Excretory Physiology - Human Anatomy and Physiology
Card 0 of 20
Which structure allows for the conscious control of holding urine?
Which structure allows for the conscious control of holding urine?
When holding urine, there are two primary sphincters that help control the release of urine. The internal urethral sphincter is composed of smooth muscle, and is therefore not consciously controlled. The external urethral sphincter is composed of skeletal muscle, which means that it can be consciously controlled.
The detrusor muscle is the smooth muscle found in the walls of the bladder. When contracted, this muscle leads to urination. The rectus abdominis is a region of the abdominal wall. When contracted, this muscle can indirectly assist in urination by reducing the volume of the abdominal cavity and pressuring the bladder.
When holding urine, there are two primary sphincters that help control the release of urine. The internal urethral sphincter is composed of smooth muscle, and is therefore not consciously controlled. The external urethral sphincter is composed of skeletal muscle, which means that it can be consciously controlled.
The detrusor muscle is the smooth muscle found in the walls of the bladder. When contracted, this muscle leads to urination. The rectus abdominis is a region of the abdominal wall. When contracted, this muscle can indirectly assist in urination by reducing the volume of the abdominal cavity and pressuring the bladder.
Compare your answer with the correct one above
Which of the following is not considered to be a function of the kidney?
Which of the following is not considered to be a function of the kidney?
The human kidney has many functions, all of which are important for sustaining life. The kidney controls blood osmolarity by filtering, reabsorbing, and secreting various ions found throughout the body. The kidney controls fluid volume in the body by this same mechanism. Additionally, the kidney produces erythropoietin and renin which stimulate the production of red blood cells and convert angiotensinogen to angiotensin I, respectively.
The human kidney has many functions, all of which are important for sustaining life. The kidney controls blood osmolarity by filtering, reabsorbing, and secreting various ions found throughout the body. The kidney controls fluid volume in the body by this same mechanism. Additionally, the kidney produces erythropoietin and renin which stimulate the production of red blood cells and convert angiotensinogen to angiotensin I, respectively.
Compare your answer with the correct one above
Which of the following is the outermost layer of the kidney?
Which of the following is the outermost layer of the kidney?
The renal capsule is the outermost structure of the kidney. It is the fibrous connective tissue kidney structure that directly surrounds the renal cortex, and is surrounded by a layer of adipose tissue that protects the kidney from trauma. The renal pyramids, renal sinus, and renal medulla are located deep within the kidney.
The renal capsule is the outermost structure of the kidney. It is the fibrous connective tissue kidney structure that directly surrounds the renal cortex, and is surrounded by a layer of adipose tissue that protects the kidney from trauma. The renal pyramids, renal sinus, and renal medulla are located deep within the kidney.
Compare your answer with the correct one above
Which of the following kidney structures is the connection point between the bladder and the kidney itself?
Which of the following kidney structures is the connection point between the bladder and the kidney itself?
The urine made within the kidney drains out from the renal pelvis and down the ureter to ultimately be stored in the bladder.
The urine made within the kidney drains out from the renal pelvis and down the ureter to ultimately be stored in the bladder.
Compare your answer with the correct one above
A patient presents with severe diarrhea and his test results show a significant loss of 
. It is likely that the physician will diagnose the patient with:
A patient presents with severe diarrhea and his test results show a significant loss of
A very large loss of 
from the patient will lead to a drastic decrease in pH. Therefore, all alkalosis disorders can be ruled out. Additionally, because the pH decrease is unrelated to an increase in carbon dioxide, it is not a respiratory issue - leaving only metabolic acidosis as a diagnosis. Cystic fibrosis involves the overproduction of thick mucous, which causes severe respiratory pathology; other systems are affected too, but excess bicarbonate secretion is not associated with this genetic disease.
A very large loss of
Compare your answer with the correct one above
Obstruction in the ureters will have what effect on the glomerular filtration rate (GFR)?
Obstruction in the ureters will have what effect on the glomerular filtration rate (GFR)?
Obstruction bilaterally in the ureters leads to decreased GFR due to increased pressure retrograde from the ureters. Bowman space pressure increases to override the GFR pressure. Bowman space pressure does not favor filtration versus GFR pressure (favors filtration).
Obstruction bilaterally in the ureters leads to decreased GFR due to increased pressure retrograde from the ureters. Bowman space pressure increases to override the GFR pressure. Bowman space pressure does not favor filtration versus GFR pressure (favors filtration).
Compare your answer with the correct one above
Which of the following is the best estimate for serum osmolality?
Which of the following is the best estimate for serum osmolality?
Serum osmolality is best estimated at around 
Serum osmolality is best estimated at around
Compare your answer with the correct one above
The glomerulus is primarily associated with which function?
The glomerulus is primarily associated with which function?
The glomerulus is a capillary structure associated with the first section of the nephron where blood enters the renal corpuscle. The glomerulus is responsible for filtering fluid, plasma, and dissolved particulates out of circulation and into Bowman's capsule, resulting in a primary filtrate that will go through the rest of the nephron.
