(5) Blood and circulation Flashcards
(In mammals) what does blood transport?
- Oxygen to organs that need it.
- Carbon dioxide away from organs.
- Nutrients to the parts the need it.
- Urea from the liver to the kidneys.
- Hormones and antibodies.
How do single celled organisms obtain oxygen?
By diffusion through the surface membrane of the cell.
What are the two types of circulatory systems?
- Single circulatory system
- Double circulatory system
What is the difference between a single and double circulatory system?
In a single circulatory system the blood is pumped from the heart directly to the rest of the body. Whereas in a double circulatory system the blood is pumped from the heart to the gas exchange organ, back to the heart and then to the rest of the body.
What are the two parts to a double circulatory system?
1) Pulmonary circulation
2) Systemic circulation
What divides the left and right side of the heart?
The septum
What does the right and left ventricle do?
The left one pumps blood to the rest of the body, while the right one pumps blood to the lungs.
Why are there valves in the heart?
To ensure the blood only flows in one direction.
What is special about cardiac muscle?
It doesn’t get fatigued.
What is the coronary circulation?
It is the heart’s own blood supply.
What hormone triggers the fight or flight response?
Adrenaline
What part of the brain controls the heart rate?
The medulla
What do arteries do?
They carry blood from the heart to the organs of the body.
What do veins do?
They carry blood from the organs back to the heart. (They have a much lower blood pressure than the arteries)
What do capillaries do?
They carry blood through organs, and bring it close to all cells in the organ. It’s walls are one cell thicc to allow for diffusion of nutrients.
What is plasma?
It is the liquid part of blood. It carries all the components of blood around the body.
What is RBC?
It is the part of blood that gives its red colour. It is responsible for carrying oxygen throughout the body.
What are lymphocytes?
They are a type of WBC, they produce antibodies to destroy microrganisms.
What are phagocytes?
They are a type of WBC, they digest and destroy bacteria.
What are platelets?
They release chemicals to make blood clot.
Do RBC have a nucleus?
No, they need the extra space for hemoglobin.
What are antigens?
They are markers on a bacteria and viruses that antibodies use to recognize foreign objects.
How do antibodies destroy pathogens?
- Causing them to stick together, so phagocytes can easily ingest them.
- Acting as a label, so it is more easily recognized by a phagocyte.
- Causing bacteria cells to burst open.
What is immunity?
It’s when the memory lymphocytes quickly identify a pathogen it previously dealt with and and produces antibodies to immediately deal with it.
What are platelets?
They are fragments of large cells made in the bone marrow.
How do platelets form a scab?
When they are exposed to air from cut skin, they produce a chemical that causes fibrinogen to change into fibrin. This traps RBC and creates a scab.
