Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Foundations Of Medicine > 9.2 Blood Flow to the Kidneys; The Nephron; Urine formation, concentration & hormone influences > Flashcards

9.2 Blood Flow to the Kidneys; The Nephron; Urine formation, concentration & hormone influences Flashcards

1
Q

Describe the passage of blood through the kidneys

A
  • Renal artery
  • Interlobular artery
  • Afferent arteriole
  • Glomerulus
  • Efferent arteriole
  • Peritubular capillary
  • Vasa recta (loop of henle)
  • Interlobular vein
  • Renal Vein
  • IVC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the three main components of a nephron?

A
  • Renal corpuscle (water and solutes removed)
  • Renal tubule (filtrate modification)
  • Collecting system (urine from each nephron empties into minor calyces)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three processes within kidney function?

A
  • Filtration
  • Rebasorption
  • Secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where does filtration occur in the nephron?

A

Only in the renal corpuscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the difference in diameter between the afferent and efferent arterioles of the glomerulus? Why is this important?

A
  • Efferent has smaller diameter
  • This causes a pressure gradient, enabling blood to move throughout the glomerulus and hence enabling filtration to occur
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the three layers of the filtration membrane of the glomerulus

A
  • Fenestrated endothelium (capillary)
  • Basement membrane (collagen -> -ve charge)
  • Pedicels of podocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What three factors of the renal corpuscle enhance glomerular filtration?

A
  • Thinness of filtration membrane
  • BP gradient
  • High surface area of capillaries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the fenestrated endothelium stop?

A

Some cells and platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the basement membrane stop?

A

Large proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do filtration slits between pedicels of podocytes stop?

A

Medium sized proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some substances that can enter through the filtration membrane?

A
  • Water
  • Small proteins
  • Amino acids
  • Glucose
  • Waste solutes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In what two ways does the basement membrane of the glomerulus act as a barrier?

A
  • Charge (negative)
  • Physical (blocks large proteins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Briefly explain the role of mesangial cells in the renal corpuscle

A
  • Control capillary diameter (and therefore blood flow rate)
  • Keeps glomerular filter free of debris by phagocytosing trapped substances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What change occurs to tubular fluid at the PCT? What aids this?

A
  • Essential substances (water, glucose, small proteins) are reabsorbed. Cells within PCT have microvilli to aid this
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What change occurs to tubular fluid at the loop of Henle?

A

Descending: water is taken out of tubular fluid (so solute conc increases)
Ascending: Na+ and Cl- are reabsorbed out of tubular fluid along conc gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What percentage of initial filtrate volume reaches the DCT?

A

15-20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What change occurs to tubular fluid at the DCT?

A

Final adjustment of filtrate composition via reabsorption and secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What change occurs to tubular fluid at the Collecting Duct?

A
  • Filtrate is carried through osmotic gradient
  • Water may/may not be reabsorbed depending on hydration status
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where does urine travel after leaving the papillary duct?

A

Collects filtrate from multiple collecting ducts and delivers it to the minor calyx

20
Q

What are the main substances extreted?

A
  • Waste products
  • Toxins
  • Urea (although this one is more complex)
21
Q

Why do we expect to see more PCT cells than DCT cells in a H&E section of a nephron?

A

PCT is more tortuous than DCT (more windy)

22
Q

Where is most of the filtrate reabsorbed? What are these substances?

A
  • PCT
  • Ions
  • Simple molecules (glucose)
  • Small proteins
23
Q

What are two structures in PCT cells that can aid their function?

A
  • Mitochondria (active transport)
  • Microvilli (SA:V)
24
Q

Describe the H&E appearance of PCT cells

A
  • Centrally located nucleus
  • Acidophilic (pink) cytoplasm
25
Q

What is descending limb of the loop of henle similar to?

A

The PCT (branches off)

26
Q

Describe the epithelium of the thin ascending limb

A

Simple squamous

27
Q

What is the structure of the thick ascending limb of the loop of Henle similar to?

A

Similar to DCT (becomes DCT)

28
Q

What vessels accompany the loop of henle?

A
  • vasa recta
  • Peritubular capillaries
29
Q

Draw a diagram of the countercurrent multiplier mechanism. How do juxtamedullary nephrons aid in this process? How is urea recycling work?

A
30
Q

What are the functions of the DCT?

A
  • Na+ reabsorbed; K+ secreted (ATPase pump)
  • Reabsorb bicarbonate (acidifies urine)
31
Q

Describe the structure of DCT cells

A
  • Few/no microvilli
  • Lots of mitochondria
32
Q

How and why do DCT cells look different to PCT cells in a H&E section?

A

Paler (less organelles; not main site of reabsorption, unlike PCT)

33
Q

What are the two components of the juxtaglomerular apparatus

A
  • Juxtaglomerular (JG) cells
  • Macula densa
34
Q

What is the function of the JG cells? Where are they located?

A
  • Endocrine cells in the afferent arteriole
  • Produce renin for RAAS system
  • Causes increase resorption of sodium in the DCT
35
Q

Where are macual densa located? What do they do?

A
  • Part of DCT
  • Monitor sodium conc in filtrate
36
Q

Name two stimuli that can cause the release of renin from the JG cells of the JGA

A
  • Sodium levels decrease in filtrate detected by Macula Densa
  • Decreased blood pressure in afferent arteriole detected by JG cells
37
Q

Structurally speaking, how are macula densa cells different from regular DCT cells?

A

More columnar

38
Q

What are diuretics?

A

Increase excretion of sodium and water

39
Q

What are some commonly encountered diuretics (colloquially speaking)

A
  • Caffeine
  • Alcohol
  • Medications
40
Q

What is hypohydration?

A

Water defecit; body water losses of >2% body mass

41
Q

What are the three most important metabolic waste products excreted in urine?

A
  • Urea
  • Creatinine
  • Uric acid
42
Q

How is urea formed?

A

By-product of AA breakdown in liver

43
Q

How is creatinine formed?

A

Formed in skeletal muscle through creatine phosphate breakdown (involved in muscle contraction)

44
Q

How is uric acid formed?

A

By-product of recycling RNA nitrogenous bases

45
Q

Which areas of the nephron does ADH act on?

A

Late DCT and collecting tube

Foundations Of Medicine (98 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions