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Flashcards in Renal Histology Deck (85):
1

Three functions of the kidney

Excretory
homeostatic
endocrine

2

How does the kidney participate in excretory functions

makes an ultra filtrate; extra water, ions, drugs and metabolic breakdown products get excreted in the urine

3

How does the kidney participate in endocrine fnxs?

Monitoring the O2 carrying capacity of the blood via erythropoietin, regulating blood pressure through the renin-angiotensin system

4

What is the apperance of the cortex?
What are the linear arrays of tubles that extend into the cortex?

granular in appearance and homogeneous in consistency.

Medullary Rays.

5

has a striated appearance and consists of 6-18 Renal Pyramids.

Medulla

6

The apex or tip of a renal pyramid is called a

Renal Papilla

7

a macroscopic subdivision consisting of a renal pyramid and its surrounding cortex.

A Kidney Lobe

8

a microscopic subdivision consisting of a medullary ray and the cortical tissue (primarily nephrons) on either side.

A Kidney Lobule

9

The Capsule consists mainly of

fibrous connective tissue and surrounds the kidney.
*The parenchyma is not subdivided by septa.

10

The kidneys receive _____ of the total cardiac output/minute. The total blood volume of
the body passes through the kidneys every_____ minutes

20-25%
4-5

11

_____ ml of fluid is extracted from the blood each minute as filtrate [180 L/day].
•_____ ml is reabsorbed in the kidney tubules
• ___ml is excreted as urine

125 extracted
124 reabsorbed
1 ml excreated

12

The order of arterial supply to the kidney

Renal a.--> Lobar a.-->Interlobar a.--> arcuate a. --> Interlobular a. --> Afferent arteriole

13

- supplies tubules of the cortical nephrons

-long capillary loops supplying tubules of juxtamedullary nephrons

• Tubular Plexus

• Vasa Recta

14

Glomerulus is a two capillary system consisting of:

Tubular plexus and Vasa recta

15

Components of the Nephron

Renal Corpuscle
Renal Tubule

16

- an epithelial-lined Tubule that varies in size, shape and function along its length

Renal tubule (part of nephron)

17

• The kidney produces an_________ of the blood, but
it recycles many components that are in the filtrate.
Other compounds are added to the filtrate as it goes
through the tubular system

ultrafiltrate

18

If primarily from a Developmental Viewpoint, a nephron consists of

Renal Corpuscle, Proximal Tubule, Loop of Henle, Distal Tubule [collecting ducts not included]

19

If primarily from a Functional Viewpoint, a nephron consists of:

Renal Corpuscle, Proximal Tubule, Loop of Henle, Distal Tubule & Collecting Duct

20

Renal Corpuscle has Four Components

Glomerulus
Visceral Layer of the Renal Capsule (Bowman’s)
Parietal Layer of the Renal Capsule
Mesangium

21

is a spherical, double-layered sac (Renal Capsule) that surrounds a network of capillaries (Glomerulus -ball of thread).

The renal corpuscle

22

_____ where the arterioles enter and exit and a _______ that is continuous with the proximal convoluted tubule.

Vascular Pole
Urinary Pole

23

a network of capillary loops supplied and drained
by an arteriole.

Glomerulus

24

The Afferent (supplying) Arteriole is larger in
diameter than Efferent (draining) Arteriole. Why?

This size difference creates a pressure differential that
drives glomerular filtration.

25

a double-layered epithelial sac surrounding the glomerulus.

Bowmans capsule

26

The outer or Parietal Layer is a _______epithelium.
• The Visceral Layer is also ______epithelium composed of cells called Podocytes.

simple squamous
a simple squamous

27

The space between the two epithelial layers is called the ________ and is continuous with the proximal tubule. The glomerular filtrate enters this space.

Urinary Space

28

Capillary Endothelium is discontinuous, containing numerous 70-100 nm pores . The pores are freely
permeable to

water and solutes ≤ 6-8 kD and moderately permeable to molecules 8-16kD.

