Chap 2 A&P II

Blood

A fluid connective tissue consisting of living cells and a non-living matrix.

Functions of blood

Transportation (O2, CO2, nutrients, waste, hormones), regulation (fluid levels, pH, body temp), and protection (against disease, infection).

pH of blood

7.35-7.45, slightly alkaline.

Plasma

Liquid component of blood, consisting of ~92% H2O and 8% solutes (mostly proteins).

Hemopoiesis

The process of blood cell formation.

Erythropoietin (EPO)

A hormone secreted by the kidneys that increases the rate of RBC maturation.

Erythrocytes (RBCs)

Red blood cells that are biconcave discs, anucleate, and carry oxygen via hemoglobin.

Hemoglobin (Hb)

A protein in RBCs that binds oxygen; can carry 4 O2 molecules per Hb.

Lifespan of RBCs

Approximately 120 days before being recycled in the spleen.

Anemia

A condition where the oxygen carrying capacity of blood is compromised.

Types of anemia

1. Hemorrhagic anemia, 2. Decrease in RBC production, 3. Hemolytic anemia.

Leukocytes (WBCs)

White blood cells that have a nucleus and defend against infections.

Granulocytes

A class of leukocytes with cytoplasmic granules that stain; includes neutrophils, eosinophils, and basophils.

Agranulocytes

A class of leukocytes without visible cytoplasmic granules; includes lymphocytes and monocytes.

Phagocytosis

The process by which cells eat and destroy foreign microorganisms.

Platelets (Thrombocytes)

Small pieces of megakaryocytes that play a crucial role in blood clotting.

Hemostasis

The process of stopping bleeding, which includes vascular spasm, platelet plug formation, and coagulation.

Hypoxia

A deficiency in the amount of oxygen reaching the tissues, stimulating EPO secretion.

Natural killer cells

A type of lymphocyte that kills tumor cells and microorganisms.

Platelet aggregation

The clumping together of platelets in the blood, crucial for forming a blood clot.

Coagulation cascade

A series of events involving clotting factors that lead to blood clot formation.

Fibrin

A protein that forms a mesh to strengthen and stabilize blood clots.

Blood types

Classifications of blood based on the presence or absence of antigens; includes A, B, AB, and O types.

Rh factor

An antigen that can be present (+) or absent (-) on red blood cells, important for blood transfusions.

Sickle cell anemia

A genetic disorder causing abnormal hemoglobin, leading to distorted (sickle-shaped) red blood cells.

Leukopenia

A decrease in the number of white blood cells, increasing the risk of infection.

Thrombocytopenia

A low platelet count, leading to increased risk of bleeding.

Myeloid and lymphoid lineages

The two main lineages of blood cells; myeloid produces red blood cells and some white cells, lymphoid produces lymphocytes.

Blood viscosity

A measure of the thickness of blood, affecting circulation and blood flow.