1. Chapter 8 - circulation (1)
Chapter 8: The Heart
Superior Vena Cava: Brings blood from the head and arms to the heart.
Inferior Vena Cava: Brings blood from the body and legs to the heart.
Aortic Arch: Distributes oxygen-rich blood from the heart to the body.
Pulmonary Arteries: Carry deoxygenated blood from the heart to the lungs.
Pulmonary Veins: Carry oxygenated blood from the lungs back to the heart.
Page 2: Overview of Circulatory System
Key Objectives:
Identify major structures of the circulatory system.
Describe the structure and function of blood vessels.
Explain heart action and blood circulation.
Investigate heart rate, blood pressure, and their relationship with exercise.
Identify circulatory system disorders.
Page 3: Main Functions of the Circulatory System
The circulatory system has three primary functions:
Transportation: Delivers oxygen and nutrients to cells, removes waste products.
Temperature Regulation: Maintains stable internal body temperature.
Protection: Prevents blood loss and combats infections.
Page 4: The Human Heart
Structure: Muscular organ roughly the size of a fist, encased in a fluid-filled membrane (pericardium).
Tissue: Comprised of cardiac muscle tissue, which contracts involuntarily.
Page 5: Heart Chambers
Four Chambers:
Two Atria (upper, left and right sides)
Two Ventricles (lower, left and right sides)
Septum: Thick wall separating the right and left chambers of the heart.
Page 6: Circulation in the Heart
Blood flow pathway through the heart and associated veins/arteries (e.g., superior vena cava, aorta, pulmonary arteries and veins).
Page 7: Role of Valves
Valves: Ensure unidirectional blood flow.
Atrioventricular Valves: Separates atria and ventricles;
Right Side: Tricuspid valve (3 flaps)
Left Side: Bicuspide valve (2 flaps)
Semilunar Valves: Located at the exit of ventricles.
Page 8: Blood Vessel Structures
Types of Blood Vessels:
Arteries: Carry blood away from heart; possess elastic walls to manage high pressure.
Veins: Carry blood towards heart; thinner walls, larger diameter, and contain one-way valves to prevent backflow.
Page 9: Capillaries
Capillary Structure:
Connect arteries and veins.
Facilitate gas and nutrient exchange due to thin walls (one layer of cells).
Page 10: The Beating Heart
Electrical Signals: Control heartbeat; the SA node serves as the heart's pacemaker.
SA node initiates contraction in the right atrium; signals transmitted to AV node and then through the Bundle of His and Purkinje fibers.
Page 12: Electrocardiogram (ECG)
Heart Activity Recording: Measures electrical activity with three primary waves — P wave (atria contraction), QRS complex (ventricular contraction), and T wave (ventricular recovery).
Page 16: Heart Sounds
S1 (Lub): Closing of atrioventricular valves.
S2 (Dub): Closing of the semilunar valves.
Murmurs: Occur if valves do not close properly.
Page 17: Blood Pressure
Measurement: Pressure against vessel walls; varies between systolic (maximum) and diastolic (minimum) during heartbeats.
Healthy reading: 120/80.
Page 19: Cardiac Output
Definition: Volume of blood pumped from each side of the heart per minute.
Cardiac Output Formula: Heart Rate x Stroke Volume.
Average cardiac output ~5L/min.
Page 22: Cardiovascular Disorders
Leading Cause of Death: Cardiovascular disease; risk factors include smoking, poor diet, and lack of exercise.
Atherosclerosis: Buildup of plaque in arteries leading to reduced blood flow and potential blockages.
Page 25: Blood Components
Blood Composition:
Fluid Portion: Plasma (55% volume)
Solid Portion: Formed elements (45% volume), including red blood cells, white blood cells, and platelets.
Page 29: Erythrocytes (Red Blood Cells)
Function: Oxygen transport; lack a nucleus and have a lifespan of about 120 days.
Anemia: Condition marked by reduced red blood cells or hemoglobin.
Page 30: Leukocytes (White Blood Cells)
Function: Immune response; produced in bone marrow.
Types include granulocytes, monocytes, and lymphocytes.
Page 31: Platelets
Role: Essential for blood clotting; respond to injury by forming clots to prevent blood loss.
Page 35: Blood Types
ABO System: Classification based on antigens present on red blood cells; involves types A, B, AB, and O, each with specific antibodies.
Page 40: Blood Disorders
Hemophilia: Genetic disorder leading to inadequate clotting factors.
Leukemia: Cancer of white blood cells characterized by abnormal proliferation of immature blood cells.
Page 42: Lymphatic System
Function: Maintains fluid balance and protects the body via lymph collection and white blood cell proliferation.
Page 43: Human Defense System
First Line of Defense: Skin and mucus preventing pathogen entry.
Page 46: Non-Specific Defenses
Cell-mediated Immunity: Phagocytosis by neutrophils and macrophages.
Page 47: Specific Defenses
Antibody-Mediated Immunity: Involves lymphocytes recognizing and responding to foreign substances.
Page 49: Antigens and Antibodies
Antigens allow for immune recognition; antibodies help neutralize pathogens.
Page 55: Immune System Disorders
Autoimmune Disorders: Immune system mistakenly attacks body cells.
Allergies: Exaggerated immune responses to non-harmful substances.