4. Kidneys:-
Location and Description:
• “Kidney are Bean shaped organs, about 11cm long, 6cm wide and
3cm thick ; they weigh around 150g.”
The two kidneys functions:-
• excrete most of the waste products of metabolism.
• They play a major role in controlling the water and electrolyte balance
within the body and in maintaining the acid–base balance of the blood.
• production and secretion of ERYTHROPOIETIN, the hormone that
stimulates formation of red blood cells.
• Production and secretion of RENNIN, an important enzyme in the long
term control of blood pressure.
5. The waste products leave the kidneys as urine, which
passes down the ureters to the urinary bladder,
located within the pelvis.
The urine leaves the body in the urethra.
6. STRUCTURE OF KIDNEY:-
The kidneys are reddish brown
and lie on the posterior
abdominal wall, one
on each side of
vertebral column, behind
the peritoneum and
below the diaphragm.
7. Their upper extremities are on a level with the upper border of
12ththoracic, their lower extremities are on a level with the 3rd
lumbar.
The right kidney lies slightly lower than the left kidney
because of the large size of the right lobe of the liver.
With contraction of the diaphragm during respiration, both
kidneys move downward in a vertical direction by as much as
1 inch. (2.5 cm).
HILUM is the concave medial border or deep fissure of the
kidney where the renal blood and lymph vessels , ureter and
nerve enter
8.
9. The hilum extends into a large cavity called the renal sinus.
The hilum transmits, from the front backward, the renal vein, two
branches of the renal artery, the ureter, and the third branch of
the renal artery (VAUA). Lymph vessels and sympathetic fibers
also pass through the hilum.
Coverings
The kidneys have the following coverings:
Fibrous capsule: This surrounds the kidney and is closely applied
to its outer surface.
Perirenal fat: This covers the fibrous capsule.
10. Renal fascia: This is a condensation of connective
tissue that lies outside the perirenal fat and encloses the
kidneys and suprarenal glands; it is continuous laterally
with the fascia transversalis.
Pararenal fat: This lies external to the renal fascia and
is often in large quantity. It forms part of the
retroperitoneal fat.
The perirenal fat, renal fascia, and pararenal fat support the kidneys and hold
them in position on the posterior abdominal wall.
11.
12. Renal Structure
Each kidney has a dark brown outer cortex and a light brown
inner medulla. The medulla is composed of about a dozen
renal pyramids, each having its base oriented toward the
cortex and its apex, the renal papilla, projecting medially.
The cortex extends into the medulla between adjacent pyramids as
the renal columns. Extending from the bases of the renal
pyramids into the cortex are striations known as medullary rays.
13. The renal sinus, which is the space within the hilum,
contains the upper expanded end of the ureter, the renal
pelvis. This divides into two or three major calyces, each
of which divides into two or three minor calyces. Each
minor calyx is indented by the apex of the renal pyramid, the
renal papilla.
14.
15. Important Relations, LEFT Kidney
Anteriorly:
The spleen , stomach , pancreas, jejunum and splenic
flexure of the colon.
Posteriorly:
The diaphragm and muscles of the posterior abdominal
wall.
Superiorly:
The left adrenal gland.
16. Important Relations, RIGHT Kidney
Anteriorly:
The right lobe of the liver , the duodenum and the hepatic
flexure of colon.
Posteriorly:
The diaphragm, and muscles of the posterior abdominal wall.
Superiorly:
The right adrenal gland.
17.
18. Lymph Drainage
Lymph drains to the lateral aortic lymph nodes around
the origin of the renal artery.
Nerve Supply
The nerve supply is the renal sympathetic plexus. The
afferent fibers that travel through the renal plexus
enter the spinal cord in the 10th, 11th, and 12th thoracic
nerves
20. NEPHRON:-
Functional and structural unit of kidney
Approximately 1-2 million nephrones in each kidney
Each nephrons has 2 components:-
TUBULAR COMPONENT
VASCULAR COMPONENT
STRUCTURE OF NEPHRONS:-
Nephron is essentially a tubule closed at one end open
into collecting duct at other end
Closed or blind end forms cup shaped glomerular
(bowman’s capsule).
21.
22. Continuing from glomerular capsule,reminder of nephron is 3cm
long that described into 3 parts:-
PROXIMAL CONVULATED TUBULE
MEDULLARY LOOP (LOOP OF HENLE)
DISTAL CONVULATED TUBULE leading into the
COLLECTING DUCT.
CARDIAC OUTPUT:-
Kidney receive about 20% of caridac output.
Entry Hilum renal artery divides into smaller arteries and
arterioles.
Afferent arteriole enters each Glomerular capsule then
subdivides into a cluster of tiny arterial capillaries that form
GLOMERULOUS.
Efferent arteriole the blood vessel leading away from the
GLOMERULOUS.
Afferent arterioles has large diameter than efferent arterioles.
23.
