GU Systems Histology Flashcards
1
Q
What is contained in the hilum of the kidney?
A
- Renal Vessels
- Nerves
- Renal Pelvis
2
Q
What constitutes a lobe of the kidney?
A
Meduallary pyramid with overlying cortex plus 1/2 of the renal column on each side
3
Q
T or F: a major calyx is formed anytime two minor calyces join
A
True
4
Q
Where do minor calyces begin?
A
at the renal papilla
5
Q
What are the jobs of the kidneys
A
- Remove waste from the blood
- Regulate: electrolytes, plasma volume, blood pressure
- Produce hormones: Erythropoietin, Renin, activation of vit. D
** ALL of these functions are performed by nephron
6
Q
What does erythropoietin regulate?
A
- Regulates red-blood cell formation
7
Q
What does renin do?
A
- involved in control of BP
8
Q
What is the structural and functional unit of the kidney?
A
Nephron
9
Q
What does a nephron consist of?
A
- Renal Corpuscle and its tubules
10
Q
What part of the kidney actually filters blood?
A
Renal corpuscle
11
Q
T or F: collecting ducts are part of the nephron
A
FALSE, collecting ducts are NOT part of the nephron
12
Q
Tubules extend between what two structures?
A
-Corpuscles and collecting ducts
13
Q
What filters the blood and produces urine?
A
The nephron - its the functional unit of the kidney
14
Q
What are the 3 parts of the nephron and their subparts?
A
Proximal Thick Segment
- Prox. convoluted Tubule
- Prox. Straight Tubule
Thin Segment
1. Thin Limb
Distal Thick Segment
- Medullary Thick Ascending Limb
- Cortical thick Ascending Limb
- MACULA DENSA - Distal Convoluted Tubule
- Connecting segment
15
Q
What three parts of the nephron make of the Loop of Henle?
A
- Proximal Straight Tubule
- Thin Limb
- Meduallry Thick Ascending Limb
***Not that the loop of Henle contains contributions from all 3 major segments
16
Q
What is the Distal Nephron tubule distal to?
A
macula densa
17
Q
What is the job of the collecting ducts?
- are they part of the nephron?
A
- Collecting ducts move urine from nephron tubules to renal papillae
- COLLECTING DUCTS ARE NOT PART OF THE NEPHRON
18
Q
What two parts make up the collecting duct?
A
- Cortical Collecting Duct
- Medullary Collecting Duct
19
Q
Compare the lumen of a proximal tubule to that of a distal tubule.
A
Proximal:
Star-Shaped lumen and brush border
Distal:
Rounded with sharper luminal surface of cells
20
Q
Compare the diameter of proximal tubules to distal tubules.
A
Proximal:
Larger
Distal:
Smaller
21
Q
Compare the LENGTH of proximal tubules to distal tubules.
A
Proximal tubules are TWICE as long
22
Q
You are observing a cortical labyrinth, what will most of the cells in it be?
A
Proximal Tubules
23
Q
T or F: Collecting ducts have diameters comparable to that of distal tubules.
A
False, these are larger, they collect from many proximal tubules
- Their diameter is closer to that of a proximal tubule
24
Q
Which displays a larger number of nuclei collecting ducts or proximal tubules?
A
Collecting ducts
25
Compare the wall of a collecting duct to that of a proximal tubule.
Collecting ducts have smaller cuboidal cells in their walls (this gives the appearance of having more nuclei)
26
What is the epithelium of thin limbs made of?
- Low cubiodal or simple squamous
27
What is the connective tissue of the kidney parenchyma?
Interstitium
28
Where can the interstitium be found in the kidney?
Surrounding the nephrons, ducts, blood, and lymphatic vessels
29
How does the amount of interstitium change as you move towards the medulla.
It more than doubles in amount
30
Describe the cellular difference in the interstitium from the cortex to the medulla?
Cortex:
Fibroblasts and Macrophages
Medulla:
Cells resemble Myofibroblasts
31
Where can interstitial cells in the medulla be found?
- In long axes of tubular structures
| - Play a role in compressing them
32
What filters the blood in the kidney, what is produced as a result of this filtering?
- Renal Corpuscle filters blood and creates ultrafiltrate
33
How does blood enter and exit the the renal corpuscle?
Enters via Afferent arteriole
| Exits via Efferent arteriole
34
What are the components of the renal corpuscle?
Glomerulus - Capillary ball
Bowman's capsule - Parietal (outer wall) and visceral layers (on capillary)
Urinary space - between parietal and visceral layers
35
Where can mesangial cells be found and what do they do?
- Can be found surrounding capillaries
| - Phagocytose, structural support, secrete substances
36
What important substance is secreted from mesangial cells?
Interleukin I - platelet derive growth factor used for REPAIR of the Glomerulus
37
What are the 3 types of nephrons?
| - Describe differences among their loops of Henle.
1. Cortical - Short Loop of Henle
2. Juxtamedullary - Long Loop of Henle
3. Intermediate - Intermediate Loop of Henle
38
What are the two subdivisions of the cortex?
| - what do they consist of
Cortical Labyrinths (all the tortuous structures):
Renal corpuscles
Proximal Convoluted tubules
Distal Convoluted Tubules
Medullary Rays (all the straight stuctures):
Staight and ascending tubules
collecting ducts
39
What is the position of medullary rays?
between two cortical labyrinths
40
What section of the cortex could straight and ascending tubules along with collecting ducts be found?
In the medullary rays between cortical labyrinths
*Notice the ray consists of all the straight stuctures as the name implies
41
In terms of rays and labyrinths what does a lobule consist of?
