URINARY Flashcards
1
Q
what is osmoregulation
A
- regulation of solute concentrations and balance of gain and loss of water
2
Q
what is excretion
A
removing nitrogenous metabolites and other waste products
3
Q
what is osmolarity
A
solute concentration of a solution
4
Q
how do land mammals gain water
A
- drinking and eating
- using metabolic water
5
Q
how do desert animals gain/save water
A
- anatomical features (hump)
- behaviours (nocturnal)
6
Q
compare ammonia, urea and uric acid
A
ammonia - fish, need lots of water (highly soluble), dilute urine, toxic
urea - mammals, less toxic, reduced water but still required, very energetically expensive
uric acid - reptiles and birds, insoluble, secreted as paste, medium toxicity, energetically expensive
7
Q
what are the processes of the excretory system
A
- filtration = pressure-filtering of body fluids
- reabsorption = reclaiming valuable solutes
- secretion = moving toxins and other solutes from the body fluids to filtrate
- excretion = removing filtrate from the system
8
Q
what blood vessels flow to the kidneys
A
- renal artery - supplies blood to be filtered
- renal vein - drains kidney
9
Q
basic structure/flow of kidneys
A
- blood enters, passed through nephrons which have two layers (the renal medulla inner, renal cortex outer). blood resorbs water, urine with filtrate exits kidneys via ureters to urinary bladder, excreted via urethra.
10
Q
structure of nephrons
A
- ball of capillaries = glomerulus - filtration occurs, filtration of salts, glucose, amino acids into filtrate (SMALL molecules)
- bowman’s capsule surrounds glomerulus and receives filtrate
- Proximal tubule reabsorbs ions, water and nutrients into capillaries. Some secretion occurs
- loop of Henle reabsorbs water via channels formed by aquaporin proteins on descent, only salts can be reabsorbed on the way up.
- disal tubule regulates K+ and NaCl conc
- collecting duct carries filtrate to ureters
11
Q
variation in loop of henle
A
- longer = dry environment for more water reabsorption
- birds have shorter to reduce water weight
12
Q
adaptations of freshwater animals (fish and amphibians)
A
- conserve salt in distal tubules and excrete large volumes of dilute urine
- amphibians reabsorb water from urinary bladder when on land
