11.3 Kidney and Osmoregulation

Question 1

Osmolarity

Osmoregulators

Osmoconformers

Answer 1

Osmolarity:

The solute concentration of a solution

Osmoregulators:

Maintain constant internal solute concentration, even when the environment has a different osmolarity

Osmoconformers:

Internal solute concentration changes to match the environment. (Marine invertebres)

Question 2

Malpighian tubules

Answer 2

The outpocketings of the digestive tract that are immersed circulatory fluid.

The tubules secrete nitrogenous wastes in the form of uric acid, excreted with feces.

carry out osmoregulation in insects

Question 3

Draw and Label the Human Kidney

Answer 3

Question 4

Nephron label

(Must annotate during exams)

Answer 4

• Glomerulus
• Afferent Arteriols
• Efferent Arteriols
• Bowman’s Capsule
• Proximal Convoluted Tubule
• Decending limb (Thick, Thin)
• Loop of Henle
• Accending limb (Thin, Thick)
• Distal Convoluted Tubule
• Collecting Duct

Glomerulus is in the Cortex

Loop of Henle is in the Medulla

Question 5

Afferent arteriole

Answer 5

Brings blood from renal artery

Question 6

Efferent arteriole

Answer 6

Helps generate pressure needed for filtration by restricting blood flow

Question 7

Bowman’s capsule

Answer 7

Highly porous, collects filtrate
1. As the blood moves into the kidney via afferent arterioles it enters
2. This glomerulus is encapsulated by the Bowman’s capsule
3. the basement membrane between the bowmans capsule and glomerulus filters the blood

Question 8

Glomerulous

Answer 8

Capillary bed where high pressure filtration occurs

Question 9

Proximal convoluted tubule

Answer 9

selectively reabsorbs Water, nutrients and salts by active transport back into blood

Question 10

Loop of henle

Answer 10

• Descending and ascending limbs Water and salt reabsorption
• maintains hypertonic conditions
• The length of the loop of Henle is positively correlated with the need for water conservation in animals
• Water conservation can be improved by having a longer loop of Henle, which increase the salt gradient in the medulla

Question 11

Distal convoluted tubule

Answer 11

Water and salts are reabsorbed back into blood

Question 12

Collecting duct

Answer 12

Carries filtrate to renal pelvis in kidney

The amount of water released from the collecting ducts to be retained by the body is controlled by anti-diuretic hormone (ADH).
ADH is released from the posterior pituitary in response to dehydration
This means less water remains in the filtrate, urine becomes concentrated and the individual urinates less

Question 13

Vesa recta

Answer 13

Blood capillaries that run along loop of henle

Question 14

Osmoregulators

Answer 14

Maintain constant

Question 15

Osmoconformers

Answer 15

Change to environment (oyster)

Question 16

Dehydration and overhydration

Answer 16

Dehydration:
- Dehydration is a loss of water from the body such that body fluids become hypertonic
- Blood pressure will drop (less water in plasma) and the heart rate will increase to compensate for this
- The individual will become lethargic and experience an inability to lower body temperature due to no sweat

Overhydration:
- over-consumption of water makes body fluids hypotonic
- produce excessive quantities of clear urine in an effort to remove water from the body
- The hypotonic body fluids will cause cells to swell (due to osmotic movement), which can lead to cell lysis and tissue damage

Question 17

Treatment of kidney failure by hemodialysis or kidney transplant

Answer 17

hemodialysis
- Kidney dialysis involves the external filtering of blood in order to remove metabolic wastes in patients with kidney failure

• Kidney dialysis treatments typically last about 4 hours and occur 3 times a week

kidney transplant
- does not address the underlying issue affecting kidney function
- The transplanted kidney is grafted into the abdomen, with arteries, veins and ureter connected to the recipient’s vessels
- Donors must typically be a close genetic match in order to minimise the potential for graft rejection