The blood system Flashcards
What does the circulatory system do?
This transports substances around the body
What is the heart?
This is a organ, which pumps blood around the body.
What is the wall of the heart made of ?
This is made of muscle tissue
What are the four chambers of the heart
This is the left/right atrium and the left/right ventricle of the heart
How does blood enter the heart?
The blood enters the heart through the atrium. The atria then contracts forcing blood to the ventricle. The ventricle then forces blood out of the heart to arteries.
How is the direction of the blood flow kept in the right direction ?
There are heart valves which keep the blood flowing in one direction.
How does the blood flow through the organs
This is as its pumped out the heart through the arteries, which flow through the organs
How is the blood returned to the heart
The blood is returned to the heart through the veins
What are the two circulatory systems for
One is for the lungs and the other is for the organs of the body.
How are arteries specialised?
They have thick walls containing muscle and elastic fibres for the high pressure of blood flowing through.
How are veins specialised ?
- They have a bigger Lumen and thinner walls to help blood flow, despite low pressure
- They have valves to keep blood flowing in the right direction.
What happens when arteries narrow?
The blood flow is restricted.
What is used to deal with coronary heart disease, when fatty tissues build up in the arteries?
Stents are used which are tubes that are inserted into arteries keeping them open and squashes fatty acid build up making lumen bigger.
How does blood flow inside organs.
There are narrow, thin-walled blood vessels (CAPILLARIES) .
How does waste substances and substances needed leave body tissues
The capillaries flow through the body tissues and because they have thin walls, substances in blood can diffuse into cells and waste substances can be diffused into blood.
