Gross anatomy of Urinary System

describes all detail gross and microscopic anatomy of urinary system. it also covers major clinical aspects of urinary system.

1. Dr Laxman Khanal BPKIHS 07-06-2013 Anatomy of Urinary System

2. Urinary system

3. Where is the micturation center in the brain?? Which of the following is found exclusively in the renal medulla? a.Proximal convoluted tubules b. Distal convoluted tubules c. Collecting ducts d. Thin loops of Henle Space for enlargement of bladder is …………. a. Space of Reitzius b. Verumontanum c. Urogenital raphe d. Pelvic space In kidney the less vascular area separating anterior and posterior segment is known as…………. a. Brodie’s line b. Canton’s line c. Calot’s line d. Seshachalam’s line Test yourself

4. life expectancy of individual with a single kidney is the same as those with two kidneys. ( T/F) Most common position of ectopic kidney is hypogastric region of abdomen. ( T/F) Widest and most dilated part of urethra is…………. a. Membranous b. Prostatic c. Penile d. External meatus T/F

5. Key feature of kidneys Relationship of kidneys Renal fascia and its extension Macroscopic study of kidney Structure and function of urineferous tubules Key relation and constrictions of Ureters Support of bladder and its relationship Neural pathway of micturation Objectives of class

6. Formation of urine Regulate volume and chemical composition of blood (water, salts, acids, bases). Produce- Renin – regulates BP/ kidney function Erythropoeitin – stimulates RBC production from marrow. Metabolism of Vitamin D to active form ( by PCT). Functions

7. Two Kidneys Perform all functions except actual excretion. Two Ureters Convey urine from Kidneys to Urinary Bladder Urinary Bladder Holds Urine until excretion Urethra Conveys urine from bladder to outside of body Components of urinary system

8. A pair of bean shaped organs located against posterior abdominal wall retro- peritoneally . Each kidney presents 2 surfaces, 2 ends and 2 borders. Long axis of kidney is directed downward and laterally so upper end is nearer to the midline. Extend from T12 to L3 kidneys/ key features

9. Left kidney is nearer to midline and to diaphragm than the right one. Medial border presents a concavity called as hilum. Transpyloric plane passes through the upper part of right hilum and lower part of left hilum kidneys/ key features

10. Position of kidneys

11. Anterior relation

12. Anterior relation

13. Posterior relation

14. Posterior relationship Ribs-11and 12 for left and 12 th for right Muscles- 3 muscle Nerves- 3 nerves Diaphragm Remember

15. Angle between the lower border of the 12 th rib and lateral border of erector spinae. It overlies the lower part of kidney. Tenderness can be felt in this area in case of perinephric abscess. Renal angle

16. Fibrous capsule ( true capsule) Perinephric fat Renal fascia( fascia of Gerota) Paranephric fat Covering of the kidneys

17. Fibrous capsule formed by condensation of fibrous stroma of the kidney. In nephropexy , fibrous capsule is divided and sutured with the posterior abdominal wall. Perinephric fat is abundant along the border of kidneys, in lower pole and in the renal sinus. Renal fascia is made up of condensation of extra-peritoneal connective tissue. Covering of the kidneys

18. Consists of two layers Anterior layer or fascia of Toldt Posterior layer of Fascia of Zuckerkendl Laterally both layer fused and continued with the fascia transversalis Medially , anterior layer is continuous with the similar layer of the opposite side in front of the aorta and IVC. Renal Fascia or fascia of G erota

19. Medially posterior layer covers the back of kidney and renal vessels and blends with the psoas fascia. Above , both layer fuse and re-split to cover suprarenal gland. At the upper end of the gland two layers fuse and continuous with the subdiaphrgmatic fascia forming the suspensory ligaments of suprarenal gland. Coverings of kidney

20. Below , two layer do not fuse , extend downward along the ureter and are finally lost in extra-peritoneal connective tissue of iliac fossa. Paranephric fat is located in between the renal fascia and anterior layer of thoraco -lumbar fascia. Coverings of kidneys

21. Macroscopic structure

22. When splited longitudinally it presents 2 parts Kidney proper – it is made up of outer cortex and inner medulla. Cortex lies in between renal capsule and renal pyramid ( cortical arch), and extends in between pyramid as renal column. Medulla is made up of renal pyramid. Renal sinus Macroscopic structure

