Renal System Flashcards
What happens in Bowman’s capsule?
filtrate from the blood plasma collected and filtered into the glomerulus
What happens in the proximal tubule?
reabsorption of water, solutes and proteins into blood vessel
secretion of ions into tubule
How does the Loop of Henle aid reabsorption?
creates osmotic pressure which causes water/ions to be reabsorbed
descending loop: increased osmotic pressure, more water leaves
ascending loop: decreased osmotic pressure, less water leaves, ions leave via Na+/K+ pumps
How much blood plasma is filtered via Bowman’s capsule?
20%
How much filtered plasma is excreted?
<1%
What are the 3 forces involved in the passive diffusion of blood plasma into Bowman’s capsule? What is each one’s pressure?
Glomerular capillary blood pressure (+50mmHg)
Plasma colloid osmotic pressure (-30mmHg)
Bowman’s capsule hydrostatic pressure (-15mmHg)
What is the net pressure in Bowman’s capsule which allows for passive diffusion?
10mmHg
Which 3 layers does blood plasma have to pass through to reach Bowman’s capsule?
Endothelium
Basal Lamina
Podocyte inner layer
What causes hyperosmolarity of the filtrate in the tubule?
decreased osmotic pressure in the ascending Loop of Henle, leaving an increased volume of water in the tubule
What causes the release of vasopressin?
Hyperosmolarity in the tubule
Where is vasopressin made and stored?
Synthesised in the hypothalamus
Stored in posterior pituitary
What is the function of vasopressin?
facilitating water reabsorption via water channels (aquaporins)
Vasopressin also known as?
ADH (Antidiuretic hormone)
What are aquaporins?
Vesicles which can transport water across cells/membranes
Where else can aquaporins be found?
crystalline lens fibres and epithelium
trabecular meshwork
corneal endothelium
RPE
conjunctival epithelium
lacrimal gland epithelium
retinal Mueller cells
ciliary body epithelium
