physiology Flashcards
normal range for bicarbonate
22-28mmol/L
normal range for pH
7.35-7.45
normal range for PCO2
35-45 mmHg or 4.7- 6.0kPa
where does excess sodium go in patients whom sodium intake exceeds output
ECF by action of Na/K pump
glomerulus does what
filters small solutes from blood
role of antidiuretic hormone (ADH) in the kidney
ADH regulates water balance by increasing the reabsorption of water in the collecting ducts, allowing the body to conserve water when necessary.
made in supraoptic and paraventricular nuclei of hypothalamus and released by post pituitary
role of the loop of Henle
loop of Henle plays a crucial role in establishing the concentration gradient in the kidney, allowing for the reabsorption of water and solutes in the collecting ducts
descending- aquaporins allow water to be reabsorbed into interstitial fluid
ascending- reabsorbs sodium and chlorine from filtrate into interstitial fluid
gets saltier as you go down medulla
proximal tubule
reabsorbs ions into blood, water, nutrients, removes toxins and adjusts filtrate pH
distal tubule
selectively secretes and absorbs different ions to maintain blood ph and electrolyte balance
collecting duct
reabsorbs solutes and water from filtrate
how does hyperkalaemia occur in acidosis
in acidosis, the H ions go into cells to get out of blood, K then goes into blood to neutralise cell
role of aldosterone
in presence of ADH, increases aquaporins to increase BV to increase BP
stimulates genes that promote protein synthesis
increases action of sodium potassium pump. promotes reabsorption of sodium not potassium.
parathyroid hormone is released where and does what
distal tubule and collecting. released in low plasma calcium to increase calcium reabsorption. also acts on proximal tubule and increases phosphate excretion in urine so that more free unbinded calcium
also activates cAMP and protein kinase A
what is secretion
The process by which additional substances (e.g., drugs, excess ions) are actively transported from the blood into the renal tubules to be excreted in the urine.
what is reabsorption
The process by which most of the filtrate is returned to the blood via the renal tubules, allowing the body to retain necessary substances (e.g., glucose, amino acids, electrolytes).
What are the two main parts of the nephron?
The renal corpuscle (which includes the glomerulus and Bowman’s capsule)
The renal tubule (which includes the proximal tubule, loop of Henle, and distal tubule)
where should glucose be reabsorbed
proximal tubule
constriction of afferent arteriole will do what to hydrostatic pressure
decrease it downstream at the glomerular capillaries and decrease GFR
diabetes insipidus is due to
insufficent ADH or collecting ducts not responding to ADH
what cells in distal tubule deal with metabolic acidosis/ alkalosis
intercalated A (acidosis) and B (alkalosis) cells
steps for ABG interpretation
look at ph
look at bicarb. low bicarb means metabolic, high means respiratory
look at PCO2 to see if compensated or not
high anion gap causes
methanol
uraemia
diabetic ketoacidosis
paracetamol
iron
lactic acidosis
ethylene glycol
salicylates
normal anion gap causes
addisons
bicarbonate loss
chloride excess
diuretics
causes of respiratory acidosis
hypoventilation
airway obstruction
lung disease
weak respiratory muscles
drugs
guillain barre syndrome
