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Expert solutions
Bio 2301 Human Physiology - Lecture Exam 4
Questions and Answers (100% Correct
Answers) Already Graded A+
Functions of the renal system
✓✓ - Nitrogenous waste management
- Ions/electrolytes
- Water balance
- pH/hydrogen ions
- Organic nutrients
Nitrogenous Waste Management
✓✓ - Nitrogen containing wastes are eliminated in the urine
- These wastes are: creatinine (from the breakdown of creatine in muscles), uric
acid (from the breakdown of nucleic acids - DNA & RNA), urea (from the
breakdown of protein), ammonium ions
Which ions/electrolytes are eliminated in the urine?
✓✓ Na+, K+, HCO3-, Cl-
What organic nutrients are elminated in the urine?
✓✓ Urobilinogen (from the breakdown of hemoglobin)
Water balance
✓✓ - The kidneys can save water (put it back into the blood) or lose water (in
urine) depending on the condition of the blood
- When a person is dehyradted they put very little water in the urine and will
produce a small volume of concentrated urine
What happens if there are too many H+ in the blood?
✓✓ The kidneys will elminated in the urine
What is the functional unit of the kidney?
✓✓ The nephron - makes the urine
,2
Expert solutions
What are you altering when you make urine?
✓✓ The volume and composition of the blood
The kind of urine you make depends on what the _________
✓✓ - body needs
- If more water is needed in the blood because you are dehydrated, then you will
make a small volume of concentrated urine
- If you have extra water in your blood, then you will make a large volume of
dilute urine
What are the 2 parts of the nephron?
✓✓ - Glomerulus = a tuft of capillaries which are involved in filtration
- Rental tuble
4 parts of the renal tuble
✓✓ - Bowman's capsule: functions in filtration and surrounds the glomerulus
- Proximal convoluted tubule: functions in reabsoroption
- Loop of Henle: has descending and ascending limbs
- Distal convoluted tubule: functions in secretion
What are the blood vessels surrounding all of the renal tubule?
✓✓ Peritubular capillary beds
What are the special capillaries that run parallel to the loop of Henle on
some nephrons?
✓✓ Vasa recta
What are the three processes involved in making urine?
✓✓ - Filtration
- Reabsorption
- Secretion
Filtration
,3
Expert solutions
✓✓ - Fluid and solutes leave the blood of the glomerulus and enter into the renal
tubule at the Bowman's capsule
- This is due to a pressure gradient
- It is a relatively nonspecific process
- Anything that is small enough to get through the holes in the glomerulus will be
present in the filtrated, and that includes a lot of stuff you do not want to lose
from the body
Reabsorption
✓✓ Substances are taken out of the filtrate at the proximal convoluted tubule and
put back into the blood of the peritubular capillaries
Secretion
✓✓ Substances/wastes are taken out of the blood in the peritubular capillaries,
put into the filtrate, and will come out in the urine
Glomerular membrane
✓✓ - The glomeruli are tufts of capillaries present in the cortex of the kidney
- Since they are capillaries, blood is flowing through them
- Unique in 2 ways: they have a fenestrated endothelium (has holes in it) and they
are both fed and drained by arterioles (usually the arteriole only brings blood)
What does the filtration require?
✓✓ A filter and a pressure gradient
What do the fenestrations provide?
✓✓ The filter
Where does the pressure gradient come from?
✓✓ - The fact that the glomeruli are both fed and drained by arterioles
- Arterioles are high pressure vessles so a high pressure coming in (via afferent
arteriole) and high pressure leaving (via efferent arteriole)
Is pressure higher going in or out of the glomerulus? Why?
✓✓ Afferent arterioles have a larger diameter than efferent aterioles so there is a
higher pressure coming into the glomerulus (afferent) than leaving it (efferent)
, 4
Expert solutions
Three filtration pressures at work at the glomerulus
✓✓ - Glomerular hydrostatic pressure (GHP)
- Glomeruluar Osmotic Pressure (GOP)
- Capsular hydrostatic pressure (CHP)
Glomerular hydrostatic pressure (GHP)
✓✓ - Main pressure pushing for filtration
- Due to the volume of blood in the glomerulus and the blood pressure in the
glomerulus (GHP = BV x BP)
- It causes fluid and solutes to leave the blood of the glomerulus and enter into
Bowman's capsule
Glomeruluar Osmotic Pressure (GOP)
✓✓ - This pressure opposes filtration
- Opposes filtration and is due to the presence of plasma proteins in the
glomerulus
- Causes fluid and solutes to be pulled back into the glomerulus
Capsular hydrostatic pressure (CHP)
✓✓ - This pressure also opposes filtration
- Due to the presence of fluid and solutes in Bowman's capsule
- Causes fluid and solutes to be pushed out of the Bowman's capsule and go back
to the glomerulus
Net filtration pressure (NFP) equation
✓✓ GHP - (GOP + CHP)
Glomerular filtration rate (GFR)
✓✓ - 125 ml/min
- Definition: the volume of filtrate formed every minute - it is directly related to
the net filtration pressure
Clearance
✓✓ - A measure of how quickly a substance is removed/cleared from your blood
done either by your kidneys or liver
- For substances handled by the kidneys, it is determined by measuring the
amount of that substance in your blood and your urine over a 24 hour period
Expert solutions
Bio 2301 Human Physiology - Lecture Exam 4
Questions and Answers (100% Correct
Answers) Already Graded A+
Functions of the renal system
✓✓ - Nitrogenous waste management
- Ions/electrolytes
- Water balance
- pH/hydrogen ions
- Organic nutrients
Nitrogenous Waste Management
✓✓ - Nitrogen containing wastes are eliminated in the urine
- These wastes are: creatinine (from the breakdown of creatine in muscles), uric
acid (from the breakdown of nucleic acids - DNA & RNA), urea (from the
breakdown of protein), ammonium ions
Which ions/electrolytes are eliminated in the urine?
