Ureter, Urinary Bladder and Male/Female Urethra (Structures and Walls) - Urinary System Anatomy

PS! at 6:23 I incorrectly said that the Median Umbilical ligament is a remnant of the umbilical arteries. It is, in fact, a remnant of the fetal urachus. Content: Introduction: 0:00 Functions of the Ureter: 00:50 Course of the Ureter: 01:44 Parts of the Ureter: 03:09 Constrictions of the Ureter: 03:53 Layers of Ureter Wall: 04:13 Urinary Bladder: 06:01 Layers of Urinary Bladder Wall 08:08 Anatomy of the Male Urethra: 10:06 Anatomy of the Female Urethra: 14:24 ☕Support me at: Function of the Ureter: - From the Renal Pelvis - Ureter is a muscular tube that moved urine throguh peristaltic movement. Course of the Ureter: - Enters Lesser Pelvis and crosses structures: ○ In Male: Crosses Ductus Deferens ○ In Female: Pass between Broas Ligament of the Uterus (Ligamentum Latum Uteri) and Cardinal Ligament of the Uterus (ligamentum cardinale Uretri) - Opens up as the Ureteric Orifices (Ostium Ureteris) Parts of the Ureter: - Abdominal Part (Pars Abdominalis) - Pelvic Part (Pars Pelvica) - Intramural Part (Pars Intramuralis) - 7-8 mm in Diameter Narrowings of the Ureter: - Upper Narrowing: Junction with the Renal Pelvis - Middle Narrowing: Line Terminalis - Lower Narrowing: Intramural Part Layers of the Ureter Wall: - Tunica Mucosa - Lower 1/3 ○ Glands in Tela Submucosa ○ 3 layers of Tunica Muscularis § Inner part: Longitudinal Msucle Fibers § Middle Part Circular Muscle Fibers § Outer Part: Longitudinal Muscle fibers - Upper Part 2/3 ○ 2 layers of Tunica Muscularis § Inner part: Longitudinal Msucle Fibers § Outer Part Circular Muscle Fibers - Tunica Adventitia Urinary Bladder (Vesica Urinaria) - Sac which stores urine (250-500ml) - Median Umbillical Ligament (Ligamentum Umbilicale Medianum) - Apex of Bladder (Apex Vesicae) - Body of Bladder (Corpus Vesicae) - Fundus of Urinary Bladder (Fundus Vesicae) - Emptu Urinary Bladder ○ Behind Pubic Symphysis (Symphysis Pubica) ○ Has anterior Surface and Posterior Surface - Full Urinary Bladder ○ Above the pubic symphysis - Right Ureteric Orifice (Ostium Ureteris Dextrum) - Left Ureteric Orifice (Ostium Ureteris Sinistrium) - Internal Urethral Orifice (Ostium Urethrae Internum) - Trigone of Bladder (Trigonum Vesicae) - Interureteric Crest (Plicae Interureterica) Layers of the Urinary Bladder Wall: - Tunica Mucosa ○ Transitional Epithelium ○ Umbrella Cells ○ Lamina Propria - Tela Submucosa ○ Loose connective tissue ○ No folds in trigone of bladder (trigonum vesicae) - Tunica Muscularis ○ Consist of three muscle layers § Inner part: Longitudinal Msucle Fibers § Middle Part Circular Muscle Fibers □ Inernal Urethral Sphincter (musculus sphincter urethrae internus) § Outer Part: Longitudinal Muscle fibers - Tunica Adventitia or Tunica Serosa ○ Tunica Adventitia if it faces pelvis ○ Tunica Serosa if it faces peritoneum Anatomy of the Male Urethra: - Internal Urethral Orifice (Ostium Urethrae Internum) - External Urethral Orifice (Ostrium Urethrae Externum) - Length 15-22 cm - Diameter: 5-7 mm - Parts of male urethra: ○ Prostatic Urethra (Pars Prostatica) § Urethral Crest (Crista Urethralis) § Seminal Colliculus (Colliculus Seminalis) § Prostatic Utricle (Utriculus Prostaticus) § Openings of the ejaculatory ducts (Ductus Ejaculatorius) § Prostatic Ductules (Ductuli Prostatici) ○ Membranous Urethra (Pars Membranacea) § Between prostate and bulb of penis (Bulbus Penis) § Surrounded by External Urethral Sphincter (musculus sphincter urethrae externus) ○ Spongy Urethra (Pars Spongiosa) § Located inside body of penis (corpus penis) § Bulb of Penis region: Duct of Bulbo-Urethral Gland (Glandula Bulbourethralis) - Narrowins of the Male Urethra: ○ Internal Urethral Orifice (Ostium Urethrae Internum) ○ Membranous Part (Pars Membranacea) ○ External Urethral Orifce (Ostium Urethrae Externum) - Enlargements of the Male Urethra ○ Prostatic Urethra (Pars Prostatica) ○ Spongy Urethra (Pars Spongiosa) ○ Navicular Fossa (Fossa Naviculare Urethrae) - Walls of the Male Urethra ○ Tunica Mucosa § Urethral Lacuna (Lacuna Urethralis) § Navicular Fossa (Fossa Navicularis) § Valve of the Navicular Fossa (Vulva Fossa Navicularis) ○ Tunica Muscularis § Internal Urethral Sphincter (Musculus sphincter urethrae Internus) § External Urethral Sphincter (Musculus Sphincter Urethrae Externum) Female Urethra Anatomy: - 2-5 cm long - 8-12 mm in diameter - Internal Urethral Orifice (Ostium Urethrae Internum) - External Urethral Orifce (Ostium Urethrae Externum) ○ Behind Vlitoral Glans (Glans Clitoris) - Walls of the Female Urethra ○ Tunica Mucosa § Urethral Lacuna (Lacuna Urethralis) ○ Tunica Muscularis § Internal Urethral Sphincter (Musculus sphincter urethrae Internus) § External Urethral Sphincter (Musculus Sphincter Urethrae Externum) Sources: - Biorender - University notes and lectures