Human Physiology: Blood & Circulation

Key Concepts on Human Physiology: Blood and Circulation

• Blood: A specialized connective tissue composed of plasma and blood cells.
• Plasma: The liquid component of blood, primarily water (90-92%) with dissolved nutrients, hormones, and waste products.
• Coronary Circulation: Supplies blood to heart muscle (myocardium).
• Systemic Circulation: Blood flow from the left ventricle to body tissues.
• Pulmonary Circulation: Blood flow from the right ventricle to the lungs for oxygenation.
• Baroreceptors: Sensory nerve endings that help regulate blood pressure.
• Cardiac Cycle: The sequence of events in one heartbeat, including systole and diastole phases.
• Erythropoiesis: Formation of red blood cells in the bone marrow.
• Heart Structure: Composed of four chambers (two atria and two ventricles) with valves to ensure unidirectional blood flow.

Functions of Blood

• Transportation: Carries oxygen, nutrients, hormones, and waste products.
• Regulation: Helps maintain pH, temperature, and osmotic balance.
• Protection: Immune function through white blood cells (WBCs) and clotting via platelets.

Blood Composition

• Red Blood Cells (RBCs): Transport oxygen; lack a nucleus in mammals.
• White Blood Cells (WBCs): Crucial for immune responses; exist in various forms (e.g., neutrophils, lymphocytes).
• Platelets: Cell fragments important for clotting processes.

Maintenance of Blood Pressure

• Systolic Pressure: Pressure during heart contraction.
• Diastolic Pressure: Pressure during heart relaxation.
• Regulated by Baroreceptors: Send signals to the central nervous system to adjust heart rate and blood vessel dilation.

Heart Disease Overview

• Types of Heart Disease: Includes coronary artery disease, heart failure, arrhythmia, heart attacks.
• Risk Factors: High cholesterol, hypertension, smoking, diabetes, obesity, family history.
• Symptoms of Heart Attack: Chest pain, discomfort in other body areas, shortness of breath, nausea.

Treatment Options

• Pacemaker: Device implanted to regulate heartbeat.
• Angioplasty: Procedure to open blocked coronary arteries.
• Coronary Bypass Surgery: Creating a new route for blood to reach the heart muscle when arteries are blocked.
• Heart Transplant: Replacing a damaged heart with a healthy one.

Treatment Considerations

• Open Heart Surgery Types: On-pump, Off-pump, Robot-assisted.
• Post-operative care: Includes monitoring, diet modifications, and gradually increasing physical activity.

Practical Skills

• Identifying Blood Cell Types: Utilize a microscope to view blood slides and distinguish between various blood cells.