Department of Human Anatomy

The Urinary System

The State Medical and Pharmaceutical University “Nicolae Testemitanu”Republic of Moldova

Lecturer Globa Lilian

Uro-genital Apparatus

Urinary Systemfor secretion and

discharge of the urine

Genital Systemconcerned with process of

reproduction

Have common sources and ways of the development, topographic sites, blood and nerve supply

Overview of the Urinary System

4 components

Functions Controlling the water and electrolyte balance,

maintain the acid-base balance Regulates blood concentrations of sodium,

potassium, chloride and calcium Regulates blood volume and blood pressure Production of urine- waste products (urea and

uric acid) Reabsorb important nutrients from urine Endocrine (rennin, angiotensin, erythropoietin)

Anatomy

1. Kidney

Each kidney is about:

Length 11.25 cm

Breadth 5-7.5 cm

Width 2.5 cm

The weight:

Male 125-175 g

Female 115-155 g

Anatomy

2. Ureter* Connects

kidney to

urinary

bladder

Anatomy

3. Urinary

bladder

* Stores

urine

Anatomy

4. Urethra

* Drains

urine from

bladder

Coverings of the Kidneys

The kidneys have the following coverings:

Fibrous capsule Perirenal fat Renal fascia with

anterior and posterior layers

Pararenal fat

Fixation of the Kidneys

The elements that held kidneys in position:

Peri- and para renal fat Renal fascia with anterior and posterior layers Vascular pedicle Intrabdominal pressure

Anatomy of the Kidney

Outer cortexInner medulla

MedullaMedulla dividedinto pyramids and columa renalis

One pyramid with corresponding cortex form renal lobe

CortexCortex divided

into pars convoluta and pars radiata

Calyx

One minorcalyx per pyramid

Minor Calyx

Major Calyx

Fusion of severalminor calyces

Usually 2-3major calycesper kidney

Fornical Apparatus

Renal Pelvis

Fusion of major calyces

Opening to theureter

Human Kidney

Urogram

The Nephron

Basic structural and functional unit of kidney

The Nephron

Filtration of blood Production of urine 1,25 million per kidney 85 miles of tubes per kidney

Components of Nephron

1. Renal corpuscle:a. Glomerulus – a net-work of convoluted capillaries

b. Glomerular (Bowman’s) capsule – a hollow chamber surrounding the glomerulus

2. Proximal convoluted tubule

3. Loop of Henle (descending and ascending limbs)

4. Distal convoluted tubule

The Nephron

The Nephron

Epithelia filterthe urine

Glomerulus

Glomerulus and Capsule

afferent arteriole

efferent arteriole

urine

Proximal Convoluted Tubule

Loop of Henle

only part foundin medulla

The Juxtaglomerular Apparatus

afferent arteriole

efferent arteriole

urine

Distal Convoluted Tubule

Collecting (Straight) Duct

Collecting Duct

Not part of nephron Collects urine from distal convoluted tubules

of many nephrons Opens at tip of pyramid Urine drains into minor calyx

Collecting Duct

Important Relations, Right KidneyAnteriorly:

the suprarenal gland, the liver, the descended part of the duodenum, coils of jejunum, the right colic flexure.

Posteriorly: the diaphragm, the XII-rib, the psoas, quadratus lumborum, and transversus

abdominis muscles (the renal lodge) the costodiaphragmal recess of pleura, the subcostal, iliohypogastric and ilioinguinal nerves

Important Relations, Left KidneyAnteriorly:

the suprarenal gland, the spleen, the stomach, the pancreas, coils of jejunum, the left colic flexure.

Posteriorly: the diaphragm, the XI-XII rib, the psoas, quadratus lumborum, and transversus

abdominis muscles (the renal lodge) the costodiaphragmal recess of pleura, the subcostal, iliohypogastric and ilioinguinal nerves

Anterior Relation of both Kidneys

1 – area hepatica;

2 – area colica;

3 – area jejunalis;

4 – area duodenalis;

5 – glandulae suprarenales;

6 – aa. renales;

7 – vv. renales;

8 – area gastrica;

9– area lienalis;

10 – area pancreatica;

11– area colica.

Ureter

Drains urine from kidney to urinary bladderLength 25-30 cm

Four parts:

1. Abdominal

2. Pelvic

3. Intramural

4. Intravesical

Ureter

Three constrictions:

1. Ureteropelvic

2. Iliac

3. Ureterovesical

Urinary Bladder

ureter opensinto posteriorwall ofbladder

Surfaces:*Posterior (fundus or base)*Anterior (contacts with pubic symphysis and retropubic space of Retzius )*Superior (covered by peritoneum)Apex continues with median umbilical ligamentNeck contains internal urethral sphincter

External urethral

Sphincter

Internal urethral

Sphincter

Urinary Bladder -- Male

Urinary Bladder -- Female

Development of the kidney

Ureteric Bud• Ureter• Pelvis • Major Calyces• Minor Calyces• Collecting Tubules

Metanephrogenic Cup• Glomerular capsule (covers a cluster

of capillaries - Glomerulus )• Proximal• Loops of Henle• Distal convoluted tubules

Three sets of structures appear during the development of the urinary system:

1. Pronephros2. Mesonephros (Mǖllerian Duct)3. Metanephros (responsible for permanent kidney)

arise from two sources:

Abnormalities

VVĂ MULȚUMESC PENTRU Ă MULȚUMESC PENTRU ATENȚIE!ATENȚIE!