Physiology - Endocrine etc. Flashcards
What is renin released in response to?
- In response to decreased renal perfusion pressure (detected by renal baroreceptors in afferent arteriole)
- Increased renal sympathetic discharge (B1 effect)
- Decreased NaCl delivery to macula densa cells
What do ANP and BNP relax smooth muscle via?
cGMP
- > increases GFR
- Decreases renin
Dilates afferent arteriole, promoting natriuresis
Where is the macula densa located and what substance does it detect?
- DCT
- NaCL
How can Beta blockers decrease BP?
Inhibiting B1 receptors of the JGA, decreasing renin release
What is EPO released in response to?
Hypoxia
What cells is EPO released in response to?
Interstitial cells in peritubular capillary bed
What is vit D also known as?
Calciferol
What are the inactive and active forms of vitamin D called?
- Calcidiol
- Calcitriol
What converts vit D to its active form (calcidiol to calcitriol)?
1 alpha-hydroxylase
- PTH stimulates this
Vit D increases the absorption of what substance in the small bowel?
Calcium
What cells secrete dopamine in the kidney?
PCT cells
What is the effect of dopamine in the kidney?
- Promotes natriuresis (Na+ secretion)
At low doses dilates interlobular arteries, afferent and efferent arterioles, increases RBF, little to no change in GFR
At higher doses it acts as a vasoconstrictor
What can cause hypokalemia (K+ shifting into cells)
- Hypo-osmolarity
- Alkalosis
- Beta-adrenergic agonist (increased Na+/K+ATPase)
- Insulin (increased Na+/K+ATPase)
What can cause hyperkalemia (K+ shifting out of cells)
- Digoxin (blocking of Na/K ATPase channels)
- Hyperosmolarity
- Lysis of cells
- Acidosis
- Beta blocker
- Sugar (hyperglycemia)
- Succinylcholine (increased risk in burns/muscle trauma)
Hyperkalemia? - DO LABSS
What can hyponatremia cause?
- Nausea
- Malaise
- Stupor
- Coma
- Seizures
