Renal System Anatomy PDF

L31- RENAL SYSTEM Dr.Pugazhandhi Bakthavatchalam Assistant Professor of Anatomy and Physiology, AUACAS, American University of Antigua  LEARNING OUTCOMES At the end of this session the student would be able to: Structures of the urinary system. Define nephrology, kidney functions....

L31- RENAL SYSTEM Dr.Pugazhandhi Bakthavatchalam Assistant Professor of Anatomy and Physiology, AUACAS, American University of Antigua  LEARNING OUTCOMES At the end of this session the student would be able to: Structures of the urinary system. Define nephrology, kidney functions. Anatomy and histology of the Kidney and nephron. Anatomy of Ureter and Urinary bladder and Urethra. Blood supply and its significance. 24-Oct-24 2  KIDNEYS - LOCATION Retroperitoneally in post.abdominal wall By side of vertebral column T12 – L3 vertebrae Right kidney is lower d/t liver Left is longer, narrower & nearer to vertebral column.  COVERINGS From within outwards Fibrous capsule ( true capsule) Perinephric fat ( adipose capsule) Renal fascia ( false, fascia of Gerota) Paranephric pad of fat  Holds the kidney in position  Normal renal mobility~ 3cm KIDNEY – PRESENTING PARTS anterior Two posterior surfaces lateral Two Medial -HILUM borders upper Two lower ends STRUCTURE OF KIDNEY  Cut section - 1.Renal substance. 2.Renal sinus.  Renal substance Contains 1.Outer cortex. 2.Inner medulla. 24-Oct-24 7 MEDULLA 8-18 Renal pyramid Pyramid -Pale striated conical structure Base towards cortex Apex towards renal sinus opens into minor calyx at renal papilla 24-Oct-24 8 CORTEX Granular in appearance Contains- 1. Renal columns- between the adjacent pyramids 2. Cortical arches- between the base of pyramid and the surface of kidney 24-Oct-24 9  RENAL SINUS Space within the kidney extending from the hilum Wall of the sinus is lined by capsule Contents: Renal vein Renal artery Renal pelvis 24-Oct-24 10  KIDNEY: ARTERIAL SUPPLY  Renal arteries (RA) – right & left  Lateral branch of abdominal aorta – at the level of L1 & L2 Right renal artery Left renal artery 11 KIDNEY: RENAL VEIN (RV)  Anterior to RA  Opens into inferior vena cava  Left RV longer (7.5cm) than right (2.5cm) Left RV receive- left gonadal & left suprarenal veins before opening into IVC Right renal Left renal 12 vein vein Venous drainage Left is longer Left drains adrenals & gonads Left crosses front of aorta below SMA (Superior Mesenteric Artery) (varicocele is common in left) Cross across brodel’s line  kidneys Lymphatic drainage - lateral aortic nodes Nerve supply - Sympathetic – T10-L1 (explains referred pain from loin – groin) - Parasympathetic – vagus  Ureter Retroperitoneal Muscular tube ~25cm long, 3mm diameter Function: Conveys urine from kidney Abdominal to urinary bladder Divided into: Pelvic - Abdominal part - Pelvic part  Course of ureter In the abdomen, Descends along medial edge of psoas major Left kidney Crosses common iliac artery at the pelvic brim Renal pelvis In the pelvis, Aorta Runs on the lateral wall of Common iliac a. pelvis, parallel to anterior Psoas margin of greater sciatic notch External iliac a. Turns forward and medially to the urinary bladder at the ischial spine. Urinary bladder Course of ureter Pierces urinary bladder obliquely Enter outer surface of bladder ~ 5cm ureter Vas apart deferens Seminal  Oblique passage forms one vesicle way ‘flap valve’  Internal pressure of filling bladder  Intramural passage collapse  Contraction of bladder musculature act as sphincter  prevent reflux of urine  Constrictions of ureter 1. Ureteropelvic junction - Tip of transverse L2 process 2. At the pelvic brim - Bifurcation of common iliac artery - Sacroiliac joint 3. Entering the urinary bladder - Medial to ischial spine URETER: ARTERIAL SUPPLY  Supplied by branches Renal artery from:- Gonadal artery Abdominal aorta Common iliac artery Abdominal