Circulatory system in Humans Flashcards
(38 cards)
What is the function of the arteries?
What is the structure?
What are some key facts?
- Carry blood away from the heart
- Thick outer walls and layers of muscle
- Arteries don’t have valves and is under high pressure by the heart
What is the function of veins?
What is the structure?
What are some key facts?
- Carry blood back to the heart
- Thin walls, thin layers of muscle, valves
- Blood in veins is lower pressure then arteries, have valves which stop the blood from flowing backwards
What are the capillaries?
What is the structure?
What are some key facts?
- Found within tissues and organs
- Walls are only one cell thick
- Brings nutrients and oxygen to tissues and remove waste products, thin walls needed to enable them to perform their function
What do all blood vessels contain?
An endothelium lining in the lumen, but the wall of the capillary is made of a single layer of endothelial cells.
What does blood flow through in tissues and organs?
Capillaries
How do useful substances like glucose and oxygen reach body cells?
They diffuse out of blood into surrounding tissue
How do waste substances like carbon dioxide leave body cells?
They diffuse from the cells into the blood
What feature of capillaries helps diffusion?
Their thin walls provide a short diffusion distance
Why is it important that capillaries form extensive networks?
So every cell is close to a capillary, ensuring efficient exchange of substances
What is cardiovascular disease?
A disease of the heart or blood vessels
What causes an atheroma to form?
Fatty deposits (plaque) building up inside an artery, when an atheroma is formed it causes the walls of the artery to harden and narrow.
What can blood clots or a build up of plaque cause?
Blood flow to the heart, brain, or body can be reduced as a result of blood clots or build up of plaque
What happens if an atheroma forms in an coronary artery?
The blood flow to vital organs is reduced, this reduces the supply of glucose and oxygen to the heart muscle, this causes a heart attack.
What are the main risk factors of cardiovascular disease?
- smoking
- high blood pressure
- a diet high in fat or salt
- genes
- lack of exercise
What is statins? What are the advantages and disadvantages to it?
- Medicinal drugs taken daily
Advantages - lower the level of cholesterol in the blood
Disadvantages - many side effects such as headaches or memory loss
What is angioplasty? What are the advantages and disadvantages to it?
- A small uninflated balloon placed in a partially blocked artery and inflated, forces the blood vessel to widen and removes blockage
Advantages - Improves blood flow and prevents heart attack
Disadvantages - Only a temporary measure unless the patient makes lifestyle changes
What are the advantages and disadvantages to life style changes?
- Includes eating a low fat and salt diet and exercising
Advantages - reduce the risks of cardiovascular disease and lower blood pressure
Disadvantages - a high level of self discipline is needed to maintain these changes
What is the heart made out of?
Cardiac muscle which contracts to pump blood around the body
Where does the right side of the heart pump blood to?
The lungs
Where does the left side of the heart pump blood to?
The body
What are the four chambers of the heart?
- Left atrium
- Right atrium
- Left ventricle
- Right ventricle
Why does the left ventricle have thicker walls then the right?
It has thicker muscular walls as it pumps blood further around the body
Why does the right ventricle have thinner walls then the left?
It has thinner walls due to it only pumping blood to the lungs, a shorter distance
What is the process of blood flowing through the heart?
1) Veins carry blood back to the heart
2) Blood enters an atrium
3) Blood flows through a valve and into a ventricle
4) Blood flows through a semi lunar valve
5) Arteries carry blood away from the heart
