Anatomy of kidneys

Swaroopa Beulah Perumalla

1. Excretory system A.SWAROOPA MSC(NURSING)

2. VITAL ORGANS

3. Organs of the Renal System 2Kidneys 2Ureters Urinary bladder Urethra Not many structures, but very important ! Figure 23.1a 3

4. Kidneys LOCATION: Kidneys are a pair of excretory organs situated on the posterior abdominal wall, above the waist, extending from upper border of T12 to L3 vertebra, partially protected 11 th & 12 th pairs of ribs.

5. Renal Anatomy Paired retroperitoneal bean-shaped organs Located in the dorsal upper lumbar region Encased in the renal fat pad

6. Kidneys Right kidney is slightly lower than the left because the liver occupies considerable space on the right side superior to the kidney. “THEY ARE THE RETRO PERITONEAL ORGANS”

7. Kidneys COLOR AND SHAPE: Red color and bean shaped. CAPSULES OR COVERINGS OF KIDNEYS Fibrous capsule, Peri -renal fat, Renal fascia and Para-renal fat

8. 11 cm 6cm 3cm 8 HEIGHT & WEIGHT: Each kidney is 11 cm (4-5”) long, 6 cm (2-3”) broad and 3 cm (1”) thick, weight 150 g in males and 135 g in females .

9. ORGANS ASSOCIATED WITH THE KIDNEYS SUPERIORLY- RIGHT ADRENAL GLAND. ANTERIORLY- RIGHT LOBE OF THE LIVER , DUODENUM, & HEPATIC FLEXTURE OF THE COLON. POSTERIORLY- 12 TH RIB DIAPHRAGM , MUSCLES OF POSTERIOR ABDOMINAL WALL (PSOAS MAJOR, QUADRATUS LUMBORUM & TRANSVERSUS ABDOMINIS.

10. Peritoneal relations: The kidneys are retroperitoneal. Certain areas of each kidney are covered in anteriorly by peritoneum, whereas others are "bare“.

11. 12

12. Internal Structure of the Kidney Renal pyramids Renal papilla Renal Columns Renal Lobe 13

13. Human Kidney

14. Protection of the Kidneys 3 layers of connective tissue: Inner layer- Renal capsule Middle layer- Adipose capsule Outer layer-Renal fascia Renal cortex Retroperitoneal space 15

15. 3 layers of tissue surrounds the each kidney DEEP LAYER ( RENAL CAPSULE ) is a smooth transparent sheet of dense irregular connective tissue that continous with the outer coat of the ureter. It serves as barrier against trauma and helps to maintain the shape of kidney.

16. Middle layer: the adipose capsule : is a mass of fatty tissue surrounding the renal capsule. it also protects the kidney from trauma. Superficial layer: renal fascia is another thin layer of dense irregular connective tissue that covers surrounding structures and to the abdominal wall.

17. GROSS STRUCTURE OF THE KIDNEY Longitudinal section there are 3 areas. Fibrous capsule Cortex Medulla

18. 19 RENAL FIBROUS CAPSULE: surrounds the kidney, made of dense fibrous connective tissue.

19. 20 CORTEX: A reddish brown layer of tissue immediately below the capsule and out side the pyramids.

20. 21 MEDULLA: the inner most layer consisting of pale conical shaped striations called renal pyramids.

21. Surface anatomy of the Kidney Hilum is located on the medial surface HILUM: it is the concave medial border or deep fissure of the kidney where the renal blood & lymph vessels , urater & nerve enters. Renal Sinus: Space within hilus . Kidneys receive blood vessels and nerves.

22. 23 RENAL PELVIS: it is the funnel shaped structure which acts as a receptacle of the urine formed by the kidney.

23. IT HAS NUMBER OF DISTAL BRANCHES CALLED CALYCES , EACH OF WHICH SOROUNDS APEX OF THE RENAL PYRAMID. URINE FORMED IN THE KIDNEY PASES THROUGH PAPILLA AT THE APEX OF THE PYRAMID INTO MINOR CALYX THEN INTO MAJOR CALYX BEFORE PASSING THROUGH THE PELVIS INTO THE URETER.

