physio 9 practical 3
increasing the radius of afferent arteriole does what?
GCP and GFP increase
If there is an increase in beaker pressure (blood pressure), what happens
GCP and GFR will increase --> increased in urine production
what will happen to the filtrate pressure in Bowman capsule and the filtration rate if you close the one way valve between the collecting duct and the urinary bladder
GFR will decrease and the hydrostatic pressure (GCP) will increase
Approximately 20% of the blood that enters the glomerular capillaries is normally filtered into Bowman's capsule, where it is then referred to as __.The unusually ___ in the glomerular capillaries promotes this filtration. Thus, the ___ can be altered by changing the afferent arteriole resistance (and, therefore, the hydrostatic pressure). In this activity you will explore the effect of blood pressure on the glomerular filtration rate in a single nephron
filtrate. high hydrostatic blood pressure glomerular filtration rate
Both the blood pressure in the __ and the___ pressure in the renal tubule can have a significant impact on the glomerular filtration rate.
glomerular capillaries filtrate
The __ and __ can be altered if the afferent or efferent arteriole is adjusted
glomerular capillary pressure (GCP) glomerular filtration rate (GFR)
a passive process in which fluid passes from the lumen of the glomerular capillary into the glomerular capsule of the renal tubule.
glomerular filtration
During glomerular filtration, blood enters the glomerulus from the afferent arteriole and protein-free plasma flows from the blood across the walls of the glomerular capillaries and into the Bowman's capsule. The __ is an index of kidney function. In humans, the filtration rate ranges from 80 to 140 ml/min, so that, in 24 hours, as much as 180 liters of filtrate is produced by the glomeruli. The filtrate formed is devoid of cellular debris, is essentially protein free, and contains a concentration of salts and organic molecules similar to that in blood.
glomerular filtration rate
The __________ is a capillary knot that filters fluid from the BLOOD into the RENAL TUBULE
glomerulus
Two arterioles are associated with each __: an afferent arteriole feeds the glomerular capillary bed and an efferent arteriole drains it.
glomerulus
where we take blood and turn it into filtrate; main site
glomerulus
The renal corpuscle consists of a "ball" of capillaries, called the __, which is enclosed by a fluid-filled capsule, called ___, or the glomerular capsule
glomerulus Bowman's capsule
During sympathetic activation, the sympathetic nerves innervating the kidneys cause decreased urine by causing constriction of the AFFERENT arteriole- less blood reaches the ___ and therefore less blood is filtered which leads to less urine produced
glomerulus filtered
___is filtered out during the filtration process. But in a non-diabetic person, there are sufficient ___ in the proximal convoluted tubules for the reabsorption of all of glucose in the filtrate.
glucose glucose carriers
diabetes mellitus
glucose/ glycosuria
urinary tract irritation by kidney stones, urinary tract infection
hematuria
hemolytic anemia, poisonous snake bites, renal disease
hemoglobin/ hemoglobinuria
However, if someone has high blood pressure, the __ may damage kidney blood vessels and reduce its ability to FILTER BLOOD
high hydrostatic pressure (GCP)
Starling forces (____ and __ pressure gradients) drive protein-free fluid between the blood in the glomerular capillaries and the filtrate in Bowman's capsule.
hydrostatic and osmotic
Under what conditions would excess glucose be eliminated in the urine?
hyperglycemia
Diuretics cause an__ in urine production. The urine produced is usually lower in solute concentration. Diuretics work by either inhibiting __or by altering the __ of the interstitial fluid (and thus affect the concentration and volume of the urine produced)
increase ADH secretion solute concentration
decreasing the efferent arteriole radius does what?
increase in GCP and GFR
In a diabetic that cannot regulate his/her blood glucose levels, high amounts of glucose might be found in blood. This will cause an__ at the glomerulus.
increase in the amount of glucose filtered out
The ___ is what draws out water from the renal tubule. An increase in the interstitial solute gradient will cause an increase in ___(as seen in the juxtamedullary nephrons).
interstitial space solute gradient H2O reabsorption
low carb diet, starvation
ketone bodies/ketonuria
The __ is both an excretory and a regulatory organ.
kidney
During low blood pressure conditions, the body can react by __ the afferent arteriole and __ the efferent arteriole to maintain the GCP and GFR.
low blood dilating constricting
Sympathetic innervation: Besides reducing the amount of urine produced, it has the effect of ___. If this persists for too long, waste products and excess ions will build up in blood and affect homeostasis.
maintaining blood volume and pressure
These arterioles are responsible for blood flow through the glomerulus
afferent arteriole efferent arteriole
An __supplies blood to the glomerulus. As blood flows through the glomerular capillaries, protein-free plasma filters into the ___, a process called glomerular filtration. An __then drains the glomerulus of the remaining blood
afferent arteriole Bowman's capsule efferent arteriole
damage to glomerular membrane (kidney trauma, poisons/heavy metals), toxins, hypertension, pregnancy, excessive protein intake
albumin/albuminuria
What hormone is responsible for increasing the water permeability of the collecting duct, allowing water to flow to areas of higher solute concentration?
antidiuretic hormone (ADH, vasopressin)
The glomerular filtration rate can be altered by changing ___ or __
arteriole resistance arteriole hydrostatic pressure.
