Urogenital System Notes

Sistemi Urogenital

• A combined system including:
  • Aparati: Excretion of metabolic waste.
  • Aparati Genital: Reproduction.
• Shared study due to:
  • Embryonic origin from the Mesonephros.
  • Close anatomical relations, especially in the Pelvis.
  • Ambiguous structures like the Urethra in males.

Stadet embrionale te zhvillimit renal (Embryonic Stages of Renal Development)

The development occurs in stages:

• Pronephros.
• Mesonephros.
• Metanephros.

Key structures involved:

• Suprarenal gland.
• Suspensory (diaphragmatic) ligament.
• Gonads (retroperitoneal).
• Mesonephric (Wolffian) duct.
• Gubernaculum.
• Urinary bladder.

Ndarja fillesave urinare e genitale (Initial Separation of Urinary and Genital Systems)

• Metanephros becomes distinct around 11 weeks.
• Key structures:
  • Suprarenal gland.
  • Kidney
  • Suspensory ligament
  • Testes (retroperitoneal).
  • Epididymis.
  • Gubernaculum.
  • Deep inguinal ring.
  • Urinary bladder.

Funksioni renal fetal (Fetal Renal Function)

• Metanephros becomes functional in the second half of the prenatal period.
• Urine excretes into amniotic fluid, mixes with fluid swallowed and reabsorbed by the fetus.
• Substances excreted in urine return to the fetal bloodstream.
• Via the placenta, they pass into the mother's blood for definitive elimination.
• Fetal excretion depends entirely on placental function.
• Renal agenesis leads to reduced amniotic fluid volume but metabolic insufficiency occurs after birth.

Funksionet e Aparatit Urinar (Functions of the Urinary System)

• Eskretimi (Excretion):
  • Removal of metabolic waste from blood plasma and deposition into urine.
• Eliminimi i mbetjeve (Waste Elimination) through other systems:
  • Digestive system: undigested food, water, salts, ionized drugs.
  • Respiratory system: $CO_2$, $H^+$, water, toxins.
  • Skin: water, $NaCl$, nitrogenous compounds (urea, uric acid, ammonia, creatinine).

Funksionet e Aparatit Urinar (Functions of the Urinary System) Part 2

• Homeostasis (electrolyte and water balance):
  • Regulation and redistribution of water and urine concentration in renal tubules.
• Regulation of pH, fluid volume, and composition.
• Production of Erythropoietin (hematopoiesis) & Renin (blood pressure regulation).

Organet urinare & funksionet (Urinary Organs & Functions)

• Ren (Kidney):
  • Urine production (parenchyma).
    • Primary urine: $180 l/24 h$ (similar to plasma; blood filtration).
    • Definitive urine: $1.8 l/24 h$ (selective reabsorption).
  • Endocrine functions: renin → erythropoietin.
• Sistemi pielo-kalicien & Ureter (Pyelocaliceal System & Ureter): Urinary transport.
• Vesica urinaria (Urinary Bladder): Deposition & Urination.
• Urethra: Excretory tube
  * Prostate in males: both urinary and genital organ.
• Structural features: Transitional epithelium (urothelium) → smooth muscle → adventitia.

Prodhimi i urines (Urine Production)

The process involves:

1. Filtration: $180 l/24 h$ (primary urine).
2. Reabsorption.
3. Secretion.
4. Excretion: $1.8 l/24 h$ (definitive urine).

• Urinary excretion = Filtration - Reabsorption + Secretion

Anatomia e veshkes (Kidney Anatomy)

The kidney features:

• Polus superior/inferior (Superior/Inferior Pole).
• Facies anterior/posterior (Anterior/Posterior Surface).
• Margo lateralis/medialis (Lateral/Medial Border).
• Sinus → Hilus.

Pozicioni dhe topografia e veshkave (Position and Topography of Kidneys)

• Located in the retroperitoneal space, behind the peritoneum.
• Posterior to the duodenum and pancreas.

Topografia & Skeletotopia (Topography & Skeletotopy)

• Spatium retroperitonealis (Retroperitoneal space).
• Regio Lumbaris (Lumbar region).
• Level: $T11/12$ - $L2/L3$.
• The right kidney is lower than the left.

Relacionet e Veshkave (Kidney Relations)

• The suprarenal glands sit atop the superior poles of both kidneys.
• The upper halves of each kidney lie in contact with the peritoneum:
  • On the right kidney: peritoneum of the hepatorenal pouch.
  • On the left kidney: peritoneum of the lesser sac medially (stomach bed) and the peritoneum of the greater sac laterally (between the kidney and spleen).
• The hilum is separated from the peritoneum:
  • On the right side: by the second part of the duodenum.
  • On the left side: by the body of the pancreas and splenic vessels.

Sintopia renale ne siperfaqet anteriore (Renal Syntopy on Anterior Surfaces)

• The lateral part of the lower pole is separated from the peritoneum by:
  • The hepatic flexure of the colon (on the right side) and.
  • The splenic flexure of the colon (on the left side).
• The medial part of the lower pole, on each side, lies in contact with the peritoneum, separating it from coils of the jejunum.

