Post abd wall. Kidney.pdf

XY2141. ANATOMY. POSTERIOR ABDOMINAL WALL. GROSS ANATOMY OF THE URINARY SYSTEM Dr Viktoriia Yerokhina, Lecturer in Medical Sciences [email protected]  LEARNING OUTCOMES ANAT.26 - Post Abdomen/Kidney ANAT.26.01 - Rev...

XY2141. ANATOMY. POSTERIOR ABDOMINAL WALL. GROSS ANATOMY OF THE URINARY SYSTEM Dr Viktoriia Yerokhina, Lecturer in Medical Sciences [email protected]  LEARNING OUTCOMES ANAT.26 - Post Abdomen/Kidney ANAT.26.01 - Review the boundaries of the posterior abdominal wall. ANAT.26.02 - Discuss the origin of the lumbar plexus and list its branches and their distributions (will be discussed in the following lectures). ANAT.26.03 - Review the abdominal aorta and its parietal and visceral branches. ANAT.26.04 - List the approximate vertebral levels of the visceral branches of the abdominal aorta and its bifurcation into the common iliac arteries. ANAT.26.05 - Discuss the inferior vena cava and its tributaries, and list the vertebral level it begins from the common iliac veins. ANAT.26.06 - Summarize the cisterna chili, and the course and termination of the thoracic duct. ANAT.26.07 - Examine the location of the kidneys and their relationship with surrounding organs and ribs 11 and 12. ANAT.26.08 - Describe the relationship pf the kidneys to the diaphragm, psoas major, quadratus lumborum and transversus abdominis aponeurosis. ANAT.26.09 - Review the kidneys in relation to the fascia, perienal and pararenal fat. ANAT.26.10 - Describe the anatomy of the cortex and medulla of the kidney. ANAT.26.11 - Summarize the flow of urine from the renal papilae to the ureter and to the urinary bladder. ANAT.26.12 - Identify the structures in the hilum of the kidney and their relationship to one another. ANAT.26.13 - Review the course, relationships, blood supply and innervation of the ureters. ANAT.26.14 - Describe the blood supply, innervation and venous drainage of the kidney. ANAT.26.15 - Discuss the location, blood supply, innervation and venous drainage of the suprarenal glands. ANAT.26.16 - Describe the location and the nerve fiber types contained within the superior hypagastric plexus. ANAT.26.17 - Identify, in radiological images, the structures in the posterior abdominal wall. ANAT.26.18 - List the sites of constriction of the ureters and explain their relationship to kidney stones. ANAT.26.19 - Explain the distribution of pain from kidney stones that are impacted(lodged) in the ureter. ANAT.26.20 - Discuss the "psoas sign" and explain why it can be positive during appendicitis (psoas sign is not always positive depending on the location of the appendix).  POSTERIOR ABDOMINAL WALL Extends from the 12th rib above to the pelvic brim below. Strong and stable, because it is constructed by bones, muscles, and fasciae. Supports retroperitoneal organs, vessels, and nerves. Components: 1. Bony part: Medially: bodies, intervertebral disc, and transverse processes of L1-L5. Laterally it is divided into upper and lower parts by the iliac crest: o part above the iliac crest is made of inner surfaces of the 12th rib; o part below the iliac crest is made of iliac fossa.  POSTERIOR ABDOMINAL WALL 2. Muscular part: Above the iliac crest - made up of psoas major, quadratus lumborum, and transversus abdominis muscles. Below the iliac crest - made up of psoas major and iliacus muscles. 3. Fasciae: Psoas major and iliacus muscles are covered by fascia iliaca. Quadratus lumborum is enclosed between the anterior and posterior layers of the thoracolumbar fascia.  POSTERIOR ABDOMINAL WALL Psoas minor muscle is only present in 60% of the population. It is located anterior to the psoas major.  THORACOLUMBAR FASCIA 2. Thoracolumbar fascia (fascia thoracolumbalis) has 3 layers: 2.1 Posterior layer (lamina posterior) – aponeurotic origin of the latissimus dorsi – covers the deep back muscles 2.2 Middle layer (lamina media) – firm aponeurotic membrane – separates the deep back muscles from the quadratus lumborum 2.3 Anterior layer (lamina anterior) – covers the quadratus lumborum ventrally. Drawings by Leonardo da Vinci in the Royal Collection of the United Kingdom  OVERVIEW OF THE URINARY SYSTEM 1. Kidneys (renes) – filter blood plasma to create urine 2. Minor and major renal calices – direct urine from the renal pyramids to the renal pelvis 3. Renal pelvis – collects urine and is continuous with the ureter 4. Ureter – the longest segment of the urinary system – located between the renal pelvis and urinary bladder 5. Urinary bladder – a hollow organ lying behind the pubic symphysis 6. Urethra – the terminal segment of the urinary system – female urethra – male urethra Urine is transported via the renal pelves and ureters to the urinary bladder before being excreted through the urethra.  