Section 5 Flashcards
What circulation do humans have?
Double circulation
The composition of blood
- plasma
- platelets
- red blood cells
- white blood cells
Plasma
- red and white blood cells
- Carbon dioxide
- digested food
- heat
- urea
- hormones
Adaptations of red blood cells
- small
- bioncave
- contain haemoglobin
- don’t have a nucleus
Phagocytes…
Ingest pathogens
Lymphocytes…
Produce antibodies
Platelets
Small fragments of cells that help blood clot
How do platelets help blood clot?
The clump together to fill in the damaged area
They are held together by a mesh of protein called fibrin
Pulmonary artery
Takes deoxygenated blood to the lungs
Aorta
Carries oxygenated blood around the body
Pulmonary vein
Brings oxygenated blood from the lungs
Vena cava
Brings deoxygenated blood into the heart
Systole
When the chambers of the heart contract and force blood out into the arteries
Diastole
When the heart relaxes and fills
Hepatic portal vein
Gut–>liver
Pulmonary
To do with the lungs
Hepatic
To do with the liver
Renal
To do with the kidneys
Capillaries role
Carry the blood really close to every cell in the body to exchange substances with them
Arteries role
Carry blood away from the heart at a high pressure
Veins
Carry blood to the heart
Arteries adaptations
- walls are strong and elastic
- walls are thick compared to the lumen
Capillaries adaptations
- one cell thick
- very small lumen
Veins adaptations
- bigger lumen to help the blood flow
- valves to keep the blood flowing in the right direction
what are the three main roles of the kidneys?
- removal of urea from the blood
- adjustment of salt levels in the blood
- adjustment of water content in the blood
describe ultrafiltration
- blood flows from renal artery to GLOMERULUS
- glomerular filtrate squeezed into Bowman’s capsule
what is the glomerular filtrate?
- water
- urea
- salts
- glucose
what is NOT icluded in the glomerular filtrate?
- big molecules such as proteins and red blood cells
- they stay in the blood
where is all the glucose reabsorbed?
in the proximal convoluted tubule
how is the glucose reabsorbed?
using active transport
what else is reabsorbed (apart from glucose)?
sufficient salts
sufficient water
what is urine made out of?
water, salts and urea
what do the kidneys control?
the body’s water content
what hormone is used to control the water content of the blood?
ADH
what does ADH do?
it makes the nephrons more permeable so more water is reabsorbed back into the blood
the release of ADH:
- the brain monitors the water content of the blood
- it instructs the pituitary gland to release ADH into the blood
