Special circulations B6

Question 1

2 ways you can control flow to an organ

Answer 1

Blood flow can be controlled extrinsically= someone else decides, Neural and hormonal (receptors)
Blood flow can be controlled intrinsically- local control- the organ tissue decides

Question 2

Blood flow is maintained constant despite changing arterial pressure

Answer 2

Autoregulation

Question 3

Blood flow changes as metabolic demand changes

Answer 3

Active hyperemia

Question 4

Period of reduced blood flow are followed by supernormal flow.

Answer 4

Reactive hyperemia

Question 5

What are the 3 levels of local control?

Answer 5

Autoregulation
Active hyperemia
Reactive hyperemia

Question 6

Smooth muscle adjusts diameter of vessels to maintain blood flow

Answer 6

Myogenic mechanism

Question 7

Metabolic by-products act as local signals to alter flow

Answer 7

Metabolic mechanism

Question 8

Blood flow in the coronary vessels to feed heart

Answer 8

Coronary flow
-Metabolic control most important
             -active hyperemia through hypoxia and adnosine
Reactive hyperemia during diastole
(little neural control)

Question 9

Blood flow to skeletal muscle

Answer 9

Skeletal flow- important during exercise

-neural most important during rest

Question 10

Blood flow to skin

Answer 10

Skin- primarily neural for body heat regulation

• little metabolic control
• hormonal regulation- histamine

Question 11

Increasing skeletal muscle CO2 production would ________ blood flow?

Answer 11

Increase

Question 12

Increasing skeletal muscle CO2 production would increase blood flow, an example of _______________ regulation.

Answer 12

Increasing metabolic demand
-Active hyperemia

(Reactive requires a loss of blood flow…)

Question 13

Know what kind of blood flow changes organs we talked about and give examples…

Answer 13

slide 5 6 7

Question 14

Process of forming clots on vessel walls in response to injury is what? what does it do?

Answer 14

Hemostasis

Prevents further blood loss

Question 15

3 stages of hemostasis

Answer 15

Vascular constriction
Formation of a platelet plug
Clot formation- coagulation

Question 16

Collagen binds to _______________ which binds to circulating platelets.

Answer 16

von Willebrand factor

Question 17

Immediately after damage, vessel ____________.

Answer 17

Constricts, slowing flow to damaged area

Question 18

Damaged endothelium release vasoactive compounds to cause ___________

Answer 18

Vasoconstriction

adenosine and Calcium

Question 19

Pain response from ________ also cause vasoconstriction

Answer 19

CNS

Question 20

What protein is responsible for platelet flug formation? (IMPORTANT)

Answer 20

Von willebrand factor

Question 21

Enzymatic cascade that converts fibrinogen into fibrin.

Answer 21

Coagulation

Question 22

If thrombus breaks off it is called a __________

Answer 22

embolus

Question 23

____________ usually originate in legs (deep vein thrombosis). They can get stuck in lung, causes ___________________

Answer 23

Venous emboli

pulmonary embolism (pulmonary hypertension and right sided heart failure

Question 24

These usually originate in atria or carotids. Get stuck in cerebral or ocular vessels, cause stroke and reitnal ischemia

Answer 24

Arterial emboli

Question 25

2 pathways of activation of clot cascade

Answer 25

Intrinsic: initiated by exposed collagen
Extrinsic: initiated by release of tissue factor

Question 26

What is an important component of an embolus?

Answer 26

The first capillary bed that an embolus goes into next is where it usually gets stuck.

Question 27

Vitamin K-dependent Factors __________ is by far the most sensitive. (IMPORTANT)

Answer 27

Factor VII

Question 28

____________ is where intrinsic and extrinsic factors converge/meet. (IMPORTANT)

Answer 28

Factor 10

Question 29

What are the steps of Clotting.

Answer 29

Clot retraction- after an hour (pulls vessel walls together)
Clot dissolution- fibrinolysis (healing the wound)
Tissue plasminogen activator (tPA)-clot buster
-used during strokes to try and break clot up

Question 30

What is the clot buster?

Answer 30

Tissue plasminogen activator (tPA)

Question 31

What does aspirin do?

Answer 31

Blocks Thromboxane A2 production
-stops platelets from sticking together.
Aspirin a day keeps the clots away

Question 32

What is a fast acting anti-platelet drug that inhibits factor IIa and Xa?

Answer 32

Heaprin

Question 33

What is a slow acting anti-platelet drug that inhibits vitamin K production, through Factor VII?

Answer 33

Warfarin (Coumadin)