Kidneys

Question 1

Osmoregulation

Answer 1

The control of water levels within the blood by osmoreceptors in the hypothalamus but processed by the kidneys

Question 2

Nephron

Answer 2

Millions within the kidney which act as filtering units. In the medulla, specifically the pyramids. Removes waste and balances water and mineral ion levels.

Question 3

Cortex

Answer 3

Darker area of the kidneys containing a high density of capillaries (blood filtering site)

Question 4

Medulla

Answer 4

Lighter area of the kidney inside the cortex. Contains nephrons and collecting duct.

Question 5

Pelvis

Answer 5

The inner most part of the kidney. It collects the urine before it passes down to the bladder.

Question 6

Ureter

Answer 6

Tube connecting the kidney to the bladder

Question 7

Bladder

Answer 7

Muscular sac holding urine

Question 8

Urethra

Answer 8

A tube which allows urine to be excreted in the bladder to be excreted.

Question 9

Bowemans capsule

Answer 9

A cup like structure where ultrafiltration takes place. It contains the glomerus a network of capillaries. Blood enters through the afferent artiole which has a much wider pathway then the exist (efferent artiole) so pressure is high. This leads to some blood solutes to be forced out of the capillary (ions, amino acids, glucose…) But larger molecules like proteins or erthocyes remain in the blood. The pores let everything through but blood cells. The basement membrane stops proteins. The podocytes have narrow slots between the finger like structure allowing only small molecules through. This creates glomerular infiltrate once it has passed through.

Question 10

Proximal convoluted tubular

Answer 10

First coiled section after bowemans capsule. Useful molecules in the glomerular infiltrate are reabsorbed back into the blood. This is selective reabsorption. It is covered in microvilli to increase the surface area. Contain many mitochondria to produce atp required for active transport to move substances back into the blood. The waste products that aren’t readsorbed are excreted in the urine.

Question 11

Loop of henle

Answer 11

Allows you to produce urine that is more concentrated meaning water can be conserved while removing waste products. The descending limb is permeable to water so h2o moves out increasing the concentration of sodium ions in the loop. The ascending limb is inoperable to water so sodium ions move out. This helps to equilibriate the pressure and concentration.

Question 12

Distal convoluted tubule and collecting duct

Answer 12

Osmosis and diffusion takes place to create optimum water potential and pH in the blood. ADH affects the permeability of the DCT and collecting duct. High levels of ADH are released when you are dehydrated leading to DCT and collecting duct becoming more permeable to water so more returns to the blood. The urine becomes more concentrated. ADH is produced by the hypothalamus and secreted by the pituitary gland. Osmoreceptors in the hypothalamus monitor osmoregulation.