Blood and organs Flashcards
What are the bloods 4 main components?
Plasma
Platelets
Red blood cells
White blood cells
Features of Plasma?
Carries everything that needs transporting in the body, eg. Blood cells, digested food, CO2, Urea, Hormones and heat
Feature of platelets?
Clot blood to prevent blood loss and infection, held tighter by protein called fibrin
Features of red blood cells?
Carry oxygen around the body
How are red blood cells well adapted for their function?
Biconcave to increase surface area for oxygen exchange
Contain haemoglobin to be able to release and exchange oxygen
Not have a nucleus so free space up for more haemoglobin
What’s the aim of the immune system?
To destroy pathogens
What do phagocytes do?
Detect foreign pathogens and engulf/digest them
Attack anything foreign
What do lymphocytes do?
Produce antibodies to lock onto a foreign antigen
Can become memory cells, so if the same pathogen returns the correct antigens are produced instantly
How does vaccination work?
Injecting an inactive pathogen to trigger an immune response, so lymphocytes produce antibodies to attack them, without there being any risk to the body
Creating memory cells for the future
What are the functions of the arteries?
Carry blood away from heart
Heart pumps blood out fast, so they have strong elastic walls
Walls are think compared to hole
Biggest artery is the Aorta
Functions of the capillaries?
Involved at the exchange of materials at tissues
Branch out from arteries, and are very small to exchange substances with every cell
Have permeable and thin walls to increase diffusion
Supply food and oxygen, take away CO2
Functions of veins?
Take blood to heart
Formed from capillaries, so bloods sat lower pressure meaning thinner walls and bigger hole
Have valves to keep blood in correct direction
Largest vein is Vena cava
Structure of the heart?
P38
How does blood travel through the heart?
Right atrium receives deoxygenated blood from vena cava
Deoxygenated blood moves to right ventricle, which pumps it to the lungs via the pulmonary artery
Left atrium receives, oxygenated blood from lungs via the pulmonary vein
Oxygenated blood moves to the left ventricle, then the whole body via the Aorta
What does the heart have to prevent the backflow of blood?
Valves
Why is the left ventricle much more muscular?
Has to pump blood to whole body, meaning higher pressure
Why does exercise increase heart rate?
Exercise increases the amount of CO2 in the blood, due to respiration
High levels of CO2 detected by receptors in Aorta, sending signals to the brain
Brain tells heart to contract more frequently and with more force
The structure of the circulation system?
P39
What carries oxygenated blood?
Arteries
What carries deoxygenated blood?
Veins
What are the exceptions to the oxygenated rule?
Pulmonary Artery and Vein
What does pulmonary mean?
To do with lungs
What does hepatic mean?
To do with liver
What does renal mean?
To do with kindneys
What do kidneys do?
Remove urea from blood
Adjust water concentration in blood
Adjust salt concentration in blood
Structure of the kidney?
P40
Structure of a nephron?
P40
What’s ultrafiltration?
Blood from renal artery flows through the glomerulus
High pressure is built, squeezes water, urea salts and glucose into bowman’s capsule
Big molecules eg. protein or blood, aren’t squeezed out, the filtered liquid in Bowman’s capsule is know as glomerular filtrate
What’s reabsorption?
All the glucose is reabsorbed in the proximal convoluted tubule via active transport
Sufficient salt is absorbed
Sufficient water is absorbed at collecting duct
What’s the release of wastes?
The remaining substances form urine, stored in the bladder and released via the urethra
What’s osmoregulation?
The body has to balance the water coming in and going out
What controls osmoregulation?
Negative feedback
What does ADH do?
Increases the permeability of the nephrons, so more water goes back into blood stream
What controls the level of ADH?
The pituitary gland
What’s negative feedback?
If something gets too high or low a mechanism will be triggered to get it back to normal