23. The urineferous tubules are the microscopic structures of the kidneys. It is made up of nephrons and collecting tubules . Nephron is the functional unit of the kidney, responsible for the actual purification and filtration of the blood. About one million nephrons in each kidney . Two types of nephrons Cortical – 85%- responsible for Na resorption Juxtramedullary – 15%- for water resorption Microscopic structure

24. The main differences in the two types of nephrons are- the length to which the loop of Henle extends into the kidney.  Position of renal corpuscle Functions Parts of the Nephrons - Renal corpscle = Bowman capsule + Glomerulus PCT Loop of Henle DCT

25. Microscopic structure

26. 3 phases of urine formation

27. Renal Corpuscle ( Malphigian body) (Glomerular plexus + Bowman’s capsule)

28. Visceral layer of renal corpuscle

29. Filtration membrane

30. Filtration

31. Nephrotic syndrome Protinuria ; hypoalbuminemia and edema

32. At the urinary pole of a renal corpuscle, the simple squamous epithelium of the parietal layer of Bowman's capsule undergoes an abrupt change to become the tall cuboidal epithelium with microvilli ( brush border appearance )of the proximal tubule. PCT

33. It has descending and ascending limbs , each having thick and thin part. Thin part makes a hair-pin bend in the deeper plane of medulla . Due to the close association of two limb, opposite flow of filtrate and variable permeability to the water is responsible for the counter-current multiplier mechanism. Loop of Henle

34. Counter-current system

35. Distal tubule cells possess their own type of Na+ transporter protein called the amiloride -sensitive epithelial Na+ channel ( ENaC ). Aldosterone , can increase the abundance of ENaC channels at the cell surface, thereby stimulating Na+ reabsorption . Part of the DCT that comes in contact with the afferent arteriole of glomerulus specialized for sppecial function .this special portion is called as macula densa . Epithelial lining is simple cuboidal . DCT

36. Juxtra -glomerular apparatus

37. Function of juxtra -glomerular apparatus

38. Collecting tubules are composed of a simple cuboidal epithelium containing two distinct cell types: principal (light) cells and intercalated (dark) cells. Principal cells of collecting tubules possess receptors for ADH on their plasma membranes. Intercalated cells adjust urinary pH by secreting either H+ ions or bicarbonate ions. These cells are also noteworthy because they synthesize a peptide called atrial natriuretic peptide (ANP) , responsible for relaxation of afferent arteriole and less reabsorption of sodium by collecting tubules. These tubules join to form – duct of Bellini , which is received by the minor calyces at the apex of renal pyramid. Collecting tubules

39. Diabetes Insipidus

40. Renal vasculature Renal arteries arises at the level of L1- L2

41. In crossing the midline to reach the IVC, the longer left renal vein traverses an acute angle between the SMA anteriorly and the abdominal aorta posteriorly. Downward traction on the SMA may compress The syndrome may include hematuria or proteinuria , abdominal pain, nausea and vomiting (indicating compression of the duodenum), and left testicular pain in men (related to the left testicular vein draining into the left renal vein proximal to the compression). Renal Vein Entrapment Syndrome “nutcracker syndrome”

42. Brodel’s Line Segmentation of kidneys

43. Branching generations after segmental artery Lobar artery Interlobar artery Arcuate artery Interlobular artery

44. Function?

45. Development

46. These are pair of muscular tubes( 25 cm) that are continuous superiorly with the renal pelvis , which is a funnel-shaped structure in the renal sinus. Consists of three parts- renal pelvis , abdominal part and pelvic part . Descend retroperitonealy and cross pelvic brim Enter posterolateral corners of bladder Run medially within posterior bladder wall before opening into interior This oblique entry helps prevent backflow of urine Ureter

47. Important relationship of Ureters : They run Inferior to the ductus deferens in males and inferior to the uterine artery in females .