24. LAYERS:-
Wall of glomerulus and glomerulus capsule consists of
single layer of epithelial cells
Wall of reminder nephron and collecting duct are formed
by single layer of squamous epithelium.
FUNCTION:-
“FORMATION OF URINE”
3 steps are involved in urine formation:-
1-FILTRATION
2-SELECTIVE REABSORPTION
3-SECRETION
25. 1-FILTRATION:-
Occur through semi-permeable walls of glomerulus and
glomerulus capsule.
filtrate– the fluid filtered
from the bloodstream
into glomerulus capsule
called filtrate.
26. GLOMERULAR FILTRATE RATE (GFR):-
The volume of filtrate formed by both kidneys each
minute called glomerular filtrate rate (GFR).
In Healthy Adult; GFR is about 125ml/min
180 liter of filtrate are formed each day by two kidneys.
2-SELECTIVE REABSORPTION:-
Many substances from filtrate are reabsorbed in the
proximal convoluted tubule that possess microvilli to
increase surface area for absorption.
Only 60-70% of filtrate reaches the distal convoluted
tubule.
27. “HORMONES that influence selective reabsorption”.
Several hormones play such a role, each being regulated
by a negative feedback mechanism.
1-PARATHYROID HORMONE:
Secreted by parathyroid glands together with calcitonin
from the thyroid gland
Increase blood calcium level and clacitonin lowers it.
2-ANTIDIURETIC HORMONE (ADH):-
Secreted by the posterior piturity gland
Increase the permeability of the convoluted tubules and
collecting duct.
increasing water reabsorption.
28. 3-ALDOSTERONE:-
Secreted by the adrenal cortex
It increase the reabsorption of sodium and water and the
excretion of potassium.
4-ATRIAL NATRIURETIC PEPTIDE(ANP):-
Secreted by the atrial of the heart due to the stretching of
the artial wall.
It decrease reabsorption of sodium and water from
proximal convoluted tubules and collecting ducts.
29.
30. 3-TUBULAR SECERTION:-
Filtration occur as blood flow through glomerulus.
The substances not required or foreign materials e.g.
drugs including penicillin and aspirin are not entirely
filter from blood because of short of time and the
molecules are too large to pass through filtration pores.
Such substances are cleared by secretion from peritubular
capillaries into the filtrate within convoluted tubules.
Tubular secretion of hydrogen (H+) is important in
maintaining normal blood pH.
35. Ureter:-
Location and Description
The two ureters are hollow muscular tubes that extend from the
kidneys to the posterior surface of the urinary bladder. The urine
is propelled along the ureter by peristaltic contractions of the
muscle coat, assisted by the filtration pressure of the glomeruli.
Each ureter measures about 10 in. (25 cm) long and resembles
the esophagus (also 10 in. long) in having three constrictions
along its course:
where the renal pelvis joins the ureter,
where it crosses the external iliac artery
where it enter to the bladder
36.
37. URETER RELATIONS:
The renal pelvis is the funnel-shaped expanded upper
end of the ureter. 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 and forward on the lateral wall of the
pelvis to enter the lateral angle of the bladder.
38. Relations, Right Ureter
Anteriorly:
The duodenum, the terminal part of the ileum, the
right colic and ileocolic vessels, the right testicular or
ovarian vessels, and the root of the mesentery of the
small intestine.
Posteriorly:
The right psoas muscle, which separates it from the
lumbar transverse processes, and the bifurcation of
the right common iliac artery.
39. Relations, Left Ureter
Anteriorly:
The sigmoid colon and sigmoid mesocolon, the left colic
vessels, and the left testicular or ovarian vessels
Posteriorly:
The left psoas muscle, which separates it from the
lumbar transverse processes, and the bifurcation of the
left common iliac artery.
40. STRUCTURE OF URETER:-
OUTER-- covering of fibrous tissues
MIDDLE--muscular layer consisting of smooth muscles
fibers.
INNER layer– the mucosa, lined with transitional
epithelium
41. Blood Supply
Arteries
The arterial supply to the ureter is as follows:
• upper end, the renal artery;
• middle portion, the testicular or ovarian artery;
• in the pelvis, the superior vesical artery.
Veins
Venous blood drains into veins that correspond to the
arteries.
42.
43. Lymph Drainage
The lymph drains to the lateral aortic nodes and the iliac
nodes.
Nerve Supply
SYMPATHTETIC nerve supply from renal, testicular,
ovarian, hypo gastric and pelvic plexus.
PARA SYMPATHTETIC nerve supply from sacral
plexus.
44. Suprarenal Glands:-
Location and Description:
The two suprarenal glands are yellowish retroperitoneal organs that lie on the
upper poles of the kidneys. They are surrounded by renal fascia (but are separated
from the kidneys by the perirenal fat). Each gland has a yellow cortex and a dark
brown medulla. The cortex of the suprarenal glands secretes hormones that
includes:
mineral corticoids: which are concerned with the control of fluid and
electrolyte balance;
glucocorticoids, which are concerned with the control of the metabolism of
carbohydrates, fats, and proteins;
small amounts of sex hormones, which probably play a role in the
prepubertal development of the sex organs.