✓✓ Na+, K+, HCO3-, Cl-
What organic nutrients are elminated in the urine?
✓✓ Urobilinogen (from the breakdown of hemoglobin)
Water balance
✓✓ - The kidneys can save water (put it back into the blood) or lose water (in
urine) depending on the condition of the blood
- When a person is dehyradted they put very little water in the urine and will
produce a small volume of concentrated urine
What happens if there are too many H+ in the blood?
✓✓ The kidneys will elminated in the urine
What is the functional unit of the kidney?
✓✓ The nephron - makes the urine
,2
Expert solutions
What are you altering when you make urine?
✓✓ The volume and composition of the blood
The kind of urine you make depends on what the _________
✓✓ - body needs
- If more water is needed in the blood because you are dehydrated, then you will
make a small volume of concentrated urine
- If you have extra water in your blood, then you will make a large volume of
dilute urine
What are the 2 parts of the nephron?
✓✓ - Glomerulus = a tuft of capillaries which are involved in filtration
- Rental tuble
4 parts of the renal tuble
✓✓ - Bowman's capsule: functions in filtration and surrounds the glomerulus
- Proximal convoluted tubule: functions in reabsoroption
- Loop of Henle: has descending and ascending limbs
- Distal convoluted tubule: functions in secretion
What are the blood vessels surrounding all of the renal tubule?
✓✓ Peritubular capillary beds
What are the special capillaries that run parallel to the loop of Henle on
some nephrons?
✓✓ Vasa recta
What are the three processes involved in making urine?
✓✓ - Filtration
- Reabsorption
- Secretion
Filtration
,3
Expert solutions
✓✓ - Fluid and solutes leave the blood of the glomerulus and enter into the renal
tubule at the Bowman's capsule
- This is due to a pressure gradient
- It is a relatively nonspecific process
- Anything that is small enough to get through the holes in the glomerulus will be
present in the filtrated, and that includes a lot of stuff you do not want to lose
from the body
Reabsorption
✓✓ Substances are taken out of the filtrate at the proximal convoluted tubule and
put back into the blood of the peritubular capillaries
Secretion
✓✓ Substances/wastes are taken out of the blood in the peritubular capillaries,
put into the filtrate, and will come out in the urine
Glomerular membrane
✓✓ - The glomeruli are tufts of capillaries present in the cortex of the kidney
- Since they are capillaries, blood is flowing through them
- Unique in 2 ways: they have a fenestrated endothelium (has holes in it) and they
are both fed and drained by arterioles (usually the arteriole only brings blood)
What does the filtration require?
✓✓ A filter and a pressure gradient
What do the fenestrations provide?
✓✓ The filter
Where does the pressure gradient come from?
✓✓ - The fact that the glomeruli are both fed and drained by arterioles
- Arterioles are high pressure vessles so a high pressure coming in (via afferent
arteriole) and high pressure leaving (via efferent arteriole)
Is pressure higher going in or out of the glomerulus? Why?
✓✓ Afferent arterioles have a larger diameter than efferent aterioles so there is a
higher pressure coming into the glomerulus (afferent) than leaving it (efferent)
, 4
Expert solutions
Three filtration pressures at work at the glomerulus
✓✓ - Glomerular hydrostatic pressure (GHP)
- Glomeruluar Osmotic Pressure (GOP)
- Capsular hydrostatic pressure (CHP)
Glomerular hydrostatic pressure (GHP)
✓✓ - Main pressure pushing for filtration
- Due to the volume of blood in the glomerulus and the blood pressure in the
glomerulus (GHP = BV x BP)
- It causes fluid and solutes to leave the blood of the glomerulus and enter into
Bowman's capsule
Glomeruluar Osmotic Pressure (GOP)
✓✓ - This pressure opposes filtration
- Opposes filtration and is due to the presence of plasma proteins in the
glomerulus
- Causes fluid and solutes to be pulled back into the glomerulus
Capsular hydrostatic pressure (CHP)
✓✓ - This pressure also opposes filtration
- Due to the presence of fluid and solutes in Bowman's capsule
- Causes fluid and solutes to be pushed out of the Bowman's capsule and go back
to the glomerulus
Net filtration pressure (NFP) equation
✓✓ GHP - (GOP + CHP)
Glomerular filtration rate (GFR)
✓✓ - 125 ml/min
- Definition: the volume of filtrate formed every minute - it is directly related to
the net filtration pressure
Clearance
✓✓ - A measure of how quickly a substance is removed/cleared from your blood
done either by your kidneys or liver
- For substances handled by the kidneys, it is determined by measuring the
amount of that substance in your blood and your urine over a 24 hour period