24. 25 THE WALLS OF THE PELVIS CONTAINS SMOOTH MUSCLE AND ARE LINED WITH TRANSITIONAL EPITHELIUM. PERISTALYSIS OF THE SMOOTH MUSCLE IN THE WALLS OF THE CALYCES PROPELS URINE THROUGH THE PELVIS , URETERS TO THE BLADDER.

25. The ureteric pelvis usually divides into two or three short tubes, the major calices, each of which subdivides into 7 to 14 minor calices. Each minor calyx receives the openings of collecting tubules on papillae that project into the calices

26. Intravenous pyelogram : Note the calices and the pelves of the ureters , which differ in shape and level.

27. Renal Pedicle: The ureter and renal vessels near the hilus form the pedicle. The renal vein anterior, the ureter is posterior, and the arteries little high.

28. The glomerular capillaries called the glomerulus. The usual direction of blood flow is: Arteries Arterioles Capillaries Venueles veins

29. BLOOD SUPPLY TO KIDNEY ARTERIAL SUPPLY ABDOMINAL AORTA RENAL ARTERIES SEGMENTAL ARTERIES INTERLOBAR ARTERIES ARCUATE ARTERIES INTER LOBULAR FORMS 5-8 CAPILLARIES

30. BLOOD SUPPLY TO KIDNEY VENOUS SUPPLY INFERIOR VENACAVA RENAL VEINS SEGMENTAL VEINS INTERLOBAR VEINS ARCUATE VEIN INTER LOBULAR VEINS

31. The Blood Supply to the Kidneys

32. Regulates blood flow to the kidney by causing vasodilation or vaso constriction of renal arterioles. Autonomic plexuses in the abdomen and pelvis

33. Filtering & phagocytosis Proliferation of lymphocytes

34. Lumbar aortic nodes

35. MUSCLES ATTACHED TO KIDNEYS QUADRATUS LUMBORUM MUSCLE ILLIACUS MUSCLE PSOAS MAJOR MUSCLE

36. 40 Parts of the kidney: 1. Renal pyramid 2. Efferent vessel 3. Renal artery 4. Renal vein 5. Renal hilum 6. Renal pelvis 7. Ureter 8. Minor calyx 9. Renal capsule 10. Inferior renal capsule 11. Superior renal capsule 12. Afferent vessel 13. Nephron 14. Minor calyx 15. Major calyx 16. Renal papilla 17. Renal column

37. MICROSCOPIC ANATOMY OF THE KIDNEYS The functional unit of the lungs is the alveolus . The functional unit of the liver is the lobule. The functional unit of the kidney is the NEPHRON and smaller number of collecting tubules. Each kidney has about 18 lobes and 1 million nephrons. 41

38. Cortical nephrons with short loop of Henle . Juxtamedullary nephrons with long loops of Henle . Two types of nephrons

39. CORTICAL NEPHRONS 85% of nephrons are in this type. Most of the parts of nephron are in cortex only. Length of LH is short. Accompanied by peritubular capillary net work. JUXTRA MEDULLARY NEPHRONS 15%. begins at the junction of the cortex and medulla. long. vasa recta. DIFFERENCES BETWEEN TYPES OF NEPHRON

40. The glomerular filtration membranes are consist of 3 layers of capillary wall. ---Endothelium . ---Basement membrane. ---Epithelial podocytes. Fluid that filtered from the capillary blood into the bowman's space is called filtrate and forms the primary urine .

41. Histology of Filtration Membrane Endothelium of glomerulus Single layer of capillary endothelium with fenestrations Prevents RBC passage; WBCs.

42. Histology of Filtration Membrane Basement membrane of glomerulus Between endothelium and visceral layer of glom. capsule Prevents passage of large protein molecules

43. Histology of Filtration Membrane Filtration slits in podocytes Podocytes specialized epithelium of visceral layer footlike extensions with filtration slits between extensions Restricts passage of medium-sized proteins

44. THE FILTRATE THEN DIFFUSES ACROSS BOWMANS SPACE AND INTO THE TUBULES OF THE NEPHRON. IN THE TUBULES SOME SUBSTANCES ARE ADDED TO THE FILTRATE AS PART OF THE URINE FORMATION. AND SOME SUBSTANCES REABSORBED OUT OF THE FILTRATE AND BACK IN TO THE BLOOD.

