Excretory Systems

Question 1

What are the two fundamental physiological functions of the kidney?

Answer 1

Excretion and osmoregulation

Question 2

Are avian loops of henle short or long? Why? Do all birds have these loops?

Answer 2

short -produce very concentrated urine.

Most birds DO NOT have loops of henle

Question 3

What are the 3 routes of eliminating ammonia?

Answer 3

Ammonotelism
Uricotelism
Ureotelism

Question 4

Describe Ammonotelism

Answer 4

Direct excretion of ammonia
common to animals living in water
eliminated through gill epithelium, skin &other permeable membranes

Question 5

Describe Uricotelism

Answer 5

Excretion of uric acid

performed by birds & most reptiles

Question 6

Describe Ureotelism

Answer 6

Excretion of urea

performed by mammals

Question 7

Freshwater fish excrete?

Answer 7

voluminous hypo-osmotic (highly dilute) urine

Question 8

Marine fish excrete? and how do they compensate?

Answer 8

small amounts of hyper-osmotic (very concentrated) urine.

They drink sea water to help w/ water loss. Actively transport salt out through gills

Question 9

Amphibians nephrons are similar to?

Answer 9

Fresh water fish.

Question 10

What is estivate(ing)?

Answer 10

dry-weather equivalent of hibernation.
Store nearly pure water to be returned to the blood when needed.
Performed by some frogs.

Question 11

Reptiles excrete? And lack?

Answer 11

uric acid

Lack loop of henle

Question 12

Which animals have salt glands?

Answer 12

birds & reptiles

Question 13

Birds excrete?

Answer 13

uric acid

Question 14

What is a urolith?

Answer 14

growth or aggregation of solid waste crystals in urine, can be found anywhere in urinary tract

Question 15

A bit about urolith formation

Answer 15

formation of crystal nidus (embryo)
initial phase called nucleation
dependant on supersaturation of urine w/ calculogenic crystalloids

Question 16

Further growth of urolith dependent on?

Answer 16

ability to remain in lumen
degree & duration of supersaturation of urine
physical characteristics of crystal nidus

Question 17

Uroliths are named according to?

Answer 17

mineral composition
location
shape

Question 18

Obstructions induced by urolith in include?

Answer 18

Urine retention
Bladder distension , abdominal pain, bladder rupture
death from uraemia or septicaemia

Question 19

Which are the most common crystals that cause blockage?

Answer 19

struvite (Mg-ammonia-phosphate)

Question 20

What are some predisposing factors to urolith formation?

Answer 20

high grain diet
silica rich soil
High Ca diet
mineral composition of water
Vitamin A deficiency

Question 21

Uroliths commonly lodge in the….?

Answer 21

sigmoid flexure

Question 22

What is scouring?

Answer 22

passage of highly fluid faecal matter, often w/ increased frequency

Question 23

What is the most common cause of scouring?

Answer 23

E. coli.

excessive intestinal motility from irritation of intestinal wall by bacterial, viral, or protozoan infection

Question 24

What animal is particularly susceptible to scours and why?

Answer 24

Neonates -especially those reared artificially

Question 25

White or yellow scours indicate?

Answer 25

inadequate colostrum, overfeeding/crowding, stress, poor sanitation

Question 26

Watery scours indicate?

Answer 26

change in diet, stress

Question 27

Bloody scours indicate?

Answer 27

infections from salmonella or coccidia

Question 28

loose, dark brown faeces indicate?

Answer 28

bleeding from lesions & ulers in abomasum or serious infection in GIT

Question 29

Name the two viruses that can lead to diarrhoea in calves

Answer 29

rotavirus

coronavirus

Question 30

Scouring in adult animals is associated w/?

Answer 30

parasite burdens
excess nutrients
poor dietary adaptation