48. At three points along their course the ureters are constricted. the first point is at the ureteropelvic junction , just inferior to the kidney. the second point is where the ureters cross the common iliac vessel s at the pelvic brim. the third point is where the ureters enter the wall of the bladder . It is the narrowest one. Ureteric constrictions

49. arteries supplying the ureters divide into ascending and descending branches, which form longitudinal anastomoses . Lymphatic drainage Upper part- lumbar node Middle part- common iliac nodes Lower part- ext. and internal iliac nodes Nerve supply- T10 to L1/ S2-S4 Ureter

50. Innermost mucus membrane - transitional epithelium Middle layer of smooth muscle -inner longitudinal and outer circular layer. In lower part additional outer longitudinal layer present. Outer layer is tunica adventitia- made up of connective tissue. Histology

51. Excessive distension or spasm of muscle caused by a stone (calculus) provokes severe pain (ureteric colic), particularly if the obstruction is gradually forced down the ureter. It is referred to cutaneous areas innervated from spinal segments which supply the ureter and shoots down and forwards from the loin to the groin . it may extend into the proximal anterior aspect of the thigh by projection to the genitofemoral nerve (L1, 2). The cremaster , which has the same innervation , may reflexly retract the testis . Referred pain of ureteric colic

52. The bladder is the most anterior element of the pelvic viscera. Although it is entirely situated in the pelvic cavity when empty, it expands superiorly into the abdomen when full. An empty bladder is somewhat tetrahedral and has a base ( fundus ), neck , apex , a superior and two inferolateral surfaces .. Urinary Bladder

53. Parts of bladder- Male

54. Parts of bladder- Female

55. Base of Bladder in male

56. Base of Bladder- female

57. The neck of the bladder surrounds the origin of the urethra. The neck is the most inferior and also the most 'fixed' part of the bladder. It is anchored into position by a pair of tough fibromuscular bands pubovesical ligaments in female and puboprostatic ligaments in male. Neck of Urinary Bladder

58. Interior of bladder

59. Interior of bladder and trigone

60. Space of Retzius

61. Ligaments of Bladder Lateral true ligaments Lateral Pubo -prostatic ligaments Medial Pubo -prostatic ligaments ( pubo -vesical ligaments in female) Median umbilical ligaments Posterior ligaments of bladder Median umbilical fold Medial umbilical fold Lateral false ligaments Posterior false ligaments

62. Histology of urinary bladder

63. Arterial supply- superior and inferior vesical artery( B/O internal iliac artery) Uterine and vaginal artery instead of inferior vesical artery in female. Venous drainage- vesical venous plexus on inferolateral surfaces of bladder. Lymphatics - external iliac and lateral aortic Nerve supply- T11-L2/S2-S4

64. Micturation is a reflex action involving sensory and motor pathway mediated by lower micturation center( spinal cord S2-S4 ).

65. Neurogenic bladder - bladder disorders due to nerve damage. Automatic or reflex bladder- due to transection of cord above the lower micturation center(S2-S4). Voluntary control is lost but reflex is intact. Autonomous bladder- destruction of lower micturation center(S2-S4). Both voluntary and reflex control is lost These are really important!!!

66. Mucosa of Trigone – mesonephric duct( mesoderm) Remaining mucosa- vesicouretharal part of cloaca ( endoderm). Apex – allantoic diverticulum Musculature part- Splanchnic layer of lateral plate mesoderm which surrounds the cloaca. Development

67. The male urethra is a muscular tube approximately 20 cm in length. The urethra in men extends from the neck of the bladder( preprostatic urethra) through the prostate gland ( prostatic urethra ) to the urogenital diaphragm of the perineum ( membranous urethra ), and then to the external opening of the glans ( penile or spongy urethra ). The female urethra is approximately 4 cm in length and extends from the neck of the bladder to the external urethral orifice of the vulva Urethra

68. Thank you Visit – www.slideshare.com for this slide and for similar slides

69. Where is the micturation center in the brain??- pons Which of the following is found exclusively in the renal medulla? a.Proximal convoluted tubules b. Distal convoluted tubules c. Collecting ducts d. Thin loops of Henle Space for enlargement of bladder is …………. a . Space of Reitzius b. Verumontanum c. Urogenital raphe d. Pelvic space In kidney the less vascular area separating anterior and posterior segment is known as…………. a. Brodie’s line b. Canton’s line c. Calot’s line d. Seshachalam’s line Test yourself

70. life expectancy of individual with a single kidney is the same as those with two kidneys. Most common position of ectopic kidney is hypogastric region of abdomen.( it is pelvis) Widest and most dilated part of urethra is…………. a. Membranous b. Prostatic c. Penile d. External meatus T/F