Transcript Urinary System

Renal System
•Gross structure of the kidneys cortex, medulla (inner and outer zones of
outer medulla and papilla or inner medulla), pyramids, renal calyxes and
pelvis, ureter.
•Gross size and weight (300~400 g) of kidneys (about 0.5% of body weight)
• in humans
Anatomy of the Kidney
The nephron is the basic unit of renal structure
and functions.
 It has a malpigian corpuscle with a vascular
glomerulus within a matrix formed by mesangial
cells and an epithelial Bowman’s capsule.
 The capsule joins a series of tubules starting with
the proximal tubule and followed by the loop of
Henle the distal tubule.
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Nephron
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Glomerulus
Bowman’s Capsule
Proximal Convoluted
Tubule
Loop of Henle
I. Proximal straight tubule
ii. Descending Thin Limb
iii. Ascending Thin Limb
iv. Distal Straight Tubule
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Distal Convoluted Tubule
branch of renal
artery
glomerulus
Bowman’s
capsule
DCT
PCT
collecting
duct
branch of
renal vein
capillaries
loop
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branch of renal
artery
glomerulus
Bowman’s
capsule
DCT
PCT
collecting
duct
branch of
renal vein
capillaries
loop
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Anatomy of the Kidney
Formation of Urine
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The initial step is the formation of a plasma ultrafiltrate
(plasma without cells or proteins) at Bowman’s space through
the action of hydrostatic pressure in the glomerular capillaries.
The ultrafiltrate flows along the tubules and is modified by
reabsorption (sodium salts, glucose, amino acids) and most
water from the when of the tubules back into the pennt?
Capsule.
The luminal fluild is also modified by secretion of solutes from
the peritubular (tubule cells) into the lumen.
Tubular Secretion and Reabsorption
Function of Collecting ducts
•The collecting ducts make the final fine
adjustments in composition of the urine through
anti-diuretic hormone stimulated water and urea
reabsorption, and aldosterone stimulated Na, K and
H transport.
Tubular Reabsorption
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Returns materials from
filtrate to blood
99% of filtrate reclaimed
– Lose 1.5 – 2 L/day as urine
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Mechanisms of
reabsorption:
– Osmosis, Solvent drag,
Pinocytosis, Active
transport & Diffusion
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Amounts reabsorbed
depends on:
– Need for substance &
Concentration gradient
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Proximal convoluted
tubule
– Always permeable to water,
reabsorbs 80% of water
passing through
– Active Transport
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Ions-Na, Cl, K, HCO3
Nutrients
– Passive Transport
 Urea, Lipid-soluble solutes
Role of kidney
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Apart from urine formation
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Blood pressure from Renin production
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RBC production from Erythropoietin
Kidney Structure
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Arteriole – Small artery
Bowman capsule – A cup-shaped capsule surrounding each glomerulus
Calyx – Cup-like collecting region of the renal pelvis
Catheter – A tube for injecting or removing fluids
Cortex – Outer region; the renal cortex is the outer region of the kidney
Creatine – A waste product of muscle metabolism
Electrolyte – A chemical that carries an electrical charge on solution
Filtration – Process whereby some substances but not all,
pass through a filter or other material
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Glomerulus – Tiny ball of capillaries in cortex of kidney
Kidney Structure
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Hilum – Depression or pit in that part of an organ where blood vessels and
nerves enter and leave
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Kidney – One of two bean-shaped organs located behind the abdominal
cavity on either side of the backbone in the lumbar region
Meatus – opening or canal
 Medulla – Inner region; the renal medulla is the inner region of the kidney
 Nitrogenous wastes – Substances containing nitrogen and excreted
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in urine
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Renal artery – carries blood to the kidney
Kidney Structure
Renal pelvis - Central blood away from the kidney.
 Renal tubules - Microscopic tubes in the kidney
 Renal vein - Carries blood away from the kidney
 Rennin - A hormone synthesized, stored and secreted by the kidney
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Sodium (Na+) - A salt (electrolyte) regulated in the blood and urine by the kidneys
Trigone - Triangular area in the bladder where the ureters enter and the urethra exits
 Urea - Major nitrogenous waste product excreted in urine
 Ureter - Tube leading from each kidney to the bladder
 Urethra - Tube leading from the bladder to the outside of the body
 Uric acid - Nitrogenous waste excreted in the urine
 Urinary bladder – Sac that holds urine
 Voiding – Expelling urine (micturation)
 Glomerulonephritis - Inflammation of the kidney glomerulus (Bright disease)
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Kidney Structure
Interstitial nephritis - Inflammation of the renal interstitium
 Nephrolithiasis - Kidney stones (renal calculi)
 Nephrotic syndrome - A group of symptoms caused by
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excessive protein loss in the urine (also called nephrosis)
Polycystic kidneys - Multiple fluid-filled sacs (cysts) within and upon the kidney
 Pyelonephritis - Inflammation of the renal pelvis and renal medulla
 Renal cell carcinoma - Cancerous tumor of the kidney in adulthood
 Renal failure - Failure of the kidney to excrete urine
 Renal hypertension - High blood pressure resulting from kidney disease
 Wilms tumor – Malignant tumor of the kidney occurring in childhood
 Diabetes insipidus - Inadequate secretion or resistance of the kidney to the
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action of antidiuretic hormone (ADH)
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Diabetes mellitus - Inadequate secretion or improper utilization of insulin
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Azot (nitrogenous)
Dips
Noct (night)
Olig (few)
Tripsy (crushing)
BUN (blood urea nitrogen)
IVP
KUB (kidney, ureter, bladder)
ADH (anti-diuretic hormone)
UTI (urinary tract infection)
CRF (chronic renal failure?, corticotropin releasing
factor?)
ARF (acute renal failure?)