Chp 14: Urogenital System

Question 0

Kidney Position: Retroperitoneal

Answer 0

Retro= behind. Peritoneal= body cavity
Dorsal body cavity
Under the peritoneal membrane
Separate from the viscera

Question 1

Kidney functions

Answer 1

180 L -> 1 L lost

1) filtration of blood
2) re absorption
- salt and water balance
3) secretion
- salt and water balance
4) production of urine (get rid of N wastes)

Question 2

Gross anatomy of kidney

Answer 2

Cortex (outer layer)
Medulla (inner layer)
Renal pelvis (urine cavity)
Ureter (tube carries urine away)

Question 3

Microscopic anatomy of nephron

Answer 3

Nephron = tubule for filtering

1) glomerulus (ball of capillaries) “renal corpuscle”
2) tubules -nephron itself
3) longitudal collecting duct

Question 4

Glomerulus

Answer 4

Ball of leaky capillaries 
Blood pressure pushes substance b/w cells 
 -water
 -glucose
 -salts
 -no proteins
Enter tubules

Question 5

Freshwater fish + Amphibs glomerulus

Answer 5

Large glomeruli bc it helps get rid of water and conserve salt

Question 6

Marine fish and amniotes

Answer 6

Marine fish have none

Amniotes have small glomeruli to conserve water not eliminate it

Question 7

Hagfish glomeruli

Answer 7

Special case; glomeruli only in posterior part of kidney because hagfish are osmoconformers.
Body fluid has same concentration as seawater.
Only purpose of glomeruli is to regulating ions

Question 8

Tubules

Answer 8

Long and coiled
Surrounded by capillaries
Salt or H2O absorbed back into blood
Extra salt secreted into tubules
Freshwater, saltwater, or desert living (flexible)

Question 9

Mammalian Nephron Tube

Answer 9

Bowman’s or renal capsule (surround glomerulus)
Proximal tubule -reabsorption of water
Loop of Henle or intermediate tubule
-countercurrent
Distal tubule -reabsorption of solutes
*remember you filter 180L/day and only lose 1L

Question 10

Collecting duct

Answer 10

Urine from nephrons

Goes to bladder or outside

Question 11

Pronephros

Answer 11

Most primitive 
Develops from mesomere of mesoderm
Nephrostome
  -opens into coelom: glomeruli 
  -lined w/ cilia
Ex: amphioxus, larval lamprey, hagfish, some bony fish

Question 12

Mesonephros

Answer 12

Mid and posterior mesomere 
Glomeruli inside body wall
Tubules are longer
Mesonephric = archinephric duct
  -urine + sperm
Ex: fish, amphibs, amniote embryos

Question 13

Metanephros

Answer 13

(Bean shape)
Ureter = metanephric duct
  -buds from mesonephric duct
Ureter induces metanephros
Posterior part of early kidneys 
Mesonephric duct remains as sperm duct (Wolffian) in male amniotes & regress in females 
Ex: reptiles, birds, mammals

Question 14

No urinary bladder

Answer 14

Agnatha - none
Cartilaginous and bony fish -vestigial 
Some reptiles (snakes + crocs) -none
Birds -none (when flying too much weight)
  -except ostriches

Question 15

Urinary bladder

Answer 15

Water conservation site ; urine storage
Amphibs
-urine empties into cloaca
-excess backs up into bladder
Turtles + lizards 
Mammals
-storage and chemical signaling

Question 16

Nitrogenous waste disposal

Answer 16

(Based on habitat)
Agnatha, bony fish, aquatic amphibs
 -excreted as ammonia across gills/skin
Cartilaginous fish, mammals
 -excreted as urea, less water
Reptiles, birds
 -excreted as uric acid (semisolid)

Question 17

Extra-renal salt excretion

Answer 17

Marine or arid environment, conserve water

1) salt gland (gills)
2) rectal gland (digitiform)
3) nasal glands
- marine birds and reptiles, desert snakes/lizards