Chapter 19 - Blood

Question 1

Circulatory Functions

Answer 1

1. Transport
2. Protection
3. Regulation

Question 2

Circulatory Function: Transport

Answer 2

move respiratory gases (O2, CO2), nutrients, wastes, hormones, stem cells

Question 3

Circulatory Function: Protection

Answer 3

• clotting prevents blood loss

- inflammation, WBCs, and antibodies fight toxins and infections

Question 4

Circulatory Function: Regulation

Answer 4

• balancing of fluid levels, pH, and temperature

Question 5

Components of Blood

Answer 5

1. Plasma - clear, extracellular fluid (matrix)
2. Formed elements:
   
   • Cells and cell fragments
   • Erythrocytes (RBCs)
   • Leukocytes (WBCs)
   • Platelets (fragments of bone marrow)

Question 6

Blood Plasma

Answer 6

• makes up little more than half of whole blood
• serum is plasma minus solids
• mostly water (92% by weight)
  
  • proteins: albumins, globulins, fibrinogen, enzymes…
  • nutrients: glucose, amino acids, lactic acid, lipids…
  • electrolytes: salts of Na, K, Mg, Ca, Cl…
  • nitrogenous wastes: urea and others
  • hormones
  • gases: O2, CO2, N

Question 7

Albumin

Answer 7

• 60%
• major contributor to blood viscosity and osmolarity; transports lipids, hormones, calcium, and other solutes; buffers blood pH

Question 8

Globulins

Answer 8

• 36%
• alpha globulins:
  
  • haptoglobulin
  • ceruloplasmin
  • prothrombin
  • others
• beta globulins:
  
  • transferrin
  • complement proteins
  • others
• gamma globulins

Question 9

Haptoglobulin

Answer 9

• alpha globulin

- transports hemoglobin released by dead erythrocytes

Question 10

Ceruloplasmin

Answer 10

• alpha globulin

- transports copper

Question 11

Prothrombin

Answer 11

• alpha globulin

- promotes blood clotting

Question 12

“Other” Alpha Globulins

Answer 12

transport lipids, fat-soluble vitamins, and hormones

Question 13

Fibrinogen

Answer 13

• 4%

- becomes fibrin, the major component of blood clots

Question 14

Erythrocytes

Answer 14

• red blood cells
• carry O2 and CO2
• discoid shape
• lacks nucleus, mitochondria, other organelles
• carries millions of hemoglobin molecules
• molecules on membrane determine blood type

Question 15

Quantity of Erythocytes

Answer 15

• RBC count:
  
  • Men: 4.6-6.2 million RBCs/micro liter
  • Women: 4.2-5.4 million RBCs/micro liter
• Hematocrit (packed cell volume)
  
  • Men: 45-52%
  • Women: 37-48%

Question 16

Hemoglobin

Answer 16

• iron-containing gas-transport protein
• found in RBC
• four globins with a heme group
• ferrous ions in center bind oxygen

Question 17

Hemopoiesis

Answer 17

• production of blood
• myeloid hemopoiesis (all types of formed elements) occurs in red bone marrow
• lymphoid hemopoiesis (lymphocytes) in lymphatic organs

Question 18

Erythropoiesis

Answer 18

• production of RBCs
• originate from hemopoietic stem cells
• erythropoiesis process lasts 3-5 days
• lifespan of RBC is approx. 120 days

Question 19

Blood Types

Answer 19

• several genetically determined blood groups with multiple types
• ABO and Rh most common
• RBC contains glycolipid antigens on membrane
• plasma contains antibodies that react against foreign antigens

Question 20

Leukocytes

Answer 20

• white blood cells (WBCs)
• protect against pathogens
• least abundant of the formed elements
• migrate out of the bloodstream into connective tissues
  
  • Kupffer cells, mast cells, macrophages in the lung, etc.
• agrnulocytes:
  
  • lymphocytes and monocytes
• granulocytes:
  
  • neutrophils, eosinophils, and basophils

Question 21

Neutrophils

Answer 21

• 60-70% of WBCs
• 4150 cells/micro liter
• 9-12 micrometer diameter
• nucleus with 3-5 lobes in S- or C-shaped array
• fine reddish to violet specific granules in cytoplasm
• differential count increases in bacterial infections
  Functions:
  