Sintopia e faqes renale posteriore (Syntopy of the Posterior Renal Surface)

• Posteriorly, the relations of both kidneys are similar, mainly involving:
  • Diaphragm and quadratus lumborum muscles.
  • Medially, overlap onto the psoas muscle.
  • Laterally, overlap onto the transversus abdominis muscle.

Mbeshtjelljet renale (Renal Coverings)

The coverings include:

• Capsula fibrosa (innermost layer).
• Indi adipoz perirenal (capsula adiposa renis) - Perirenal adipose tissue.
• Fascia renalis - Renal fascia.
• Indi adipoz pararenal (corpus adiposum pararenalis) - Pararenal adipose tissue.

Ndertimi i brendshem i veshkes (Internal Structure of the Kidney)

• Parenchyma & S.Pyelocalicien (Pyelocaliceal System).
• Parenchyma:
  • Cortex renalis (renal cortex) + Substanca Medullaris (medulla).
  • Cortex:
    • Pars convolluta (convoluted part).
    • Pars radiata (radiated part).
    • Collumnae renales (renal columns).
    • Corpusculae renales (renal corpuscles).
  • Medullaris:
    • Lobus renalis/Pyramis (renal lobe/pyramid).
    • Papilla renalis (renal papilla).
    • Area cribrosa (cribriform area).
    • Ducti papillares (papillary ducts).

System Pyelocalicien & Arteriet perifokale (Pyelocaliceal System & Perifocal Arteries)

1. Medulla (piramis) - Medulla (pyramid).
2. Cortex.
3. Calix minor (7-14) - Minor calyx.
4. Papilla.
5. Calix major (2-3) - Major calyx.
6. Sinus.
7. Collumna-Bertin - Column of Bertin.
8. Collum callicis - Neck of calyx.
9. Pelvis (ampullar/dentritic).
10. Ureter

Ndertimi KORJA E VESHKES (Kidney Cortex Structure)

• The renal cortex (cortex renis) is mainly on the kidney's surface and penetrates inward as renal columns (columnae renales or columns of Bertin), which border the kidney pyramids.
• PALCA E VESHKES (medula renis) – Kidney Medulla
  • Medulla is internal and grayish (lighter than the cortex due to less blood).
  • It consists mainly of straight renal tubules (tubuli renales recti), numbering over 100,000.
  • Appears as pyramids (pyramis) with the base towards the periphery and the apex towards the renal pelvis.
  • Two or three pyramids form renal papillae (papillae renales), with a sieve-like surface (area cribrosa).
  • The cribriform area has 15-20 straight renal tubules (tubuli renales recti) opening into it.
  • This area faces the minor calyces (calices minores); two or three unite to form major calyces (calices majores).
  • Two to three major calyces combine into the renal pelvis (pelvis renalis), with an average volume of 20-30 cc.

A renalis – Segmentet vaskulare (Renal Artery - Vascular Segments)

• A.Renalis (Renal Artery):
  • R. anterior (Anterior branch).
  • R. posterior (Posterior branch).
  • Aa. segmentales (Segmental arteries).
  • Aa. interlobares (Interlobar arteries).
• Segments:
  1. Superior.
  2. Anterior superior.
  3. Anterior inferior.
  4. Inferior.
  5. Posterior.

Uriniferous tubules (Nephron)

• Each kidney contains 1-1.5 million nephrons.

• Composed of a glomerular capsule + renal tubules.

• Proximal portion:

  • Tubuli contorti of the 1st order (Proximal convoluted tubule).
  • Ansa Henle (Loop of Henle).
  • Tubuli contorti of the 2nd order (Distal convoluted tubule).
  • Glomerular filtration (primary urine - $180 l/24$ hours)
  • Selective tubular reabsorption (countercurrent exchange system)

• Distal Portion

  • Ductus colectoris (Collecting Duct)
  • Ducti papillares (Papillary Duct)
  • Tubular secretion (Definitive urine - $1.8 l/24$ hours)

Mikrovaskulatura intrarenale (Intrarenal Microvasculature)

• A.Renalis → aa. segmentare → aa. lobare → aa. interlobare → aa. arcuatae → aa. interlobulares → al. afferentes → glomeruli → al. efferentes → plexus capillaris inter/peri-tubularis (gl.corticales) → vasa rectae medullares (vera/spuria) → V. Renalis → vv. interlobare → vv. arcuate → vv. radiales cortici → vv. stellatae → venulae rectae

Glomeruli

• Glomeruli:
  • Membranes.
  • Podocytes.
  • Poles: vascular/tubular. Dm: arteriola aferente > arteriola eferente (afferent arteriole > efferent arteriole).
  • ʺMesangial cellsʺ: cells of the supporting matrix of the vascular pole.
  • Capsule: lamina visceralis/parietalis.
  • Endothelium: fenestration → filtration.
  • Podocytes: covering peduncles → reduction of filtration spaces → hindrance for proteins.

RENAL CORPUSCLE

The filtration process within the kidney is described as:

• Selective resorption and secretion involving key components:
  • $Ca^{++}$, $PO_4$, $Na^+$
• Aparati Juxtaglomerular (Juxtaglomerular Apparatus - AJG):
  • Feedback mechanism.
  • Release of Renin → regulation of glomerular perfusion.
• Macula densa: