Renal Physiology Flashcards
why does renal physiology matter to dentistry?
-You will write prescriptions, the kidneys are a major excretion route for pharmaceuticals
-Local anesthetics are excreted through kidneys
-Patients with kidney failure need to be monitored closely and certain precautions should be made for them
-A lot of patients are on blood pressure medications
—–Limits of max BP you can treat pts
—–Clinic policy? 160/100
kidneys are a major _______ route for pharmaceuticals
excretion
local anesthetics are excreted through the …
kidneys
kidney medulla contains _____
pyramids
kidney pyramids have _____ that connect to renal pelvis
papilla
kidney pelvis drains to the _____ and then the ____
ureter
bladder
kidney nephrons are the ________
the functional unit of kidneys
how many kidney nephrons?
~1 million
what are the components of the kidney nephron?
renal tubule
glomerulus
Kidneys:
“dirty” blood goes in through the ____
“clean” blood leaves through the ____
arteries
veins
afferent vs efferent arterioles of kidneys
afferent = blood going into the glomerulus
efferent = blood leaving glomerulus
glomerular filtration creates a …
plasma-like filtrate of the blood
homeostasis
regulation of the volume of blood plasma, blood pressure, and pH
blood volume ___L
5 L
fluid in both plasma and RBC
changes in fluid will result in changes of ____
pressure
increase urine output can help relieve pressure
restricted urine output can maintain pressure (dehydration)
changes in fluid volume will start with ____
plasma
fluid in body ~__ L
~42 L
plasma, interstitial fluid, intercellular fluid
ways the body excretes fluid
breathing
sweat
crying
feces
metabolic waste products (kidneys)
urea
creatinine
bilirubin
uric acid
foreign substance waste products (kidneys)
drugs/medications
food additives
toxins
simple: how do kidneys regulate pH
simple: excrete or retain an acid or base
excrete or retain H+ ions (hydrogen ions)
excrete or retain HCO3- (bicarbonate)
kidney processes (3)
filtration
modification
excretion
blood flow of kindeys
Renal artery -> afferent arterioles -> glomerular capillaries -> efferent arterioles -> peritubular capillaries -> renal vein and out
urine flow of kineys
Glomerulus -> proximal tubules -> Loop of Henle -> distal tubule -> collecting duct -> renal pelvis -> ureters
nephrons are supplied by ____
glomerular capillaries (filtration occurs here)
single direction
peritubular capillaries: ____ & _____ occurs
reabsorption secretion
multi-direction
study
cortical nephrons compose __%
70%
juxtamedullary nephrons compose __%
30%
all nephrons are composed with the same things but they are _____
located in different places
cortical nephrons are mainly in the ___
cortex
with Loop of Henle in the medulla
*shorter
juxtamedullary nephrons span across the ___
medulla
juxtamedullary nephrons are ____
cortical nephrons are ____
(length)
juxtamedullary nephrons are LONG
cortical nephrons are SHORT
juxtamedullary nephrons have different blood supply, called
Vasa Recta
Kidneys receive ____ L of blood/min
~1.2 L
Substance is filtered but none is reabsorbed=
Substance is filtered and partially reabsorbed=
Substance is filtered and totally reabsorbed=
Substance is filtered and added back via secretion=
Substance is filtered but none is reabsorbed.
-creatine
Substance is filtered and partially reabsorbed.
-water (maintain homeostasis in times of dehydration)
Substance is filtered and totally reabsorbed.
-glucose (none in urine)
The substance is filtered and added back via secretion.
-hydrogen ions H+ (help with homeostasis)
rate of filtration equation
Hydrostatic pressure is _____ in glomerular capillaries rather than peritubular capillaries.
higher
creates concentration gradient
what will cause the contraction of mesangial cells?
histamine
angiotensin
norepinephrine
what causes the relaxation of mesangial cells?
dopamine for relaxation
Glomerular filtration rate (GFR) is typically ____ L/Day
~180 L/Day
how to modify GFR (Glomerular filtration rate)
modify the diameter of the afferent/efferent arterioles
Decreased diameter of afferent = decreased pressure in the glomerulus and decreased GFR.
Dilation is the opposite
constriction of efferent = increased resistance to leave glomerulus and increase GFR. (minor)
Major constriction will cause blood to be trapped (with proteins) and ____ oncotic pressure and ____ GFR.
increases oncotic pressure
decreases GFR
What does the sympathetic nervous system do to GFR and Renal Blood Flow (RBF)?
fight or flight
angiotensin II
???? slide16
Prostaglandins and NO
????? slide 16
Autonomic Regulation (GFR)
Macula Densa (Distal Tubule)
–Detects changes in Na+
–Initiates release of renin
study
high Na levels = want filtration to be less because we want to retain water
contraction of mesangial cells
release of renin
release angiotensin
??? slide 16
what detects Na+ changes?
