Circulatory System
What is the main function of the circulatory system?
To transport substances such as oxygen, nutrients, hormones and waste products around the body.
How many chambers does the human heart have?
Four chambers.
Which blood vessels allow the exchange of substances between the blood and body tissues?
Capillaries.
What deposits can build up inside arteries and narrow them?
Atherosclerotic plaques, which contain cholesterol, fats and other substances.
Name one lifestyle change that can reduce the risk of cardiovascular disease.
Regular exercise, a healthy diet, quitting smoking or reducing excessive salt intake.
Why is the heart called a double pump?
It pumps blood twice be cycle - once to the lungs and the other to the rest of the body.
Which chamber pumps blood to the lungs?
The right ventricle.
Which blood vessels contain valves to prevent the backflow of blood?
Veins.
cardiovascular disease involves the narrowing of which heart arteries?
Coronary artery
What type of medication lowers blood cholesterol by reducing its production in the liver?
Statins.
What is the role of valves in the circulatory system?
Prevents the backflow of blood / forces blood to travel in one direction
What is the name of the valve between the left atrium and left ventricle?
The mitral valve, also called the bicuspid valve.
What is the name of the largest artery in the human body?
The aorta.
What is the name of a condition in which an abnormal heart rhythm occurs?
Arrhythmia.
What small mesh tube can be inserted into a narrowed artery to help keep it open?
A stent.
What is the name of the circuit that carries blood between the heart and lungs?
Pulmonary circulation.
Give two factors that can cause/contribute to low blood pressure.
dehydration, medications, Standing up suddenly, Blood loss, pregnancy, alcohol consumption, excessive sweating.
How do the thick, elastic walls of arteries help them function?
They withstand the high pressure of blood pumped from the heart and stretch and recoil to help maintain blood flow.
Explain how atherosclerosis can lead to a heart attack.
Plaque builds up inside a coronary artery, narrowing it and reducing blood flow. If a plaque ruptures, a blood clot may form and block the artery, depriving heart muscle of oxygen and causing tissue damage.
What type of medication helps prevent blood clots by reducing the ability of platelets to stick together?
Antiplatelet medication, such as aspirin.
Why does blood pressure decrease as blood travels through the capillaries?
Resistance and friction within the small blood vessels cause blood pressure to decrease, allowing slower exchange of substances with tissues
Why is the muscular wall of the left ventricle thicker than that of the right ventricle?
It needs to generate greater pressure to pump blood around the entire body.
How are capillaries adapted for the exchange of oxygen, nutrients and waste products?
They are very thin/ Their walls are one cell thick, providing a short diffusion distance, and their extensive networks provide a large surface area for exchange.
How can smoking increase a person's risk of cardiovascular disease?
Smoking damages blood vessel linings, promotes plaque formation and blood clotting, and reduces the oxygen-carrying capacity of blood due to carbon monoxide.
How does coronary artery bypass surgery improve blood supply to the heart muscle?
A blood vessel graft creates an alternative route for blood to flow around a narrowed or blocked coronary artery, restoring blood supply to the heart muscle.