AP 4 lecture 5

Question 1

What are the main anatomical structures of the kidney?

Answer 1

Renal cortex, renal medulla, renal pelvis, renal pyramids, calyces, and ureter

Question 2

What is the function of the renal cortex?

Answer 2

The renal cortex contains the glomeruli and parts of the nephron, and it plays a key role in filtration and the formation of urine.

Question 3

What is the function of the renal medulla?

Answer 3

The renal medulla contains the loops of Henle and collecting ducts, which are involved in concentrating urine.

Question 4

What is the structure of the nephron?

Answer 4

The nephron consists of the glomerulus, Bowman’s capsule, proximal convoluted tubule (PCT), loop of Henle, distal convoluted tubule (DCT), and the collecting duct.

Question 5

What are the two types of nephrons in the kidney?

Answer 5

Cortical nephrons and juxtamedullary nephrons

Question 6

What is the role of cortical nephrons?

Answer 6

Cortical nephrons are involved in basic filtration and are located primarily in the renal cortex.

Question 7

What is the role of juxtamedullary nephrons?

Answer 7

Juxtamedullary nephrons have longer loops of Henle that extend into the medulla and play a crucial role in concentrating urine.

Question 8

What is renal physiology?

Answer 8

Renal physiology refers to the study of kidney function, including filtration, reabsorption, secretion, and excretion processes that maintain homeostasis.

Question 9

What is the glomerular filtration rate (GFR)?

Answer 9

GFR is the amount of filtrate formed by the kidneys per minute, indicating how efficiently the kidneys are filtering blood.

Question 10

What is the average GFR in a healthy adult?

Answer 10

Approximately 120-125 mL/min

Question 11

What factors affect GFR?

Answer 11

Blood pressure, blood volume, and the condition of the filtration membrane

Question 12

What is the filtration membrane in the kidney?

Answer 12

The filtration membrane consists of the endothelial cells of glomerular capillaries, the basement membrane, and podocytes.

Question 13

What substances pass through the filtration membrane?

Answer 13

Water, electrolytes, glucose, amino acids, and small solutes

Question 14

What substances are retained by the filtration membrane?

Answer 14

Proteins, blood cells, and large molecules are retained.

Question 15

What is the flow of blood through the kidney?

Answer 15

Blood flows through the renal artery → segmental arteries → interlobar arteries → arcuate arteries → interlobular arteries → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries/vasa recta → interlobular veins → arcuate veins → interlobar veins → renal vein

Question 16

What is the flow of urine through the kidney?

Answer 16

Urine flows from the nephron (collecting ducts) → renal papilla → minor calyx → major calyx → renal pelvis → ureter → bladder

Question 17

What is the juxtaglomerular apparatus (JGA)?

Answer 17

The JGA is a structure that helps regulate blood pressure and GFR, consisting of juxtaglomerular cells, macula densa, and extraglomerular mesangial cells.

Question 18

What is the function of the juxtaglomerular cells?

Answer 18

Juxtaglomerular cells secrete renin in response to low blood pressure or low sodium levels, which helps regulate blood pressure.

Question 19

What is the function of the macula densa?

Answer 19

The macula densa detects sodium concentration in the distal convoluted tubule and signals the juxtaglomerular cells to release renin if sodium levels are low.

Question 20

What is the renin-angiotensin-aldosterone system (RAAS)?

Answer 20

RAAS is a hormone system that regulates blood pressure and fluid balance, initiated by renin secretion from the juxtaglomerular cells.

Question 21

How does blood pressure influence GFR?

Answer 21

Increased blood pressure increases GFR, while decreased blood pressure reduces GFR.

Question 22

How do the kidneys regulate blood volume?

Answer 22

The kidneys regulate blood volume by adjusting the reabsorption of water and sodium, influenced by hormones like aldosterone and ADH.

Question 23

What is tubular reabsorption?

Answer 23

Tubular reabsorption is the process by which water, ions, and nutrients are reabsorbed from the nephron back into the bloodstream.

Question 24

What is tubular secretion?

Answer 24

Tubular secretion is the process by which waste products and excess ions are secreted into the nephron for excretion in the urine.

Question 25

How does the loop of Henle contribute to urine concentration?

Answer 25

The loop of Henle creates a concentration gradient in the renal medulla, allowing water to be reabsorbed and urine to be concentrated.