All Human Anatomy and Physiology Resources
Example Questions
Example Question #11 : Excretory And Digestive Physiology
What is the main purpose of the vasa recta?
Maintains countercurrent multiplication to prevent disregulation in the concentration gradients set up in the renal medulla
Reabsorbs the majority of the solute from the filtrate
Secretes the majority of the and ions into the filtrate
Maintains appropriate temperature in the renal medulla to allow for regular blood flow
Provides the nephron with oxygen-rich blood
Maintains countercurrent multiplication to prevent disregulation in the concentration gradients set up in the renal medulla
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.
Example Question #92 : Systems Physiology
Which of the following is the most concentrated part of the nephron?
Proximal convoluted tublue
Thin descending loop of Henle
Distal convoluted tubule
Collecting duct
Thick ascending loop of Henle
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.
Example Question #93 : Systems Physiology
If the efferent arteriole becomes constricted, what is likely to occur in the nephron?
Fluid backup will cause the nephron to rupture
The increased hydrostatic pressure will elevate glomerular filtration rate
Glomerular filtration rate will remain the same
The increased osmotic pressure will elevate glomerular filtration rate
Glomerular filtration rate will decrease due to a loss in blood pressure
The increased hydrostatic pressure will elevate glomerular filtration rate
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.
Example Question #12 : Excretory And Digestive Physiology
The release of renin ultimately results in the stimulation of which gland?
Adrenal medulla
Adrenal cortex
Thyroid gland
Anterior pituitary gland
Adrenal cortex
Renin is a hormone released by granular cells in the juxtaglomerular apparatus, near the nephron glomerulus. These cells monitor the pressure of the filtrate in the distal convoluted tubule. The release of renin will stimulate a cascade of angiotensin I and II. Angiotensin II will ultimately stimulate the adrenal cortex to release aldosterone and increase sodium reabsorption and potassium excretion from the filtrate, leading to water retention.
Example Question #13 : Excretory And Digestive Physiology
Which of the following directly stimulates the release of aldosterone?
Renin
Adrenocorticotropic hormone
Vasopressin
Angiotensinogen
Angiotensin II
Angiotensin II
Aldosterone is a steroid hormone that is released from the adrenal cortex. The function of aldosterone is to increase reabsorption of sodium ions from the distal tubule. Increased sodium ion concentration in the blood then causes the diffusion of water from the nephron into the circulatory system, preventing water loss due to excretion and increasing blood pressure and volume)
Release of aldosterone is mediated by the renin-angiotensin system (RAS). When juxtaglomerular cells detect low blood pressure, they release renin. Renin travels to the liver, where there angiotensinogen is produced, and cleaves angiotensinogen to produce angiotensin I. Angiotensin I then travels to the lungs, where angiotensin converting enzyme (ACE) cleaves it to produce angiotensin II. Angiotensin II then travels to the adrenal cortex to stimulate release of aldosterone into the blood.
Adrenocorticotropic hormone is secreted by the anterior pituitary and acts on the adrenal cortex to stimulate release of cortisol and cortisone, but does not affect aldosterone release. Vasopressin is released by the posterior pituitary and helps the body to retain water; it is not related to aldosterone release.
Example Question #3 : Help With Raas Physiology
Which of the following is not an effect of angiotensin II?
Dilutes the urine in order to rid the body of excess fluid
Vasoconstricts the afferent and efferent arterioles to maintain glomerular filtration rate
Stimiulates antiporters to increase reabsorption in the proximal convoluted tubule
Promotes the effects of aldosterone to further increase reabsorption
Indirectly increases blood volume via the action of antidiuretic hormone
Dilutes the urine in order to rid the body of excess fluid
Angiotensin II is a major influence on the kidney's function when the body needs to retain fluid - it works in tandem with antidiuretic hormone and aldosterone to accomplish this. Angiotensin II will also act upon the afferent and efferent arterioles in order to control the glomerular filtration rate and stimulates reabsorption to ensure that the body is keeping necessary solutes/molecules. Diluting the filtrate in the nephron is the opposite effect that angiotensin has on the kidney.
Example Question #4 : Help With Raas Physiology
Too much of which of the following substances would cause chronic hypertension (high blood pressure)?
Prostacyclin
Brain natriuretic peptide
Nitric oxide
Angiotensin II
Atrial natriuretic peptide
Angiotensin II
Angiotensin II (part of the RAAS) works in the body to cause vasoconstriction in an effort to raise blood pressure. Too much of this substance will cause hypertension, another name for elevated blood pressure. Nitric oxide and prostacyclin work to vasodilate and lower blood pressure. Atrial natriuretic peptide and brain natriuretic peptide are released by the body to lower blood pressure in volume overloaded states.
Example Question #1 : Help With Kidney Physiology
Which of the following is not considered to be a function of the kidney?
Maintaining fluid levels in the body
Stimulation of red blood cell production
Regulation of blood osmolarity
Conversion of angiotensinogen to angiotensin I
Thermoregulation
Thermoregulation
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.
Example Question #2 : Help With Kidney Physiology
Which of the following is the outermost layer of the kidney?
Renal sinus
Renal cortex
Renal medulla
Renal pyramid
Renal capsule
Renal capsule
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.
Example Question #3 : Help With Kidney Physiology
Which of the following kidney structures is the connection point between the bladder and the kidney itself?
Renal pelvis
Renal medulla
Urethra
Collecting duct
Ureter
Ureter
The urine made within the kidney drains out from the renal pelvis and down the ureter to ultimately be stored in the bladder.