A & P 2 Quiz 2

Front 1

Functions and Properties of Blood

Back 1

Involved in respiration, nutrition, waste elimination, thermoregulation, immune defense, water and acid-base balance, and internal communication.

Front 2

Plasma

Back 2

clear extracellular fluid, makes up 55% of blood volume.

Front 3

Formed elements

Back 3

blood cells and platelets, makes up the remaining 45%

Front 4

Viscosity

Back 4

resistance of a fluid to flow due to cohesion between its particles (i.e. fluid thickness). Blood is 4.5-5.5 as viscous as water due to plasma proteins and formed elements. Any change in viscosity can put strain on the heart and lead to cardiovascular problems.

Front 5

Osmolarity

Back 5

total molarity of dissolved particles in a fluid. The relative osmolarity between blood and tissues affects the rate and direction of fluid transfer.

Front 6

High blood osmolarity

Back 6

draws fluid from tissues and causes high blood pressure

Front 7

Low blood osmolarity

Back 7

keeps fluid in tissues and causes swelling (edema).

Front 8

Blood osmolarity is a product of

Back 8

sodium ions, proteins and red blood cell levels.

Front 9

Plasma proteins

Back 9

3 major categories of plasma proteins: albumins (transport), globulins (transport, defense), and fibrinogen (clotting).

Front 10

Nonprotein nitrogenous substances

Back 10

amino acids come from catabolism of proteins and nitrogenous wastes are toxic products of amino acid catabolism.

Front 11

hemopoiesis

Back 11

production of formed elements of blood

Front 12

Hemocytoblasts

Back 12

stem cells that constantly multiply and are capable of differentiation into cell lines that give rise to all the formed elements.

Front 13

Erythrocyte (red blood cell) production

Back 13

1. Hemocytoblasts differentiate into proerythroblasts which possess receptors for the hormone erythropoietin (EPO). EPO is secreted by the kidneys.
2. EPO stimulates proerythroblasts to become erythroblasts which then multiply and synthesize hemoglobin (iron-containing pigment that transports oxygen in red blood cells).
3. The nucleus and ER of the erythroblasts degenerate to form the mature erythrocyte in the bloodstream.
4. Lowered oxygen levels in the blood cause increased secretion of EPO and subsequent increase of RBCs in the blood.
5. Vitamins C, B12, folic acid, copper and iron are all necessary for erythropoiesis and hemoglobin synthesis and must be acquired in the diet.

Front 14

Leukocyte (white blood cell) production

Back 14

1. Hemocytoblasts differentiate into 3 types of progenitor cells.
a. B progenitors- become B lymphocytes.
b. T progenitors- become T lymphocytes.
c. Granulocyte-macrophage colony-forming units- become granulocytes and monocytes.
2. All these progenitor cells possess receptors for colony-stimulating factors (CSFs). Different CSFs stimulate production of different leukocytes dependent on the body’s immunity needs.

Front 15

Platelet production

Back 15

thrombopoiesis. Platelets are not true cells.
1. Hemocytoblasts differentiate into megakaryoblasts which possess receptors for the hormone thrombopoietin. Thrombopoietin is secreted by the liver and kidneys.
2. When the megakaryoblast receives thrombopoietin, it becomes an enormous cell called a megakaryocyte, with multiple sets of chromosomes. Platelets are fragments of cytoplasm and plasma membrane that break off from the megakaryocyte.

Front 16

Erythrocytes

Back 16

have two principal functions: to deliver oxygen from the lungs to tissues and to deliver carbon dioxide from the tissues to the lungs.
A. Red blood cells are disc-shaped with a thick rim and a sunken center due to the loss of the nucleus. This biconcave shape increases the cell’s surface area and speed of gas transfer.
B. The plasma membrane of an erythrocyte contains glycoproteins and glycolipids that determine a person’s blood type.
C. Erythrocytes contain peripheral proteins actin and spectrin that allow them to survive folding, stretching and bending as they pass through capillaries.
D. RBCs possess almost no organelles and use only anaerobic fermentation to produce ATP.
E. The cytoplasm of an erythrocyte is 33% hemoglobin, the red pigment that gives the cell its name.
F. Hemoglobin- consists of 4 protein chains called globins, each with a ferrous ion (Fe+2) attached to it (the heme group).
1. Each heme group can carry one molecule of O2.
2. Each erythrocyte contains about 280 million molecules of hemoglobin.
3. Hemoglobin carries about 20% of the blood CO2 by binding it to the globins.

Front 17

erythrocytes have an average lifespan of

Back 17

120 days. Because they have no nucleus, they cannot produce proteins to repair themselves.

Front 18

where are the majority of RBCs removed from the blood stream?

Back 18

by the spleen.
2. Macrophages in the spleen digest plasma membrane fragments and break the hemoglobin into heme groups and globins.
3. Globins are broken down into amino acids and re-asbsorbed by the body.
4. Iron from the heme group is recycled and the rest is turned into bile pigments, which are collected by the liver and made into bile.

Front 19

Blood types

Back 19

A, B, AB and O based on the glycoproteins and glycolipids (antigens) on the surface of red blood cells. They are 3 forms of the same gene. A and B are dominant over O but are equally expressed together (type AB blood).

Front 20

Antigens

Back 20

can be recognized by the body’s immune system and attacked by antibodies that are keyed to that specific antigen.