Transport
Oxygen (O2) and nutrients delivery to cells.
Removal of metabolic wastes to lungs and kidneys for elimination.
Hormones transport from endocrine organs to target organs.
Regulation
Maintains body temperature by absorbing and distributing heat.
Maintains pH levels via buffers (normal pH 7.35-7.45).
Ensures adequate fluid volume in the circulatory system.
Protection
Prevents blood loss through clot formation initiated by plasma proteins and platelets.
Defends against infection with agents of immunity (antibodies, complement proteins, white blood cells).
Fluid Connective Tissue
Matrix: nonliving fluid (plasma)
Formed elements: living cells (erythrocytes, leukocytes, platelets).
Hematocrit Levels
Erythrocytes: ~45% of whole blood.
Normal values: Males 47% ±5%, Females 42% ±5%.
WBCs and platelets are less than 1% (Buffy coat).
Plasma makes up ~55%.
Physical Characteristics
Color varies with oxygen content: scarlet red (high O2), dark red (low O2).
Blood pH: 7.35-7.45.
Average volume: Males 5–6 L, Females 4–5 L.
Blood Plasma
Sticky, straw-colored fluid (~90% water).
Contains over 100 dissolved solutes (nutrients, gases, hormones, wastes).
Plasma Proteins
Most abundant solutes: produced mainly by the liver.
Albumin: 60% of plasma proteins, functions include carrier, blood buffer, and contributes to osmotic pressure.
Structure
Biconcave disc shape, lacks organelles, and is anucleate.
Filled with hemoglobin (Hb) for gas transport.
Function
Dedicated to respiratory gas transport.
Hb can bind up to four O2 molecules.
Production (Erythropoiesis)
Occurs in red bone marrow, takes about 15 days.
Stages include hematopoietic stem cells to proerythroblasts, then to various forms before becoming mature RBCs.
Regulation
Erythropoietin (EPO) stimulates RBC production, released by kidneys in response to low oxygen levels.
Anemia
Abnormally low O2-carrying capacity.
Types: hemorrhagic, iron-deficiency, pernicious anemia, aplastic anemia, renal anemia.
Polycythemia
Excess RBCs increase blood viscosity.
Types include polycythemia vera and secondary polycythemia due to low O2 levels.
Functions
Defense against disease.
Types: Granulocytes (neutrophils, eosinophils, basophils) and Agranulocytes (lymphocytes, monocytes).
Production
Stimulated by interleukins and colony-stimulating factors.
Myeloid stem cells and lymphoid stem cells give rise to specific types.
Steps in Hemostasis
Vascular spasm
Platelet plug formation
Coagulation
Disorders of Hemostasis
Thromboembolic disorders (thrombosis, embolism).
Bleeding disorders (thrombocytopenia, hemophilia).
Functions
Returns fluids to blood, houses immune cells.
Components
Lymphatic vessels, lymph, lymph nodes.
Lymphoid Organs
Primary: thymus, red bone marrow.
Secondary: lymph nodes, spleen, MALT.
Functions
Immune surveillance, cleanses blood, stores breakdown products (iron).
Composed of white pulp (immune function) and red pulp (destruction of aged blood cells).
Function
Maturation of T cells, with the presence of thymic corpuscles for regulatory T cells development.
Blood and Lymphatic System Review
Transport
Regulation
Protection
Fluid Connective Tissue
Hematocrit Levels
Physical Characteristics
Structure
Function
Production (Erythropoiesis)
Regulation
Anemia
Polycythemia
Functions
Production
Steps in Hemostasis
Disorders of Hemostasis