  • phagocytize bacteria
  • secrete antimicrobial chemicals

Question 22

Eosinophils

Answer 22

• 2-4% of WBCs
• 170 cells/micro liter
• 10-14 micrometer diameter
• nucleus usually with two large lobes connected by thin strand
• large orange-pink specific granules in cytoplasm
• differential count fluctuates greatly for variety of reasons
  Functions:
  
  • phagocytize antigen-antibody complexes, allergens, and inflammatory chemicals
  • secrete enzymes that weaken or destroy parasites such as worms

Question 23

Basophils

Answer 23

• 3-8% of WBCs
• 40 cells/micro liter
• 8-10 micrometer diameter
• nucleus large and irregularly shaped, but typically obscured from view
• coarse, abundant, dark violet specific granules in cytoplasm
• differential count relatively stable (increases in chickenpox, sinusitis, diabetes mellitus, myxedema, and polycythemia)
  Functions:
  
  • secretes histamine (vasodilator)
  • secretes heparin (anticoagulant - promotes mobility of other WBCs by preventing clotting)

Question 24

Monocytes

Answer 24

• 3-8% of WBCs
• 460 cells/micro liter
• 12-15 micrometer diameter
• nucleus ovoid, kidney-shaped, or horseshoe-shaped
• abundant light violet cytoplasm with sparse, fine, nonspecific granules
• sometime very large with stellate or polygonal shapes
• differential count increases with infections and inflammation
  Functions:
  
  • differentiate into macrophages
  • phagocytize pathogens, dead neutrophils, and debris of dead cells
  • present antigens to activate other cells of immune system

Question 25

Lymphocytes

Answer 25

- 25-33% of WBCs - 2200 cells/micro liter - Diameters: * small class = 5-8 micrometers * medium class = 12-12 micrometers * large class = 14-17 micrometers - nucleus round, ovoid, or slightly dimples on one side - uniform dark violet color nucleus with light blue cytoplasm (small class = very little cytoplasm) - differential count increases in diverse infections and immune responses Functions: * several functional classes * destroy cancer cells, cells infected with viruses, and foreign cells * present antigens to activate other immune cells * coordinate actions of other immune cells * secrete antibodies * serve in immune memory

Question 26

Leukocyte Life Cycle

Answer 26

- leukopoiesis - production of WBCs - granulocytes and monocytes stay in red marrow until needed - B lymphocytes and natural killer cells mature in bone marrow - T lymphocytes mature in thymus - Leukocyte life span ranges (few days to decades)

Question 27

Platelets

Answer 27

- small fragments of megakaryocytes that aid in blood clotting - NO nucleus but do have other organelles, an open canlicular system, and pseudopods (when activated) Functions: * clot formation * vasoconstriction * clot dissolving * destruction of bacteria * stimulation of mitosis for healing

Question 28

Platelet Production

Answer 28

- thrombopoiesis - some hematopoietic stem cells become megakaryoblasts - megakaryocotes sprout proplatelet tendrils in red marrow - many proplatelets are broken into platelets within lung capillaries

Question 29

Hemostasis

Answer 29

- hemostsis - cessation of bleeding - platelets release serotonin and clotting factors - serotonin triggers vasoconstriction - platelet plug seals vessels - clotting factors convert fibrinogen to sticky fibrin - once crisis passes, platelets secrete growth factors to trigger healing and other factors that cause dissolving of the clot

Question 30

Hematology in Old Age

Answer 30

- elderly do not adapt well to stresses on hemopoietic system due to many possible causes: * inadequate nutrition * inadequate exercise * atrophy of the kidneys * limited number of cell divisions of stem cells - thrombosis = abnormal clotting in unbroken vessels (can cause stroke, heart failure)

Question 31

Erythrocyte Disorders

Answer 31

- Anemia = decreased oxygen carrying * depressed erythropoiesis or hemoglobin synthesis * hemolysis * hemorrhage - Polycythemia = excessive RBCs * cancer of bone marrow

Question 32

Leukocyte Disorders

Answer 32

- Leukopenia = WBC deficiency * heavy metal poisoning * radiation exposure * AIDS - Leukemia = high WBC counts * cancer of hematopoietic tissue

Question 33

Thrombocytopenia

Answer 33

- platelet deficiency - leukemia - radiation