chapter 36: body fluid regulation and excretory system Flashcards
what are the two components of animal excretory systems?
- osmoregulation
- excretion
what is osmoregulation
balancing of water
water following solutes (salt)
what are nitrogenous waste products?
-Amino acids & nuclei acids
-Excess nitrogen released
-Ammonia, urea, or uric acid
what are some excretory organs in invertebrates?
Most insects have tubular excretory organs
Planarians
Flame cells
Earthworm:
Nephridia
how do insect excretory systems work?
-Malpighian tubules
-Attached to gut
-Aquatic environments reabsorb little water
-Dry environments reabsorb most water
how does osmoregulation in cartilaginous fishes work?
Nearly isotonic to seawater
Excess salts secreted by kidneys & rectal gland
what are the 4 steps of the human urinary system?
- kidneys produce urine
- ureters transport urine
- urinary bladder stores urine
- urethra passes urine to outside
what are the 5 reasons kidneys are important?
- Osmoregulation
- Water balance
- Maintain blood volume
- Regulate Blood pressure
- Produce urine
what are the three main parts of the kidneys?
- Renal cortex
- Renal medulla
- Renal pelvis
what are nephrons
Each kidneys composed of over 1 million tiny tubules called nephrons
what are the 5 main parts of the renal cortex?
-glomerulus
-proximal convoluted tubule
-loop of the nephron
-distal convoluted tubule
-collecting duct
what are the three main components of urine formation?
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
osmosis plays a big role
what is glomerular filtration?
-Blood pressure moves small molecules
-Water, nutrients, salts, wastes
-Glomerular filtrate
-Blood cells & proteins too large to cross
-Concentration of protein in blood is higher in post-glomerular blood than in arterial blood
what is tubular reabsorption?
-Substances move across tubules
-Osmosis
-Nutrient molecules are taken back into blood from urinary filtrate
what is tubular secretion?
-Second way substances are removed from blood & added to tubular fluid
-Rid body of potentially harmful compounds that were not filtered into glomerulus
-H+, uric acid, salts, ammonia, creatine, and penicillin
what are the 4 ways the kidneys contribute to homeostasis?
- Excrete metabolic wastes
- Maintain the water-salt balance
- Maintain acid-base balance
- Secrete hormones
how do the kidneys maintain the water-salt balance?
-Most water and salt (NaCl) reabsorbed
-Excretion of hypertonic urine is dependent
what happens in the loop of nephron?
-Salt diffuses out
-Urea leeks collecting duct
-Hypertonic environment
-Water drawn out
how do hormones control the reabsorption of salt?
-Blood volume (therefore pressure) in part regulated by salt absorption
-Not sufficient to promote glomerular filtration secrete renin
-Series of enzymatic reactions
-Reabsorption of Na+ distal tubule
how do kidneys maintain the acid-base balance?
-Cells influenced by pH
-Bicarbonate (HCO3-) buffer system
-Urine is typically acidic because of typical excess of H+ ions
-Ammonia (NH3) provides buffer
Excretion is a process in which ____ is (are) removed from the body
a.
Feces
b.
Salt
c.
Metabolic wastes
d.
Hormones
e.
Water
c.
Metabolic wastes
When ________ and _________ are broken down excess nitrogen is released that must be eliminated by the excretory system.
a.
nucleic acids; sulfur
b.
proteins; salts
c.
glucose; fatty acids
d.
amino acids; nucleic acids
d.
amino acids; nucleic acids
Malpighian tubules are the excretory system attached to the gut in
a.
Planarians
b.
Humans
c.
Earthworms
d.
Insects
d.
Insects
The concentration of protein in the blood is higher in post-glomerular blood than in arterial blood because
a.
Protein is digested and then concentrated in glomerular (Bowman’s) capsule
b.
Reabsorption of protein occurs
c.
Water concentration increases and protein concentrations decrease
d.
Water passes into the capsule, but protein molecules are too large to move into the capsule and are concentrated in the blood
e.
The kidney manufactures and then stores protein in the glomerulus
d.
Water passes into the capsule, but protein molecules are too large to move into the capsule and are concentrated in the blood
