Chapter 9 - Circulatory system Flashcards
What is the function of the red blood cells ?
to carry oxygen around the body
How are red blood cells adap[ted for their function ?
- biconcave shape
- have no nucleus
What is the function of the white blood cells ?
they are important for defence against disease
What re the two types of WBC ?
Phagocytes and lymphocytes
What is the purpose of the platelets ?
They convert fibrogen to fibrin, the fibrin the =n helps to clot the blood.
What is the function of the plasma ?
liquid part of the blood. Transports cells, food molecules, carbon dioxide, hormones and urea around the body
What happens if a red blood cell is placed into water ?
It will take up the water due to osmosis and it will burst in a process called cell lysis
Describe areteries
- blood flows away from the heart
- thick walls
- high blood pressure
- has no valves
- small lumen
Describe veins
- blood flows back to the heart
- relatively thin walls
- low blood pressure
- does have valves
- large lumen
Describe capillaries
- blood flows from the arteries to the veins
- one cell thick
- low blood pressure
- doesn’t have valves
What are the purpose of valves ?
To keep the flow of blood going in the same direction (unidirectional) and to prevent backflow
What is the pulmonary vein ?
carries oxygenated blood from the lungs to the ehart
What is the aorta ?
carries oxygenated blood from the heart around the body
What is the vena cava ?
carries deoxygenated blood from the body back to the heart
What is the pulmonary artery ?
carries deoxygenated blood from the heart to the lungs
What is the hepatic artery ?
carries oxygen and glucose to the liver
What is the hepatic portal vein ?
carries digested food from the small intestine to the liver
What is the hepatic vein ?
carries glucose and amino acids from the liver around the body.
What is the renal artery ?
Carries blood rich in urea to the kidneys for excretion
What is the renal vein ?
Carries purified blood from the kidney to the vena cava
What does double circulation mean ?
one circulation system to and from the lungs and one circulation system from the heart to the body
Describe the movement of blood during double circulation
Blood moves from the RV to the lungs the picks up oxygen. The oxygenated blood then moves to the LA to the LV where it is pumped around the body. Where it is again deoxygenated and pumped back to the RA
How does exercise affect someone heart rate ?
When doing vigorous exercise their pulse rate will go up
Why does our heart rate rise when we exercise ?
Because when we exercise we contract our muscles more vigorously. So more energy is needed so therefore more oxygen is needed at each muscle for respiration to occur. Also to supply the muscles with glucose.
