1. Chpt. 44 Osmoregulation & Excretion
Julianna Diddle
Ethan Coombes

2. What is an osmoconformer?
Where is homeostasis regulated in mamals vs. reptiles?
What is an osmoconformer?
What is an osmoregulator?
Regulated internally = MAMMALS
--Regulated externally = REPTILES
-An animal that doesn’t actively adjust its internal osmolarity
An animal that must control its internal osmolarity because its
body fluids are not isoosmotic with the outside environment

3. -hyperosmotic
-ioosmotic
-hypoosmotic
-saltwater
-freshwater

4. What special characteristics do anhydrobiotic animals have?
They can lose almost all body water
& survive in a dormant state if their habitats dry up.

5. What are the three types of nitrogenous waste, what is different about them, and what is an animal that excretes each type?
Ammonia(NH3)
-most toxic
-Excreted by aquatic animals
Urea
-low toxicity
-Requires less water to dilute & can store large quantities
-Mamals, adult amphibians, sharks, some bony fish, & turtles
--Uric Acid
-Least toxic
-Insoluble
-Can be excreted with little water loss but energetically expensive
-Insects, land snails, many reptiles, & birds

6. What are the four main steps of the excretory process?
1. Filtration
2. Reabsorption
3. Secretion
4. Excretion

7. Kidney
Renal Artery
Renal vein
Ureters
Urinary Bladder
Urethra

8. What is the pathway of filtrate after leaving the glomerular capsule?
What is the functional unit of the kidney? (1,000,000/kidney in humans)
What is the pathway of filtrate after leaving the glomerular capsule?
What are the two types of nephrons?
Nephron
Proximal tubule, loop of Henle (descending & ascending loops), distal tubule,
collecting duct, renal pelvis, ureter
1.) Juxtamedullary
Extend into medulla, important for water conservation
2.) Cortical
Loop of Henle stays in the cortex

9. What is the pathway for blood supplying each nephron?
Systems that expend energy to create concentration gradients are –.
Afferent arteriole, glomerular capillaries, Efferent arteriole,
peritubular capillaries, vasa recta
Countercurrent multiplier systems

10. What is the condition of increased urination called?
What is the hormone that regulates water balance & increases collecting duct permeability to water
What is the condition of increased urination called?
Antidiuretic Hormone (ADH)
-Diuresis

11. What does the RAAS do? (Renin-Angiostentin-Aldosterone System)
What is the peptide hormone that opposes RAAS & is released by the atria of the heart in response to increased blood volume & pressure?
-Works with the Juxtaglomerular apparatus (JGA) to drop blood pressure & blood volume & triggers JGA to release renin
-Angiostentin II & Aldosterone reduce renin secretion in response to JGA
Atrial Natriuretic Factor (ANF)

12. What is osmoregulation?
What is excretion?
Solute balance & gain or loss of water
-Elimination of nitrogenous wastes