Chapter 17 - Physiology of the Kidney

Question 1

In the process of urine formation - the kidney regulates….

Answer 1

1. volume of blood plasma (contributes significantly ro the regulation of blood pressure)
2. Concentration of waste products in the plasma
3. concentration of electrolytes (Na+, K+, HCO3-)
4. pH of plasma

Question 2

The [] is the functional unit of the kidney

Answer 2

Nephron

Question 3

Blood enters the kidney through the renal artery. What is the arterial pathway it travels until the blood reaches the glomeruli?

Answer 3

• Renal artery -> Interlobar artery -> Arcuate artery –> Afferent Arterioles -> glomeruli.

Question 4

What is the glomeruli?

Answer 4

capillary networks that produce a blood filtrate that enters the urinary tubules.

Question 5

What does the arcuate arteries/veins “basically” cut in half (visually)?

Answer 5

The renal cortex and renal medulla

Question 6

Which blood vessel unloads oxygen ath the glomerulus capillary bed? Efferent or Afferent?

Answer 6

• Neither
• The Afferent arteriole brings the blood to the glomerulus to be filtered. The blood remaining in the glomerulus. Leaves through the efferent arteriole.
• This blood is delivered to another capillary network - peritubular capillaries

Question 7

What are the tubular portions of the nephron?

Answer 7

1. Glomerular capsule
2. Proximal convulted tubule
3. Descending limb of the loop of Henle
4. Ascending limb of the loop of Henle
5. Distal Convoluted Tubule

Question 8

What structures consitutue the Renal Corpuscle?

Answer 8

• Glomerular Capsule (Bowman’s Capsule)
• Associated glomerulus.

Question 9

In the proximal convoulted Tubule - During the process of [] , salt, water, and other molecules are transported from the lumen, through the tubular cells and into the surrounding [] capillaries…

Answer 9

1. Reabsorption
2. Peritubular Capillaries

Question 10

What are the two types of nephrons and how do they differ?

Answer 10

• Juxtamedullary Nephron
  
  • next to the medulla and have longer nephron lopps
• Cortical Nephrons
  
  • originate in the outer layers of the cortex
  • Shorter Loops of Henle
  • More numerous

Question 11

What are the 3 primary processes for a normal Kidney?

Answer 11

1. Glomeruler Filtration
   
   1. filtering of blood that comes to each individual nephron
2. Tubular Reabsorption
   
   1. reuptake of glucose and sodium, and other things we need to retain
3. Tubular Secretion
   
   1. Need to get rid of some shit

Question 12

What are the 3 barriers for filtrate to pass through before entering the interior of the glomerulus capillary?

Answer 12

1. Capillary fenestrae
   
   1. large enough for proteins, but charged so some proteins may not make it
2. Glomerular basement membrane
   
   1. layer of collagen IV and proteoglycans
   2. barrier to plasma proteins
3. Layer of Podocytes
   1.

Question 13

What is the GFR (glomerular filtration rate)?

Answer 13

Volume of filtrate produced by both kidneys per minute

115 mL per minute for women, 125 mL per minutes for men.

180 L per day

Question 14

What does sympathetic innervation of afferent arteriole do to Kidney?

Answer 14

• Activated during flight or fight
• Vasoconstriction of arterioles - decreased GFR and decreased urine production
  
  • which helps compensate for the drop in blood pressure under these conditions.

Question 15

Describe what the mygoenic effects on the kidneys would be if…

Blood Pressure Increases -

Blood Pressure Decreases -

Answer 15

1. BP Increases - Afferent arteriole vasoconstricts to control the amount of blood hitting the capillary
2. BP Decreases - Afferent arteriole vasodilates to bring more blood into the capillary

Question 16

What is the myogenic responsibilities of the tubuloglomerular feedback, in the kidneys -

Answer 16

• The macula densa is the sensor in tubuloglomerular feedback
  
  • It detects high/low flow. This regulates the release of vasodilation/vasoconstriion elements
  • For example: If it detects high NaCl and water volumes it will cause vasoconstriction, lowering the amount of water and salt going to the capillary….negative feedback