OVERVIEW OF THE URINARY SYSTEM Ren: kidney (in Latin); Nephros: kidney (in Greek). Kidney is the main organ of the urinary system. Functions: plasma filtration, excretion of the waste products of metabolism, acid-base homeostasis, regulation of blood pressure and blood volume (via renin), hormone secretion (erythropoetin), metabolism of vitamin D.  LOCATION OF THE KIDNEY Kidneys are located in the retroperitoneal space (behind the peritoneum) on both sides of the vertebral column, opposite T12–L3. Occupy epigastric, hypochondriac, lumbar and umbilical regions.  LOCATION OF THE KIDNEY 1. Right kidney lies at a slightly lower level due to the presence of liver on the right side. 2. Left kidney is little nearer to the median plane than the right. 3. Their long axes are slightly oblique (being directed downward and laterally) so that their upper poles are nearer to each other than the lower poles. 4. Both kidneys move downward in vertical direction for 2.5 cm during respiration.  COVERINGS OF THE KIDNEY 1. Paranephric / pararenal fat – body of fat surrounding the kidney, located between the retrorenal layer of the renal fascia and the transversalis fascia 2. Renal fascia / Gerota’s fascia: 2.1 Prerenal layer of Toldt – anterior layer 2.2 Retrorenal layer of Zuckerkandl – posterior layer 3. Perinephric fat / perirenal – fat capsule, surrounded by the renal fascia 4. Fibrous / true capsule – loosely covers the kidney; attached firmly only to the vessels and the renal pelvis at the hilum of the kidney.  EXTERNAL STRUCTURES AND SEGMENTS 1. Superior pole – covered by the suprarenal gland 2. Inferior pole 3. Medial border – location of the hilum of the kidney 4. Lateral border 5. Hilum of kidney – a vertical slit on the medial border where the renal vessels enter and leave the kidney and the location of the renal pelvis 6. Anterior surface 7. Posterior surface  SEGMENTS OF THE KIDNEY 1. Superior segment 2. Inferior segment 3. Anterior superior segment 4. Anterior inferior segment 5. Posterior segment  INTERNAL STRUCTURES 1. Renal cortex – is composed of glomeruli, proximal and distal tubules 1.1 Renal columns - extensions of the cortex into the renal medulla 2. Renal medulla – is composed of intermediate tubules, tubules of the juxtamedullary nephrons and collecting ducts in renal pyramids 2.1 8-15 renal pyramids – their bases projecting outwards to the renal cortex 2.2 Renal medullary rays – slender strips of renal medulla extending into the cortex  INTERNAL STRUCTURES 3. Renal papillae – round tips of the pyramids 4. Kidney lobes – composed of renal pyramids and contiguous cortex *macroscopically visible in the early periods of development (lobulated kidney)  RENAL PELVIS AND RENAL CALICES Renal pelvis and renal calices are parts of the upper urinary tract. They collect urine from the kidney and direct it into the ureters. They have the same innervation, vascular supply and lymphatic drainage as the kidneys. 1. Minor calices – small calices encircling the renal papillae (7–18) 2. Major calices – formed by the fusion of 2–3 minor calices 3. Renal pelvis  SYNTOPY OF THE KIDNEY Anterior surface – right kidney Anterior surface – left kidney 1. Suprarenal (adrenal) gland 1. Suprarenal (adrenal) gland 2. Liver 2. Stomach 3. Duodenum 3. Pancreas 4. Jejunum 4. Jejunum 5. Right colic flexure 5. Spleen 6. Attachment of the transverse mesocolon 6. Left colic flexure 7. Attachment of the transverse mesocolon SYNTOPY OF THE KIDNEY Anterior relations of the kidneys  SYNTOPY OF THE KIDNEY Posterior relations of two kidneys are the same except that right kidney is related to one rib while left kidney is related to two ribs 1. Diaphragm 2. Psoas major 3. Quadratus lumborum 4. Transverse abdominal  SYNTOPY OF