liver disease (hepatitis, cirrhosis)
bilirubinuria/ bile pigments
bacterial infection
bladder infection/ nitrites
Closing of the valve to the beaker collecting urine represents a ___. This blockage will cause an increase in the ___ in the Bowman's capsule and result in a decrease in the __ since that fluid pressure will oppose filtration
blockage of the collecting duct hydrostatic pressure (GCP) GFR
what will happen to the GCP and GFR if both of these arteriole radii changes are implemented simultaneously with low bp condition
both will rise above baseline values
collect fluid that comes out of glomerulus
bowman capsule
Glucose is not very large and is therefore easily filtered out of the plasma into Bowman's capsule as part of the filtrate.To ensure that glucose is reabsorbed into the body so that it can fuel cellular metabolism, glucose___ are present in the ___ cells of the nephron.
carrier proteins proximal tubule
Organisms (such as desert rats) living in arid conditions are able to __ (and lose less H2O during urination) since the interstitial fluid solute gradient is very high.
concentrate their urine
According to the data, decreasing the radius of the afferent does what?
decrease in GCP and GFR
activation of sympathetic nerves that innervate the kidney leads to a ___production. knowing that fact what do you think the sympathetic nerves do to the afferent arteriole
decreased urine production constrict arteriole (decrease radius)
A decrease in blood pressure causes what?
decreases GCP and GFR
__ cause increased in urine output by lessening the gradient between tubule and intersitital fluid
diuretics
removes excess fluids by increasing urine production thus lowering blood pressure
diuretics
People with high blood pressure may be prescribed __ to cause an increase in __ which will reduce __
diuretics urine production blood plasma volume and blood pressure.
The reabsorbed solutes and water that move into the interstitial space between the nephrons need to be returned to the blood, or the kidneys will rapidly swell like balloons. The __ surrounding the renal tubule reclaim the reabsorbed substances and return them to general circulation. Peritubular capillaries arise from the ___ exiting the glomerulus and empty into the renal veins leaving the kidney.
peritubular capillaries efferent arteriole
Normally, the number of glucose carriers is constant in a human kidney and that it is the__ that varies during the day.
plasma glucose
The filtrate flows from Bowman's capsule into the start of the renal tubule, called the ___, then into the __, a U shaped hairpin loop, and, finally, into the __ before emptying into a __. From the ___, the filtrate flows into, and collects in, the minor calyces (kidneys).
proximal convoluted tubule loop of Henle distal convoluted tubule collecting duct
urinary tract inflammation
pyuria/WBC
movement of filtrate out of the tubules, across the interstitial fluid and into blood of the capillaries
reabsorption
If there are excessive amounts of glucose in the filtrate, there will not be enough carriers for the ___ of all the glucose in the filtrate. 4. This will result in the presence of glucose in __
reabsorption urine
All of the following are functions of the kidney except: a. regulate the body's acid-base balance b. regulate the body's electrolyte balance c. regulate plasma volume d. regulate smooth muscle function of bladder
regulate smooth muscle function of bladder
Collectively, the glomerulus and Bowman's capsule are called the__
renal corpuscle
the function of the ___to process the filtered fluid,
renal tubule
Each of the million nephrons in each kidney contains two major parts: (1) a tubular component, the __, and (2) a vascular component, the __
renal tubule renal corpuscle
Aldosterone / Thyroid hormone acts on the distal convoluted tubule to cause sodium to be reabsorbed and potassium to be excreted.
Aldosterone
Starling forces / Tubular secretions are responsible for driving protein-free fluid out of the glomerular capillaries (glomerulus) and into Bowman's capsule.
Starling forces
Circle True or False: The glomerular filtration rate in humans is such that in 24 hours, approximately 180 liters of filtrate is produced.
True
The diameter of the efferent arteriole is smaller than the diameter of the afferent arteriole, thus ___blood flow out of the glomerulus. Consequently, the pressure in the glomerular capillaries forces fluid through the endothelium of the capillaries into the lumen of the surrounding ___. In essence, everything in the blood except for the blood cells (red and white) and __ is filtered through the glomerular wall. From the Bowman's capsule, the filtrate moves into the rest of the ___ for processing. The job of the tubule is to reabsorb all the beneficial substances from its lumen and allow the wastes to travel down the tubule for elimination from the body
restricting Bowman's capsule plasma proteins renal tubule
Glucose is first absorbed by __ at the apical membrane of proximal tubule cells and then it leaves the tubule cell via __ along the basolateral membrane.
secondary active transport facilitated diffusion
substances move from the blood, through the interstitial to the tubule
secretion
what happens to the glucose concentration in the urinary bladder as glucose carriers are added to the proximal tubule
the glucose concentration decreases in the urinary bladder
As the solute gradient in the interstitial space is increased,what happens?
the urine produced becomes more concentrated (increases) and urine volume decreases
how are rats able to concentrate their urine?
they are able to loss less H20 during urination because the interstitial fluid solute gradient is high
During urine formation, the process of tubular secretion / tubular reabsorption leaves behind mostly salt water and wastes after moving most of the filtrate back into the blood
tubular reabsorption
moves most of the filtrate back into the blood, leaving mainly salt water and the wastes in the lumen of the tubule. Some of the desirable, or needed, solutes are actively reabsorbed, and others move passively from the lumen of the tubule into the interstitial spaces
tubular reabsorption
essentially the reverse of tubular reabsorption and is a process by which the kidneys can rid the blood of additional unwanted substances, such as creatinine and ammonia
tubular secretion
filtrate is reabsorbed back in the blood at several locations along the __.
tubule
Because carrier proteins are needed to move glucose from the lumen of the nephron into the interstitial spaces, there is a limit to the amount of glucose that can be reabsorbed. When all glucose carriers are bound with the glucose they are transporting, excess glucose in the filtrate is eliminated in __
urine
if the one way valve of the collecting duct and the urinary bladder is blocked, the ___ is 0
urine volume
