Anatomy of the Urinary System (Lecture 1) PDF

Anatomy of the Urinary System: GEMP I: Lecture 1 Mrs Natasha Loubser [email protected] School of Anatomical Sciences Office: 2P20 2024  Outline Kidneys Position Divisions / regions Internal...

Anatomy of the Urinary System: GEMP I: Lecture 1 Mrs Natasha Loubser [email protected] School of Anatomical Sciences Office: 2P20 2024  Outline Kidneys Position Divisions / regions Internal and external features Ureters Surfaces and borders Relations Bladder Blood supply, innervation, and lymphatic drainage Surface anatomy Urethra Support structure Right midclavicular line Left midclavicular line Right & left hypochondrium [H] Epigastric [E] Right & left lumbar (flank) [L] Umbilical [U] Right & left iliac (groin) [I] RH E LH Pubic [P] Subcostal plane (L3) RL U LL Intertubercular plane (L5) RI P LI 1  The Kidneys Posterior abdominal wall T12-L3 Right kidney lies lower than the left kidney Hilum: transpyloric plane 5cm from the midline Superior part: Left: 11th rib Right: 12th rib Inferior part: Iliac crest https://sites.google.com/a/umich.edu/bluelink/resources/bluelink/unlabeled Retroperitoneal organs: S. A. D. P. U. C. K. E. R. -kidneys-and-urinary-system-images 2 Relations: Anteriorly Posteriorly 3 The Kidneys Renal capsule Perinephric (perirenal) fat Renal fascia Paranephric (pararenal) fat 4 The Kidneys Cortex (external 1/3) Renal column Medulla (internal 2/3) Renal pyramid Renal papilla (collecting ducts) Minor calyx → major calyx → renal pelvis → ureters Hilum of the kidneys & renal sinus 5 The Kidneys Renal cortex: Cortical labyrinths Renal corpuscles (Bowman, Glomeruli) Convoluted tubules of the nephron (P/DCT) Collecting tubules, blood vessels Medullary rays Straight tubules, collecting ducts Ultrafiltration Renal medulla: Medullary pyramids Straight tubules, loop of Henle, collecting ducts Renal columns Blood vessels, anchoring Reabsorption 6 The Kidneys Arterial supply: Abdominal aorta (T12) ➔ Renal arteries (L1/L2 IVD) ➔ 5 segmental arteries Superior (apical), anterosuperior, anteroinferior, inferior and posterior segments Extrahilar arteries Venous drainage: Segmental veins ➔ renal veins ➔ inferior vena cava Lymphatic drainage: Lymph vessels follow the renal arteries ➔ aortic nodes (para-aortic) 7 The Kidneys 5 segmental arteries: 2 1. Superior (apical) 1 2. Anterosuperior 3 3. Anteroinferior 4. Posterior 4 5. Inferior 4 Segmental arteries ➔ inter-lobular arteries ➔ arcuate arteries ➔ inter-lobular arteries Netter, F. H. (2014). Atlas of human anatomy. Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically oriented anatomy. 8  The Ureters Course: Apex of renal pelvis (L1) Transverse processes of L vertebrae Anterior to the bifurcation of the common iliac arteries Ischial spine Posterosuperior angle of the bladder Constrictions: 1. Pelviureteric junction 2. Level of the common iliac arteries 3. Entrance into the bladder Moore, K. L., Dalley, Atlas of A.Human F., & Agur, Anatomy. A. M. R.4th (2014). ed. Netter Clinically F. Plate oriented anatomy. 