The glomerulus is a capillary structure associated with the first section of the nephron where blood enters the renal corpuscle. The glomerulus is responsible for filtering fluid, plasma, and dissolved particulates out of circulation and into Bowman's capsule, resulting in a primary filtrate that will go through the rest of the nephron.
Compare your answer with the correct one above
Which section of the nephron does not result in a change in filtrate concentration?
Which section of the nephron does not result in a change in filtrate concentration?
The nephron is composed of multiple sections, which are used to alter the solute composition and concentration of the filtrate. The first section is the proximal convoluted tubule. While the solute composition of the filtrate will change due to reabsorption and secretion of specific solutes, the overall concentration does not change. In the proximal convoluted tubule, filtrate is kept isotonic with blood.
The nephron is composed of multiple sections, which are used to alter the solute composition and concentration of the filtrate. The first section is the proximal convoluted tubule. While the solute composition of the filtrate will change due to reabsorption and secretion of specific solutes, the overall concentration does not change. In the proximal convoluted tubule, filtrate is kept isotonic with blood.
Compare your answer with the correct one above
Which of the following nephron sections is primarily associated with the absorption of sodium ions and the secretion of potassium ions?
Which of the following nephron sections is primarily associated with the absorption of sodium ions and the secretion of potassium ions?
The distal convoluted tubule follows the loop of Henle in the nephron structure. In addition to lowering the filtrate concentration, it is also used to reabsorb sodium ions and secrete potassium ions. Aldosterone acts on the distal tubule and further stimulates these two actions.
The distal convoluted tubule follows the loop of Henle in the nephron structure. In addition to lowering the filtrate concentration, it is also used to reabsorb sodium ions and secrete potassium ions. Aldosterone acts on the distal tubule and further stimulates these two actions.
Compare your answer with the correct one above
How does antidiuretic hormone (ADH) affect the nephron?
How does antidiuretic hormone (ADH) affect the nephron?
The collecting duct of a nephron is normally impermeable to water. In the presence of antidiuretic hormone (ADH), aquaporin proteins are inserted, making the collecting duct permeable to water. Water then diffuses into the medulla due to the solute concentration of the surrounding tissues, generated from ion reabsorption in the loop of Henle. This loss of water from the urine makes it more concentrated.
The collecting duct of a nephron is normally impermeable to water. In the presence of antidiuretic hormone (ADH), aquaporin proteins are inserted, making the collecting duct permeable to water. Water then diffuses into the medulla due to the solute concentration of the surrounding tissues, generated from ion reabsorption in the loop of Henle. This loss of water from the urine makes it more concentrated.
Compare your answer with the correct one above
Which of the following is true regarding the nephron?
Which of the following is true regarding the nephron?
All of the answer choices are true. The macula densa cells are sensitive to changes in concentration of sodium chloride. A decrease in concentration of 
is detected, which stimulates the macula densa cells to secrete paracrine factors that ultimately increase the pressure in the glomerulus, and thus the glomerular filtration rate, and stimulates the release of renin, which ultimately increases blood pressure, volume and cardiac output.
All of the answer choices are true. The macula densa cells are sensitive to changes in concentration of sodium chloride. A decrease in concentration of
Compare your answer with the correct one above
The major reabsorption of water, ions, and other important molecules such as glucose occurs in what part of the nephron?
The major reabsorption of water, ions, and other important molecules such as glucose occurs in what part of the nephron?
After filtration of the blood through the glomerulus, approximately 70% of the water and salts is reabsorbed in the proximal convoluted tubule. Additionally, 100% of the glucose is reabsorbed here in a healthy, functioning nephron. The lumenal cells of the proximal convoluted tubule are lined with microvilli and are called brush border cells. Histology of the proximal convoluted tubule is indicative of these structures and the proximal convoluted tubule's lumen can be seen as "crowded" with epithelial surface area, which is distinct from the lumen of the distal convoluted tubule.
After filtration of the blood through the glomerulus, approximately 70% of the water and salts is reabsorbed in the proximal convoluted tubule. Additionally, 100% of the glucose is reabsorbed here in a healthy, functioning nephron. The lumenal cells of the proximal convoluted tubule are lined with microvilli and are called brush border cells. Histology of the proximal convoluted tubule is indicative of these structures and the proximal convoluted tubule's lumen can be seen as "crowded" with epithelial surface area, which is distinct from the lumen of the distal convoluted tubule.
Compare your answer with the correct one above
ADH (antidiuretic hormone, also known as vasopressin) has which of the following effects on nephron function?
ADH (antidiuretic hormone, also known as vasopressin) has which of the following effects on nephron function?
ADH acts upon the collecting ducts and distal convoluted tubules of nephrons to increase water reabsorption. It causes an increase in the number of aquaporins in order to allow for this.
