Blood and Cardiovascular System: Study Notes

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Blood is a vital connective tissue with several key components and functions essential for homeostasis and survival.

Formed Elements: Includes erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.
Plasma: The liquid matrix of blood, containing water, proteins, nutrients, hormones, and waste products.
Homeopoiesis: The process by which new blood cells are formed and regulated in number.
Functions: Distribution (transport of gases, nutrients, wastes), regulation (pH, temperature, fluid volume), and protection (immune response, clotting).

Main Function: Transport oxygen via hemoglobin; also carry some carbon dioxide.
Hemoglobin: The oxygen-carrying protein in erythrocytes.
Erythropoiesis: The process of red blood cell formation, regulated by erythropoietin (EPO).

Granulocytes: Neutrophils, eosinophils, basophils (contain granules in cytoplasm).
Agranulocytes: Lymphocytes, monocytes (lack visible granules).
Functions: Immune defense against pathogens, removal of debris.

Hemostasis is the process that stops bleeding and involves three main steps:

Vascular Spasm: Vasoconstriction to reduce blood flow.
Platelet Plug Formation: Platelets adhere to exposed collagen and release chemicals (e.g., ADP, serotonin, thromboxane A2) to attract more platelets.
Coagulation: Formation of a fibrin mesh that stabilizes the platelet plug.

Clot Retraction & Fibrinolysis: Clot contracts to reduce its size; fibrinolysis dissolves the clot after healing.

Heart Coverings: Pericardium (fibrous and serous layers).
Heart Wall: Epicardium, myocardium, endocardium.
Chambers: Right and left atria, right and left ventricles.
Valves: Ensure unidirectional blood flow (tricuspid, bicuspid/mitral, pulmonary, aortic).

Right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle → aorta → body.

Name	Location
Tricuspid Valve	Between right atrium and right ventricle
Pulmonary Valve	Between right ventricle and pulmonary artery
Bicuspid (Mitral) Valve	Between left atrium and left ventricle
Aortic Valve	Between left ventricle and aorta

Cardiac Cycle: Sequence of events in one heartbeat (systole and diastole).
Conduction System: SA node → AV node → bundle of His → bundle branches → Purkinje fibers.
ECG (Electrocardiogram): Measures electrical activity of the heart (P wave, QRS complex, T wave).

Arteries: Carry blood away from the heart.
Veins: Return blood to the heart.
Capillaries: Sites of exchange between blood and tissues.
Vessel Wall Layers: Tunica intima, tunica media, tunica externa (adventitia).

Blood Pressure (BP): Force exerted by blood on vessel walls.
Determinants: Cardiac output (CO), blood volume, peripheral resistance (PR).
Formula:

Regulation: Neural (baroreceptors, vasomotor center), hormonal (ADH, aldosterone), and renal mechanisms.

Additional info: The sum of extracellular and intracellular fluid equals total body water (about 40L in an average adult).