The document summarizes the anatomy and functions of the renal (kidney) system. It describes the major organs including the kidneys, ureters, urinary bladder, and urethra. It details the internal structure of the kidneys including nephrons, blood supply, and microanatomy. Kidney functions such as filtration and regulation of water and electrolytes are also discussed.
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 11th & 12th 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
COLOR AND SHAPE:
Red color and bean shaped.
CAPSULES OR COVERINGS OF KIDNEYS
Fibrous capsule,
Peri-renal fat,
Renal fascia and
Para-renal fat
7. 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.
8. ORGANS ASSOCIATED WITH THE KIDNEYS
SUPERIORLY- RIGHT ADRENAL GLAND.
ANTERIORLY- RIGHT LOBE OF THE LIVER ,
DUODENUM, & HEPATIC FLEXTURE OF THE COLON.
POSTERIORLY-12TH RIB DIAPHRAGM, MUSCLES OF
ABDOMINAL WALL (PSOAS MAJOR,
LUMBORUM & TRANSVERSUS
POSTERIOR
QUADRATUS
ABDOMINIS.
17. 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
18.
19.
20.
21.
22. 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 .
23.
24. 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 FILTRATEAND FINAL NA
REGULATION T
AKES PLACE.
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32. JUXTAGLOMERULAR APPARATUS
The distal end of the
renal tubule passes next
to the glomerulus to
formthe
juxtaglomerular
apparatus (juxta means
“next to”).
The juxtaglomerular
apparatus (JGA) consists
of cells located in and
around the glomerulus
and the glomerular
capsule
66
35. URETERS
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.
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
36. 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 pelvis
to enter the lateral angle of
the bladder
37. 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
40. • 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.
41. The Urethra
- conveys urine from the urinary bladder
outside of the body.
to the
FEMALES
3-4 cm (1.5”)
MALE
20 cm (8”)
greater risk of
urinary tract
infections
42. The male urethra has three regions:
1) prostatic urethra
2) membranous urethra
3) penile urethra.
Difficulty in voiding urine with
enlarged prostate