DETAILED ANSWERS|LATEST
Describe the basic functions of the urinary system - ANSWER Acid base regulation,
water/fluid balance, electrolyte balance, toxin and waste product removal, blood pressure
regulation, enzymes/hormone production, vitamin D
List the nerves contributing to the control of micturition - ANSWER Hypogastric-
sympathetic
Pelvic- parasympathetic
Pudendal nerves- somatic nerves
Pelvic plexus- mixed of parasympathetic and sympathetic
Identify the urachus and describe its function. - ANSWER The urachus is a fibrous cord
arising from the early fetal anterior bladder wall to the allantois, extending cranially to the
umbilicus. In the first trimester of gestation, the role of the urachus is to facilitate the
removal of the neonate's nitrogenous waste through the placenta via the umbilical cord
Describe the components of the nephron - ANSWER The functional unit of the kidney
is the nephron; each nephron consists of one renal corpuscle and its associated tubules
[proximal convoluted tubule, loop of Henle, and distal convoluted tubule]. Corpuscle,
proximal and distal located within the cortex, the loop of Henle is located in the medulla
Describe the structure, function and location of the glomerular filtration barrier -
ANSWER Made up of endothelium, basement membrane, and epithelial podocytes.
Filters the plasma into filtrate
Outline the general characteristics of the following processes: glomerular filtration, tubular
reabsorption, and tubular secretion. - ANSWER Glomerular filtration: the movement
of fluid and solutes from the glomerular capillaries into the bowman's space
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, Tubular reabsorption: the movement of materials from the filtrate in the tubules into the
peritubular capillaries
Tubular secretion: the secretion of solutes from the peritubular capillaries into the tubules
Define clearance and how this concept can be used to estimate GFR -
ANSWER Clearance- the volume of plasma cleared of a specified substance per unit
time. GFR can be estimated from clearance by using inulin or creatine, they do not undergo
reabsorption or secretion or metabolism and therefore their clearance is equivalent to GFR
Calculate clearance for a substance given its concentration in plasma and urine, and the
urine flow rate - ANSWER Cx= [Ux *V]/Px
Ux- urine concentration of x
V- urine flow rate
Px- plasma concentration
Describe the bladder's main functions of urine storage and voiding, including the neural
control of micturition and role of the urethral sphincters - ANSWER Voiding:
parasympathetic, uses pelvic nerve to contract detrusor muscle
Storage: sympathetic, uses hypogastric nerve to contract outlet and inhibit detrusor muscle,
uses the pudendal nerve to contract the (internal or external) sphincter
Define the concept of clearance and its relationship to body fluid - ANSWER The
volume of plasma needed to pass through the kidneys in a given amount of time in order to
excrete a given quantity of substance in the urine
Cx= (Ux * V)/Px
Cx= clearance, Ux= urine concentration, V= urine flow rate, Px= plasma concentration
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Describe the basic functions of the urinary system - ANSWER Acid base regulation,
water/fluid balance, electrolyte balance, toxin and waste product removal, blood pressure
regulation, enzymes/hormone production, vitamin D
List the nerves contributing to the control of micturition - ANSWER Hypogastric-
sympathetic
Pelvic- parasympathetic
Pudendal nerves- somatic nerves
Pelvic plexus- mixed of parasympathetic and sympathetic
Identify the urachus and describe its function. - ANSWER The urachus is a fibrous cord
arising from the early fetal anterior bladder wall to the allantois, extending cranially to the
umbilicus. In the first trimester of gestation, the role of the urachus is to facilitate the
removal of the neonate's nitrogenous waste through the placenta via the umbilical cord
Describe the components of the nephron - ANSWER The functional unit of the kidney
is the nephron; each nephron consists of one renal corpuscle and its associated tubules
[proximal convoluted tubule, loop of Henle, and distal convoluted tubule]. Corpuscle,
proximal and distal located within the cortex, the loop of Henle is located in the medulla
Describe the structure, function and location of the glomerular filtration barrier -
ANSWER Made up of endothelium, basement membrane, and epithelial podocytes.
Filters the plasma into filtrate
Outline the general characteristics of the following processes: glomerular filtration, tubular
reabsorption, and tubular secretion. - ANSWER Glomerular filtration: the movement
of fluid and solutes from the glomerular capillaries into the bowman's space
1
, Tubular reabsorption: the movement of materials from the filtrate in the tubules into the
peritubular capillaries
Tubular secretion: the secretion of solutes from the peritubular capillaries into the tubules
Define clearance and how this concept can be used to estimate GFR -
ANSWER Clearance- the volume of plasma cleared of a specified substance per unit
time. GFR can be estimated from clearance by using inulin or creatine, they do not undergo
reabsorption or secretion or metabolism and therefore their clearance is equivalent to GFR
Calculate clearance for a substance given its concentration in plasma and urine, and the
urine flow rate - ANSWER Cx= [Ux *V]/Px
Ux- urine concentration of x
V- urine flow rate
Px- plasma concentration
Describe the bladder's main functions of urine storage and voiding, including the neural
control of micturition and role of the urethral sphincters - ANSWER Voiding:
parasympathetic, uses pelvic nerve to contract detrusor muscle
Storage: sympathetic, uses hypogastric nerve to contract outlet and inhibit detrusor muscle,
uses the pudendal nerve to contract the (internal or external) sphincter
Define the concept of clearance and its relationship to body fluid - ANSWER The
volume of plasma needed to pass through the kidneys in a given amount of time in order to
excrete a given quantity of substance in the urine
Cx= (Ux * V)/Px
Cx= clearance, Ux= urine concentration, V= urine flow rate, Px= plasma concentration
2
