Chapter 18: The Cardiovascular System—Blood

The volume of blood in an average adult is

Approximately 5 liters.

Three homeostatic mechanisms blood helps maintain

Temperature regulation; pH balance; Water content of cells.

A normal hematocrit is about

45% of a person’s blood.

Anemia

Deficiency of red blood cells or hemoglobin.

Pigment that gives blood its red color

Hemoglobin.

Does oxygen binding affect hemoglobin color?

Yes, oxygenated hemoglobin is bright red; deoxygenated is dark red.

Why is blood slightly warmer than body temperature?

Friction and resistance in blood flow produce heat.

Normal blood pH

7.35–7.45 (average 7.4).

Buffers in blood

Bicarbonate (HCO₃⁻) and proteins.

Nitrogenous waste from protein catabolism in blood

Urea.

Organ that produces most plasma proteins

Liver.

Three solutes making up 99% of blood plasma

Water; Proteins (mostly albumin); Electrolytes.

Process of blood cell formation

Hemopoiesis.

Stem cell that begins blood cell formation

Hematopoietic stem cell.

Formed elements from myeloid stem cells

Erythrocytes; Platelets; Granulocytes; Monocytes.

Formed elements from lymphoid stem cells

Lymphocytes (B, T, and NK cells).

Hormone involved in red blood cell production

Erythropoietin.

Organs that secrete erythropoietin

Kidneys.

Three organelles missing in red blood cells

Nucleus; Mitochondria; Endoplasmic reticulum.

Function of erythrocytes

Transport oxygen and carbon dioxide.

Iron molecules in one hemoglobin

Four.

Average RBC count in adults

About 5 million cells per microliter.

Effect of strenuous exercise or altitude on RBC count

Increases RBC count.

Effect of hemolytic anemia on RBC count

Decreases RBC count.

Process of red blood cell production

Erythropoiesis.

After birth, RBCs are formed in

Red bone marrow.

Average lifespan of an RBC

About 120 days.

Folic acid and vitamin B12 are necessary for

RBC production and DNA synthesis.

Protein that transports iron

Transferrin.

Protein that stores iron in liver

Ferritin.

One important use of iron in the body

Oxygen transport in hemoglobin.

Organs where RBCs rupture and are phagocytized

Spleen and liver.

Part of hemoglobin that forms bile pigments

Heme.

Effect of COPD or poor gas exchange on RBC count

Increases RBC count (compensatory response).

Effect of polycythemia on RBC count

Increases RBC count.

Two cytokines involved in leukocyte production

Interleukins and Colony-Stimulating Factors (CSFs).

Average WBC count in adults

5,000–10,000 cells per microliter.

Four main functions of leukocytes

Defend against pathogens; Remove wastes and toxins; Attack abnormal cells; Mediate immune responses.

Two categories of leukocytes

Granulocytes and Agranulocytes.

Cells in granulocytes

Neutrophils; Eosinophils; Basophils.

Cells in agranulocytes

Lymphocytes; Monocytes.

Basophils.

20–30% of WBCs

Lymphocytes.

2–8% of WBCs

Monocytes.

50–70% of WBCs

Neutrophils.

2–4% of WBCs

Eosinophils.

Leukocyte with bi-lobed nucleus and red granules

Eosinophil.

Smallest WBC, agranulocyte with large nucleus

Lymphocyte.

Leukocyte with multi-lobed nucleus and purple granules

Neutrophil.

Largest WBC with kidney-shaped nucleus

Monocyte.

Leukocyte with blue granules obscuring nucleus

Basophil.

WBC changes with AIDS

Decreased lymphocytes (especially T cells).

WBC changes with bacterial infection

Increased neutrophils.

WBC changes with tuberculosis

Increased monocytes.

WBC changes with coronavirus (COVID-19)

Decreased lymphocytes.

WBC changes with pinworms

Increased eosinophils.

Growth factor for platelet production

Thrombopoietin.

Average platelet count

150,000–400,000 per microliter.

Function of thrombocytes

Blood clotting and hemostasis.

Hemostasis definition

The stopping of bleeding.

Three steps in hemostasis

Vascular spasm; Platelet plug formation; Coagulation.

Difference between extrinsic and intrinsic clotting

Extrinsic triggered by external trauma and tissue factor; intrinsic triggered by damage inside vessel.

Vitamin important for clotting factor formation

Vitamin K.

Cation needed during coagulation

Calcium (Ca²⁺).

Water-soluble protein in clotting

Fibrinogen.

Insoluble protein in clotting

Fibrin.

How heparin prevents clotting

Inhibits thrombin and clot formation.

Substance that dissolves clots

Plasmin.

Blood clotting uses

Positive feedback.

Thrombus vs embolus

Thrombus is stationary; embolus travels through bloodstream.

Deep vein thrombosis (DVT)

Clot in deep veins (often legs); risk factors include immobility, surgery, obesity; symptoms include swelling, redness, pain.

Blood type with B antigens, anti-A antibodies, and Rh antigens

B+.

Blood type with anti-A and anti-B antibodies and Rh antigens

O+.

Blood type with A and B antigens, no antibodies, no Rh antigens

AB-.

Blood type with A antigens, anti-B antibodies, no Rh antigens

A-.

Blood type with anti-A and anti-B antibodies, no Rh antigens

O-.

Blood type with B antigens, anti-A antibodies, no Rh antigens

B-.

Blood type with A and B antigens, no antibodies, and Rh antigens

AB+.

Blood type with A antigens, anti-B antibodies, and Rh antigens

A+.

Why Rh- mother with Rh+ baby is dangerous

Mother’s antibodies may attack baby’s RBCs, causing hemolytic disease of the newborn.