THE KIDNEY Structures related to the posterior surface of both kidneys: 11th and 12th rib subcostal nerve iliohypogastric nerve ilioinguinal nerve  VASCULAR SUPPLY 1. Abdominal aorta (aorta abdominalis) 2. Right/left renal artery (a. renalis dextra/sinistra) 2.1 Anterior branch (ramus anterior) – has 4 branches that supply the anterior segments – superior segmental artery – inferior segmental artery – anterior superior segmental artery – anterior inferior segmental artery 2.2 Posterior branch (ramus posterior) – a single branch for the posterior segment – posterior segmental artery 3. Lobar arteries (aa. lobares) – 15–20 arteries, one for each lobe  VASCULAR SUPPLY 4. Interlobar arteries (aa. interlobares) – pass through the renal cortex between the renal pyramids 5. Arcuate arteries (aa. arcuatae) – always two – run between the border between the cortex and medulla 6. Interlobular arteries, cortical radiate arteries (aa. corticales radiatae, aa. interlobulares). VASCULAR SUPPLY  VASCULAR SUPPLY 7. Afferent glomerular arteriole 8. Glomerular capillary plexus 9. Efferent glomerular arteriole 10. Peritubular capillary plexus 11. Vasa recta (arteriolae rectae) – supply the medulla (juxtamedullary nephrons) Details will be mentioned in the histology lecture!  VENOUS SYSTEM 10. Stellate veins – their course corresponds to the capsular branches 11. Interlobular veins 12. Straight venules – venules exiting from the peritubular capillary network of the medulla and connecting to the arcuate veins 13. Arcuate veins 14. Interlobar veins – connect to the renal vein 15. Vena renalis dextra / sinistra – runs from the kidney and enters the IVC. Lymphatic drainage: lateral aortic nodes, where three lymphatic plexuses terminate (one from the parenchyma, one from the fibrous capsule and one from the fat capsule)  REGIONAL ANATOMY OF THE HILUM OF THE KIDNEY In ventrodorsal direction: 4. Renal vein 5. Renal artery – four anterior segmental branches Renal pelvis 6. Renal artery – posterior segmental branch Types of the renal calices: 1. Ampullary type 2. Branching type  URETER Muscular tube that transports urine from the renal pelvis to the urinary bladder. Its peristaltic movements pass urine in waves to the urinary bladder → urine flow is not continuous 1. Abdominal part – courses in the retroperitoneal space 2. Pelvic part – courses in the lesser pelvis 3. Intramural part – passing through the urinary bladder 4. Ureteric orifice – a slit-like orifice opened only during the flow of urine.  URETER Ureter courses: Dorsally to the testicular/ovarian artery and veins – 8 Ventrally to the common and external iliac artery and vein and the genitofemoral nerve – 9 Dorsally to the ductus deferens / uterine artery - 10  CONSTRICTIONS OF THE URETER 1. At the pelviureteric junction where the renal pelvis joins the upper end of ureter (5 cm away from the hilum). 2. At the pelvic brim where it crosses the common iliac artery. 3. At the uretero-vesical junction (where ureter enters into the bladder). ! Ureteral constriction susceptible to blockage by renal calculi. A 21-year-old woman is admitted to the hospital with pain radiating from her lower back towards her pubic symphysis. A kidney stone is suspected and ultrasound reveals a stone partially obstructing the lower part of her right ureter. The stone is probably lodged where the ureter crosses which structure? A. Inferior vena cava B. Internal iliac artery C. Common iliac artery D. Fourth lumbar artery E. Inferior mesenteric artery  BLOOD SUPPLY OF THE URETER in both sexes: renal artery, internal iliac artery, superior vesicular artery and middle rectal artery in males: + testicular artery and artery to the ductus deferens in female: + ovarian and uterine arteries  URINARY BLADDER – VESICA URINARIA A subperitoneally located hollow organ It collects urine, which it releases by contractions of the detrusor muscle into the urethra Mechanism of urination: Amount of urine in the bladder increases → tension in the bladder increases → activation of the sacral parasympathetic system via visceral sensory nerves → this triggers contractions of the detrusor muscle → an urgent need to urinate/micturate *Micturition (micturitio) is the Latin term for urination.  