Macula Densa (distal tubule)
contraction of mesangial cells will contract the ____ and does what
glomerulus
slows filtration rate
study
fluid going to the proximal tubule is similar to _____
plasma in blood
reabsorption is _____ and in ____ quantities
reabsorption is selective and in large quantities
(water/solutes)
reabsorption depends on the osmolarity of the body which is
the hydration state of the body
waste products are ___ reabsorbed while glucose and electrolytes are ____ absorbed
waste products = poorly absorbed
glucose/electrolytes = well absorbed
osmolarity is high =
more concentrated urine
active transport of reabsorption
sodium-potassium pump uses ATP and sets up a gradient
Co-transport also known as secondary active transport
passive transport of reabsorption
Passive: diffusion down the concentration gradient
____ is a large proponent to what is reabsorbed
Sodium
waste products like _____ generally do not reabsorb
pharmaceuticals
study
proximal tubule has __% water and sodium reabsorbtoin
~65%
____ is absorbed with sodium in the proximal tubule
chlorine
loop of henle controls ______ of urine
concentrations of urine
loop of henle is the _____ loop and more conentrated
longer
two parts that make up the Renal counter-current exchange
thin descending aquaporins
thich ascending active transporters
*loop of henle
at the apex of loop of henle (deep in the medulla) there are very ____ osmolarity levels
high
distal tubule two cells
principal cells: P-reabsorb Na+ and secrete k+
intercalated cells: reabsorb k+ and hCO3- and secrete H+
secrete means ____ to _____
blood to urine
ADH regulation occurs at the
distal tubule
collecting duct
ADH: antidiuretic hormine (not urinating)
high blood pressure pts will take a ____ blocker to help them urinate more
ADH blocker
in the collecting duct, medullary collecting ducts are ___ permeable to urea
more
collecting duct can can pump ___ into the lumen
H+
excretion rate =
ER= (Filter rate – reabsorption) + secretion rate
Filter =
Reabsorb =
Secrete =
Excrete =
Filter: What enters the kidney tube system at the beginning
Reabsorb: Out of kidney tube system back into the body
Secrete: From the body into the kidney tubes
Excrete: out of the body in general
common electrolytes found in the body
Sodium
Potassium
Magnesium
Calcium
Chlorine
Organic anions
Proteins
urea is formed in the ___
liver
urea is the end product of ____ ____
protein metabolism
urea maintains ______ in the medulla
hyperosmolarity
urea is secreted into the very beginning of the _____ _____
ascending loop
T/F: urea maintains water levels in loop of henle
true
urea is passively reabsorbed from the
proximal tubule
collecting duct
kidneys can create ____ (hormone)
erythropoietin (EPO)
kidneys can aid the liver in ______ and retention of glucose
gluconeogenesis
adrenal glands are ____ (location)
on top of kidneys
adrenal glands produce … (3)
sex hormones
cortisol
homeostasis hormones (ie: aldosterone, vasopressin, renin, adrenaline, etc)
kidneys have lymphatic drainage, and drains via the ____ ___
thoracic duct
lymphatic trunk and ducts run near the
Lymphatic trunks and ducts flow following the bloodstream
lymphatics relieves the blood steam of ___
toxins
the lymphatic system has an abundance of _____ cells
immune cells
kidney disease/kidney failure reasons (4)
Uncontrolled hypertension
diabetes
CVD
chronic medication abuse
measure ___ in pts with kidney problems
Measure eGFR (filtration rate)
ability to filter waste and proteins
stages of kidney disease (5)
- Normal function but evidence of damage
- Work well and sometimes hindered function
- Filtering is not ideal and can manifest in health problems
- Last stage before full kidney failure (dialysis start?)
- Failure (non-working) – waste builds up in blood. Need dialysis.
common kidney problems (4)
kidney stones (ureter or kidney - build-up of solutes)
cancers (bladder, kidney, adrenal gland which spreads)
lupus (chronic inflammation causes kidney failure)
diabetes (high sugar levels)
nephrotoxic medications (7)
NSAIDS
Diuretics
ACE inhibitors
Zoledronic Acid
Acyclovir
HIV medications
Drug abuse
changes to dental tx in relation to Kidneys
amide anesthetics
codeine-based analgesics
bleeding risk
infection risk (regular prophylactic visits, more frequent post-op visits)
Kidneys filter a lot of blood daily producing ____
Kidneys filter a lot of blood daily producing urine
kidneys are essential for
homeostasis
