can someone help with the explanation

Ive just done my BY4 exam with WJEC so will give you the best i can:

Blood arrives at the kidneys through the renal artery
Afferent arteriole wider than the efferent
This increases Hydrostatic pressure
Osmotic pressure pushing into the capillaries but since hydrostatic pressure is so high,
Net effect is ultrafiltration from the capillaries in the glomerulus to the bowmans capsule
The fluid passes through pores in the capillaries and pores in the basement membrane
It is filtered by podocyte filtration slits (feet)
Large molecules such as red blood cells and proteins cannot pass through
Small molecules such as water, salts, glucose, amino acids etc can pass through
Tissue fluid moves into the proximal convoluted tubule
Main site of selective reabsorption (adaptations such as micro villi and mitochondria)
All of the above is in the cortex
Next is the loop of henle in the medulla
Sodium ions are actively pumped out of the ascending limb (impermeable to water)
creating a high concentration in the vesa recta
water moves out by osmosis of the water permeable descending limb
this is know as the counter current multiplier (adaptations to animals in dry habitats etc)
Ions are pumped out of the distal convoluted tubule and water follows by osmosis
Collecting duct passes back through medulla (stong concentration)
more water reabsorbed
There is some info about ADH aswell, key words;

osmoreceptors
hypothalamus
posteria pituitary
Antidiuretic Hormone
permeability to water
negative feedback loop