PARTS OF THE URINARY BLADDER 1. Body of bladder (corpus vesicae) – covered by peritoneum 2. Fundus of bladder (fundus vesicae) – bottom part of the bladder – in males, it is in close proximity to the prostate and rectum – in female, it is close to the vagina 3. Neck of bladder (cervix vesicae) – located on the inferior surface of the bladder and is continuous with the urethra – in males, it prevents semen from flowing into the bladder during ejaculation  PARTS OF THE URINARY BLADDER 4. Apex of bladder (apex vesicae) – directed towards the pubic symphysis 5. Median umbilical ligament (ligamentum umbilicale medianum) – ligament extending from the apex of the bladder to the umbilicus on the anterior abdominal wall.  SYNTOPY OF URINARY BLADDER 1. Anterior: pubic symphysis 2. Posterior: rectum in males, vagina in female 3. Superior: small intestine in the peritoneal cavity, uterus in female 4. Inferior: prostate in males, urogenital diaphragm in females.  SYNTOPY OF URINARY BLADDER 5. Transversal fascia 5.1 Retropubic space / space of Retzius – a space between the urinary bladder and pubic symphysis 6. Vesicoumbilical fascia of Delbet - a fascia located between the medial umbilical ligaments and median umbilical ligament in the shape of a triangle.  SYNTOPY OF URINARY BLADDER 7. Parietal peritoneum – covers the superior surface of the bladder 7.1 Recto-vesical pouch of Proust – the space between the rectum and urinary bladder (only in males) 7.2 Vesico-uterine pouch – the space between the uterus and urinary bladder (only in females)  SYNTOPY OF URINARY BLADDER 8. Paravesical space – space surrounding the urinary bladder inside the pelvic cavity between the urinary bladder and pelvic walls 9. Rectovesical septum – plate of CT between the urinary bladder and the rectum (only in males) 9.1 Vesico-vaginal septum – plate of CT between the urinary bladder and the vagina with the adjacent cervix of the uterus. SYNTOPY OF URINARY BLADDER  INTERNAL STRUCTURES 1. Ureteric orifices (ostia ureterum) – slit-like openings for the ureters in the bladder wall – there are no sphincter muscles around these orifices 2. Trigone of bladder (trigonum vesicae) – a triangle- like area in the infero-posterior part of the bladder – ureteric orifices +internal urethral orifice = 3 corners of the trigone – its mucosa is not folded  INTERNAL STRUCTURES 3. Interureteric crest (plica interureterica) – fold in the bladder wall between the ureteric orifices 4. Retrotrigonal fossa (fossa retrotrigonalis) – hollow space behind the interureteric crest 5. Internal urethral orifice (ostium urethrae internum) – internal opening of the urethra 5.1 Uvula of bladder (uvula vesicae) – a mucous fold.  FIXATION OF THE BLADDER Smoooth muscles 1. Rectovesicalis (m. rectovesicalis) – extends from the rectum to the anterior wall of the neck of the urinary bladder 2. Pubovesicalis (m. pubovesicalis) – extends from the pubic rami to the posterior wall of the neck of the urinary bladder 3. Rectourethralis (m. rectourethralis) – extends from the rectum to the urethra (only in males) 4. Puboprostaticus (m. puboprostaticus) – extends from the pubic rami to the prostate.  FIXATION OF THE BLADDER Ligaments 5. Rectovesical ligaments (ll. rectovesicalia) – extends from the rectum to the posterior wall of the urinary bladder 6. Pubovesical ligaments (ll. pubovesicalia) – extends from the pubic symphysis to the anterior wall of the urinary bladder 7. Vesicouterine ligaments (ll. vesicouterina) – extends from the urinary bladder to the uterus (only in females) 8. Puboprostatic ligaments (ll. puboprostatica) – extends from the pubic rami to the prostate (only in males) MUSCLES INVOLVED IN MICTURITION AND CONTINENCE Urinary bladder muscles 1. Detrusor muscle (m. detrusor vesicae) – three layers of smooth muscle (inner plexiform, middle circular and external longitudinal layer) innervated by the parasympathetic system 2. Sphincter vesicae (m. sphincter vesicae) – a single layer of circular smooth muscle extending around the neck of the bladder innervated by the sympathetic system – in male, prevents semen from flowing into the bladder during ejaculation 3. Trigonal muscles (mm. trigoni vesicae) – bundles of smooth muscle located in the trigone of bladder, organised in a loop-like fashion → enables them to control the opening and closure of the internal urethral orifice and ureteral orifices.  