45. LOOP OF HENLE REABSORPS THE WATER AND IONS FROM THE URINE AND CONTROLS THE CONCENTRATION OF URINE. THICK PORTION THIN PORTION DISTAL CONVOLUTED TUBULE: regulate Na, K, PH AND FURTHER DILUTION OF URINE TAKES PLACE. COLLECTING DUCT WHICH JOINS WITH SEVERAL TUBULES TO COLLECT THE FILTRATE AND FINAL NA REGULATION TAKES PLACE. 57

46. PROXIMAL CONVOLUTED TUBULE (PCT)

47. LOOP OF HENLE

48. Descending limb of the loop of henle

49. ASCENDING LIMB OF THE LOOP OF HENLE

50. DISTAL CONVOLUTED TUBULE( DCT)

51. COLLECTING DUCT

52. TUBULE HISTOLOGY PCT : cuboidal cells with apical microvilli Descending Loop and beginning of Ascending Loop: simple squamous epithelium. Ascending limb of the Loop: cuboidal & columnar epithelial cells. DCT, collecting ducts : cuboidal with specialized cells.

53. The Nephron

54. JUXTAGLOMERULAR APPARATUS The distal end of the renal tubule passes next to the glomerulus to form the juxtaglomerular apparatus ( juxta means “next to”). The juxtaglomerular apparatus (JGA) consists of cells located in and around the glomerulus and the glomerular capsule. 66

55. KIDNEY FUNCTIONS

56. The ureter is continous with the funnel shaped renal pelvis. The ureters are the tubes that convey urine from the kidneys to the urinary bladder. URETERS The two ureters are muscular tubes that extend from the kidneys to the posterior surface of the urinary bladder where the urine is propelled along the ureter by peristaltic contractions

57. The ureter is a retroperitoneal, distensible muscular tube that connects the kidney with the bladder.

58. Because of this arrangements ( psoas major muscle, sacro illiac joint , posterior wall of the bladder ) when urine accumulates and the pressure in the bladder rises, the ureters are compressed and the openings occluded. This prevent reflux of urine into the ureters (towards kidneys).

59. Ureter relations It lies within the hilum of the kidney and receives the major calyces It enters the pelvis by crossing the bifurcation of the common iliac artery in front of the sacroiliac joint It runs downward & forward on the lateral wall of the pelvi s to enter the lateral angle of the bladder

60. RELATIONS TO URETER ANTERIOR : Duodenum, Terminal part of the ileum, Right colic vessels, Iliocolic vessels, Right testicular or ovarian vessels. POSTERIOR : Right psoas muscle, Bifurcation of the right common iliac artery

61. CONSIST OF 3 LAYERS OF TISSUE: Outer covering of fibrous tissue. 2) Middle muscular layer consisting of smooth muscle fibers. 3) Inner layer the mucosa, lined with transitional epithelium.

62. Blood Supply Upper end is supplied by the renal artery Middle portion by (gonadal) testicular or ovarian artery In the pelvis is supplied by the superior vesical artery

63. The lymph drains to the lateral aortic nodes and the iliac nodes

64. NERVE SUPPLY Sympathetic supply from renal, Testicular, ovarian hyogastric & pelvic plexus. Para sympathetic supply from sacral plexus .

65. Ureters Each ureter has three constrictions along its course, 1- Where the renal pelvis joins the ureter, 2- As it crosses the pelvic brim, 3- Where it pierces the bladder wall ( intra-mural part)

66. SUPRARENAL GLANDS The two suprarenal glands are yellowish retroperitoneal organs that lie on the upper poles of the kidneys They are surrounded by the renal fascia Separated from the kidneys by the perirenal fat Each gland has a yellow cortex and a dark brown medulla

67. LEFT SUPRARENAL GLANDS Left suprarenal gland is crescentic in shape . Extends along the medial border of the left kidney from the upper pole to the hilum It lies behind the : The pancreas, The stomach It rests posteriorly on the diaphragm

68. RIGHT SUPRARENAL GLANDS The right suprarenal gland is pyramidal in shape and caps the upper pole of the right kidney. It lies behind the right lobe of the liver and extends medially behind the IVC. It rests posteriorly on the diaphragm.

