kidney function

Question 1

What is osmoregulation?

Answer 1

Osmoregulation is the control of water and salt levels in the body.

It involves controlling both water and salt levels.

Question 2

What is the role of the pituitary gland in osmoregulation?

Answer 2

The pituitary gland releases ADH (antidiuretic hormone) into the bloodstream to control water reabsorption in the kidneys.

Question 3

What effect does ADH have on the collecting duct?

Answer 3

ADH increases the permeability of the collecting duct walls, allowing more water to be reabsorbed back into the blood.

Question 4

How does alcohol and caffeine affect urine production?

Answer 4

Alcohol and caffeine can inhibit the release of ADH, leading to increased urine production.

Question 5

On average, how much urine does a person produce a day?

Answer 5

1-1.5 litres

Question 6

What happens to a cell in a hypertonic solution?

Answer 6

Water leaves the cell, causing it to shrink (crenation).

Question 7

What happens to a cell in a hypotonic solution?

Answer 7

Water enters the cell, causing it to swell and potentially burst (lysis).

Question 8

What is the ideal condition for cells concerning water potential?

Answer 8

Isotonic conditions are ideal, where there is no net flow of water into or out of the cell.

Question 9

How does the body gain water?

Answer 9

Water is gained from food, drink, and metabolism.

Question 10

How does the body lose water?

Answer 10

Water is lost in urine, sweat, water vapour in exhaled air, and faeces.

Question 11

What determines the volume and concentration of urine?

Answer 11

The amount of water reabsorbed in the kidneys, influenced by ADH levels.

Question 12

What are aquaporins?

Answer 12

Aquaporins are water-permeable channels inserted into the cell membrane of the collecting duct in response to ADH.

Question 13

What triggers the production of ADH?

Answer 13

Decreased water potential in the blood triggers osmoreceptors in the hypothalamus to produce ADH.

Question 14

What is the consequence of low ADH levels in the blood?

Answer 14

Less water is reabsorbed, leading to more dilute urine with a higher (less negative) water potential.

Question 15

What is the half-life of ADH?

Answer 15

ADH has a half-life of 20 minutes.

Question 16

Fill in the blank: Osmoregulators monitor the body’s water potential and are located in the _______.

Answer 16

Hypothalamus

Question 17

True or False: A hypertonic solution has a lower solute concentration than the inside of the cell.

Answer 17

False

Question 18

What is the function of neurosecretory cells?

Answer 18

Neurosecretory cells produce ADH in response to low water potential and release it into the bloodstream.

Question 19

What sequence occurs when ADH is present?

Answer 19

1. Osmoreceptors detect low water content. 2. ADH is produced and secreted. 3. ADH binds to receptors in the collecting duct. 4. Aquaporins are inserted into the membrane. 5. Water is reabsorbed. 6. Urine becomes more concentrated.

Question 21

What is the main function of the kidney?

Answer 21

To filter blood, remove nitrogenous wastes, and rebalance blood for ions and water

Question 22

What structures are visible through dissection of the kidney?

Answer 22

Medulla, cortex, and pelvis

Question 23

What is the role of the renal artery?

Answer 23

Supplies the kidney with oxygenated blood

Question 24

What are arterioles?

Answer 24

Smaller blood vessels that connect arteries to capillaries

Question 25

What does the afferent arteriole do?

Answer 25

Carries blood towards the glomerulus

Question 26

What does the efferent arteriole do?

Answer 26

Carries blood away from the glomerulus

Question 27

What is the function of the cortex of the kidney?

Answer 27

This is where the urine collects

Question 28

What is the function of the medulla of the kidney?

Answer 28

Dense capillaries take blood to the nephrons

Question 29

What is the function of the pelvis of the kidney?

Answer 29

Tubules of the nephrons form the pyramids and collecting ducts

Question 30

What is the nephron?

Answer 30

The functional unit of the kidney responsible for urine formation

Question 31

How many nephrons are there in each kidney?

Answer 31

About 1 million

Question 32

What are podocytes?

Answer 32

Specialized cells in the Bowman’s capsule that form filtration slits

Question 33

What is ultrafiltration?

Answer 33

Filtering small molecules from the blood at high pressure

Question 34

What is selective reabsorption?

Answer 34

The process of reabsorbing useful small molecules into the blood

Question 35

Where does selective reabsorption mainly occur?

Answer 35

In the proximal convoluted tubule (PCT)

Question 36

What substances are reabsorbed in the proximal convoluted tubule?

Answer 36

* Water * Salts * Glucose * Amino acids

Question 37

What role do microvilli play in the proximal convoluted tubule?

Answer 37

Increase the surface area for diffusion

Question 38

What is the role of mitochondria in the proximal convoluted tubule?

Answer 38

Generate ATP for active transport

Question 39

What is the Loop of Henle's primary function?

Answer 39

To conserve water and produce concentrated urine

Question 40

What is the countercurrent multiplier system?

Answer 40

The mechanism that creates a steep concentration gradient in the Loop of Henle

Question 41

What is the role of the distal convoluted tubule (DCT)?

Answer 41

Reabsorption of inorganic mineral ions and regulation of pH

Question 42

What hormone affects the permeability of the DCT?

Answer 42

Anti-diuretic hormone (ADH)

Question 43

What is the function of the collecting duct?

Answer 43

Osmoregulation and final water balance before urine formation

Question 44

What happens to the urine as it passes through the collecting duct?

Answer 44

More water is reabsorbed depending on blood water potential

Question 45

What substances indicate a malfunction in the nephron when found in urine?

Answer 45

* Glucose * Erythrocytes * Plasma proteins

Question 46

What disease may be indicated by glucose in urine?

Answer 46

Diabetes (mellitus)

Question 47

What is the role of adrenaline in the body?

Answer 47

Causes various effects depending on the type of cell it binds to

Question 48

What type of receptors does adrenaline bind to?

Answer 48

Adrenaline receptors

Question 49

What does cAMP stand for?

Answer 49

Cyclic adenosine monophosphate