MUSCLES INVOLVED IN MICTURITION AND CONTINENCE Muscles surrounding the urethra 4. Internal urethral sphincter (m. sphincter urethrae internus) - composed of smooth muscle tissue 5. External urethral sphincter (m. sphincter urethrae externus) - composed of striated muscle tissue  VASCULAR SUPPLY Arteries: – superior vesical arteries from the umbilical artery – inferior vesical artery from the internal iliac artery – vesical branches from the surrounding arteries (obturator, inferior gluteal, uterine and vaginal arteries) Veins: – vesical venous plexus via the vesical veins into the internal iliac vein – connections with the prostatic/vaginal venous plexus and pudendal plexus of Santorini Lymphatic drainage: – paravesical nodes, which drain to the common iliac, external and internal iliac nodes  URETHRA FEMININA – FEMALE URETHRA Anatomical parts – length of the female urethra is 2.5 to 4 cm 1. Pars intramuralis – bladder part – runs through the neck of the urinary bladder 2. Pars pelvica – pelvic part – between the urinary bladder and the pelvic floor 3. Pars perinealis – perineal part – runs through the muscle tissue of the pelvic and urogenital floor  URETHRA MASCULINA – MALE URETHRA Length of the male urethra is about 20 cm Parts: 1. Pars intramuralis – runs through the neck of the urinary bladder 2. Pars prostatica – runs through prostate 3. Pars intermedia (pars membranacea, diaphragmatica) – runs through the muscle tissue of the pelvic and urogenital floor 4. Pars spongiosa – runs in the corpus spongiosum of urethra (bulbourethral glands end here) 4.1 Fossa navicularis – terminal section in the glans of the penis 5. Ostium urethrae externum – outer ostium of the urethra. COURSE OF THE URETHRA  ADRENAL GLAND A paired organ. Right adrenal gland is triangular in shape; Left is semilunar-shaped. Adrenal glands are positioned on the upper poles of the kidneys (retroperitoneally) at the level of T11– T12 (right is situated more caudally than the left one). Fixation of the adrenal glands is provided by vessels. Adrenal veins leave the glands through the hilum, which is situated on the anterior surface. Adrenal gland is covered by a thin capsule which emits septa into the gland. On cross section, the gland consists of cortex and medulla. Cortex produces mineralocorticoids, glucocorticoids and androgens. Medulla is responsible for catecholamine secretion.  SYNTOPY 1. Cranially: diaphragm, subhepatic space 2. Caudally: upper pole of the kidney 3. Ventrally on the right side: liver 4. Ventrally on the left side: stomach 5. Ventrally on both sides: prerenal layer of the renal fascia, perirenal fat capsule 6. Dorsally: perirenal fat capsule, retrorenal layer of the renal fascia, pararenal fat body, diaphragm, costodiaphragmatic recess 7. Medially on the right side: inferior vena cava 8. Medially on the left side: abdominal aorta 9. Laterally: pararenal fat body  BLOOD SUPPLY Arterial blood supply: 1. Superior adrenal/suprarenal artery – from the inferior phrenic artery 2. Middle adrenal/suprarenal artery – from the abdominal aorta 3. Inferior adrenal/suprarenal artery – from the renal artery Venous drainage: – suprarenal veins (on the right side into IVC, on the left into the left renal vein) Lymphatic drainage: lumbar nodes and posterior mediastinal nodes  NEPHROLITHIASIS Stones usually form in the collecting ducts of the kidneys but may be deposited along the entire urogenital tract from the renal pelvis to the urethra. Their localization and size determine the specific symptoms. Small kidney stones may also be asymptomatic and detected incidentally. PAIN: severe unilateral and colicky flank pain (renal colic) Radiates anteriorly to the lower abdomen, groin, labia, testicles, or perineum Paroxysmal or progressively worsening Area around the kidneys may be tender on percussion (costovertebral angle tenderness) Hematuria Nausea, vomiting, and reduced bowel sounds Dysuria, frequency, and urgency Passage of gravel or a stone Patients are usually unable to sit still and move around frequently (opposed to patients with peritonitis, who usually prefer to lie still) REFERENCES