Renal Flashcards
What is reabsorbed by the PCT?
Na+, Cl-, H2O, glucose
How much blood is filtered by the kidneys?
~120ml/min-1
How is most of the H2O removed in the PCT?
Na+ is actively transported out and H2O diffuses along the new concentration gradient
What is ADH, how does it work and where is it produced?
Antidiuretic hormone is produced in the hypothalamus and released from the post. pituitary gland.
It increases the H2O permeability of the CD and DCT promoting reabsorption of H2O.
Also increases arterial BP- vasopressin
What is the renin-angiotensin-aldosterone system?
It stimulates ADH release, arterial vasoconstriction and promotes drinking.
Renin is produced by the juxtaglomerular apparatus –> catalyses conversion of angiotensin I- angiotensin II in the lungs –> stimulates the release of aldosterone.
This ^ reabsorption of Na+ & H2O
What is Atrial natriuretic hormone?
Peptide released from the atria of the heart when extracellular volume is ^.
It increases natriuresis
How is GFR calculated?
GFR = Urine conc x urine vol.
_____________________________
Plasma conc.
What are the different types of shock?
Hypovolaemic- empty circulation
Cardiogenic- failure of the heart to pump
Obstructive- blockage of heart or major vessel- P.E.
Maldistributive- Abnormal dilatation small arteries - sepsis/anaphylaxis
What happens in septic shock?
Vessels become leaky –> hypovolaemia = \/ cardiac output.
Myocardium damaged by cytokine storm
Hypoxia can occur from microvascular changes/intravascular coagulation
Mitochondrial failure = cell death
What is anaphylactic shock?
Extreme hypersensitivity (Type 1) to a previously met antigen. --> massive degranulation of mast cells = histamine
What is hypovolaemia?
~20% of blood volume is lost –> shock
What are the treatments for hypovolaemic shock?
Stop active bleeding
ORS, ABCDE
70ml/kg hartmanns- don’t if BP stable >80 systolic
What is the osmolality of the human body?
~290mOsm
What is the osmolarity of 0.9% NaCl and why doe is only go extracellularly?
290mOsm, and because Na+ and Cl- are extracellular ions
What is haematuria?
> 3 RBC per high power field in freshly voided, centrifuged urine