10 KIDNEYS + EXCRETION Flashcards
1
Q
How is carbon dioxide excreted from the body
A
Lungs via blood plasma
2
Q
How is urea excreted by the body
A
Kidneys and skin
3
Q
How is urea formed
A
- Amino acids in blood enter liver by hepatic artery and hepatic portal vein
- Excell amino acids are broken down into carbohydrates and ammonia
- Ammonia is very toxic, and is converted to urea
- Amino acids that are needed and urea are released into the blood by the hepatic vein
4
Q
What are the 3 layers of the kidney
A
- Outer cortex
- Middle medulla
- Inner pelvis
5
Q
Describe the process of ultrafiltration
A
- Diameter of the efferent arteriole at the exit of the glomerulus is smaller than the diameter of the afferent arteriole at the entrance
- Causes a build up in pressure in capillaries forming the glomerulus
- Pressure forces small moleucles out of capillaries into Bowman’s capsule
- Forms golmerular filtrate
6
Q
What is in glomerular filtrate
A
- urea
- glucose
- amino acids
- salts
7
Q
Describe the process of selective reabsorption
A
- Glomerular filtrate travels to PCT where specialised cells within the walls move moleucles like glucose back into the bloodstream
- They move by diffuison, but also by active transport (with ATP)
8
Q
Describe the process of water reabsorption
A
- Loop of Henle concentrated urine by transporting salt into the blood by active transport, causing water to diffuse into blood
- Collecting duct changes permeability with levels of ADH to absorb more water
9
Q
Describe osmoregulation and the role ADH has in it
A
- ADH is released by the pituitary gland in the hypothalamus
- ADH diffuses from the capillaries to bind with receptors on the surface of collecting duct cells
- When ADH binds, the coillecting duct becomes more permeable to water
- More water is reabsorbed, and urine is more concentrated
10
Q
What are the organs of excretion
A
Kidneys, skin and lungs
11
Q
Structure path of urinary system
A
- Kidney
- Ureter
- Bladder
- Urethea
12
Q
Describe the structure of a nephron (path)
A
- Glomerulus
- Bowman’s capsule
- Proximal Convoluted tubule
- Loops of Henle
- Collecting Duct
13
Q
What is the contents of urine
A
Water, urea and ions
14
Q
Describe osmoregulation and the role ADH has in it
A
- ADH is released by the pituitary gland in the hypothalamus
- ADH diffuses from the capillaries to bind with receptors on the surface of collecting duct cells
- When ADH binds, the coillecting duct becomes more permeable to water
- More water is reabsorbed, and urine is more concentrated
15
Q
Describe the process of water reabsorption
A
- Loop of Henle concentrated urine by transporting salt into the blood by active transport, causing water to diffuse into blood
- Collecting duct changes permeability with levels of ADH to absorb more water
