B9 - transport in mammals Flashcards
(32 cards)
What is the circulatory system?
A system of blood vessels with a pump and valves to ensure one-way blood flow.
What are the main purposes of the circulatory system?
To deliver oxygen and nutrients to cells and remove waste products like carbon dioxide.
What do veins do?
Carry blood towards the heart.
What do arteries do?
Carry blood away from the heart.
What are capillaries and their function?
Tiny blood vessels where exchange of oxygen, nutrients, and waste occurs between blood and tissues.
What does oxygenated blood mean?
Blood that is high in oxygen.
What does deoxygenated blood mean?
Blood that is low in oxygen.
How many chambers does the mammalian heart have?
Four – two atria and two ventricles.
Why is the left ventricle thicker than the right?
Because it pumps blood at a higher pressure to the whole body.
What is double circulation?
The system where blood flows separately through the lungs (pulmonary) and the rest of the body (systemic).
Why do mammals have double circulation?
To keep oxygenated and deoxygenated blood separate, and to maintain pressure differences.
What is the function of the pulmonary artery?
To carry deoxygenated blood from the heart to the lungs.
What is the function of the pulmonary vein?
To carry oxygenated blood from the lungs to the heart.
What is the function of the vena cava?
To return deoxygenated blood from the body to the heart.
What is the function of the aorta?
To carry oxygenated blood from the heart to the rest of the body.
What do heart valves do?
Prevent backflow of blood and ensure one-way flow.
What is the septum in the heart?
A muscular wall that separates the left and right sides of the heart.
What are coronary arteries?
Blood vessels that supply the heart muscle with oxygen and nutrients.
What is the main structural difference between fish and mammal hearts?
Fish have a two-chambered heart; mammals have four chambers.
Why is the heart structure of reptiles and amphibians less efficient?
Because their ventricles are not fully separated, allowing some mixing of oxygenated and deoxygenated blood.
What is coronary heart disease (CHD)?
A condition where coronary arteries become narrowed or blocked, reducing blood flow to the heart muscle.
What lifestyle factors increase the risk of CHD?
Smoking, poor diet, lack of exercise, high blood pressure, and high cholesterol.
How does exercise reduce the risk of CHD?
It lowers blood pressure, improves cholesterol, and strengthens the heart and blood vessels.
How does diet affect CHD risk?
A healthy diet lowers LDL (bad) cholesterol and helps maintain healthy body weight.
