Brainscape's Knowledge GenomeTM

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


See full index

ANKI cards > KIDNEY HISTOPHYSIOLOGY > Flashcards

KIDNEY HISTOPHYSIOLOGY Flashcards

1
Q

What are the three main functions of the urinary system?

A

Excretion (removing organic wastes from blood), elimination (discharging these wastes as urine), and homeostatic regulation (controlling blood plasma volume and solute concentration), are vital for maintaining internal balance and removing toxins.

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

Which structures make up the urinary tract?

A

The urinary tract comprises the ureters, urinary bladder, and urethra, which together transport and eliminate urine formed by the kidneys, ensuring waste removal from the body.

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

What role does the kidney play in the urinary system?

A

The kidneys are responsible for filtering blood and excreting waste products as urine, maintaining a balance of electrolytes, water, and pH, which is essential for overall physiological stability.

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

What is the functional unit of the kidney?

A

The nephron.

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

How does the urinary system regulate blood pressure?

A

By controlling blood volume and excreting or retaining water and electrolytes, the kidneys influence blood pressure, which is essential for proper circulatory function and organ perfusion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which ions are regulated by the urinary system?

A

Sodium, potassium, calcium, and chloride are regulated by the kidneys to ensure electrolyte balance, which is critical for nerve and muscle function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two main regions of the kidney?

A

The kidney consists of the cortex (outer layer) and medulla (inner region). The cortex contains the bulk of nephrons, where blood filtration begins, while the medulla is involved in concentration processes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the nephron’s role in the kidney?

A

The nephron is the kidney’s functional unit, responsible for filtering blood, reabsorbing nutrients, and excreting waste, making it integral to urine formation and blood cleansing.

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

What distinguishes cortical nephrons from juxtamedullary nephrons?

A

Cortical nephrons are located in the outer cortex and perform most blood filtration, while juxtamedullary nephrons are closer to the medulla and play a key role in urine concentration.

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

What supplies blood to the kidneys?

A

The renal artery supplies the kidneys with blood, ensuring they receive a continuous flow for filtration and waste removal, which is crucial for maintaining blood purity.

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

What is the significance of kidney vascularization?

A

The extensive blood supply allows kidneys to filter the entire blood volume multiple times a day, which is necessary for toxin removal and fluid regulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does renal microcirculation aid kidney function?

A

Microcirculation in the kidneys enables efficient nutrient and waste exchange in the nephron’s capillary networks, crucial for reabsorption and secretion processes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the two capillary networks in renal microcirculation?

A

The glomerular capillaries (filtration) and peritubular capillaries (reabsorption and secretion) work together to ensure that the blood is filtered and nutrients are reclaimed as needed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why are two capillary beds essential in the nephron?

A

The glomerular bed enables filtration, while the peritubular bed allows for selective reabsorption and secretion, ensuring efficient waste removal and nutrient conservation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is the glomerular capillary bed supplied?

A

It is supplied by the afferent arteriole and drained by the efferent arteriole, creating pressure for filtration in the glomerulus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the primary function of peritubular capillaries?

A

They facilitate exchange between blood and nephron, allowing reabsorption of valuable substances like glucose and electrolytes and the secretion of wastes.

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

What is the significance of the proximity of peritubular capillaries to the nephron loop?

A

Their close association allows efficient exchange, especially critical in the loop of Henle where water and salts are reabsorbed.

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

How do peritubular capillaries differ in cortical vs. juxtamedullary nephrons?

A

In juxtamedullary nephrons, they form vasa recta, supporting the osmotic gradient needed for water reabsorption, while in cortical nephrons, they help reclaim solutes.

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

What are the components of the renal corpuscle?

A

It includes the glomerulus and glomerular (Bowman’s) capsule, which together initiate the filtration of blood into a protein-free filtrate.

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

What is the function of the glomerular capsule?

A

It surrounds the glomerulus, capturing filtrate and directing it into the tubules, where further processing into urine occurs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the glomerular filtration barrier?

A

A selective barrier allowing small molecules to pass but blocking proteins and cells, ensuring that only waste and small solutes enter the filtrate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the three components of the glomerular filtration membrane?

A

Capillary endothelium, basement membrane, and podocyte filtration slits create a precise filtering system to separate waste from essential blood components.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do cortical and juxtamedullary nephrons differ?

A

Cortical nephrons are located in the cortex, while juxtamedullary nephrons extend into the medulla.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does countercurrent multiplication achieve in the kidney?

A

It concentrates urine by creating an osmotic gradient in the medulla.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where does the countercurrent multiplier primarily occur?

A

In the Loop of Henle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What role does the Na+/K+/2Cl- symporter play in the ascending limb?

A

It actively transports ions, contributing to the osmotic gradient.

25
Q

What is the primary function of the nephron loop in conjunction with the vasa recta?

A

To create a high osmolarity in the medulla, establishing the osmotic gradient.

26
Q

How does ADH affect the distal tubules and collecting ducts?

A

It increases their permeability to water, enhancing water reabsorption.

27
Q

Which mechanism is essential for establishing the medullary osmotic gradient?

A

The countercurrent multiplier mechanism

28
Q

What is the main role of the descending limb of the Loop of Henle?

A

Reabsorption of water.

29
Q

What characterizes the epithelium of the thin descending limb?

A

Thin, simple squamous epithelium.

