Anatomy and Physiology Chapter 19

functions of blood

1. transport of gases, nutrients, and waste products

2. regulation of pH and osmosis

3. maintenance of body temperature

4. protection against foreign body substances

5. clot formation

examples of gases, nutrients, and waste products

oxygen, vitamin D, and CO2

normal pH of most body tissues

7.35 to 7.45

maintenance of body temperature

warm blood shunted to the interior of the body

protection against foreign body substances

antibodies

clot formation

hemostasis

plasma

liquid part of blood; 91% water; remainder is proteins, ions, nutrients, waste products, gases, and regulatory substances

plasma proteins

albumins, globulins, and fibrinogens

albumins

regulate viscosity and osmotic pressure

globulins

transports lipids, carbohydrates, hormones, ions, and antibodies

fibrinogens

involved in blood clotting

function of plasma ions

involved in osmosis, membrane potentials, and acid-base balance

examples of plasma ions

Ca+ and Na+

plasma nutrients

glucose, amino acids, cholesterol, and vitamins

plasma waste products

urea, uric acid, bilirubin, and lactic acid

uric acid

breakdown products of protein metabolism

bilirubin

breakdown products of RBCs

lactic acid

end product of anaerobic respiration

plasma gases

oxygen and carbon dioxide

plasma regulatory substances

hormones and enzymes

formed elements

red blood cells (erythrocytes)

white blood cells (leukocytes)

platelets (thrombocytes)

red blood cells (erythrocytes)

biconcave discs, anucleate, contain hemoglobin, and transport CO2 and O2

types of white blood cells (leukocytes)

granulocytes and agranulocytes

granulocytes

cytoplasm contains large granules and has a multilobed nuclei

3 distinctive types of granulocytes

neutrophils, eosinophils, and basophils

agranulocytes

cytoplasm contains small, granules and nuclei not lobed

2 distinctive types of agranulocytes

lymphocytes and monocytes

platelets (thrombocytes)

cell fragments that form platelet plugs and release chemicals

another name for hematopoeisis

hemopoiesis

hematopoesis

process of blood cell production

stem cells

proerythroblasts

myeloblasts

lymphoblasts

monoblasts

megakaryoblasts

proerythroblasts

develop into red blood cells

myeloblasts

develop into basophils, neutrophils, and eosinophils

lymphoblasts

develop into lymphocytes

monoblasts

develop into monocytes

megakaryoblasts

develop into platelets

red blood cells

found in higher concentration in male than in female plasma

components of red blood cells

1/3 hemoglobin and 2/3 lipids

red blood cell function

transport oxygen from lungs to tissues

transport carbon dioxide from tissues to lungs

transportation of oxygen from lungs to tissues by RBCs

98.5% attached to hemoglobin

1.5% dissolved in plasma

transportation of carbon dioxide from tissues to lungs by RBCs

7% in plasma

23% with O2 in hemoglobin

70% transported as bicarbonate ions

blood constitution of total body weight

8%

number of RBCs in females

4.8 million

number of RBCs in males

5.4 million

rate of RBC production

replenishes 3 million RBCs per second

hematocrit

47% for males and 42% for females

oxyhemoglobin

transports oxygen

deoxyhemoglobin

low volume

carbaminohemoglobin

transports carbon dioxide

hemoglobin composition

four globin molecules (polypeptide chains), four heme molecules, and iron

globin molecule

transports CO2 (carbonic anhydrase involved)

heme molecule

each contains one iron atom and transports oxygen

hemoglobin iron function

required for oxygen transport; absorbed in small intestine; lost in urine, feces, menstrual fluid

length of RBCs in circulation (enucleated)

120 days

erythropoiesis

production of red blood cells

production of red blood cells

1. stem cells

2. proerythroblasts

3. early erythroblasts

4. intermediate erythroblasts

5. late erythroblasts

6. reticulocytes

erythropoietin

hormone stimulates RBC production; produced by kidneys in response to low blood O2 levels; production takes place in the red bone marrow

anemia

a decrease in the normal number of RBCs; this results in a decreased ability of the blood to transport oxygen

hypoxia

a condition of insufficient oxygen concentration; even if the number of RBC count is normal

white blood cells

protect body aganist microorganisms and remove dead cells and debris

movement of white blood cells

ameboid, diapedesis, and chemotaxis

ameboid movement

pseudopods walking with false feet

diapedesis

elongate and move either between or through endothelial cells of capillaries passing through membranes; leukocytes squeeze between the cells of a capillary wall and enter the tissue space outside the blood vessel

chemotaxis

attraction to and movement toward foreign materials or damaged cells

life span of leukocytes

very short, generally only a few days in a healthy body; in a period of an infection only a few hours

normal amount of leukocytes

5K-10K/cubic mm

leukocytosis

above 10K/cubic mm

leukopenia

below 5K/cubic mm

neutrophils

become motile, phagocytize bacteria; lasts 1 to 2 days

contribution of neutrophils to total WBC count

60-70%

neutrophil function

phagocytize antigen-antibody complexes and other foreign matter; secrete lysozyme

eosinophils

leave circulation and enter tissue during inflammatory response; prevalent in allergic reactions

contribution of eosinophils to total WBC count

2-4%

eosinophil function

release chemicals that help destroy tapeworms, flukes, pinworms, and hookworms

basophils

least common; inflammatory response and allergic reactions

contribution of basophils to total WBC count

less than 1%

basophil function

produce histamine and heparin

lymphocytes

responsible for antibody production; principle cells of immune system

contribution of lymphocytes to total WBC count

20-25%

lymphocyte function

forms B and T cells

monocytes

become macrophages; phagocytic cells

contribution of monocytes to total WBC count

3-8%

monocyte function

break down antigens, present them to lymphocytes for recognition

platelets

cell fragments pinched off from megakaryocytes in red bone marrow; important in preventing blood loss; form platelet plugs; promote formation and contraction of clots

normal amount of platelet cells

130-160K/cubic mm

WBC acryonym

Never: neutrophils (highest concentration)

Let: lymphocytes

Monkeys: monocytes

Eat: eosinophils

Bananas: basophils (lowest concentration)

hemostasis

arrest of bleeding

events preventing excessive blood loss

vascular spasm, platelet plug formation, and coagulation or blood clotting

vascular spasm

vasoconstriction of damaged blood vessels

coagulation

normally blood maintains its liquid state as long as it remains in the vessels; thickens and forms a gel out of the body

thrombosis

clotting in unbroken vessel; blood clots too easily

stages of coagulation

1. activation of prothrombinase

2. conversion of prothrombin to thrombin

3. conversion of fibrinogen to fibrin

coagulation factors

proteins found in plasma; circulate in inactive state until tissues are injured; damaged tissues and platelets produce chemicals that begin activation of the factors

coagulation pathways

extrinsic and intrinsic

result of coagulation

blood clot

blood clot

a network of threadlike fibrin fibers, trapped blood cells, platelets, and fluid

extrinsic clotting pathway

begins with chemicals outside of blood; has 3 stages

stage 1 of extrinsic clotting pathway

1. damaged tissues release tissue factor (TF; factor III)

2. when Ca2+ is present, forms complex with factor VII, activating factor X

3. prothrombinase is formed

stage 2 of extrinsic clotting pathway

prothrombinase converts prothrombin into thrombin

stage 3 of extrinsic clotting pathway

1. thrombin converts fibrinogen to fibrin

2. thrombin activates factor XIII which stabilizes clot