Exam 2 (Lecture 9)

Question 1

What is the significance of edema?

Answer 1

1) Can be fatal if it occurs in the lungs or brain

2) It can cause damage such as compartment syndrome (muscle necrosis and tendon damage)

3) It can be an indication of an underlying disease:
- Protein loss (in kidney or GI)
- Lack of production by liver (hepatic failure)

*MAY be reversible IF primary cause is eliminated.

Question 2

What are the consequences of dehydration?

Answer 2

Decreased:
- cardiac output
- blood volume
- tissue perfusion
- renal function

*10-12% dehydration can be fatal

Question 3

How do you recognize dehydration?

Answer 3

CBC/Chem:
- Increased solids in blood (increased PCV)
- Increased albumin (increased density of proteins; hypoproteinemia

Clinical Signs:
- Skin tenting
- Tacky gums
- Sunken eyes
- Increased CRT (should be < 2 seconds)

Question 4

What is hyperemia?

Answer 4

Increased amount of blood in tissues within vessels
- Red color to skin

Question 5

What is active hyperemia?

Answer 5

Increased ARTERIAL blood in capillary beds
- Bright red
- Warm

Physiologic:
- Exertion (exercises)
- Blushing

Pathologic:
- Inflammation
- Hyperthermia

Question 6

What is passive hyperemia?

Answer 6

Increased VENOUS blood in capillary beds
- Decreased venous blood flow OUT of capillary bed
- +/- edema
- Dark red/purple
- Cool

Question 7

What happens during hyperemia (like during inflammation or exercise)?

Answer 7

There is an increased blood flow to the area.

Question 8

What happens with congestion (like with cyanosis or hypoxia)?

Answer 8

There is a decreased outflow of blood (deoxygenated blood cannot leave)
- due to something like local obstruction or congestive heart failure

Question 9

What is the point of the coagulation cascade?

Answer 9

To make fibrin.

Question 10

What are disorders of hemostasis?

Answer 10

1) Hemorrhage
2) Thrombosis

Question 11

What causes a contusion (bruise)?

Answer 11

RBCs leave the blood vessels and go to tissues.

Question 12

What is hemostasis?

Answer 12

The arrest of bleeding from a defect in a blood vessel.

Question 13

What are the two types of hemostasis?

Answer 13

1) Primary hemostasis
2) Secondary hemostasis

Question 14

What is primary hemostasis?

Answer 14

Initial vascular and platelet response to injury
- vasoconstriction
- platelet plug

Question 15

What is secondary hemostasis?

Answer 15

Formation of fibrin
- intrinsic pathway
- extrinsic pathway

Question 16

What are the regulators of hemostasis?

Answer 16

1) Vessel wall
- Endothelial cells

2) Platelets
- Thrombocytes (fragments of megakaryocytes)
- Decrease in platelets = thrombocytopenia

3) Coagulation
- Generates fibrin
- intrinsic and extrinsic (have common pathway)

Question 17

What does the complex homeostatic mechanism allow?

Answer 17

Thrombus and antithrombotic events
- Allow clotting when necessary and keep blood flowing
- They both happen in the same places all the time

Question 18

What are the 4 basic events that occur following a vessel injury?

Answer 18

1) Vessel constriction

2) Platelet activation and aggregation
- Primary platelet plug

3) Coagulation cascade forms fibrin
- Meshwork that stabilized the primary platelet plug

4) Fibrinolysis
- When the crisis is over
- Dissolution of clot = fibrin degradation products (FDP)

Question 19

What are the steps in fibrinolysis (clot breakdown)?

Answer 19

• There are numerous activators, including histamine and ATIII

Plasminogen > Plasmin > Fibrin > Fibrin degradation products (FDPs)