ADH acts upon the collecting ducts and distal convoluted tubules of nephrons to increase water reabsorption. It causes an increase in the number of aquaporins in order to allow for this.
Compare your answer with the correct one above
If the efferent arteriole becomes constricted, what is likely to occur in the nephron?
If the efferent arteriole becomes constricted, what is likely to occur in the nephron?
The efferent arteriole carries blood away from the glomerulus, and so if it is constricted, the blood pressure behind it will increase. The raise in blood pressure will result in an increase in hydrostatic pressure, pushing additional fluid through the glomerulus i.e elevated glomerular filtration rate. While high hydrostatic pressure does cause damage to the nephron, the nephron rupturing is too extreme of a statement and requires assumptions that are not necessarily valid.
The efferent arteriole carries blood away from the glomerulus, and so if it is constricted, the blood pressure behind it will increase. The raise in blood pressure will result in an increase in hydrostatic pressure, pushing additional fluid through the glomerulus i.e elevated glomerular filtration rate. While high hydrostatic pressure does cause damage to the nephron, the nephron rupturing is too extreme of a statement and requires assumptions that are not necessarily valid.
Compare your answer with the correct one above
Concentration and dilution of urine is a major responsibility of what part of the nephron?
Concentration and dilution of urine is a major responsibility of what part of the nephron?
As filtrate passes through the Loop of Henle, the level of concentration of the fluid that will become urine is determined by the length of the loop of Henle (how far into the medulla it dips) and, the osmolality of the medulla. Depending on the levels of circulating hormones, the distal convoluted tubule and collecting duct could be the part of the nephron that determines the concentration of the urine, but to a lesser extent than the length of the loop of Henle.
As filtrate passes through the Loop of Henle, the level of concentration of the fluid that will become urine is determined by the length of the loop of Henle (how far into the medulla it dips) and, the osmolality of the medulla. Depending on the levels of circulating hormones, the distal convoluted tubule and collecting duct could be the part of the nephron that determines the concentration of the urine, but to a lesser extent than the length of the loop of Henle.
Compare your answer with the correct one above
The descending limb of the loop of Henle is __________.
The descending limb of the loop of Henle is __________.
The descending limb of the loop of Henle is both water permeable and solute impermeable. These properties of the limb allow the filtrate moving through the nephron to become either concentrated or diluted depending on the circumstance.
The descending limb of the loop of Henle is both water permeable and solute impermeable. These properties of the limb allow the filtrate moving through the nephron to become either concentrated or diluted depending on the circumstance.
Compare your answer with the correct one above
The vessels surrounding the Loop of Henle are called __________.
The vessels surrounding the Loop of Henle are called __________.
The afferent and efferent arterioles are located near the glomerulus and control the glomerular filtration rate by constriction and dilation. The peritubular capillaries wind around the proximal convoluted tubule and the distal convoluted tubule to allow for reabsorption and secretion there. The vasa recta on the other hand wind around the loop of Henle and maintain countercurrent multiplication.
The afferent and efferent arterioles are located near the glomerulus and control the glomerular filtration rate by constriction and dilation. The peritubular capillaries wind around the proximal convoluted tubule and the distal convoluted tubule to allow for reabsorption and secretion there. The vasa recta on the other hand wind around the loop of Henle and maintain countercurrent multiplication.
Compare your answer with the correct one above
What is the main purpose of the vasa recta?
What is the main purpose of the vasa recta?
The vasa recta wind around the loop of Henle and maintain a countercurrent multiplication to prevent any disregulation or washout of the concentration gradient that has been set up in the renal medulla. Without this gradient, the nephron would be unable to concentrate filtrate. Since the vasa recta carry venous blood, it's oxygen concentration is low and thus needs to go through the pulmonary circuit to pick up more oxygen.
The vasa recta wind around the loop of Henle and maintain a countercurrent multiplication to prevent any disregulation or washout of the concentration gradient that has been set up in the renal medulla. Without this gradient, the nephron would be unable to concentrate filtrate. Since the vasa recta carry venous blood, it's oxygen concentration is low and thus needs to go through the pulmonary circuit to pick up more oxygen.
Compare your answer with the correct one above
Which of the following is the most concentrated part of the nephron?
Which of the following is the most concentrated part of the nephron?
Thin descending loop of Henle is the most concentrated part of the nephron. As you progress up and down the nephron, the closer the nephron is to the medulla, the more concentrated it is. This ability is due to the increases absorption of water and the inability to reabsorb solute at this level.
The other mentioned parts of the nephron are permeable to solute and some water and thus are not as concentrated as the thin descending loop of Henle.
Thin descending loop of Henle is the most concentrated part of the nephron. As you progress up and down the nephron, the closer the nephron is to the medulla, the more concentrated it is. This ability is due to the increases absorption of water and the inability to reabsorb solute at this level.
The other mentioned parts of the nephron are permeable to solute and some water and thus are not as concentrated as the thin descending loop of Henle.
Compare your answer with the correct one above