Chapter 24 Part 2 Flashcards
BP within glomerulus high due to arteriole size; pushes water and solutes out of blood to capsular space
Glomerular hydrostatic pressure
What will increase glomerular hydrostatic pressure?
Afferent arteriole is wider and efferent arteriole is smaller
Oppose glomerular hydrostatic pressure, pulls fluid back into capillary
Blood colloid osmotic pressure
Oppose glomerular hydrostatic pressure; pressure in Bowman’s capsule, impedes movement of water and solutes
Capsular hydrostatic pressure
Rate at which the volume of filtrate is formed
Glomerular filtration rate
What are some influencing factors of GFR?
net flirtation pressure, renal auto regulation
what happens to GFR when you increase net filtration pressure
increase
Maintains BP and GFR
renal autoregulation
Maintain normal glomerular BP; cause smooth muscle cells to relax which causes blood volume to increase which helps with GFR and glomerular BP to stay constant
Mogenic mechanism
Increases systemic BP by increasing NaCl in filtrate, signals smooth muscle cells on afferent arterioles to vasoconstrictor which causes a decrease in blood volume
Tubuloglomerular feedback mechanism
Decrease urine output to conserve fluid; AP is sent to afferent and efferent arterioles which result in vasoconstriction which decreases blood flow causing glomerular BP to decrease
Sympathetic stimulation
What is the stimulus for hormonal control to regulate GFR
Stretch in the atria
Released from heart and targets afferent arterioles that causes vasodilation, increases blood flow going in glomerulus, glomerular pressure increases and GFR increases
Atrial natriuretic peptide
What nutrients are reabsorbed in the proximal convoluted tubules?
Glucose, amino acids, lactate
What hormones and proteins are reabsorbed in the PCT
Insulin, angiotensin, any hormone/protein
Where does sodium reabsorption occur in the nephron loop?
All through the loop
Produced by adrenal cortex; secreted in response to high K+ and low Na+ levels in blood, increases the number of sodium potassium pumps which increase the reabsorption of sodium and secretion of potassium
Aldosterone
Produced by the heart; stimulus from stretch of heart wall; inhibit reabsorption of sodium (more sodium in nephron),
Atrial natriuretic peptide
where does water absorption occur?
Entire nephron
Where does potassium absorption occur?
Mostly PCT
Cells that reabsorb K+ continuously (not dependent on anything)
Intercalated cells
Cells that secrete K+ based on aldosterone
Principle cells
Where are bicarbonate ions absorbed?
mostly PCT
Why do we need HCO3?
Control pH (buffers hydrogen ions)
part of the nephron that regulates urine pH
collecting duct
What are the 3 waste products?
Urea, uric acid, creatinine
Protein breakdown in liver
urea
Where is urea filtered?
Glomerulus
Nucleic acid breakdown in liver
Uric acid
where is uric acid filtered?
Glomerulus
Metabolism in muscle tissue
creatinine
Where is creatinine secreted?
DCT
What 2 mechanisms create a concentration gradient in the kidneys?
Countercurrent multiplier and countercurrent exchange
Contraction of internal urethral sphincter, inhibits contraction of detrusor muscle
Sympathetic neurons
Contraction of detrusor muscle, relaxation of internal urethral sphincter
Parasympathetic neurons
Contraction of external urethral sphincter
Somatic motor neurons
What is the storage reflex controlled by?
Sympathetic stimulation and somatic motor stimulation
Allows relaxation of detrusor muscle, contraction of internal urethral sphincter to store urine
Sympathetic stimulation
Allows contraction of external sphincter to keep urine in
Somatic motor stimulation
What is the micturition reflex controlled by?
Parasympathetic and somatic nervous system
What is the reflex pathway for micturition?
- baroreceptors detect stretch of bladder wall, AP created
- AP sent to ons and bladder
- Results end with detrusor muscle to contract and internal urethral sphincter relax
- AP sent to cerebral cortex for sensation ot urinate
