Transport in Animals

Transport in Animals

• Transport in animals is a system of blood vessels, a pump (heart), and blood.
• The heart is a muscular pump made of cardiac muscle that keeps the heart contracting without stopping.
  • Its function is to pump blood around the body to supply cells with nutrients and oxygen, and to remove waste products like carbon dioxide.
• The heart activity can be monitored by electrocardiogram(ECG), pulse rate, and listening to valve sounds.
• Physical activity affects heart rate.
• Coronary heart disease is caused by the blockage of coronary arteries. Risk factors include diet, lack of exercise, stress, smoking, genetic predisposition, and age.
• Arteries, veins, and capillaries are different blood vessels with varying wall thickness, lumen diameter, and valve presence.
  • Arteries carry blood away from the heart, and veins return blood to the heart. Capillaries connect arteries and veins, allowing for the exchange of materials.
• Blood consists of red blood cells, white blood cells, platelets, and plasma.
  • Red blood cells transport oxygen, using hemoglobin.
  • White blood cells are involved in phagocytosis and antibody production.
  • Platelets help with clotting.
  • Plasma transports blood cells, ions, nutrients, urea, hormones, and carbon dioxide.
• Blood clotting prevents blood loss and pathogen entry.
• Fish have single circulation, while mammals have double circulation (more efficient).
• The mammalian heart has atrioventricular and semilunar valves to ensure one-way blood flow.
• The left ventricle has a thicker muscle wall than the right ventricle.
  • The left ventricle pumps blood to the whole body, while the right ventricle pumps blood to the lungs.
• The heart's rhythm is due to valves closing (lub-dub sounds).
• Pulse rate is the number of pulses per minute.
• Blood pressure is the pressure created in arteries during heart beats (systolic and diastolic pressures).
• The measurement of Blood pressure is done by using sphygmomanometer.
• The normal blood pressure is 120/80 mm/Hg.

Components of the Human Circulatory System

• The human circulatory consists of the heart, blood vessels (arteries, veins, and capillaries), and blood.
• The rhythmic sounds (Lub-Dub) made by the heart are due to the closure of heart valves.
• The heart's activity can be monitored by ECG, pulse rate (number of heartbeats per minute), and listening to heart valve sounds (like "lub-dub").

How to Measure Pulse

• Use two fingers on the inside of the wrist.
• Feel the artery pulsing.
• Count the number of pulses for a minute.
• Repeat and average for accuracy.

Improving Lifestyle to Treat CHD

• Exercise helps prevent weight gain and lower blood pressure.
• A healthy diet low in saturated fats and salt can reduce coronary heart risk.
• Avoiding smoking is crucial.

Coronary Heart Disease Treatments

• Drugs (like statins) can lower cholesterol and anti-hypertensive drugs can help lower blood pressure.
• Surgery (bypass) involves replacing a blocked coronary artery with a blood vessel taken from another part of the body.
• Angioplasty uses a balloon to open a narrowed artery, often with a metal stent to keep it open.

Pulmonary and Systemic Circulation

• Pulmonary circulation pumps deoxygenated blood to the lungs and returns oxygenated blood to the heart.
• Systemic circulation pumps oxygenated blood to the rest of the body and returns deoxygenated blood to the heart.

Changing Heart Rates

• Heart rate increases during exercise and happiness, due to adrenaline. It decreases during rest or sleep.
• More trained athletes have a stronger heart muscle, enabling them to achieve the same task with fewer beats.

The Blood Circulation

• Diastole: Heart relaxes
• Systole: Heart contracts (ventricular systole - ventricles contract and atrioventricular valves close)
• Atrial systole: The atria contract

Function of the Blood Vessels

• Arteries carry oxygenated blood, except the pulmonary artery. They have thick walls due to high blood pressure and maintain high pressure to move the blood. Their lumen is narrow to maintain high pressure.
• Capillaries are for exchange of substances between blood and cells.
• Veins carry deoxygenated blood, except the pulmonary vein. They have thin walls, low pressure but valves to prevent backflow.

Blood Composition

• Plasma (55%) is a yellowish fluid containing water, dissolved substances (nutrients, waste products, etc.).
• Blood cells(45%) including: Red blood cells (transport oxygen using hemoglobin), White blood cells (immune response), Platelets (blood clotting).

Adaptation of Red Blood Cells

• Red blood cells are small and flexible to squeeze through capillaries.
• Their biconcave shape increases the surface area to volume ratio for efficient oxygen transport.
• They lack nucleus to maximize the space for hemoglobin.

Blood Clotting

• Blood clotting stops blood loss & prevents pathogen entry.
• Damaged blood vessels expose platelets to air initiating a clotting cascade.