front 37

Angiotensin II regulates aldosterone release and is a very important _______ agent

Back 37

vasoconstrictor

Front 38

Veins are constricted like arterioles (alpha1-receptors and NE); however, veins have very little basal ____. Also, veins are much more sysceptible to physical influences due to thin ____.

Back 38

tone

walls

Front 39

Which circulation?
Control of vascular resistance dominated by metabolic needs
Compression of vessels during systole increases vascular resistance and decreases flow
Direct neural effects on resistance vessels are minimal
Some sympathetic vasoconstriction but usually over-ridden by medabolic demand

Back 39

Coronary circulation

Front 40

Which circulation?
Intrinsic tone high and flow controlled by metabolic demands
Vasoconstriction by high sympathetics during exercise can blunt metabolic dilation
Rhythmic isometric contraction leads to pulsatile venous contraction in exercise

Back 40

Skeletal Muscle Circulation

Front 41

Flow quite constant, local metabolic demands determine flow
Strongly autoregulated
Low blood CO2 leads to low blood flow leads to dizziness
Minimal autonomic neural effects

Back 41

Cerebral Circulation

Front 42

Portal circulation
Receives large CO and contains lots of blood
High flow at rest, increases with more metabolic demands
Richly innervated by sympathetics

Back 42

Splanchnic Circulation

Front 43

High flow considering tissue mass
Sympathetic can decrease flow to nearly zero
Strongly autoregulated
Specialized vascular anatomy

Back 43

Renal Circulation

Front 44

Specialized vascular anatomy (venous plexus)
Arterioles and venous plexus richly innervated by sympathetics
Local bradykinin formation increases blood flow

Back 44

Cutaneous circulation

Front 45

Increase of body temperature leads to _____ in sympathetic activity to the skin and _____ flow
Low body temperature leads to _____ in sympathetic activity and shunting of blood ____ from surface

Back 45

reduction
increase

increase
away

Front 46

Low pressure due to low resistance due to large vessels
Compliant arterial system
Arterioles constrict when exposed to a hypoxic environment

Back 46

Pulmonary Circulation