A&P II: Chapter 17 AI

Plasma (55%) + formed elements ((RBCs, WBCs, platelets 45%))

The main components of blood

Transport (O₂, nutrients), Regulation (temp, pH, fluid), Protection (clotting, immunity)

The three main functions of blood

plasma

Made up of ~90% water + proteins (albumin, globulins, fibrinogen) + nutrients, electrolytes, wastes, gases

albumin

Maintains osmotic pressure and blood volume

Erythrocyte (RBC)

Biconcave discs without nucleus → large surface for gas exchange

Hemoglobin (Hb)

This protein carries oxygen; 4 heme + globin; iron binds O₂; oxyHb = bright red, deoxyHb = dark red

hematocrit

% of blood volume made of RBCs (~45%)

Erythropoietin (EPO)

This hormone controls RBC production; Comes from kidneys and stimulates red bone marrow

Erythrocyte (RBC)

This cell lives for ~120 days; destroyed by macrophages; heme → iron (recycled) + bilirubin (excreted in bile)

Leukocyte (WBC)

This cell defends against infection and disease

Neutrophils, Lymphocytes, Monocytes, Eosinophils, and Basophils

Mnemonic for leukocytes in terms of abundance: “Never Let Monkeys Eat Bananas” means

Neutrophil

These leukocytes phagocytize bacteria (first responders)

Eosinophil

These leukocytes kill parasites; involved in allergy and asthma response

Basophil

These leukocytes release histamine and heparin during inflammation

Lymphocyte

These leukocytes mount immune response via T cells or B cells (antibody production)

Monocyte

These leukocytes become macrophages for phagocytosis of pathogens and debris

platelets

These are cell fragments from megakaryocytes

platelets

These fragments form a temporary plug and initiate clotting

hemostasis

The process to stop bleeding:

1. Vascular spasm

2. Platelet plug

3. Coagulation

Vascular spasm

First step of hemostasis

Platelet plug

Second step of hemostasis

Coagulation

Third step of hemostasis

Calcium (Ca²⁺)

Ion that is essential for clotting

Natural anticoagulants

This prevents over-clotting; Heparin, antithrombin, and protein C

fibrinolysis

Breakdown of fibrin clot by plasmin

Rh factor

Rh⁺ has D antigen; Rh⁻ lacks → important in pregnancy (HDN)

anemia

Low RBC count, low hemoglobin, or defective Hb (e.g., sickle cell, iron deficiency) leads to this

polycythemia

Excess RBCs → ↑ viscosity; can occur at high altitudes

leukemia

Cancer of leukocytes producing immature non-functional cells

Complete blood count (CBC)

Anemia, infection, clotting issues, immune status is revealed by this

chemotherapy

This treatment destroys rapidly dividing cells → ↓ RBCs, WBCs, platelets.

transfusion reaction

Incompatible blood causes agglutination and hemolysis → renal failure/shock

4.5–5.5 mil/µL

Normal values of erythrocytes

4.8–10.8 k/µL

Normal values of leukocytes

150–400 k/µL

Normal values of platelets

7.35–7.45

Normal values of pH