Ion and water balance 3 Flashcards
Transport in Tubule regions
differences in transport and permeability is due to what?
differences in epithelium along the tubule
Transport in the proximal tubule
most reabsorption of solutes and water takes place in proximal tubule; solutes reabsorbed by Na cotransport what>
glucose, lactate , aa, water soluble vitamins, phosphates
Transport in the proximal tubule
water follows reabsorption beacuse of what?
osmosis
Transport in the proximal tubule
proximal tuble also carries out what?
secretion
Transport in the proximal tubule
What are the organic Anions?
cAMP, cGMP, oxalate, short chain FA, Urate, Alpha-ketoglurate
Transport in the proximal tubule
what are the organic cations?
epinephrine, ACh, choline, dopamine, histamine, serotonin,
Proximal tubule also secretes what?
drugs and toxins
Ion and water transport in the Loop of Henle
Characteristics of the Desending limb?
permeable to water
water is reabsorbed
volume of primary urine decreases
primary urine becomes more concentrated
Ion and water transport in the Loop of Henle
Characteristics of the Ascending limb?
impermeable to water
ions are reabsorbed
primary urine becomes dilute
Ion and water transport in the Loop of Henle
reabsorbed ions accumulate where?
interstitial fluid
Ion and water transport in the Loop of Henle
in the reabsorption of ions the osmotic gradient is created by what?
the medulla
which creates osmotic gradient for reabsorption of water
Transport in the distal tubule
what can the distal tubule reabsorb?
salts and water
Transport in the distal tubule
what can the distal tubule secrete?
potassium
Transport in the distal tubule
Transport function of distal tubule is affected by what?
hormones
Transport in the distal tubule
parathormone does what?
increases Ca reabsorption
Transport in the distal tubule
Aldosterone does what?
increases K secretion and Na reabsorption
Transport in the distal tubule
Vasopressin does what?
increase water reabsorption
Glomerular Filtration Rate (GFR)
GFR is determined by what?
the pressure across glomerular wall
Glomerular Filtration Rate (GFR)
what are the three main forces on the GFR?
Glomerular capillary hydrostatic pressure
Bowmans capsule hydrostatic pressure
Oncotic pressure-osmotic pressure due to protein concentration in blood
Intrinsic regulators of GFR
what are the three pathways?
Myogenic regulation
tubuloglomerular feedback
mesangial control
Intrinsic regulators of GFR
myogenic regulation function?
constriction/dilation of affected arteriole
Intrinsic regulators of GFR
Tubuloglomerular feedback pathway function?
Juxtaglomerular apparatus
macula densa cels in distal tubule
juxtaglomerular cells beside the afferent arteriole
macula densa cells of distal tubule control diamerer of afferent arteriole
Intrinsic regulators of GFR
mesangial control pathway function
increase/decrease flow into glomerulus stretches/constricts capillaries, messangial cells also increase permeability of filter
Regulation of Urinary function
Hormones affect what?
kidney function
Regulation of Urinary function
What is the steroid hormones?
aldosterone- slow response
Regulation of Urinary function
peptide hormones
Vasopressin (ADH)- rapid response
renin-angiotensin- rapid and slow response
Vasopressin
Also called what?
Antidiuretic hormone (ADH)
Vasopressin
is what type of hormone?
peptide hormone
Vasopressin
is produced
and released by what/where?
in hypothalamus and released by posterior pituitary
Vasopressin
increase what?
increases water reabsorption from the collecting ducts and distal tubles by increasing number of Aquaporins
Vasopressin
Normally collecting ducts do not reabsorb what?
water
Vasopressin release is stimulated by what?
increase plasma osmolarity detected by osmorecetors in the hypothalamus
Vasopressin
release of this is inhibited by what?
increase blood pressure detected by strech receptors in atria and baroreceptors in carotid and aortic bodies
Aldosterone
what is it and what does it control?
it is a mineralcorticoid which controls ion excretion
Aldosterone
produced where?
adrenal cortex in tetrapods
Aldosterone
what is this stimulated by? (5)
angiotensin 2
high K
ACTH
decreased blood pressure sensed by stretch receptors in atria