324 Retroperitoneal organs: S. A. D. P. U. C. K. E. R. 9 The Ureters Blood supply: Ureteric branches from the renal vessels, gonadal vessels, [abdominal aorta], common iliac vessels, internal iliac vessels Superior: renal vessels Middle: gonadal vessels, [abdominal aorta] Inferior (pelvic): common iliac artery, inferior vesical artery, vesical venous plexus Lymphatic drainage Superior: aortic/ caval lymph nodes Middle: common iliac nodes Inferior: external/ internal iliac lymph nodes 10 Kidneys & Ureters Renal nerve plexus: Sympathetic: Abdominopelvic splanchnic nerves [least splanchnic nerves] T11-L2 (Pain, visceral afferent fibres) Parasympathetic: Vagus nerve (CN X) 11 The Bladder External: Hollow, strong muscular walls Apex: superior edge of the pubic symphysis [median umbilical ligament] Fundus: opposite the apex Body: between the apex & fundus Neck: origin of the urethra Internal: Detrusor muscles Internal urethral sphincter Trigone Ureteric and urethral openings Inter-ureteric torus 12 The Bladder Superior surface Peritoneum, small intestine, sigmoid colon Posterior surface Seminal vesicles, ampulla of the ductus deferens, rectovesical septum, rectovesical pouch, rectum Uterus, uterine tubes, uterovesical pouch Inferolateral surfaces Pubic bones, pelvic floor Retropubic space (apex) Prostate gland (neck - ) 13 Atlas of Human Anatomy. 4th ed. Netter F. The Bladder Arterial supply [anterior trunk of the internal iliac artery] Superior vesical artery Anterosuperior parts Inferior vesical artery [males]; Vaginal artery [females] Fundus and neck Venous drainage Vesical venous plexus Inferior vesical to internal iliac vein Internal vertebral venous plexus Lymphatic drainage Superolateral: external iliac nodes Fundus and neck: internal iliac nodes 14 The Bladder Innervation: Sympathetic: Hypogastric plexus ➔ vesical plexuses [T11-L2/L3] Inhibit (relaxes) detrusor muscle – expansion Contracts internal urethral sphincter Pain from superior surface Parasympathetic: Pelvic splanchnic nerves (S2-S4) Motor to detrusor muscle, contracts bladder Relaxes internal urethral sphincter Afferent (reflex and pain) fibres 15 The Urethra Females: Straight tube [~ 4cm] Runs from the internal urethral orifice in bladder distally along anterior wall of vagina Opens into vaginal vestibule – external urethral orifice Males: Intramural: Neck of the bladder ~ internal urethral sphincter Prostatic: Prostate Urethral crest Prostatic sinuses Prostatic ducts Seminal colliculus Prostatic utricle Ejaculatory ducts 16 The Urethra Males [cont.]: Membranous: Inferior prostate gland to the perineal membrane External urethral sphincter Most susceptible to injury during catheterisation Penile (Spongy): Bulb of the penis to the external urethral orifice Corpora spongiosum Narrowest part Bulbourethral glands Navicular fossae 17 The Urethra – males Arterial supply: Prostatic branches of inferior vesical and middle rectal arteries Intramural, prostatic, membranous Dorsal artery of the penis Spongy Venous drainage: Prostatic venous plexus Lymphatic drainage: Internal iliac lymph nodes Intramural, prostatic, membranous Deep inguinal lymph nodes Spongy 18 The Urethra – females Arterial supply: Internal pudendal artery Vaginal arteries Venous drainage: Veins follow the arteries of the same name Lymphatic drainage: Internal iliac lymph nodes 19 The Urethra Innervation: Females: Vesical nerve plexus and pudendal nerve: mixed sympathetic and parasympathetic and visceral afferents Males: Prostatic nerve plexus: mixed sympathetic and parasympathetic and visceral afferents Dorsal nerve of the penis 20 Resources Clinically oriented anatomy by Moore, Dalley, and Agur, 8th ed, 2018 McMinn’s clinical atlas of human anatomy by Abrahams et al., 8th ed, 2020 Gray’s anatomy: the anatomical basis of clinical practice by Stranding, 41st ed, 2016 Atlas of Human Anatomy by Netter F. 4th ed, Gray’s anatomy for students by Drake et al., 2020 https://thecomicalanatomist.com/category/urinarysystem/