Kidney Spec Flashcards
Excretion
Removal of toxic waste products of metabolism (urea and creatine)
Osmoregulation
Maintenance of optimal water potential of body fluids
What does the proximal convoluted tubule consist of
Cuboidal epithelium containing numerous of mitochondria with surface microvilli and basal invaginations
Descending limb
Cuboidal epithelium, which is permeable to water
Ascending limb
Impermeable to water
DCT and collecting duct insists of
Cuboidal epithelium
Structure of the filter
Squamous endothelium of the blood capillaries in the glomerulus.
Basement membrane as affect the filter.
Podocytes in the wall of the Bowmans capsule
Main driving force for ultra filtration
High blood pressure within Glomerular capillaries
Opposes blood pressure
Osmotic gradient from the filtrate in the nephron into the glomerular capillaries opposes the blood pressure
Which arteriol is wider in diameter
Afferent
Why is the resistance to further filtration
Due to back pressure of the filtrate in the nephron
Selective readsorption
In the proximal convoluted tubule there is active transport of salt, glucose and amino acids from the filtrate into the cuboidal epithelium and then into the capillaries of the vasa recta system
How is osmotic gradient made in and what is it responsible for
Lorene on the site potential in the cuboidal epithelium and blood capillaries. Resultant osmotic gradient responsible for the bulk of water reabsorbed
In DCT And CD selective readsorption
In the distal convoluted tubule/collecting duct there is facultative reabsorption of water dependent on the permeability of the epithelial lining which, in turn, is dependent on the level of 80 H in the blood
How is cone filtrate made at apex of loop
The loss of water from the descending limb concentrates on filtrate at the apex of the loop
What exits the ascending limb
Sodium and chlorine ions into the surrounding medulla tissue
Why do we create a salt gradient
For the somatic recovery of water from the filtrate as it passes through the descending limb of the loop of henle, the DCT and CD
What are o’s preceptors on the hypothalamus sensitive to?
The solute potential of the blood
Why is there variation in the ADH synthesis by the hypothalamus
In relation to the solute potential of the blood
Where is ADH stored and released
From the pituitary gland into the blood stream
What does ADH do
Increases the permeability of the distal convoluted tubule and collecting ducts to water
Negative feed back by role of ADH in o’s regulation in mammals
The solute potential of the blood lowered during exercise.
The corrective mechanism involves increased ADH synthesis and release into the bloodstream. Consequent increased reabsorption of water from the filtrate into the blood.
Increase solute potential of the blood results in decreased ADH secretion thereby inactivating the corrective mechanism
