Excretory Products N Their Elimination Flashcards
Kidneys are retro peritoneal in position.
T/F
True.
Retro peritoneal structures lie outside the peritoneum (parietal peritoneum) I.e covered by peritoneum on one side.
Kidneys are located between ___________ vertebres.
12 thoracic and 3 lumbar I.e T12 - L3
With respect to size, length of each kidney is about _____ and width ______ and depth ______.
10-12cm in length
5-7cm in width
2-3cm in depth (thickness)
In humans _________ kidney is lower than ______ in position,because __________.
Right kidney is lower in position than the left.
Right kidney is pushed downwards by massive liver.
In rabbits, the case is reverse I.e right is higher than the left kidney.
If the renal fascia is ruptured, the kidney loses its position and descends downwards, a condition is called
Nephrotosis or floating kidneys.
Renal cortex protrudes into renal medulla at
Columns of bertini or renal columns.
It is the space between 2 consecutive renal pyramids.
Functional units of kidney are
Nephrons or uriniferous tubules.
Each kidney has about _______nephrons.
100,000 nephrons.
** 1 million nephrons (NCERT)
Parietal membrane of bowmans capsule is made of
Simple squamous epithelium.
visceral membrane of bowmans capsule is made of
Special cells called podocytes.
These are irregular cells that line the glomerular capillary wall.
What is nephric filtrate?
It is filtered blood, having the composition as that of blood except formed elements and large proteins.
Blood is comparatively concentrated than nephric filtrate.
Renal affarent/efferent arterioles has comparatively greater lumen while affarent/efferent arteriole has lesser lumen.
Renal affarent arterioles has comparatively greater lumen while efferent arteriole has lesser lumen.
What is filtration membrane?
It’s thickness is _______.
It’s m/o wall of blood vessel wall and visceral layer of bowmans capsule.
Thickness = 0.24m
What is GCHP ?
Glomerular blood capillary hydrostatic pressure: pressure exerted by blood on blood vessel wall.
It’s a positive pressure.
Equal to 60mmHg.
Sends blood plasma out of blood vessel into capsular space, through fenestra.
What is CHP?
Capsular hydrostatic pressure : pressure exerted by nephric filtrate onto the blood vessel wall.
It’s a negative pressure.
Equal to 20mmHg.
What is BCOP?
Blood colloidal osmotic pressure: pressure exerted by nephric filtrate over blood.
It’s a negative pressure.
Equal to 30mmHg.
What is GFR?
Glomerular filtration rate: amount of nephric filtrate formed per min or per day.
Per min = 125ml
Per day = 180L
What is urine outflow?
99% of nephric filtrate is reabsorbed and only 1% is excreted as urine = 1.5-2L /day. This is k/a urine outflow.
Filtration fraction for a normal kidney is
15-20%.
Filtration fraction = GFR/RPF =125/650=20%
What is RPF?
Amount of blood plasma that enters the kidneys per minute.[(55% of 1200) =650].
Volume of blood that enters the kidney per min is
1100-1200ml which is 1/5th of cardiac output.
_____is the major site for tubular reabsorption.
proximal convulated tubule .
What is tubular reabsorption ?
tubular reabsorption means the absorption of electrolytes and water into nearby blood vessels.
____________ is reabsorbed in proximal convulated tubule .
Na+ , K+ , H2O, small amount of urea, bicarbonate ion.
70-80% of electrolytes are reabsorbed which include 100% of glucose and amino acids.
What is tubular secretion?
Secretion of substances like electrolytes from blood vessels into renal tubule.
At proximal convulated tubule, electrolytes like __,__,__ are secreted from blood vessels into nephric filtrate in renal tubules.
H+ , K+ , NH4+
What is tubular absorptive maxima(TAM)?
max. Amount of substance or electrolyte that can be absorbed per 100ml of the nephric filtrate.
For glucose, TAM = 180mg/dl
Normal blood sugar level is equal to ____?
120mg/dl.
As it exceeds 120mg/dl, glucose will start appearing in urine.
Thin segment of descending limb of loop of Henele is lined with _______ epithelium which is permeable for _____ and impermeable for ______.
Squamous epithelium
Permeable for water; impermeable for ions.
Thin segment of ascending limb of loop of Henele is lined with _______ epithelium which is permeable for _____ and impermeable for ______.
Ciliate cuboidal epithelium
Permeable for ions ; impermeable for water.