29

The luminal
surface of the capillary endothelium has a negative charge because it is coated with a

glycocalyx consisting of negatively charged proteoglycan molecules.

30

is the primary barrier that prevents protein from entering the glomerular filtrate.

Basement Membrane

31

consists of epithelial cells called Podocytes because of their 1o and 2o foot processes (pedicles).

The Visceral Layer of Bowman’s Capsule

32

The space between pedicles is called the_____ and is bridged by an electron dense Filtration Slit Diaphragm, a modified ______ consisting of the protein _____

Filtration Slit
adherens junction
Nephrin.

33

Four functions of the mesangium

Functions:
• physical support
• regulation of glomerular blood flow
• turnover of glomerular basement membrane

34

• cells and ECM that abut the inner surface of the glomerular basement membrane

Glomerular Mesangium

35

ECM contains

fibronectin and collagen

36

specialized pericyte/smooth muscle cells:
• contain receptors for
• secrete

(ANP) and antiotensin II
endothelin, cytokines and PGEs

37

Location of convoluted portion of proximal tubule

begins at the urinary pole
and located in cortex

38

convoluted portion of proximal tubule
Fnx:
Cell Type:
Mitochondria?

substantial reabsorption
cuboidal/columnar cells with granular cytoplasm and basal nuclei
Numerous mitochondria at base of cell
provide energy for transport

39

Straight Portion: also Thick Descending Limb of
Henle has what cell type?

• cuboidal epithelium

40

Loop of Henle: Length is determined by the location of its renal corpuscle with respect to the:

corticomedullary junction

41

_________located external to the juxtamedullary zone, have short loops that have only
a Descending Thin Limb

Cortical Nephrons

42

_______ are long looped and
have Ascending and Descending Thin Limbs

Juxtamedullary Nephrons

43

thick portions of the loop are lined with _______, but the thin segments are lined with simple ______

cuboidal epithelium

squamous epithelium

44

cell membranes in the ascending thin limb between
epithelial cells are interdigitated, resulting in

water impermeability

45

Straight portion: Thick Ascending
• lined with
• scant microvilli,______junctions
• Lateral & basal membane interdigitations
•______ mitochondria

cuboidal epithelium
efficient tight
abundant

46

Straight portion: thick ascending
-What's reabsorbed?
-relationship with water
-What's secreted?

• Impermeable to water
• Na2+, Cl-, and water reabsorbed
• glucose, amino acids, proteins reabsorbed through facilitated transport
• H+ions secreted

47

Convoluted Portion (Early Distal Tubule)
• lined with
•_____ microvilli
•_____ basal interdigitations
•______ mitochondria

cuboidal epithelium
scant
fewer
fewer

48

Convoluted Portion: early distal tubule:
What is reabsorbed?
What is secreted>

• Na2+ (Aldosterone responsive), Cl-, K+, HCO3 reabsorbed
• K+, urate, H+ions, N3H secreted

49

Contains Cuboidal cells (Principal [light] &
Intercalated [dark] cells) with Distinct cell borders

Collecting Tubules (Late Distal
Tubule) & Collecting Ducts

50

transition segment between the nephron and the collecting duct

Collecting Tubules (Late Distal Tubule)

51

epithelium contains principal cells

Collecting tubules: late distal tubules

52

Collecting tubules: late distal tubules
Antidiuretic Hormone (ADH) dependent segment where:

Na2+ is reaborbed and K+
is secreted

53

Renal Tubular Disease:
Caused by:
How reabsorptive secreatory functions affected:

• Caused by toxins, drugs, infections, metabolic disturbances, ischemia
• Affects reabsorptive and secretory functions resulting in either polyuria or oligo/anuria

54

Acidosis in renal failure results because of failure of

H ion excretion

55

Collecting ducts are lined with

Lined with cuboidal to columnar epithelium

56

have one primary cilium and Antidiuretic Hormone (ADH) sensitive AQP-2 water channels.

