83 terms


PCOM SD Human Physiology Spring 2011 - Functions, gross & micro anatomy, glomerular filtrate, formation of urine, urine concentration & dilution, pH maintenance in body
1. Maintain water concentration
2. Maintain elecrolyte balance
3. Filter nitrogenous wastes
4. Secretes hormone erythropoietin to stimulate erythropoesis
5. Help regulate blood pressure via renin secretion
6. Primary site where vitamin D is converted to its active form
Name the 6 functions of the kidneys.
Name the functional unit of the kidney
renal artery
Blood supply comes to the kidney via the _________ ___________.
(a) afferent arteriole, (b) efferent arteriole, (c) peritubular capillaries, (d) vasa recta
Within the glomerular capsule, blood flows thru both the cortical nephron & juxtaglomerular nephron first thru the (a)__________ __________, out thru the (b)_________ __________ then thru the (c)_________ ____________. In the juxtamedullary nephron blood flows thru another set of capillaries off the efferent arteriole called the (d) ________ __________.
glomerular filtrate
Substances & plasma that collect in the glomerular (Bowman's) space to be processed and eventually become urine, is known as ___________ ____________.
formed elements, albumin
_____________ ____________ & ____________ do NOT go thru filtration slits.
filtration slits, basement membrane
The glomerular filtration barrier is comprised of __________ ___________ and ____________ _____________.
Filtration slits are found on ________________ in the visceral layer of the glomerular (Bowman's) capsule.
The basement membrane is found in the epithelial layer of the ____________.
T or F: A MAJORITY of the glomerular filtration leaves the body via urine.
glomerular filtration rate (gfr)
The rate at which filtration is formed is called the _____________ _______________ _____________ (______).
The kidneys are located ______________ at levels of T12 to L.
renal corpuscle
The glomerulus, balls of capillaries, are found in the ____________ _____________.
Bowman's space
Glomerular filtration occurs in ____________ _____________.
plasma solutes
Glomerular filtration is composed of _________ ________ from blood.
1-proximal convoluted tubule, 2-loop of Henle, 3-distal convoluted tubule
Name the 3 parts of the renal tubules in the order that filtrate passes thru them.
T or F: A MAJORITY of filtrate is reabsorbed into the body.
glomerular (Bowman's) capsule
The function of the glomerular capillaries is to filter plasma solutes into the _____________ (_____________) ____________.
vasa recta
Urine is diluted and concentrated in the __________ ________, lateral-like blood vessels connecting the sides of the loop of Henle in the juxtamedullary nephron.
hydrostatic, increase
Blood pressure in glomerular capillaries/fluid pressure in Bowman's space or the filtration going into Bowman's capsule is ___________ pressure. Therefore, if there is an increase in blood pressure, will the filtration rate increase or decrease?
Plasma proteins that are too large to pass into the glomerular capsule stay in the blood and are kept in the capillaires due to ___________ pressure.
net filtration pressure
The balance of force that opposes filtration & that encourages filtration is referred to as _____ _____________ ___________.
myogenic mechanism, tubulo-glomerular mechanism
Name the 2 intrinsic, autoregulatory mechanisms that regulate mean arterial pressure within the nephron.
If increasing systemic blood pressure causes the afferent arterioles to constrict, restricting blood flow into the glomerulus, does this increase or decrease glomerular blood pressure?
myogenic mechanism
What is the intrinsic autoregulatory process that causes constriction or dilation of the afferent arterioles to maintain a constant GFR?
filtrate flow rate
Sodium-chloride concentration in the blood directly correlates with the ____________ ___________ __________.
tubuloglomerular feedback mechanism
What is the intrinsic autoregulatory process that monitors the amount of sodium-chloride of filtrate in the glomerulus?
macula densa cells
Name the structure between the loop of henle & DCT that directs the process of the tubuloglomerular feedback mechanism.
When GFR increases & sodium-chloride concentration increases, the macula densa cells release a chemical that _______________ (constricts or dilates) the afferent arteriole.
If the macula densa cells trigger a vasoconstrictor chemical causing an constriction of the afferent arteriole, does the NFP & GFR increase or decrease?
If sodium-chloride is low, do macula densa cells cause the afferent arteriole to constrict or dilate?
sympathetic nervous system, renin-angiotensin mechanism
Name the 2 extrinsic controls that participate in GFR regulation.
extrinsic controls
In cases of extreme changes in blood pressure, which takes precedence in the nephron - extrinsic controls or intrinsic controls?
angiotensin II
What hormone stimulates reabsorption of sodium?
atrial natriuretic peptide (ANP)
Name the hormone that affects several processes that lowers sodium content in the blood.
proximal convoluted tubule (PCT)
100% of glucose is reabsorbed in the ______________ ____________ __________ (_____).
sodium co-transport (passive diffusion)
Glucose enters the tubule cell via __________ ________ (__________ __________).
sodium potassium pump (active transport)
Glucose moves out of the tubule cells via the ________ ___________ ____________ (____________ ___________).
tubular reabsorption, tubular secretion
Name the 2 processes that occur during the flow of filtrate thru the nephron.
