The Circulatory System Flashcards
Four blood components?
-Plasma
-Platelets
-Erythrocytes
-Leukocytes
Function of plasma?
Transports waste, nutrients, hormones and water around the body
Function of platelets?
Form clots to stop bleeding and prevent pathogens from entering
Where are erythrocytes and leukocytes produced?
In the bone marrow
Function of erythrocytes?
-Contain haemoglobin to carry oxygen
Structure of erythrocytes?
-No nucleus so they can contain more haemoglobin
-Small and flexible to fit through narrow blood vessels
-Biconcave shape to maximise surface area for oxygen absorption
Three types of leukocytes?
-T lymphocytes
-B lymphocytes
-Phagocytes
Function of T-Lymphocytes?
Destroy pathogens and abnormal cells
Function of B-Lymphocytes?
Make antibodies which attach to bacteria and viruses
Function of Phagocytes
Ingest and destroy pathogens such as bacteria
What is the difference between single and double circulation?
Single circulation: blood only does one loop from heart to lungs to body.
Double circulation: blood goes through the heart twice, heart to lungs to heart to body
Function of arteries?
Carry oxygenated blood away from the heart and deliver it to cells around the body
*Exception: pulmonary artery (carries deoxygenated blood from heart to the lungs)
Structure of arteries?
-Under high pressure
-Smaller lumen
-Thick outer walls
Function of veins?
Carry deoxygenated blood from the body to the heart
*Exception: pulmonary vein (carries oxygenated blood from lungs to the heart)
Structure of veins?
-Under low pressure
-Have valves to prevent back flow
-Larger lumen
-Thinner outer walls
Functions of capillaries?
-Join up arteries and veins as well as going to every cell in the body to deliver nutrients, water, oxygen, glucose and remove waste
-Has a role in gas exchange of oxygen and carbon dioxide in the lungs
Structure of capillaries?
-One cell thick to allow for diffusion to occur
-Very small lumen
Four blood vessels in the heart?
-Vena cava
-Pulmonary artery
-Pulmonary vein
-Aorta
Function of the vena cava?
B > RA
Vein bringing in deoxygenated blood from the body to the right atrium of the heart
Function of the pulmonary artery?
RV > L
Takes deoxygenated blood to the lungs from the right ventricle of the heart
Function of the pulmonary vein?
L > LA
Takes oxygenated blood from the lungs into the left atrium of the heart
Function of the aorta?
LV > B
Takes oxygenated blood from the left ventricle of the heart to the body
Four chambers of the heart?
-Right atrium
-Left atrium
-Right ventricle
-Left ventricle
Why is the left side of the heart more muscular?
It pumps blood all around the body so it has further to go, therefore it needs to be a higher pressure and have more muscle.
The right side only pumps blood to the lungs so it doesn’t have to go as far.
