65: Urinary System II (Histo) Flashcards Preview

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Flashcards in 65: Urinary System II (Histo) Deck (43)
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1
Q

thick descending portion of loop of Henle

A

Proximal Straight Tubule

2
Q

Where is the Proximal Straight Tubule found?

A

in the medullary ray of the cortex & also in outer medulla

3
Q

Longer in juxtamedullary nephrons and are found in the medulla

A

Thin segment of Loop of Henlé

4
Q

What type of epithelium is in the Thin segment of Loop of Henlé?

A

thin simple squamous in both ascending and descending limbs in short nephrons

5
Q

Arteriole and venule rectae form loops parallel to the loop of Henlé (fenestrated capillaries)

Help maintain osmotic gradient in interstitium

A

Vasa Recta (Countercurrent exchange system)

6
Q

Hypertonic interstitium

A

causes loss of water from the arterioles as they descend into medulla and gain water into the venules as they ascend to the corticomedullary
junction

7
Q

Also called distal straight tubule

A

Thick ascending limb

8
Q

Where is the Distal Straight Tubule found?

A

in the medullary ray of the cortex & also in outer medulla

9
Q

Functions of Distal Straight Tubule

A

Transports ions from the lumen of the tubule to the interstitium via active transport

Reabsorbs: Ca2+, Mg 2+, Na+, & HCO3-

Secretes: K+, H+, NH4

Parathyroid regulated Ca2+ reabsorption

Relatively impermeable to H20

Highest Na+/K+ ATPase
activity

10
Q

What type of epithelium is in the Distal convoluted tubule?

A

Simple cuboidal epithelium

11
Q

Fewer and shorter microvilli however extensive basal folds

Apically placed nucleus

A

Distal convoluted tubule

12
Q

Modified cells of the distal straight tubule

Located at vascular pole

Senses changes in Na+
concentration w/n lumen of the distal tubule

A

Macula densa

13
Q

regulates blood pressure

A

Juxtaglomerular apparatus

14
Q

Juxtaglomerular apparatus components

A

Macula densa

Extraglomerular mesangial cells
(Lacis / Polkissen cells)

Juxtaglomerular cells (JG cells): modified smooth muscle cells of
afferent arteriole
Produce renin ( cleaves angiotensinogen to angiotensin I)
15
Q

potent vasoconstrictor

stimulates aldosterone secretion from adrenal cortex

A

angiotensin II

16
Q

What does aldosterone stimulate?

A

reabsorption of Na+ and secretion of K+ by

connecting tubules and collecting ducts

17
Q

Connecting tubules

A

Connect DCT to cortical collecting duct

Contain cells from DCT and CD (principal
cells)

Play important role in secretion of K+ into
lumen

18
Q

Found in the medullary ray of the cortex

A

Cortical collecting duct

19
Q

What leads into cortical collecting duct?

A

Connecting tubules

20
Q

All nephrons within a renal lobule drain into ____ cortical collecting duct

A

one

21
Q

What epithelium makes up cortical collecting duct?

A

simple cuboidal epithelium

22
Q

What epithelium makes up Medullary collecting ducts?

A

simple cuboidal transitions to simple

columnar epithelium

23
Q

Ducts of Bellini

A

several Medullary collecting ducts that merge to form papillary ducts

24
Q

Most abundant cells of collecting ducts

Pale staining

true basal infoldings

Single primary cilium: short scattered microvilli

Abundant ADH regulated Aquaporins
(AQP- 2) channels

A

Light or principal cells

25
Q

least abundant cells of collecting ducts

Not present in the inner medulla

Microvilli and microplicae at apical
cytoplasm

Secretion of H+ or bicarbonate

A

Dark or intercalated cells

26
Q

Where do Medullary collecting ducts empty?

A

at the area cribrosa (a

region having a sieve-like appearance) on the apex of a renal papilla

27
Q

connective tissue of

the kidney which surrounds the nephrons, ducts and neurovasculature

A

Renal interstitium

28
Q

What are the two main cell types of cortical interstitium?

A

fibroblasts and

mononuclear cells

29
Q

resemble myofibroblasts
present along the
descending vasa recta

A

Medullary interstitium

30
Q

functions to transit and store urine

A

Excretory Passages

31
Q

What are some Excretory Passages?

A

minor and major

calices, renal pelvis, ureter, urinary bladder and urethra

32
Q

Excretory passages have _____, _______, and ______

A

mucosa
muscularis
adventitia

33
Q

Transitional epithelium

A

Superficial: single layer of dome
shaped (umbrella) cells, shape of the cell depends on the
filling state

Intermediate (pear shaped cells) abundant desmosomes

Basal layer: stem cells

Abundant tight junctions: impermeable to salts and water

34
Q

on the apical surface of superficial cells of Urothelium (contains crystalline uroplakin which contributes to the permeability barrier)

A

Urothelial plaques

35
Q

Apical scalloped surface of Urothelium covered by the ______

A

Uroplakin

36
Q

Fusiform vesicles of Urothelium

A

Flattened elliptical vesicles

37
Q

conduit between the renal pelvis and the urinary bladder

A

Ureter

38
Q

Layers of Ureter

A

–Mucosa: Epithelium + lamina propria

–Muscularis:

upper two-thirds, has longitudinal layer surrounded by circular layer of
smooth muscles

lower one-third has an
additional longitudinal smooth muscle layer towards the outside
(Contraction of these muscle layers produces peristaltic
waves)

–Adventitia

39
Q

Urinary bladder cells

A

Mucosa: Epithelium + fibroelastic CT

40
Q

_______ of the bladder is thick and consists of smooth muscle arranged in an inner longitudinal, middle circular
and outer longitudinal layer (oblique orientation of muscles)

A

Muscularis

41
Q

Conveys urine from the bladder to be evacuated outside

A

Urethra

42
Q

Segments of Male urethra

A

–Prostatic : transitional epithelium

– Membranous: pseudostratified columnar

– Spongy : Pseudostratified columnar until the fossa navicularis where it is lined by
stratified squamous epithelium

– Mucus-secreting glands (of Littre) are located in the subepithelial connective
tissue throughout the passage.

43
Q

Segments of Female urethra

A

short compared to male’s

Initial part lined by transitional epithelium and
terminal part by stratified squamous epithelium

Muscularis is composed of an inner longitudinal and an outer circular layer of smooth muscle