Chapter 16

Question 1

Describe the composition of plasma.

Answer 1

• (mostly) water
• ions
• organic molecules
• trace elements + vitamins
• gases

Question 2

List the major functions of plasma proteins.

Answer 2

• albumins –> carriers for various substances
  - major contributions to plasma colloid
  osmotic pressure
• globulins –> clotting factors, enzymes,
  antibodies, carriers for various substances
• fibrinogen –> forms fibrin threads essential
  to blood clotting
• transferrin –> iron transport

Question 3

List the cellular elements of blood + describe the functions.

Answer 3

• red blood cells –> transport oxygen + CO2
  - aka erythrocytes
• white blood cells (5 types) –> immune function
  - aka leukocytes
• platelets –> cell fragments essential to blood
  clotting
  - aka thrombocytes

Question 4

Define hematopoiesis.

Answer 4

production of blood cells

Question 5

Define the subtypes of hematopoiesis.

Answer 5

• erythropoiesis –> production of RBC
• leukopoiesis –> production of WBC
• thrombopoiesis –> production of platelets

Question 6

What is hematopoiesis controlled by?

Answer 6

cytokines

Question 7

Where are blood cells produced?

Answer 7

in bone marrow

Question 8

Where is the site of production of erythropoietin (EPO)?

Answer 8

primarily kidney cells

Question 9

Where is the site of production of thrombopoietin (TPO)?

Answer 9

primarily liver

Question 10

Give the usefulness of a complete blood count.

Answer 10

Can help a doctor determine what aspect is not within normal range and can help with diagnosis

Question 11

Describe mature red blood cells.

Answer 11

lack a nucleus + biconcave disc shape

Question 12

Describe the importance of hemoglobin.

Answer 12

• plays a role in oxygen transport

Question 13

Describe the importance of iron.

Answer 13

iron is what allows us to bind the oxygen

Question 14

what does hematocrit show (aka packed red cell volume)?

Answer 14

see what percentage of the blood is RBCs

Question 15

A hemoglobin molecule is composed of _____ protein globin molecules, each centered around a heme group.

Answer 15

4

Question 16

What is heme?

Answer 16

a ring that contains an iron atom at its center

Question 17

How is iron transported?

Answer 17

• iron comes from diet
• transported in blood
• iron taken up in bone marrow
• excess iron stored in liver

Question 18

How long do RBCs live for?

Answer 18

about 120 days (4 months)

Question 19

What happens to remnants of heme groups?

Answer 19

they’re converted to bilirubin + excreted as bile

Question 20

Describe the production, structure, and functions of platelets.

Answer 20

• production –> 10 day life span
• structure:
  - cell fragments from megakaryocytes
  - smaller than RBCs
  - smooth until activated (“sticky” when
  activated)
• functions –> important for stopping blood
  loss, immunity, and inflammation

Question 21

Distinguish between hemostasis and coagulation.

Answer 21

hemostasis –> stops bleeding
coagulation –> clotting

Question 22

Diagram the key steps of hemostasis.

Answer 22

1) vasoconstriction
2) platelet plug –> begins w/ platelet adhesion
3) coagulation –> exposed collagen + tissue
factor lead to a clot
4) coagulation cascade

Question 23

Diagram the key steps of fibrinolysis.

Answer 23

1) Plasminogen is activated by tissue plasminogen activator (tPA)
2) broken down into plasmin
3) plasmin breaks fibrin polymer into fibrin fragments

Question 24

Diagram the key steps of coagulation.

Answer 24

1) exposed collagen binds + activates platelets
2) release of platelet factors
3) factors attract more platelets
4) platelets aggregate into platelet plug

Question 25

What converts fibrinogen to fibrin (polymerized strands)?

Answer 25

thrombin