Biology Chapter 44 Flashcards
Osmoregulation
regulates solute concentrations and balances the gain and loss of water
Excretion
gets rid of nitrogenous metabolites and other waste products
Osmolarity
the solute concentration of a solution that determines the movement of water across a selectively permeable membrane
Osmoconformers
consisting only of some marine animals, are isoosmotic with their surroundings and do not regulate their osmolarity
Osmoregulators
expend energy to control water uptake and loss in a hyperosmotic or hypoosmotic environment
anhydrobiosis
An adaptation where some aquatic invertebrates in temporary ponds lose almost all their body water and survive in a dormant state
Transport epithelia
are epithelial cells that are specialized for moving solutes in specific directions
Key functions of most excretory systems
filtration
reabsorption
secretion
excretion
Filtration:
Filtering of body fluids
Reabsorption:
Reclaiming valuable solutes
Secretion:
Adding nonessential solutes and wastes from the body fluids to the filtrate
Excretion:
Processed filtrate containing nitrogenous wastes, released from the body
flame bulb
The smallest branches of the network are capped by a cellular unit
The osmolarity of urine is regulated by…
nervous and hormonal control
Antidiuretic hormone (ADH)
makes the collecting duct epithelium more permeable to water
Proximal tubule
filtrate volume decreases, but its osmolarity remains the same
Countercurrent multiplier system
allows the vasa recta to supply the kidney with nutrients, without interfering with osmolarity gradien
What enzyme does juxtaglomerular apparatus (JGA) release?
Renin
Renin-angiotensin-aldosterone system (RAAS)
part of a complex feedback circuit that functions in homeostasis
Renin triggers the formation of what peptide?
angiotensin II
Angiotensin II
raises blood pressure and decreases blood flow to the kidneys
Aldosterone
increases blood volume and pressure
atrial natriuretic peptide (ANP)
hormone released in response to an increase in blood volume and pressure and inhibits the release of renin
Two primary solutes affecting osmolarity are:
NaCl and urea
Urine is hyperosmotic to body fluid. True or False
True
The collecting duct carries filtrate through the _____ to the renal pelvis
Medulla
What does the distal tubule regulate?
the K+ and NaCl concentrations of body fluids
What does the controlled movements of ions contribute to?
pH regulation
What does aquaporin proteins form?
Channels where reabsorption of water continues through
Where does reabsorption of ions, water, and nutrients take place.
in the proximal tubule
What does the filtrate in Bowman’s capsule contain?
salts, glucose, amino acids, vitamins, nitrogenous wastes, and other small molecules
Kidneys
excretory organs of vertebrates function in both excretion and osmoregulation
Malpighian tubules
remove nitrogenous wastes from hemolymph and function in osmoregulation
Metanephridia
consists of tubules that collect coelomic fluid and produce dilute urine for excretion
protonephridium
a network of dead-end tubules connected to external openings