45. The medulla of the suprarenal glands secretes the catecholamines ,
epinephrine and nor epinephrine.
RIGHT SUPRANRENAL GLAND:-
The right suprarenal gland is pyramid shaped and caps the upper pole of
the right kidney.
It lies behind the right lobe of the liver and extends medially behind the
inferior vena cava.
It rests Posteriorly on the diaphragm.
LEFT SUPRARENAL GLAND:-
The left suprarenal gland is crescentic in shape and extends along the
medial border of the left kidney from the upper pole to the hilus.
It lies behind the pancreas, and the stomach
It rests Posteriorly on the diaphragm.
46. Blood Supply
Arteries
The arteries supplying each gland are three in number: inferior
phrenic artery, aorta, and renal artery.
Veins:
A single vein emerges from the hilum of each gland and drains
into the inferior vena cava on the right and into the renal vein
on the left.
Lymph Drainage:
The lymph drains into the lateral aortic nodes.
Nerve Supply:
Preganglionic sympathetic fibers derived from the splanchnic
nerves supply the glands. Most of the nerves end in the
medulla of the gland.
48. Urinary Bladder:-
The urinary bladder is situated immediately behind the pubic bones within the
pelvis. It stores urine and in the adult has a maximum capacity of about 500 ml.
The bladder has a strong muscular wall. Its shape and relations vary according
to the amount of urine that it contains.
The empty bladder in the adult lies entirely within the pelvis; as the bladder
fills, its superior wall rises up into the hypo gastric region.
In the young child, the empty bladder projects above the pelvic inlet; later,
when the pelvic cavity enlarges, the bladder sinks into the pelvis to take up the
adult position.
The empty bladder is pyramidal , having an apex, a base, and a superior and two
inferolateral surfaces; it also has a neck.
49. The apex of the bladder points anteriorly and lies behind
the upper margin of the symphysis pubis. It is connected to
the umbilicus by the median umbilical ligament (remains
of urachus).
The base, or posterior surface of the bladder, faces
Posteriorly and is triangular. The superolateral angles are
joined by the ureters, and the inferior angle gives rise to the
urethra.
50.
51.
52. Blood Supply
Arteries
The superior and inferior vesical arteries, branches of
the internal iliac arteries.
Veins
The veins form the vesical venous plexus that
drains into the internal iliac vein.
Lymph Drainage
Internal and external iliac nodes.
54. DISEASES OF KIDNEYS:-
GLOMERULONEPHRITIS (GN):-
Inflammatory conditions of the glomerulus.
CAUSES:
It is caused by immune responses.
High blood pressure
In many cases,GN has autoimmune components which produces
immune complexes that lodges in glomerulus capillaries causing
inflammation.
APPEARANCE:
Proliferative-increased no. of cells of glomeruli.
Membranous –thickening of basement membrane of glomerular
epithelium.
SYMPTOMS:
Pink or cola colored urine from RBC’s (hematuria).
Foamy urine due to excess protein(proteinuria).
56. HYPERTENSION:-
“High blood pressure resulting from kidney
disease.”
CAUSES:
Ischaemia (if renal blood vessel damage)
The reduced blood flow stimulates the RAAS ,raising
the blood pressure still further.
Raising blood pressure may Damage to Glomeruli
And Chronic Kidney Disease.
57. CHRONIC KIDNEY DISEASES:-
“When GFR has fallen to around 20% of normal kidney.”
MAIN CAUSES:
Diabetes mellitus
Glomerulonephritis
Hypertension
If GFR and filtrate volumes are reduced then reabsorption
of water is impaired. This results in production of 10ml of
urine per day.
Reduced glomerular filtrate leads to accumulation of waste
substances in blood such as urea and Creatinine.
59. TUMOURS OF THE KIDNEY:-
BENIGN tumour are relatively uncommon
MALIGNANT tumour are most common in kidney or bladder.
RENAL ADENOCARCINOMA:-
Tumour of tubular epithelium.
Occur in 50 years of age in male.
SYMPTOMS:
Back pain
Anaemia
Weight loss
Fever
This disease is most common in CIGRETTE SMOKERS.
60. NEPHROBLASTOMA (wilms’ tumour):-
Most common in children under 10 years.
Usually occur in the first 4 years
SYMPTOMS:
Abdominal pain
Hypertension
Haematuria
Usually unilateral but rapidly becomes very large and
invade renal blood vessels causing early spread to lungs.
61. TUMOURS OF THE BLADDER:-
Not clear whether benign and malignant .
Tumour are often multiple and recurrence is common.
CAUSES:-
Cigarette smoking
Prolonged use of analgesic