ADH (anti-diuretic hormone)
In order for sodium reabsorption to take place in the collecting duct, what hormone must be released?
descending Loop of Henle
Where does water reabsorption into the renal medulla take place?
ascending Loop of Henle
Where does sodium reabsorption into the renal medulla take place?
thin ascending loop of Henle
Sodium is actively reabsorbed in the nephron as it uses the active transport like in tubular reabsorption of glucose except in what area where it is passively transported via Na Channels into and out of cells?
Name the hormone that stimulates the nephron to take in more sodium.
juxtamedullary nephron
In what part of the nephron does the concentration & dilation of urine take place?
Osmolarity of the interstitial fluids in body tissues is monitored by what?
aquaporins, peritubular capillaries
ADH acts on the nucleus of the tubular cells in the DCT & collecting duct to create ______________ that are inserted into cell membranes creating water channels that reabsorb water out of the filtrate as it passes into the ___________ __________.
hypothalamus, ADH
When dehydration occurs osmoreceptors send signals to the "thirst center" and a group of neurons in the supraoptic nucleus of the __________________ to begin manufacturing ________.
When filtrate has the same osmolarity as blood, it is said to be ____________.
When filtrate has less osmolarity than blood, it is said to be ____________.
When filtrate has more osmolarity than blood, it is said to be ____________.
Loop of Henle of the juxtamedullary nephron
Where is the countercurrent multiplier located?
vasa recta of the juxtamedullary nephron
Where is the countercurrent exchanger located?
collecting duct, intermedullary interstitium, thin Loop of Henle
Name the 3 parts of the "urea recycling center."
sodium, chloride, urea
Name the 3 substances present in the medullary interstitium that contribute to its osmolarity.
Does the osmolarity of the renal medulla become higher or lower with increasing depth into the medulla?
As filtrate moves down the descending Loop of Henle, what happens to the osmolarity? Does it become isoosmotic, hyperosmotic, or hypoosmotic?
As filtrate leaves the ascending Loop of Henle & enters the DCT is it isoosmotic, hyperosmotic, or hypoosmotic?
Under normal circumstances, does urine leave the body in a concentrated or dilute form?
Under normal circumstances, what substance is the collecting duct permeable to?
blood & medullary interstitium
Within the vasa recta, the exchange of solutes (Na, Cl, urea) happens between what 2 entities?
The function of the vasa recta is to maintain the ________________ in the medullary interstitium.
high, water, sodium chloride
Within the descending loop of the vasa recta, blood is moving into area of ______ osmolarity. __________ from blood plasma moves into the medullary interstitium & _________ moves into the vasa recta.
Due to the high concentration of NaCl in the bottom of the loop in the vasa recta, blood is _______________ to the fluid in the medullary interstitium and moves very slowly.
water, sodium chloride
Within the ascending loop of the vasa recta, _______ flows into the vasa recta and __________ ____________ flows into the medullary interstitium.
As blood flow from the ascending loop of the vasa recta moves into the renal vein, it is _______________ compared to the blood in the medullary cortex.
T or F: Urea is recycled in the vasa recta entering the descending loop & exiting the ascending loop.
7.35, 7.45
Body tissues must maintain pH within the range of ________ to ________.
If body tissue pH drops below 7.35, a state of _________ occurs.
If body tissue pH rises above 7.45, a state of _________ occurs.
acceptor, greater
A base is a hydrogen _____________. The less free hydrogen in the body tissues, the __________ the pH.
donor, lower
An acid is a hydrogen _________. The more free hydrogen in the body tissues, the ________ the pH.
chemical buffers, respiration, renal mechanisms
Name the 3 mechanisms that maintain pH in body tissues.
monohydrogen phophate, dihydrogen phosphate
Name the 2 chemical buffers found with the nephrons of the kidney.
Name the most abundant base in the body, found inside & outside of cells.
amino acid, carboxyl group
Name the 2 protein chemical buffers that can act as a base or acid, also known as amphoteric molecules.
carbon dioxide, carbonic acid, hydrogen, carbonic acid
In cellular respiration, the body's pH is maintained thru a reversible equilibrium among ____________ ___________ plus water exchanged with a _____________ _____________ and __________________ plus a bicarbonate ion also exchanged with ____________ _________.
bicarbonate ion (HCO3)
The pH of blood varies directly with ___________ ______.
With metabolic acidosis, does respiration increase of decrease?
bicarbonate ion, hydrogen
Name the 2 ions involved in pH balance in the renal mechanism.
In the renal mechanism, if the urine is too acidic, does the body need to reabsorb or excrete hydrogen?
In the renal mechanism, if the urine is too alkaline, does the body need to reabsorb or excrete hydrogen?
renal mechanism
Among the 3 mechanisms that maintain the pH balance, which one is the "last line" of defense kicking in when the other 2 fail, taking hours to days to establish equilibrium