Nephron
If the juxtaglomerular apparatus is not working, what hormone/enzyme will not be produced?
Renin
What is the difference between afferent and efferent arterioles
Afferent - into the glomerulus (arrive)
Efferent - exit renal corpuscle
Amount of water in plasma, filtrate, reabsorbed and urine
Plasma - 3 L
Filtrate - 180 L
Reabsorbed - 178 L
Urine - 1-2L
Which glomerular filtration is the fast, slow and medium?
Fast - renal
slow - hormonal
medium - neural regulation
Filtrate
water, small molecules, ions that pass through membrane
What are the three ways filtration occurs in the filtration membrane?
Fenestrae, filtration slits, and filtration membrane
In what order does venous drainage occur?
Peritubular capillaries -> interlobular veins -> arcuate veins -> interlobar veins -> renal veins
Amount of protein in plasma, filtrate, reabsorbed and urine
plasma - 200 g
filtrate - 2 g
reabsorbed - 1.9 g
urine 0.1 g
Explain renal autoregulation
stretching in the glomerular capillaries triggers myogenic contraction of smooth muscle in afferent - reduces GFR. Pressure and flow monitored in macula densa for tubuloglomerular feedback to the glomerulus causing arterioles to consitrct of dilate
Renal fraction
part of the total cardiac output that passes through the kidneys. 21%
If there is more mitochondria present what does that mean?
The area needs more energy to work optimally
What are peritubular capillaries and what occurs in them
a plexus around the proximal and distal tubules, gas exchange occurs
Amount of glucose in plasma, filtrate, reabsorbed, and urine
plasma - 3 g
filtrate - 162 g
reabsorbed - 162 g
urine - 0 g
Explain neural regulation of GFR
Renal blood vessels supplied with sympathetic fibers that release norepinephrine causing vasoconstriction. Mostly extreme during drops of BP where afferent would dilate and efferent would constrict
Filtration fraction
part of plasma that is filtered into lumen of Bowmans capsules 19%
If there is a lot of microvili present what does that mean?
Things need to be moved
The arterial supply goes from the renal arteries to the afferent arterioles. What are the arteries in the middle
Segmental, interlobar, arcuate, interlobular
Amount of urea in plasma, filtrate, reabsorbed and urine
plasma - 1 g
filtrate - 54 g
reabsorbed - 24 g
urine - 30 g
What are the two hormones used to regulate GFR
Angiotensin 2 - vasoconstrictor, reduces GFR
ANP (atrial natriuretic peptide) - increase in BP stretches cardiac atria, this hormone relaxes the glomerulus by increasing surface area for filtration
Renal plasma flow rate
Renal blood flow rate times the fraction of blood that is in plasma
Which has a longer loop of Henle?
Juxtamedullary cells
Why does the afferent need a wider area than the efferent arteriole?
To maintain BP in the glomerulus
Amount of creatinine in plasma, filtrate, reabsorbed and urine
plasma - 0.03 g
filtrate 1.6 g
reabsorbed - 0 g
urine - 1.6 g
Which cells secrete renin and would this happen in high or low BP cases
Juxtaglomerular cells in low BP cases
Renal blood flow rate
1176 mL/min