PRELIM-renal function Flashcards
how many percent of blood that is pumped by the heart are being filtered by the kidney?
25%
Plasma filtrate must pass through three glomerular filtration
barrier cellular layers: the ___, the ___, and the ___
capillary wall membrane,
basement membrane (basal lamina)
visceral epithelium of
Bowman’s capsule.
The endothelial cells of the capillary wall differ from those in other capillaries by containing pores and
are referred to as ___.
fenestrated
In addition to the structure of the glomerular filtration bar
rier that prohibits the filtration of large molecules, the barrier
contains a ____ positive charge even though they are small enough to pass
through the three layers of the barrier
shield of negativity that repels molecules with a
example of a component being repelled by a shield of negativity
albumin
albumin (the primary protein associated with
renal disease) has a positive charge and would easily pass
through the barrier
what are the Factors influence the actual filtration process
- Cellular structure of the capillary walls and bowman’s capsule
- Hydrostatic and oncotic pressures
- Feedback mechanisms of the renin angiotensin-aldosterone system
a part of glomerulus that is
o Containing pores and are referred to as fenestrated
o Pores increase capillary permeability but do not allow the passage of large molecules and blood cells
- Capillary wall membrane
a part of glomerulus that is
o Restriction of large molecules occurs as the filtrate passes
- Basement membrane
a part of glomerulus that is
o Thin membranes covering the filtration slits formed by the intertwining processes of the podocytes of the inner layer of bowman’s capsules
- Visceral epithelium of bowman’s capsule
- Prevent a marked decrease in blood flowing through the kidney, thus preventing an increase in the blood level of toxic waste products
Dilation of the afferent arterioles and constriction of the efferent arterioles
a mechanism of the arterioles managed by the juxtaglomerular apparatus
to prevent over-filtration or damage to the glomerulus
constriction of the afferent arterioles and the dilation of the efferent
regulates the flow
of blood to and within the glomerulus. The system responds
to changes in blood pressure and plasma sodium content that
are monitored by the juxtaglomerular apparatus
The renin-angiotensin-aldosterone system
what are the function of angiotensin II
: causing vasodilation of the afferent arterioles and constriction of the efferent arterioles
: stimulating reabsorption of sodium and water in the proximal convoluted tubules,
: triggering the release of the
sodium-retaining hormone aldosterone by the adrenal cortex
: Release of antidiuretic hormone from hypothalamus.
the action of ___ is to produce a constant pressure within the
nephron
angiotensin II
only difference between the compositions of the filtrate and the plasma is the __
absence of plasma protein, any protein-bound substances, and cells.
the specific gravity of a fluid leaving the glomerulus and stating that it is really an ultrafiltrate of the plasma is __
specific gravity of 1.010
what are the two/2 cellular mechanisms involved in tubular reabsorption
active transport and passive transport.
a cellular mechanism involved in reabsorption that needs a carrier protein contained in the membrane of the renal tubular epithelial cells
active transport
active transport is responsible in reabsorption of ____ in ____
glucose, amino acids, and salts in the proximal convoluted tubule,
chloride in the ascending loop of Henle,
sodium in the distal convoluted tubule.
passive transport is responsible in reabsorption of ____ in ____
WATER in Proximal convoluted tubule
Descending loop of Henle
Collecting duct
urea in Proximal convoluted tubule
Ascending loop of Henle
sodium in Ascending loop of Henle
the movement of molecules across a
membrane as a result of differences in their concentration or
electrical potential on opposite sides of the membrane
passive transport
what is it called to a physical differences in the concentration or electric potential on opposite sides of the membrane; related to passive transport
gradient
which part of the nephron is impermeable to water?
ascending loop of henle
if the concentration of the substances needed to be reabsorved reached the ___ the substances will appear on the urin
maximal reabsorptive capacity
The plasma concentration at
which active transport stops is termed the ___.
renal threshold
renal threshold for glucose
160-180 mg/dl
Glucose appearing in the urine of a
person with a normal blood glucose level is the result of
tubular damage and not diabetes mellitus.
true or false
true
A non fasting
patient with high glucose intake would not have a normal
blood glucose.
true or false
true
Renal concentration begins in the ___, where the filtrate is exposed to the high
osmotic gradient of the renal medulla
descending and ascending
loops of Henle
Water is removed by
osmosis in the descending loop of Henle, and sodium and
chloride are reabsorbed in the ascending loop. Excessive reab
sorption of water as the filtrate passes through the highly con
centrated medulla is prevented by the water-impermeable walls
of the ascending loop. This selective reabsorption process is
called the ___ and serves to maintain
the osmotic gradient of the medulla
countercurrent mechanism
The final concentration of the filtrate through the reabsorption
of water begins in the ___ and -__
late distal convoluted tubule and continues in the collecting duct
in collecting duct, A high level of ADH
will what the permeability and what will happen to the urine concentration
A high level of ADH
increases permeability, resulting in increased reabsorption of
water, and a low-volume concentrated urine
what is the actual final determinant of urine volume and concentration?
chemical balance in the body
2 purpose of tubular secretion
eliminating waste products not filtered by the glomerulus
regulating the acid–base balance in the body through the secretion of hydrogen ions.
The major site for removal of these nonfiltered substances/ or for the secretion is
the ___
proximal convoluted tubule
ammonia is
produced from the breakdown of the __
amino acid glutamine.
explain how bicarbonate ions are kept in the plasma and prevented from getting ecreted by the hydrogen ions
the secretion
of hydrogen ions (H+) by the renal tubular cells into the filtrate
prevents the filtered bicarbonate from being excreted in the
urine and causes the return of a bicarbonate ion to the plasma.
where does the hydrogen ions are secreted?
in the proximal convoluted tubule
aside from the distal convoluted tubule, which part of the nephron is able to secret ammonium ion as well?
collecting duct
A disruption
in these secretory functions can result in ___, the inability to produce an acid urine.
metabolic acidosis or
renal tubular acidosis