Lecture 22-Excretory System Flashcards
The average human lungs are composed of _____% water.
90%
The average human body is composed of _____% water.
60%
The average human skin is composed of _____% water.
80%
The average human blood is composed of _____% water.
82%
The average human brain is composed of _____% water.
70%
The average human muscle is composed of _____% water.
75%
The average human bones are composed of _____% water.
22%
Maintaining internal water balance, or __________, is extremely important.
Osmoregulation
__________ is a special type of diffusion of water across a selectively permeable membrane.
Osmosis
In osmosis, water moves from an area of __________ to __________ free water concentration.
Higher to lower
In osmosis, water moves from an area of __________ to __________ solute concentration.
Lower to higher
Osmosis occurs whenever two solutions separated by the membrane differ in __________.
Osmolarity
Total solute concentration expressed as morality (milliOsmoles/L).
Osmolarity
Water flows by osmosis from a __________ solution to a __________ one.
Hypoosmotic—->Hyperosmotic
Hypoosmotic: __________ solute concentration, __________ free water concentration.
Lower, higher
Hyperosmotic: __________ solute concentration, __________ free water concentration.
Higher, lower
__________ __________ must be removed.
Metabolic wastes
Nitrogenous wastes are produced in the form of __________, which is very toxic.
Ammonia
Ammonia needs to be __________ or __________ to less toxic ones.
Diluted, converted
Nitrogenous wastes must be __________ _____ __________ to be excreted from the body.
Dissolved in water
The removal of metabolic wastes has a large impact on an animal’s:
Water balance
The three different types of nitrogenous wastes are:
Ammonia, urea, and uric acid
Very low toxicity, conversion from ammonia costs energy.
Urea
Highly toxic, highly soluble, easily lost by diffusion.
Ammonia
Nontoxic, does not dissolve in water, energetically very expensive.
Uric acid
Found in fish.
Ammonia
Found in mammals.
Urea
Found in birds.
Uric acid
__________ is the process that removes metabolic waste from the body through osmoregulation.
Excretion
Excretion is the process that removes metabolic waste from the body through __________.
Osmoregulation
Excretion is different from __________.
Defecation
The 4 main stages of excretion are:
Filtration—–> Reabsorption —–> Secretion —–> Excretion
Water and small solute from blood to excretory tubule.
Filtration
Processed filtrate released as urine.
Excretion
Nonessential solutes and wastes added to excretory tube.
Secretion
Valuable solutes (glucose, salt, vitamins, hormones, animo acids) and water back to blood.
Reabsorption
What in the excretory ruble makes filtering possible?
Selectively permeable membrane
The excretory system is an efficient __________ __________.
Filter system
The glomerulus is the site for:
Filtration
Glomerular capillaries and epithelial tissues in the Bowman’s capsule are permeable through these, but not blood cells and large molecules.
Water and small solutes
__________ __________ contains water, salts, glucose, amino acids, vitamins, nitrogenous wastes, etc.
Initial filtrate
Specialized regions of a nephron are the sites for __________ and __________.
Reabsorption, secretion
What is the direction of filtrate flow?
Bowman’s capsule —–> proximal tubule —–> Loop of Henle —–> distal tubule —–> collecting duct —–> urine
In the Loop of Henle, the descending limb is permeable to __________ but not to __________.
Water, solutes
In the Loop of Henle, the ascending limb is permeable to __________ but not to __________.
Solutes, water
In the Loop of Henle, the descending limb is permeable to water but not to solutes, but the ascending limb is permeable to solutes and not to water. This is very important in establishing __________ ___________ inside the kidneys.
Concentration gradient
Reabsorption of ions, water, nutrients; secretion of H+ and ammonia.
Proximal tube
Reabsorption of water.
Descending limb of the Loop of Henle
Reabsorption of salt.
Ascending limb of the Loop of Henle
In the reabsorption of salt, salt diffuses out at the __________ __________.
Thin segment
In the reabsorption of salt, active transport of salt happens at the __________ __________.
Thick segment
Reabsorption of salt, water, and bicarbonate; secretion of K+ and H+.
Distal tubule
Reabsorption of salt, water, and urea.
Collecting duct
The kidneys __________ __________ by maintaining osmolarity gradient.
Concentrate urine
__________ and __________ contribute to the osmolarity gradient.
NaCl and urea
Countercurrent system that expends energy to create concentration gradient.
Countercurrent multiplier system
The kidney has one of the highest __________ __________ of any organ.
Metabolic rates
_____ L of blood flows through a pair of kidneys each day.
1,600
Nephrons process _____ L if initial filtrates.
180
_____% of water, sugar, amino acids, vitamins, and nutrients are reabsorbed in blood.
99%
_____ L of urine is produced each day.
1.5
Some foods we take in are __________ and can have effects on kidney function (ex: alcohol and caffeine).
Diuretic
Inhibits ADH (antidiuretic hormone) secretion.
Alcohol
Inhibits reabsorption of Na+, increases glomerular filtration rate.
Caffeine
A painful inflammation of the joints caused by deposits of uric acid crystals.
Gout
When urine does not have the correct balance of fluid and a combination of minerals and acids.
Nephrolithiasis (kidney stones)
In the vertebrate kidney, the portion of a nephron that helps refine filtrate and empties it into a collecting duct.
Distal tubule
The location in the kidney where processed filtrate, called urine, is collected from the renal tubules.
Collecting ducts
One of the tiny blood vessels that form a network surrounding the proximal and distal tubules in the kidney.
Peritubular capillary
The capillary system in the kidney that serves the Loop of Henle.
Vasa recta
A duct leading from the kidney to the urinary bladder.
Ureter
The pouch where urine is stored prior to elimination.
Urinary bladder
A tube that releases urine from the mammalian body near the vagina in females and through the penis in males; also serves in males as the exit tube for the reproductive system.
Urethra
Two solutes contribute to the osmolarity of the interstitial fluid:
NaCl and urea
Flatworms have __________, branching internal tubules.
Protonephridia
Annelids have __________, which collect coelomic fluid from the adjacent anterior segment.
Metanephridia
Insects have __________ __________, outpocketings of digestive tract that remove nitrogenous wastes.
Malpighian tubules