30
Q

What distinguishes the thick ascending limb of the nephron loop?

A

It is impermeable to water and actively reabsorbs Na+ and Cl-.

31
Q

Which structures are not found in the renal medulla?

A

Renal corpuscles.

32
Q

What is primarily located in the renal medulla?

A

Loops of Henle and collecting ducts.

33
Q

How does the medulla contribute to urine concentration?

A

It creates an osmotic gradient necessary for water reabsorption.

34
Q

What is the main function of the proximal convoluted tubule?

A

Reabsorption of water, ions, and organic nutrients.

35
Q

How does the brush border of the PCT aid in its function?

A

It increases surface area, enhancing absorption.

36
Q

Why is the PCT rich in mitochondria?

A

To provide energy for active transport, especially for the Na+/K+ ATPase pump.

37
Q

What is the function of mesangial cells in the glomerulus?

A

They provide structural support, regulate blood flow, and are phagocytic, removing trapped particles.

38
Q

How do mesangial cells respond to injury or disease?

A

They can proliferate and secrete inflammatory cytokines, contributing to glomerular injury.

39
Q

Which hormone influences mesangial cell contraction, and what is its effect?

A

Angiotensin II; it causes contraction of mesangial cells, which can decrease glomerular filtration.

40
Q

How does the brush border of the PCT enhance its function?

A

It increases the surface area for reabsorption of water, ions, and nutrients.

41
Q

What type of junctions are found in the PCT, and what is their permeability characteristic?

A

Tight junctions, which are “leaky” to allow some paracellular transport.

42
Q

How does this osmotic gradient help in urine concentration?

A

It allows for water reabsorption in the collecting ducts when ADH is present.

43
Q

Why is the hyperosmotic gradient essential for the kidney’s function?

A

It enables the kidney to produce concentrated urine, conserving water.

44
Q

What role does the countercurrent multiplier play in urine concentration?

A

It establishes an osmotic gradient in the medulla, which is essential for water reabsorption and urine concentration, especially in the presence of ADH.

45
Q

How does the Loop of Henle contribute to the countercurrent multiplier system?

A

The descending limb reabsorbs water, while the ascending limb actively reabsorbs sodium and chloride ions, creating a hyperosmotic environment in the medulla.

46
Q

What is the relationship between the countercurrent multiplier and ADH?

A

ADH increases the permeability of the collecting ducts to water, allowing more water reabsorption along the osmotic gradient set by the countercurrent multiplier.

47
Q

What are the primary functions of the distal convoluted tubule?

A

The DCT is involved in secretion of ions, acids, drugs, and toxins, and it also allows for variable reabsorption of water, sodium, and calcium under hormonal regulation.

48
Q

Describe the cellular characteristics of the DCT.

A

The DCT is lined with low cuboidal cells, with central nuclei that protrude into the lumen. The lumen appears more even and wider than in the proximal tubule.

49
Q

How does the DCT contribute to acid-base and electrolyte balance?

A

It secretes ions like hydrogen and bicarbonate, influencing blood pH, and reabsorbs sodium and calcium, contributing to electrolyte homeostasis.

50
Q

What structural adaptations in the DCT cells support their function?

A

The DCT cells have well-developed tight junctions to prevent paracellular movement, lateral membrane interdigitations for increased surface area, and numerous mitochondria to supply ATP for active transport.

51
Q

Why is the DCT largely impermeable to water?

A

The tight junctions between cells in the DCT limit water movement, so water reabsorption here is controlled hormonally, particularly by ADH.

52
Q

What is the significance of the high mitochondrial content in DCT cells?

A

High mitochondrial density provides energy for active transport processes, such as the Na+/K+ ATPase pump, which regulates ion concentrations.

53
Q

Describe the structural composition of the collecting duct.

A

The collecting duct is composed of pale-staining cuboidal to columnar principal cells, which are involved in water reabsorption, and dark-staining intercalated cells, which regulate acid-base balance.

54
Q

How is water reabsorption in the collecting duct regulated?

A

Water reabsorption is controlled by antidiuretic hormone (ADH), which increases the permeability of the collecting duct cells to water.

55
Q

What is the role of intercalated cells in the collecting duct?

A

Intercalated cells are crucial for acid-base balance, as they secrete hydrogen ions to lower urine pH and regulate bicarbonate levels.

56
Q

What type of epithelium lines the renal calyces, renal pelvis, ureters, and bladder?

A

Transitional epithelium, also known as urothelium.

57
Q

How does transitional epithelium adapt to the stretching of the bladder?

A

It can appear as 5-6 layers when relaxed and 2-3 layers when stretched, allowing it to expand without compromising its impermeability to urine

58
Q

What is unique about the surface cells of transitional epithelium?

A

Known as umbrella cells, they can flatten when stretched, maintaining a barrier that prevents urine from leaking into surrounding tissues.

59
Q

What is the main function of the umbrella cells in the bladder?

A

They provide a flexible yet impermeable barrier that prevents urine from penetrating the bladder wall.

60
Q

How does the structure of the urothelium aid in its function within the urinary tract?

A

Its ability to stretch and contract helps accommodate fluctuating urine volumes without compromising the epithelial barrier.

61
Q

Why is it important for the urothelium to remain impermeable to urine?

A

To prevent urine from damaging surrounding tissues and to avoid fluid and electrolyte imbalances.

ANKI cards (10 decks)

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