Flashcards in B5 - Waste disposal Deck (31):
What is excretion?
The process of getting rid of waste from the body.
Which body organs excrete waste?
The kidneys, skin, lungs and liver all excrete waste.
What does urine contain?
Urine contains water, salt and urea.
What is urea?
Urea is a nitrogen containing substance which is cleared from the blood by kidneys and is excreted in urine.
What is egestion?
Egestion is the removal of solid waste.
What is the difference between egestion and excretion?
Excretion is the removal of waste made by the body, egestion is the removal of waste that is not made by the body.
What is the ureter?
The ureter is the tube that connects the bladder and the kidney.
What does the renal artery do?
The renal artery brings blood containing waste substances to the kidney.
What is urea made from?
Urea is made in the liver from unwanted amino acids.
What does the renal vein do?
The renal vein takes filtered blood away from the kidneys.
Why is it important that the blood in the kidneys is filtered under high pressure?
So that most of the liquid is forced out of the glomerulus into the Bowman’s capsule which surrounds it. This does not work properly in people who have very low blood pressure.
What is a nephron?
A nephron is a kidney tubule which filters blood.
What does the glomerulus do?
It removes useful and waste materials from the blood.
What are Proximal Convoluted Tubules?
Proximal Convoluted Tubules are coiled up tubes next to the Bowmans Capsule.
What do PCT's do?
This is the place where all that useful glucose is re-absorbed from the ultra-filtrate and put back into the blood.
What happens at the Loop of Henlé?
This part of the nephron is where water is reabsorbed.
What happens at the Distal Convoluted Tubules?
This is where most of the salts in the ultra-filtrate are re-absorbed.
What are Collecting Ducts?
Collecting ducts run through the medulla and are surrounded by loops of Henlé.
What do Collecting Ducts do?
It collects the liquid produced by lots of nephrons.
What is uric acid?
Uric acid contains nitrogen and is poisonous at high concentrations.
What factors affect the amount of urine produced?
- the amount of water you drink
- the surrounding temperature
- the type of exercise you do
When will you produce a small amount of concentrated urine?
- when you drink a small amount of water
- when you sweat a lot
- during vigorous exercise
What does the skin excrete?
The skin excretes sweat.
What does sweat contain?
Sweat contains water and salt.
What are the two layers of the skin called?
The outer epidermis and the dermis underneath.
Where does hair grow?
Hair grows in follicles.
Why is sweating important?
Sweating regulates body temperature.
What is reabsorption controlled by?
Reabsorption is controlled by ADH (anti-diuretic hormone)
Where is ADH made?
ADH is made in the pituitary gland in the brain.
What does ADH do?
ADH increases permeability of the nephrons so that more water is reabsorbed.