Blood and Hematopoesis

Question 1

what are 4 important functions of the blood system?

Answer 1

• gas exchange
• immunity
• tissue repair and regeneration
• tissue homeostasis

Question 2

what are characteristics of plasma?

Answer 2

• nutrients
• waste
• signaling
• 55% of blood components

Question 3

what are characteristics of RBCs?

Answer 3

• oxygen transport
• CO2 conversion
• 45% of blood components

Question 4

what are characteristics of white blood cells?

Answer 4

• immunity
• clotting and repair
• signaling
• part of buffy coat
• <1% of blood components

Question 5

what is a characteristic of platelets?

Answer 5

• hemostasis
• part of buffy coat
• <1% of blood components

Question 6

what is hematopoesis?

Answer 6

-production of blood cells (erythrocytes and leukocytes)

Question 7

where are blood cells produced?

Answer 7

• produced from hematopoetic stem cells in the bone marrow
• many mature in the periphery

Question 8

Which 3 cells are components of the adaptive immune system?

Answer 8

lymphocytes:

-plasma cell, T cell, and NK cell

Question 9

Which 5 cells are components of the innate immune system?

Answer 9

monocytes:

• macrophage
• dendritic cell

granulocytes:

• neutrophil
• eosinophil
• basophil

Question 10

which 3 cells that assist in hematopoesis reside in the bone marrow?

Answer 10

stem cells, progenitor cells, and blast cells

Question 11

what are some important characteristics of erythrocytes?

Answer 11

• packed with hemoglobin
• carbonic anhydrase
• CO2 exchange
• high surface area to volume ratio
• flexible
• no nucleus or organelles

Question 12

what is the lifespan of a typical erythrocyte?

Answer 12

• 120 days
• 1-2% of total volume is replaced daily

Question 13

what is hematocrit?

Answer 13

• erythrocyte blood count
• between 40-50%
• can be influenced by environmental factors

Question 14

what hormone drives erythropoesis?

Answer 14

erythropoietin (EPO)

Question 15

T or F: hypoxia increases lactic acid and EPO production

Answer 15

true

Question 16

what does the production of RBCs require?

Answer 16

• iron
• folic acid (vitamin B9)
• cobalamin (vitamin B12)

Question 17

what are the major functions of leukocytes?

Answer 17

• kill pathogens
• clear damaged tissues
• initiate cellular repair
• development
• organ homeostasis

Question 18

what are some characteristics of neutrophils?

Answer 18

• primary inflammatory cell (“first responders”)
• granulocyte
• multilobed nuclei
• several effector mechanisms, including phagocytosis, degranulation, and net formation
• restricted to vasculature
• must be recruited to sites of inflammation

Question 19

what are some characteristics of granulocytes?

Answer 19

• 3 major classes: mast cells, basophils, and eosinophils -dense granules that contain antimicrobials, NTs, pro-inflammatory signals, and growth factors
• degranulation upon activation
• predominantly reside in peripheral tissues
• respond to parasites and worms

Question 20

what are some characteristics of monocytes?

Answer 20

• differentiate into macrophages or dendritic cells
• kill pathogens, clear debris
• phagocytose antigens
• activate the adaptive immune system (lymphocytes)

Question 21

what are some characteristics of lymphocytes?

Answer 21

• T cells, B cells, and NK cells
• adaptive immune system
• cellular: T cells and NK cells
• humoral: B cells
• pathogens and diseased self-tissue
• immune memory (basis of immunizations)
• often require monocyte activation

Question 22

what are some characteristics of megakaryocytes?

Answer 22

• reside within the bone marrow
• secrete platelets

Question 23

what are platelets?

Answer 23

• small cell fragments
• organelles, but no nucleus
• involved in hemostasis
• necessary for clot formation and removal
• form plugs
• contain protein-rich granules
• involved in the inflammatory response
• structural-protein dense

Question 24

what is hemostasis, and what are the three mechanisms that drive it?

Answer 24

prevention of blood loss

1) vascular constriction
2) platelet plug
3) coagulation - fibrin matrix formation and fibroblast recruitment

Question 25

draw the coagulation pathway

Answer 25

Question 26

what two pathways produce prothrombin activator?

Answer 26

1) intrinsic pathway - begins in the blood
2) extrinsic pathway - begins at the site of tissue trauma

*these pathways function simultaneously

Question 27

what do the intrinsic and extrinsic pathways produce, and what are some simiilarities of these pathways?

Answer 27

• leads to the production of prothrombin activator
• most factors in pathway are proteases
• vitamin K is essential
• fibrinolysis degrades the fibrin meshwork