Biology Urinary System Flashcards
___ of amino acids in the liver leads to the production of nitrogenous wastes, such as urea an ammonia
deamination
Excretion is distinguished from ___, the removal of indigestible material such as dietary fiber
elimination
In the lungs, ___ and water vapor diffuse from the blood and are continually exhaled
carbon dioxide
Each ___ is composed of one million functional units called nephrons
kidney
The ___ is divided into three regions: the outer cortex, the inner medulla, and the renal pelvis
kidney
A nephron consists of a bulb called Bowman’s capsule, which embraces a special capillary bed called a ___
glomerulus
___ capsule leads to a long, coiled tubule divided into functionally distinct units: the proximal convoluted tubule, the loop of Henle, the distal convoluted tubule, and the collecting duct
Bowman
The ___ is positioned such that the loop of Henle and collecting duct run through the medulla, while the convoluted tubules and bowman’s capsule are in the cortex
nephron
___ forces 20 percent of the blood plasma entering the glomerulus through its capillary walls and into the surrounding Bowman’s capsule (filtration)
blood pressure
The fluid and small ___ entering the nephron are called the filtrate (filtration)
solutes
The filtrate is ___ with blood plasma (filtration)
isotonic
___ is a passive process driven by the hydrostatic pressure of the blood
filtration
Secretion: The nephron secretes waste substances such as acids, ions, and other metabolites from the interstitial fluid into the filtrate by both passive and active ___
transport
Reabsorption: essential substance (glucose, salts, and amino acids) and water are ___ from the filtrate and returned to the blood
reabsorbed
Reabsorption: occurs primarily in the proximal convoluted ___ and is an active process
tubule
Reabsorption: movement of these molecules is accompanied by the passive movement of water because water passively follows ___
solute
Reabsorption: after the passive movement of water, results in the formation of concentrated urine, which is ___ to the blood
hypertonic
Once the ___ is concentrated in the nephron, it flows into the ureter and is considered urine
filtrate
The ___brings the urine from the kidney to the urinary bladder, where urine collects until expelled
ureter
The ___ is the site of filtration; plasma and blood solutes are filtered and become the filtrate
glomerulus
Dump the HUNK H+ Urea NH3 K+
Major waste products excreted in the urine
The ___ first enters the proximal convoluted tubule (PCT)
filtrate
In the ___, almost 70 percent of filtered sodium will be reabsorbed
PCT
The nephron walls in the PCT are permeable to water; therefore, large amounts of water follow the sodium, thus being reabsorbed through ___
osmosis
Reabsorbed solutes (taken from the nephron) re-enter circulation through the peritubular capillaries, which are part of the ___ (capillaries that surround the nephron)
vasa recta
In addition to ___, the PCT is also the site of secretion for waste products, such as hydrogen ions, potassium ions, ammonia, and urea
reabsoprtion
Filtrate from the ___ enters the descending limb of the loop of Henle, which dives deep into the medulla before turning around to become the ascending limb of the loop of Henle
PCT
The descending limb is permeable to only water, and because the ___ of the medulla increases deeper into the kidney, water leaves the filtrate (osmosis) as it goes deeper into the medulla
osmolarity
The ascending limb of the loop of Henle is only permeable to salts and is ___ to water
impermeable
In the ascending limb, at the deeper parts of the ___, salt concentrations are high, but decrease as the ascending limb rises
medulla
In ascending limb, increasing amounts of salt are removed from the ___ as it travels up the loop of Henle
filtrate
At the transition from the inner to outer medulla, the loop of Henle thickens, becoming the ___ ascending limb of the loop of Henle
thick
The thick ascending limb of the loop of henle’s thickening occurs due to the ___ of the cells lining the tube, which is due to the increased number of mitochondria
enlargement
In the thick ascending limb of the loop of henle, the extra ___ produce additional ATP needed to power active transporters that pump out Na+ and Cl- from the filtrate
mitochondria
The thick ascending limb of the loop of henle is also known as the ___ segment
diluting
After the thick ascending limb of the loop of henle, next the filtrate enters the ___ convoluted tubule (DCT)
distal
The ___ responds to aldosterone, which promotes sodium reabsorption and, therefore, water reabsorption
DCT
The final concentration of the ___ will depend largely on the permeability of the collecting duct, which is responsive to both aldosterone and antidiuretic hormone (ADH)
urine
As ___ of the collecting duct increases (extends into the medulla), so too does water reabsorption, resulting in further concentration of the urine
permeability
The collecting duct almost always reabsorbs ___, but the amount is variable
water
When the body is well hydrated, the collecting duct will be fairly ___ to salt and water
impermeable
When in water conservation mode, ADH and aldosterone will each act to increase ___ of water, thus, producing more concentrated urine
reabsorption
Once the ___ leaves the collecting duct, it can then leave the kidney
filtrate
The process of regulating the concentration of ___ in urine is known as the countercurrent multiplier system, a system in which energy is used to create a concentration gradient
solutes
The ___ the osmolarity gradient, the more concentrated the urine
greater
___ is a steroid hormone that upregulates the active transport of sodium and potassium ions along the distal convoluted tubule and collecting duct, resulting in decreased excretion of sodium ions and increased excretion of potassium ions in the urine
aldosterone
More Na+ ions are ___ than K+ ions that are excreted
reabsorbed
The Na+/K+ disparity causes more water ___ since water flows to the area of higher solute concentration through osmosis
reabsorption
___ (ADH) directly affects water reabsorption in the distal convoluted tubule and collecting ducts by opening additional aquaporins (water channels) in these structures
antidiuretic hormone (ADH)
Via ADH, the opening of water channels allows water to leave the ___ and be reabsorbed more readily
nephron
Both ADH and aldosterone cause a decrease in urine output and a corresponding increase in blood pressure, allowing the body to ___ for periods of dehydration or other causes of low blood pressure
compensate
Aldosterone does not affect the osmolarity of the blood, because it reabsorbs both salt and water; while ADH does affect the ___ of the blood, because it primarily acts to reabsorb water
osmolarity
Increases in blood Co2 result in a right shift of the bicarbonate buffer system (via the Le Chatelier Principle), thus increasing H+ ___ and decreasing pH
concentration
Decreases in blood CO2 do the opposite, resulting in an ___ pH (more basic)
increased
___ regulation (as opposed to Respiratory) affects blood pH through changes in HCO3 and H+, which is regulated in the kidney
metabolic
As the ___ secretes more H+ into the urine, the more basic (higher pH) the blood becomes and vice versa
kidney
The more HCO3- excreted (less reabsorbed) the more acidic the blood will become, due to the ___ shift of the bicarbonate buffering system
equilibrium
Compensation mechanisms that affect HCO3- (as opposed to PCO2 in the lungs - brief) are performed by the ___, and therefore the compensatory effect can take longer to manifest
kidneys
