Histology Of The Urinary System

stroma+ parenchyma capsules fibrous capsule adipous capsule renal fascia

stroma: capsule+interstitium parenchyma: nephrons and collecting ducts

structural and functional unit 1 million/kidney organization: renal corpuscle Bowman s capsule (parietal layer- simple squamous epithelium, visceral layer- podocytes) glomerulus (fenestrated arterial capillary, afferent and efferent arteriole)

renal tubule proximal tubule loop og Henle (thin and thick limb) distal tubule reunient tubule

EPITHEL

UNIT OF THE URINARY SYSTEM renal corpuscle Malpighi

capsula glomeruli / Bowman s capsule: visceral layer + parietal layer

pars convoluta

NEPHRON renal tubules

proximal tubule

pars recta

intermedial tubule distal tubule

collecting tubules

ansa nephroni / Henle s loop

podocyte, simple squamous epithelium simple cuboidal epithelium with microvilli simple squamous

pars recta pars convoluta

reunient tubule

papillary duct

endothel

glomerulus / rete mirabile

simple cuboidal simple cuboidal cuboidal and columnar epithel columnar epithel

proximal tubule

distal tubule macula densa

RENAL CORPUSCLE Malpighi et Apparatus juxtaglomerularis

afferent arteriole podocyte GLOMERULUS

Bowman s space

Bowman s capsule: parietal layer

Juxtaglomerular apparatus FUNCTION: Components

Localisation

1. Juxtaglomerular cells

tunica media of the afferent arteriole

(granular myoepithel cells)

1. autoregulation of kidney circulation 2. regulation of blood pressure renin secretion

(distal tubule, modified, dens cells with microvilli)

pars convoluta tubuli dist. lying to the vascular pole

3. Extraglomerular mesangial cells

vascular pole

AT-II. = angiotenzin-II., RR = blood pressure, NOS = nitrogen-monoxide synthase, NO = nitrogen-monoxide

RR

(stimulus for secretion: RR , Na+ , 1-rec. adrenerg stimulation),

NOS

2. Macula densa

AT-II.

NO

vasodilation

Na+ - osmoreceptor, NOS NO vasodilation

transmitting signs ( from macula densa, adrenerg nerve ends),

catabolism of AT-II. (angiotensinase-II.)

Proximal vs. Distal Tubule proximal tubule

distal tubule

characteristics

few cell, narrow lumen

more cell, Wide, round lumen

kefeszegély microvilli

YES

no

size of the cuboid cell, staining

high, acidophilia

low, mild acidophilia

presence of basal striation

yes

yes

Intercalar cells

no

few

Proximal tubule vs. Distal tubule

Distal tubule vs. Collecting tubule

Corpusculum renale corticale short loop nephron

Corpusculum renale juxtamedullare long loop nephron

80%

20%

short

long, deep to the renal papilla

Presence of vasa recta

no

YES

Reunient tubule

1 belongs to one nephron

1 belongs to more nephrons

Occurence

Henle s loop

tunica mucosa epithelium mucosae: urothelium/transitional epithelium lamina propria mucosae: thick, loose connective tissue + blood vessels and nerves elongated folds cross section: starshaped lumen

tunica muscularis inner elongated outer spiral smooth muscle

tunica adventitia (connective tissue, blood and lymph vessels, nerves)

lumen (star shaped)

Urothelium Lamina propria mucosae

Stratum longitudinale Tunica muscularis Stratum circulare

Tunica adventitia

epithelium mucosae = urothelium

lamina propria mucosae

tunica mucosa lamina epithelialis mucosae: urothelium lamina propria: thin lamina muscularis mucosae tunica submucosa: connective tissue + elastic fibers + nerves + blood and lymph vessels tunica muscularis inner longitudinal middle cirular m. sphincter vesicae outer longitudinal m. detrusor urinae + vegetative plexus with ganglion cells + blood vessels and lymphatic vessels tunica subserosa et tunica serosa tunica adventitia

urothelium

lamina muscularis mucosae

lumen lamina propria mucosae

Tunica muscularis

Tunica submucosa

superficial cells

lamina epithelialis mucosae = urothelium

lamina propria mucosae

polygonal cells

superficial cells

columnar basal cells

lamina propria mucosae

superficial cells

urothelium

polygonal cells columnar basal cells

lamina propria mucosae