- 1/2 of a labyrinth
| - 1 entire ray
42
What structures will you see when looking at kidney medulla tissue?
- Loop of Henle only (consists of proximal straight tubule, thin limb, and distal straight tubule)
43
T or F: the kidney receives 1/4 of the cardiac output
True
44
Where does most of the blood in the kidney go?
To the cortex
45
Describe the arterial branching pattern in the kidney.
1. Renal a.
2. Interlobar a.
3. arcuate a.
4. Interlobular a.
5. Afferent arterioles --> glomerulus --> Efferent arterioles
6. Peritubular capillaries
46
Where does the arteriole rectae come from?
Efferent arterioles of juxtamedullary glomeruli (these are deeper)
47
What marks the boundaries of lobules on histological sections?
Interlobular a.
48
What are the 3 main functions of the nephron and where do these occur?
Filtration - renal corpuscle (to make ultrafiltrate)
Reabsorption - proximal convoluted tubule (get back electrolytes and glucose)
Secretion - tubules (ions and NH3 get peed out)
49
T or F: Bowman's capsule is the filtration apparatus of the renal corpuscle
FALSE, Bowman's capsule is just a capsule the filtration apparatus is contained in the glomerulus
50
Where does ultrafiltrate exit Bowman's capsule.
at the urinary pole
51
What are the 3 parts of the filtration apparatus in the glomerulus?
1. Fenestrated Endothelium (capillary)
2. Glomerular basement membrane
- Basement membrane of glomerulus
- Basement membrane of podocytes
52
What interdigitates around glomerular capillaries?
- Podocytes
53
What is created by the spaces left between the feet of the podocyte and what spans these structures?
- Filtration slits
| - Filtration slit membrane spans between each "foot"
54
Describe the endothelium of the capillaries in the filtration apparatus in terms of number and size of fenestrations.
Fenestations are larger and more numerous
55
What in the filtration apparatus restricts the movement of particles on the basis of size?
The basal lamina - albumin and hemoglobin cannot pass through
56
What is the ultimate barrier that restricts molecules based on size in the filtration apparatus?
Lamina Densa
57
What molecules are allowed to pass through the lamina densa?
1. neutral proteins under 70,000 Da
| - charged particles typically won't pass
58
Does albumin usually appear in urine.
NO, this is indicative of pathology
59
What is nephrotic syndrome and what disease is it often associated with this?
- Proteinurea - thicker than normal basal lamina but its still leaky
- Hypoalbuminemia - albumin is osmoregulatory so peeing is out leads to low BP (no blood getting pulled back into capillaries)
- Edema - caused by low colloidal BP
**Seen in diabetes mallitis patients
60
How do reabsorbed particles make their way back into circulation from renal tubules where they get reabsorbed?
They go into the peritubular capillaries to reenter circulation
61
How are ions and drugs exceted into the urine?
Peritubular capillaries release the material into the tubules (into provisional urine)
62
Where does most reabsorption occur in the greatest proportions?
In peritubular capillaries surrounding the proximal convoluted tubules
63
Where does secretion occur in the greastest proportions?
In the thin limb and distal tubules
64
What is the juxtaglomerular apparatus?
- Where is it located?
- What does it include?
- Located in the split between afferent and efferent arterioles
Includes:
- Macula densa (arteriole side, part of distal tubule)
- Juxtaglomerular cells (attached to both arterioles)
- Mesangial cells (fill the spaces between the arterioles)
65
What is an important task of the juxtaglomerular appartus?
- regulates blood pressure
66
How do macula densa cells differ from other cells in the distal tubule?
- What do they do?
They are narrower and taller
| - Monitor Na+ concentration
67
What are juxtaglomerular cells made of and what do they do?
- Specialized SMOOTH MUSCLE cells of the efferent and afferent arterioles
- activate the renin-angiotensin-aldosterone system when Na+ or BP is low
68
What is the relationship between juxtaglomerular cells and macula densa cells?
Macula densa sense the environment and tell the JG cells when to release renin
69
What is the only part of the extretory passage not lined by transitional epithelium (aka uroepithelium)?
The lower part of the urethra
70
What layering of every tissue except the urethra?
1. Mucosa
2. THIN submucosa
3. Muscularis
4. Adventitia (or serosa)
***ABSENCE OF THE MUSCULARIS MUCOSA IN URINARY PASSAGEs
71
What lines the lower part of the urethra?
Stratified or pseudostratified columnar epithelium
72
What is the arrangement of the muscularis in the ureter?
| - What do these do?
1. Inner longitudinal
2. Middle circular
3. Outer longitudinal (only distal end of ureter)
- Peristalic contractions to contribute to urine flow
73
How is the muscularis different in the bladder from the ureter?
Its thicker
74
T or F: the bladder has adventitia all the way around
False, it has serosa on the superior side
75
Which has more microvilli, proximal convoluted tubule or proximal straight tubule and why?
Proximal convoluted because it is more involved in absorption
76
What part of the kidney nephron contains macula densa cells?
THICK CORTICAL ASCENDING LIMB
77
Where can proximal tubules be found?
These are anything before the macula densa
78
Where is urine concentrated?
loop of Henle
79
What structures empty into the minor calyx?
Ducts of Bellini
80
what is the area cribosa?
portion of apex at papilla pierced by 10-20 ducts of bellini
81
What type of tube forming cell in the kidney presents with a halo around the nucleus?
Collecting duct cell
82
T or F: podocytes are part of the visceral layer Bowman's capsule
True
83
T or F: Juxtaglomerular cells detect and respond to low blood volume
True
