Blood

How much is blood volume percentage wise?

8% of total body weight

What is blood volume for male vs female?

male: 5-6 liters and female: 4-5 liters

What is blood made up of?

plasma and formed elements

what is a hematocrit?

ratio of formed elements to plasma (in reality it is the % of erythrocytes

what type of tissue is blood?

connective tissue (cells in tissue are not producing the matrix/plasma

What is blood plasma? What are the 7 characteristics of blood plasma?

extracellular liquid matrix

1. water

2. over 100 different dissolved solutes

3. plasma proteins (most abundant solute in the blood)

4. electrolytes

5. nutrients

6. nitrogenous wastes

7. respiratory gases

How much, what, and why is water in blood plasma?

• Blood plasma 90% water (solvent)

• Important for transport, temperature regulation

What are the plasma proteins in blood plasma?

1. not taken up by cells and used for fuel or nutrients

2. most produced by the liver

3. Albumen: 60% of plasma proteins

4. globulins: 36% of plasma proteins

5. clotting proteins: 4% of plasma proteins

6. others: enzymes, hormones produced by other cells

Why is albumen important?

1. most important to maintain plasma osmotic pressure (to keep water in the blood)

2. transport substances

3. pH buffer

why are globulins important?

1. transport substances

2. include antibodies (protective)

Why are clotting proteins important?

1. prevent blood loss

2. include fibrinogen and prothrombin (last two of clotting sequence)

What are electrolytes in blood plasma?

sodium, potassium, calcium, bicarbonate ions

why are sodium ions important in blood plasma?

2nd major contributor to plasma osmotic pressure

why are bicarbonate ions important in blood plasma?

helps maintain normal blood pH

What nutrients are in blood plasma?

glucose, fatty acids

what nitrogenous wastes are in blood plasma?

lactic acid, creatinine, and urea (from deamination)

what respiratory gases are in blood plasma and what are they bound to?

1. carbon dioxide: bound with bicarbonate ion in plasma

2. oxygen: most bound to hemoglobin in RBC

what are the 6 characteristics of formed elements (erythrocytes)?

1. biconcave discs with thin centers

2. no mitochondria

3. few other organelles

4. no nucleus

5. all blood cells arise from same “stem cell”: hemocytoblast

6. once committed to a certain cell pathway a stem cell can not change back

what is important about biconcave discs with thin centers?

perfect shape for gas exchange (huge surface area: 30% more than a spherical shape)

what is important about RBCs not having mitochondria?

1. generate ATP anaerobically

2. do not consume any oxygen (perfect for gas transport)

what is important about RBCs having few other organelles?

discounting water, RBCs are 97% hemoglobin

what is important about RBCs not having a nucleus?

1. can not divide

2. lifespan is 120 days

3. formed in red bone marrow by erythropoiesis

4. spleen takes RBCs out of body, keeps iron and reuses it, throws rest of RBC as waste into blood, liver takes out the waste

what is important about stem cell commitment to a certain pathway?

1. takes 15 days to go from hemocytoblast to reticulocyte

2. reticulocyte is a young RBC

3. reticulocytes become full mature 2 days from release

4. reticulocyte count is used as an index of the rate of RBC formation (should be 1-2% of all RBCs)

What are the 3 characteristics of formed elements: thrombocytes?

1. stem cell forms a megakaryoblast

2. platelets are cell fragments that rupture from megakaryoblast extensions

3. function in hemostasis (stoppage of bleeding)

How does the stem cell form a megakaryoblast?

by repeated mitosis with no cell division

what are characteristics of platelets?

1. no nucleus

2. degenerate in 10 days if not involved in clotting and less than 10 if involved

3. contain actin and myosin

what is platelets function in hemostasis?

mostly involved in forming the temporary plug

what are 3 phases in hemostasis?

1. vascular spasms

2. platelet plug formation

3. coagulation (blood clotting)

what are the 6 steps of platelet plug formation?

1. injury to the lining of a vessel exposes collagen

2. platelets swell, form spiky processes, and stick to collagen

3. release several chemicals

4. positive feedback system: more platelets are attracted

5. within 1 minute, platelet plug formed (temporary)

6. limited to intermediate area by a chemical (prostacyclin or PGI2) produced by endothelial cells of vessel lining

what is coagulation and some characteristics?

1. blood transformed from a liquid into gel

2. involve 30 different procoagulants (clotting factors)

3. vitamin K is required for the synthesis of 4

4. final reactions: chemicals released from platelets in the presence of calcium ions cause the formation of prothrombin activator

5. If you can’t make 1 of the 30 clotting factors, you won’t be able to clot

Last two reaction of clotting factor reactions

1. prothrombin activator activates prothrombin (plasma protein) into thrombin (active enzyme)

2. thrombin activates fibrinogen (plasma protein soluble) into fibrin (insoluble)

what is fibrin and characteristics?

1. insoluble threads

2. glue platelets in clot together

3. plasma becomes gel like

4. forms a web and traps formed elements that try to pass through

how fast does clot form and stabilize?

it forms and stabilizes in 3-6 minutes after vessel damage (does not mean permanence)

what is clot retraction?

1. actin and myosin in platelets contract

2. pull on fibrin strands and squeeze out serum (serum: plasma without clotting factors)

What are 2 characteristics of formed elements: leukocytes?

1. only formed elements that are complete cells (have nuclei and organelles)

2. only 1% of total cells (5 types of cells though)

what are the 5 types of leukocytes?

1. neutrophil

2. eosinophil

3. basophil

4. lymphocyte

5. monocyte