me: ch. 10 renal system

Question 1

What structures make up the renal system?

Answer 1

Pair of kidneys
-pair of ureters
-urinary bladder
-urethra.

Question 2

Function of kidneys

Answer 2

1. The kidneys remove nitrogenous wastes (ike urea, creatinine and uric acid)
2. regulate electrolyte balance
3. regulates volume of H2O in body
4. Secrete erythropoetin(Hypoxemia stimulates the kidneys to release erythropoietin, which boosts red blood cell production in the bone marrow to improve oxygen transport.)

Maintain blood pH

Regulate blood pressure (aldosterone, adh, angiotension)

Eliminate drugs/hormones

Activate Vitamin D3

Perform gluconeogenesis (when glucose made from non-carbhydrate like protein (maybe when hungry)

Question 3

How is nitrogenous waste formed from proteins?

Answer 3

Proteins → Amino acids → Amino group is removed during oxidative deamination, forming ammonia (NH₃) and an alpha-keto acid.

Question 4

What is oxidative deamination?

Answer 4

amino group is removed from an amino acid, forming ammonia (NH₃ - for excretion via urea) and an alpha-keto acid.

Question 5

Why is ammonia toxic?

Answer 5

: Ammonia is highly toxic and soluble, which is why it must be converted or excreted quickly.

Question 6

What are ammonotelic animals?

Answer 6

ammonia directly into water
ex) fish

Question 7

What are ureotelic animals?

Answer 7

convert ammonia to urea in liver which is less toxic and soluble

ex) humans

Question 8

What are uricotelic animals?

Answer 8

Animals that excrete nitrogen to uric acid (e.g., birds, reptiles)

it’s non-toxic, insoluble, and stored longer in the body.

Question 9

What is the downside of uric acid accumulation?

Answer 9

can accumulate in joints, causing gout.

Question 10

What is uric acid made from, and what is its structure?

Answer 10

Made from purines (adenine & guanine); contains 4 nitrogen atoms.

Question 11

What are the characteristics of uric acid excretion?

Answer 11

Excretes more nitrogen, but costs 6 ATP → more energy-intensive.

Question 12

What is creatine, and how is it used in muscle energy?

Answer 12

A straight-chain compound that can be phosphorylated to creatine phosphate; this stores energy.

Question 13

How is creatine phosphate used in muscles?

Answer 13

When muscles contract, phosphate from creatine phosphate is transferred to ADP to make ATP.

Question 14

What is creatinine used for clinically, what does high creatinine suggest?

Answer 14

To estimate glomerular filtration rate (eGFR), a marker of kidney function.

high creatinine means low GFR, kidneys not working properly

.7-1.3 is normal level (dont think important)

Question 15

What happens in renal failure?

Answer 15

It’s not filtered → increase in urea in blood = uremia (toxic).

Question 16

What is intravenous pyelography?

Answer 16

Used by iodine contrast creatine to improve X-ray image; used to diagnose renal failure (dark areas mean blockage).

Question 17

Which kidney is lower?

Answer 17

Right kidney is lower than the left.

Question 18

What is ptosis?

Answer 18

Ureter blocked → causes hydronephrosis.& kidney in pelvic region called nephroptosis

Question 19

What is renal aplasia?

Answer 19

No kidney.

Question 20

What is dysplasia?

Answer 20

Malformation.

Question 21

What is hypoplasia?

Answer 21

Small kidneys.

Question 22

What are renal calculi and how are they treated?

Answer 22

Kidney stones and treated through and Lithotripsy (laser breaks stone)

Question 23

Can the kidney regenerate? What are renal failure treaments?

Answer 23

No

Dialysis or kidney transplant. (not important i think)

Question 24

What types of cells are in the nephron’s collecting tubules?

Answer 24

Intercalated cells and principal cells.

Question 25

What do Type B intercalated cells do?

Answer 25

*Excrete HCO₃⁻ into urine during alkalosis (too little acid).

Question 26

What do principal cells do?

Answer 26

*Regulate Na⁺ and water retention under aldosterone.

Question 27

How many nephrons are in each kidney and how long are they?

Answer 27

1 million at 3.5 cm

Question 28

What are the characteristics of PCT and DCT cells?

Answer 28

*PCT cells: Cuboidal, with microvilli (brush border for 80% reabsorption). DCT cells: Cuboidal, without microvilli (secretory, not absorptive).

Question 29

What is the blood flow pathway through the kidney?

Answer 29

Aorta → Renal artery → Segmental artery → Interlobar artery → Arcuate artery → Cortical radiate artery → Afferent arteriole → Glomerulus → Efferent arteriole → Cortical radiate vein → Arcuate vein → Interlobar vein → Renal vein →

Question 30

What percent of cardiac output goes to the kidneys per minute? How much blood passes through the kidneys approximately every 4 minutes?

Answer 30

20–25% & About 5 liters every 4 min

Question 31

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

Answer 31

Cortical nephrons (85%): normally used, Shorter Loop of Henle, make urine 4x more concentrated than plasma. 300 mosmols Juxtamedullary nephrons (15%): Longer Loop of Henle, highly concentrated urine, up to 16x more concentrated - used in stressful situations (seen in desert rodents like Jerboa).

Question 32

What is the difference between the parietal and visceral layers of Bowman's capsule?

Answer 32

Parietal layer: Flat, squamous cells. Visceral layer: podocytes (Specialized cells) that wrap around fenestrated capillaries with foot processes.

Question 33

What is the juxtaglomerular apparatus (JGA)?

Answer 33

The JGA regulates Glomerular Filtration Rate (GFR) through macula densa cells and juxtaglomerular cells.

Question 34

*How do macula densa cells influence GFR?

Answer 34

detects concentration of filtrate: If the filtrate is highly concentrated, macula densa cells secrete adenosine, which causes vasoconstriction of the afferent arteriole, reducing GFR. If the filtrate is dilute, they secrete prostaglandin E2 (PGE2), causing vasodilation and increasing GFR.

Question 35

*What is the role of juxtaglomerular (JG) cells in regulating blood pressure?

Answer 35

JG cells in the afferent arteriole release renin (released when bp is too low) which converts angiotensinogen to angiotensin II, causing vasoconstriction of the efferent arteriole, restoring GFR (goes higher).

Question 36

Which of the following does blood flow through before the afferent arteriole?

Answer 36

cortical radiate artery

Question 37

Normal concentration of urine in cortical nephron is

Answer 37

1200 mosmols

Question 38

efferent a has cappilary thta goes around the nephron. What are they called and where are they located

Answer 38

vasa recta: capilary near (counter current) peritubular plexus: near pct & dct