Principal (light) Cells in collecting ducts

57

In the presence of
ADH, urea and water diffuse out of the collecting duct and into the renal interstitium.
What is the result?

This increases urine tonicity

58

in the absence of ADH, water is
excreted from the collecting ducts leading to

Polyuria and hypotonic urine (Diabetes Insipidus).

59

acts as a flow sensor in collecting ducts. This function is mediated by two
proteins Polycystin 1 & 2.

The single, nonmotile Primary Cilium

60

– Defects in these proteins result in polycystic kidney disease.

Polycystin 1 & 2.

61

the Space Between the Tubules

Renal Interstitium

62

• interstitial (stromal) tissue is
found in the

renal cortex & medulla

63

Renal interstitium components has what 2 componements?

• interstitial CT
• interstitial cells (fibroblasts) in cortex & medulla

64

Tubular-Interstitium-Vascular Interaction provides a mechanism for modifying and concentrating urine and as what three components?

• Collecting ducts
• Loops of Henle
• Vasa Recta

65

________- urine concentration
_________- protects ion gradient

Countercurrent Multiplier
Countercurrent Exchanger

66

three components of JG apparatus

Renin producing
Extraglomerular mesangial cells
Macula densa

67

Renin producing JG cells are what type of cell and located where?

special smooth muscle cells
in wall of afferent arteriole

68

Extraglomerular mesangial (lactis) cells are connected to JG cells via _________

gap junctions

69

Macula Densa
– _____ of the distal convoluted tubule.
– detects ____ and _____concentration for JG cells resulting in alterations of the
filtration rate and auto-regulation of blood volume

columnar cells
Na2+ and Cl-

70

JG apparatus components can increase systemic blood pressure (BP) & blood volume
(BV) through the

angiotensin system

71

_____ stimulates angiotensin
conversion/increase in aldosterone secretion/increased Na and water reabsorption

Renin

72

Function of erythropoietin

• increase mitosis of red blood cell precursors
• increase release of red cells from marrow

73

Erythropoietin is mostly likely made by _______ and transported to __________

• Probably produced by cortical interstitial cells
• Transported to bone marrow

74

What stimulates production of Erythropoietin?

• Production stimulated by
- high altitude
- hemorrhage
- impaired pulmonary function

75

What are clinical indications for acute kidney fail?

oligouria <400ml/day, unexpected weight gain or
edema, increased toxins in blood
*Prognosis depends on cause, severity, treatment, age

76

Progression of End Stage renal disease

Irreversible injury-->ESRD--> uremia + hematuria

77

Nephrons are connected to a collecting duct system found mostly in the

medulla

78

collect urine and transport it to the urinary bladder
hollow organs with lumen and wall with several layers

Calyces, Pelvis, Ureters

79

Mucosa in calyces,pelvis, ureters
• _____ (uro)epithelium
• lamina propria contains

transitional
abundant elastic tissue

80

Muscular organization of Calyces, Pelvis, Ureters


• smooth muscle
• in ureter -2 layers in the upper 2/3 of the ureter;
3 layers lower 1/3 of the ureter

81

Urinary Bladder
•______ epithelium
• ____layers of smooth muscle

Transitional
3

82

Male Vs female urethra

Male: 15-20 cm; 3 parts
(prostatic, membranous, penile)
• Transitional – pseudostratified sq. and Shared urinary &
reproductive systems
Female:
3-5 cm
• Transitional – pseudostratified sq. and Urinary system only

83

Benign Prostatic Hypertropyhy
also known as nodular hyperplasia seen in:

• Older males >45 years
• Can cause urethral obstruction

84

Common in USA (7-21/1000), Increased in men, sedintary individual
• Hereditary disposition
• Hypercalcemia, pH change, supersaturation of ions encourage it

Kidney stones

85

Bladder Cancer
• Associated with_____
• Majority in US involve the ______

smoking
uroepithelium