part: supplied by vessels originating medial to ureter 19  URETER: VENOUS DRAINAGE  Abdominal part ureter –  renal &  gonadal vein (testicular or ovarian)  Pelvic part ureter –  Internal iliac vein  Superior vesical vein  Uterine & Vaginal veins (in female)  Middle rectal vein Renal vein  Inferior vesical vein Gonadal (male) vein 20 APPLIED ANATOMY Renal & ureteric calculi Renal calculus pass from kidney renal pelvis ureter Ureteric calculus cause severe intermittent pain as it is gradually forced down. Obstruction of urinary flow Pain passes inferoanteriorly Renal calculus disease  URINARY BLADDER Hollow muscular organ Acts as reservoir of urine  Position: In children, it is abdomino-pelvic In adults, it is a pelvic organ When distended it becomes abdomino-pelvic. Shape:  Tetrahedral when empty.  Ovoid when distended. Parts:  Apex  Base Superior  3 surfaces 2 Infero lateral Anterior Posterior  3 borders 2 Lateral  Neck.  Trigone of the Bladder  It is an equilateral triangle on the inner aspect of the base of the bladder  Uvula vesicae- elevated structure formed by median lobe of prostate, near the internal urethral orifice  During benign prostatic hypertrophy internal urethral orifice narrow & there will be frequent micturition Blood supply:  Superior vesical artery– br. of internal iliac artery  Inferior vesical artery– br. of internal iliac artery  Obturator artery  Inferior gluteal artery  In female, a br. of uterine artery  Veins correspond to the arteries and form a vesical venous plexus along the inferolateral surface of the bladder and finally drain into the internal iliac vein. Nerve supply:  Supplied by the vesical plexus of nerves containing both sympathtic and parasympathetic components. Applied anatomy Cystoscopy: The interior of the bladder and its orifices can be examined with a cystoscope. URETHRA- MALE URETHRA  Is a common tubular passage for the elimination of urine & semen  Extends from the internal urethral orifice at the apex of the trigone of the bladder to the external urethral orifice close to the tip of the glans penis  Total length is 18 – 20 cm  Is divided into 3 parts a. Prostatic part b. Membranous part c. Spongy part  Description  Prostatic part: of parts  It runs almost vertically downwards through the prostate from the base to slightly in front of the apex  The prostatic urethra is the widest & most dilatable part of male urethra & about 3cm long  Features in the posterior wall(floor) of prostatic urethra:  Urethral crest: - Is a median longitudinal mucous fold  Colliculus seminalis (Verumontanum) : - Is a rounded elevation in the middle of the crest & presents 3 orifices a. Prostatic utricle in the middle b. Ejaculatory duct on each side Arterial supply; Inferior vesical, middle rectal,internal pudendal. Veins correspond to the arteries. Lymphatic drainage; Prostatic & membranous parts drain into external & internal iliac lymph nodes. Spongy part;deep inguinal nodes Nerve supply; Sympathetic fibres L1 & L2 segments Parasympathetic fibres S2,S3,S4 segments Somatic fibres, derived from the urethral branch of the pudendal nerves  Female urethra  Is about 4cm long & 6mm in width  Begins from the internal urethral orifice of the bladder  Passes downwards and forwards embedded in the anterior wall of the vagina  It pierces the perineal membrane & opens in the vestibule  Where the external orifice is situated in front of the vaginal opening & about 2.5cm behind the glans clitoridis Glands around the female urethra 1. Urethral glands 2. Para-urethral glands 3. Greater vestibular glands 4. Urethral lacunae  REFERENCES Drake R.L., Gray’s Anatomy for Students, 2nd Edition, 2009, Churchill Livingstone Moore, Clinically Oriented Anatomy, 6th Edition, 2009, Lippincott Williams & Wilkins Textbook of Medical Physiology – Guyton & Hall Medical Physiology – R.K Marya 24-Oct-24 34