Primary Method of Transport: Nutrients and gases are primarily transported through the body via the circulatory system.
Components: Composed of blood vessels, a pump (heart), and valves for one-way blood flow.
Single Circulatory System (Fish)
Heart Structure: Fish have a two-chambered heart (Atrium and Ventricle).
Blood Flow: Blood passes through the heart only once for a complete circuit.
Deoxygenated Blood: From body capillaries to the Atrium -> Ventricle -> Gills (oxygen absorption).
Oxygenated Blood: Flows from gills to body capillaries completing one circuit.
Types of Circulation:
Gill Circulation: Blood pumped to gills for oxygenation.
Systemic Circulation: Blood travels to the rest of the body.
Double Circulatory System (Mammals)
Heart Structure: Mammals have a four-chambered heart (2 Atriums and 2 Ventricles).
Blood Flow: Blood passes through the heart twice for every complete circuit of the body.
Deoxygenated Blood Flow:
Enters right atrium via vena cava.
Moves to right ventricle.
Pumped to lungs via pulmonary artery for oxygenation.
Oxygenated Blood Flow:
Enters left atrium via pulmonary vein.
Moves to left ventricle.
Pumped to body via aorta.
Circulation Types:
Pulmonary Circulation: Right side of the heart pumps deoxygenated blood to lungs.
Systemic Circulation: Left side pumps oxygenated blood to the body.
Advantages of Double Circulation
Higher Demand: Mammals are larger and require more oxygen and glucose for respiration.
Efficiency: Faster and more efficient delivery of oxygen and glucose due to higher blood pressure.
Structures of the Mammalian Heart
Right Atrium: Receives deoxygenated blood from the body via vena cava.
Tricuspid Valve: Separates right atrium and right ventricle.
Right Ventricle: Pumps deoxygenated blood to lungs via pulmonary artery.
Pulmonary Vein: Brings oxygenated blood back to the heart.
Bicuspid Valve: Separates left atrium and left ventricle.
Left Ventricle: Pumps oxygenated blood to the body via aorta.
Septum: Muscle wall separating the two sides of the heart, preventing blood mixing.
Coronary Arteries: Supply oxygen-rich blood to the heart muscle itself.
Heart Muscle and Activity Monitoring
Muscle Thickness: Ventricles have thicker walls than atria; left ventricle thicker than right.
Monitoring: Heart activity can be monitored using ECG, pulse rate, and stethoscope.
Physical Activity and Heart Rate
Experiment: Measure resting pulse, then exercise, and record heart rate recovery.
Reason for Increase: Muscle cells require more oxygen and glucose during exercise, and waste products must be removed quickly.
Coronary Heart Disease (CHD)
Definition: Blockage of coronary arteries leading to oxygen starvation in heart muscles, resulting in a heart attack.
Cause: Buildup of cholesterol and fatty substances in the arteries.
Risk Factors:
Poor diet (high in saturated fats).
Lack of exercise.
Diabetes and obesity.
Stress (increases blood pressure).
Smoking (increases blood pressure and clot risk).
Genetics (family history).
Age (risk increases with age).
Gender (males at higher risk).
Prevention: Avoid smoking, maintain a healthy diet, and exercise regularly.
Conclusion
Review of key concepts in the transport system of animals, particularly focusing on the differences between single and double circulatory systems, heart structures, and coronary heart disease.