High-Yield Points:
• Bladder lies on the floor of the pelvic cavity (when empty) and extends into the abdomen when full.
• Parts: apex (cranial), body, neck (caudal); trigone = triangular area where 2 ureters enter and urethra exits.
• Held by a median vesical ligament containing the urachal remnant and paired lateral vesical ligaments containing the round ligaments/remnants of the umbilical arteries.
• Cystotomy site (cattle): cranial midline of bladder via paramedian/ventral midline approach.
• Urethra (Pelvic part):
– Female cow: the urethra is short (approximately 10 cm) and opens on the floor of the vestibule. The nearby suburethral diverticulum can misdirect a catheter; length and configuration differ in other species.
– Male: long, in two parts — pelvic urethra (intra-pelvic) + penile urethra. Sigmoid flexure in ruminants/pig.

Urinary Bladder & Pelvic Urethra

Urinary Bladder: A muscular reservoir lying on the pelvic floor, dorsal to the pubis, ventral to the rectum (male) or to the uterus/vagina (female). It has three parts: apex, body, and neck. Internally, the trigone is a smooth triangular area bounded by the two ureteric openings (dorsally) and the urethral opening (caudally).

Wall layers: Mucosa (transitional epithelium) → submucosa → smooth muscle (the detrusor, in 3 layers) → serosa.

Ligaments:
• Median ligament (vestige of urachus) attaches bladder apex to ventral abdominal wall.
• Lateral ligaments (× 2) contain the round ligaments of the bladder (remnants of umbilical arteries).

Female Urethra: A short tube running from the bladder neck to the vestibular floor. A suburethral diverticulum lies immediately caudal to the external urethral opening in female ruminants and is also described in the sow; its size and catheterization importance vary by species.

Male Urethra: Much longer, divided into:
• Pelvic part: from bladder neck through the pelvic cavity, surrounded by accessory glands and the urethralis muscle. Contains the colliculus seminalis where deferent ducts and vesicular gland ducts open.
• Penile part: exits over the ischial arch and runs through the penis to the external urethral orifice. In bull, ram, boar — bears a sigmoid flexure for retraction of penis.