69. Suprarenal Glands The cortex secretes hormones include: Mineral corticoids , which control fluid and electrolyte balance. Glucocorticoids , which control carbohydrates, fats, and proteins. Sex hormones , which probably play a role in the prepubertal development of the sex organs The medulla secretes the catecholamine, epinephrine and norepinephrine

70. Blood Supply ARTERIES: Three arteries supplying each gland, 1- Superior suprarenal artery: from inferior phrenic artery 2- Middle suprarenal from aorta. 3- Inferior suprarenal from renal. VEINS : A single vein emerges from the hilum of each gland: The right suprarenal vein drains into the IVC . The left suprarenal vein drains into the left renal

71. 88 URINARY BLADDER Collapsible muscular sac. Stores and expels urine. Lies on pelvic floor posterior to pubic symphysis . Males: anterior to rectum. Females: just anterior to the vagina and uterus.

72. The Final Common Pathway Urinary bladder hollow muscular organ generally smaller in females due to presence of a uterus retroperitoneal in the pelvic cavity, posterior to the pelvic symphysis freely movable. Bladder muscle is detrusor muscle.

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75. The openings of the two ureters and the urethra mark a triangular area called the trigone on the bladder floor. S T R U C T U R E OF “TRIGONE”

76. Bladder- structure 3 layers Outer layer Loose connective tissue Middle layer Smooth muscle and elastic fibres Inner layer Lined with transitional epithelium 93

77. Bladder histology: Sphincters control entry from ureters . Exit at the urethra. circular smooth muscle fibers form internal urethral sphincter. lower is the external urethral sphincter with skeletal muscle for voluntary control.

78. URETHRA small tube from floor of bladder to exterior of body. females -- fairly straight path exits anterior to vagina. males -- passes through the prostate gland and exits through the penis.

79. The Urethra - conveys urine from the urinary bladder to the outside of the body . FEMALES MALE 3-4 cm (1.5”) 20 cm (8”) greater risk of urinary tract infections

80. The male urethra has three regions: prostatic urethra 2) membranous urethra 3) penile urethra. Difficulty in voiding urine with enlarged prostate

81. URETHRAL SPHINCTERS IN BOTH SEXES: Internal Urethral Sphincter- under involuntary control of smooth muscle. External Urethral Sphincter - under voluntary control of skeletal and levator ani muscle. internal urethral sphincter external urethral sphincter

82. HISTOLOGY FEMALE: THREE COATS Inner mucosa, Intermediate thin layer of spongy tissue with plexus of veins. Outer muscular coat continuous with the bladder. MALE TWO LAYERS Inner mucous membrane and a muscularis Outer submucosa tissue with various accessory structures which connect to it. Both genders have a stratified squamous epithelial lining.

83. 100 KNOW: - Micturation center of brain: pons . -Parasympathetic : to void. -Sympathetic : inhibits micturation .

84. Nursing applications

85. CONGENITAL ANOMALIES OF KIDNEY : AGENESIS (one or both fetal kidney are absent). HYPOPLASIA (Small kidney). ECTOPIC KIDNEYS ( kidney is located in an abnormal position.  HORSE SHOE KINEYS ( the kidneys are fused together at the lower end or base.) PAN CAKE KIDNEYS ( renal fusion anomaly of the kidneys of the crossed fused variety) POLY CYSTIC KIDNEY ( progressive enlargement of cysts in the kidneys )

86. HYPOPLASIA ECTOPIC KIDNEY HORSE SHOE PCKD PANCAKE KIDNEY

87. Epispadias & hypospadias : Mutual opening located on dorsal or superior surface of the penis. Ventral or inferior surface of the penis.

88. Addison’s disease, chronic adrenal insufficiency , hypocortisolism , and  hypoadrenalism ) is a rare, chronic  endocrine system disorder in which the  adrenal glands  do not produce sufficient  steroid hormones  ( glucocorticoids  and often  mineralocorticoids )

89. Urinary tract infections is the inability to empty the bladder completely. URINARY RETENTION

90. CHRONIC RENAL FAILURE

91. Dialysis the clinical purification of blood by dialysis, as a substitute for the normal function of the kidney.