BIO 436 Lecture- Kidneys Review
Questions and Correct Answers
What is the structure of the urinary system? ✅- paired kidneys are on either side of
vertebral column below diaphragm (about size of fist)
- right kidney is slightly lower than the left kidney
- urine flows from kidneys into ureters which empty into bladder
What are the functions of the kidney? (6) ✅1. regulates extracellular fluid volume
2. regulates osmolarity of ECF
3. regulates ion concentrations of ECF
4. regulates pH of ECF (only way which body can remove metabolic acids)
5. produces hormones
6. excretes wastes and foreign substances from plasma
Water gain = water loss ✅
What is the kidney divided into? ✅outer cortex and inner medulla
What is the nephron? ✅- functional unit of kidney responsible for forming urine
- 1 million nephrons/kidney
- is a long tube and has associated blood vessels
- composed of renal corpuscle and renal tubule
What are the 6 regions of the nephron? ✅1. Bowman's capsule
2. Proximal convoluted tubule
3. Descending limb of loop of Henle
4. Distal convoluted tubule
5. Ascending limb of loop of Henle
6. Collecting duct
What are the 3 functions that the nephron has to process blood into filtrate and urine?
✅(1) glomerular filtration
(2) tubular reabsorption
(3) tubular secretion
What is glomerular filtration? ✅passive process in which fluid passes from the lumen
of the glomerular capillary into the glomerular capsule of the renal tubule because of
hydrostatic pressure
What is tubular reabsorption? ✅moves most of the filtrate back into the blood, leaving
mainly salt water and the wastes in the lumen of the tubule
, What is tubular secretion? ✅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
What is the osmolarity of blood in the glomerulus the same as? ✅osmolarity of
filtrate/ultrafiltrate
What is the major control of GFR (glomerular filtration rate)? ✅by changing diameter of
afferent arteriole
What is the normal GFR? ✅180 L/day
What happens to GFR if afferent arteriole undergoes vasoconstriction? ✅decreased
glomerular capillary BP, which leads to decreased net filtration pressure
What happens to GFR if afferent arteriole undergoes vasodilation? ✅increased
glomerular capillary BP, which leads to increased net filtration pressure
What is the formula for the amount of excretion from the body? ✅Excreted = Filtered -
Reabsorbed + Secreted
Why is Na+ reabsorption an active process? ✅because of the Na+/K+ ATPase pump
on basolateral membrane
How much water is absorbed in the proximal convoluted tubule? ✅33-60%
How much water is reabsorbed when the glomerular filtrate reaches the distal
convoluted tubule? ✅85%
How does the kidney accomplish this massive reabsorption? ✅- kidney produces huge
osmotic gradient to draw H2O back into blood
- gradient produced by "countercurrent mutiplier system"
What is aldosterone? ✅mieralocorticoid released from adrenal cortex under the control
of the body's renin-angiotensin system
What does aldosterone cause? ✅1) a decrease in blood potassium levels
2) a high rate of urinary sodium reabsorption, which will produce an increase in volume
of blood
What are the 2 main reasons for aldosterone production? ✅1. to excrete potassium so
it doesn't increase in plasma
Questions and Correct Answers
What is the structure of the urinary system? ✅- paired kidneys are on either side of
vertebral column below diaphragm (about size of fist)
- right kidney is slightly lower than the left kidney
- urine flows from kidneys into ureters which empty into bladder
What are the functions of the kidney? (6) ✅1. regulates extracellular fluid volume
2. regulates osmolarity of ECF
3. regulates ion concentrations of ECF
4. regulates pH of ECF (only way which body can remove metabolic acids)
5. produces hormones
6. excretes wastes and foreign substances from plasma
Water gain = water loss ✅
What is the kidney divided into? ✅outer cortex and inner medulla
What is the nephron? ✅- functional unit of kidney responsible for forming urine
- 1 million nephrons/kidney
- is a long tube and has associated blood vessels
- composed of renal corpuscle and renal tubule
What are the 6 regions of the nephron? ✅1. Bowman's capsule
2. Proximal convoluted tubule
3. Descending limb of loop of Henle
4. Distal convoluted tubule
5. Ascending limb of loop of Henle
6. Collecting duct
What are the 3 functions that the nephron has to process blood into filtrate and urine?
✅(1) glomerular filtration
(2) tubular reabsorption
(3) tubular secretion
What is glomerular filtration? ✅passive process in which fluid passes from the lumen
of the glomerular capillary into the glomerular capsule of the renal tubule because of
hydrostatic pressure
What is tubular reabsorption? ✅moves most of the filtrate back into the blood, leaving
mainly salt water and the wastes in the lumen of the tubule
, What is tubular secretion? ✅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
What is the osmolarity of blood in the glomerulus the same as? ✅osmolarity of
filtrate/ultrafiltrate
What is the major control of GFR (glomerular filtration rate)? ✅by changing diameter of
afferent arteriole
What is the normal GFR? ✅180 L/day
What happens to GFR if afferent arteriole undergoes vasoconstriction? ✅decreased
glomerular capillary BP, which leads to decreased net filtration pressure
What happens to GFR if afferent arteriole undergoes vasodilation? ✅increased
glomerular capillary BP, which leads to increased net filtration pressure
What is the formula for the amount of excretion from the body? ✅Excreted = Filtered -
Reabsorbed + Secreted
Why is Na+ reabsorption an active process? ✅because of the Na+/K+ ATPase pump
on basolateral membrane
How much water is absorbed in the proximal convoluted tubule? ✅33-60%
How much water is reabsorbed when the glomerular filtrate reaches the distal
convoluted tubule? ✅85%
How does the kidney accomplish this massive reabsorption? ✅- kidney produces huge
osmotic gradient to draw H2O back into blood
- gradient produced by "countercurrent mutiplier system"
What is aldosterone? ✅mieralocorticoid released from adrenal cortex under the control
of the body's renin-angiotensin system
What does aldosterone cause? ✅1) a decrease in blood potassium levels
2) a high rate of urinary sodium reabsorption, which will produce an increase in volume
of blood
What are the 2 main reasons for aldosterone production? ✅1. to excrete potassium so
it doesn't increase in plasma
