Title: Anatomy / 9 Urinary system

Q: Kidney (Task, shape&size, position)
A: Task: Cleaning system by filtering ~130 liters of blood daily to remove waste products, toxins & excess water.
Shape & Size: Bean-shaped organ, approximately 10 cm long.
Position: Located retroperitoneally (= behind the peritoneum)
- The left kidney is caudal (below) the spleen.
- The right kidney is caudal the liver.

Q: kidney (suprarenal gland, casings, internal structure, functional components)
A: Suprarenal Gland: Located at the superior pole of the kidney;
Casings (from outer to inner):
- Renal fascia.
- Adipose capsule.
- Renal capsule.
Internal Structure:
- renal cortex: outer layer, containing the renal corpuscles and convoluted tubules;
- renal medulla: contains the medullary pyramids, where urine is concentrated;
- renal pelvis: funnel-shaped structure that collects urine and directs it to the ureter;
Functional Components: The Nephron is the smallest functional component. Consisting of the following parts:
- Renal Corpuscule: Consists of the Glomerulus and Bowman's capsule.
- Tubules Proximal tubule → Loop of Henle → Distal tubule → Connecting piece → Collecting duct.

Q: Ureter (characteristics)
A: Characteristics:
- Dimensions: Approximately 25 cm long and 5 mm wide.
- Lumen: It has a characteristic star-shaped lumen.
- Wall Structure: Consists of 3 layers:
- Mucosa with urothelium
- Muscle layer.
- Adventitia (outer connective tissue layer).

Q: urinary
bladder (Position, characteristics, sections, sphincter)
A: Position: Located in the pelvic cavity; classified as a subperitoneal organ
Characteristics:
- It is a muscular hollow organ.
- The mucosa consists of urothelium (transitional epithelium).
- It has a holding capacity of approximately 1 liter.
Parts: Divided into the fundus, corpus (body), and apex.
Sphincter:
- Internal sphincter: Involuntary.
- External sphincter: Voluntary.

Q: urethra
(= Hahnröhre)
A: Male Urethra:
- Length: Approximately 20 cm.
- Parts: Divided into 3 parts:
- Prostatic part.
- Membranaceous part.
- Spongious part.
- Curvatures: constant at symphysis & flexible
Female Urethra:
- Length: Significantly shorter, approximately 3–5 cm.
- Position: Located directly ventral of the vagina.
- Opening: Opens into the vaginal vestibule.

Q: Ureter (Constrictions & Task)
A: Constrictions:
- The ureter features 3 anatomical constrictions where it is naturally narrower:
- At the start of the ureter where it leaves the renal pelvis;
- At the crossing of the pelvic vessels;
- During its passage through the bladder wall;
Task:
- The transport of urine from the renal pelvis to the urinary bladder