Lecture 9- Renal- Kidney structure and function Flashcards
2 main fxns of the kidney
regulation of water and salt balance
removal of metabolic wastes/drugs
2 other functions of the kidney besides the main 2
gluconeogenesis
production of hormones
3 hormones of the kidneys
erythropoietin
renin
1,25-dihydroxyvitamin D
chronic ESRD requires
dialysis
ESRD patients have a reduced ability to eliminate … and excess … is converted to …
nitrogenous wastes
nitrogen
ammonium
excess ammonium in ESRD patients has direct effects on oral health– the blood is … which leads to an …. pH in the oral cavity
alkalized
increased
manifestations of renal disease on oral health include…
ammonia breath
gingival enlargement
xerostomia
teeth problems (premature loss, narrow pulp chambers, necrosis beneath fillings/crowns)
contraindications for ESRD patients
nephrotoxic drugs such as tetracycline, acyclovir, aspirin, NSAIDs
increased susceptibility to bleeding due to destruction of platelets
the kidney is a … organ in the abdominal cavity with a … and …
retroperiotoneal
inner medulla
outer cortex
kidney is composed of many …. which is the functional unit of the kidney
nephrons
in the renal cortex, blood is filtered in … and filtrate passes through the tubules of the nephron
glomeruli
in the renal medulla, there are portions of nephron tubule involved with … and … of urine
concentration
collection
tubules empty into …. and then into the ureter
renal pelvis
ureters drain into the …. and the… is drained by the urethra
bladder
each kidney contains about …. nephrons
1.2 x 10^6
a nephron includes a cluster of … and a long, hollow tube with a wall that is …
capillaries
one cell layer thick
what are the parts of a nephron
renal corpuscle= glomerulus +capsule
proximal (convoluted) tubule
loop of henle
distal (convoluted) tubule
collecting duct (chared by several nephrons)
there are 2 types of nephrons that differ in the position of the renal corpuscle and length of the medullary tubules
superficial or cortical nephrons
juxtamedullary nephrons
regulating blood composition involves these 3 renal processes
- filtration
- secretion
- reabsorption
filtration occurs in the …. capillaries; … % of plasma entering glomerulus is filtered
glomerular
15-20%
blood leaving the glomerular capillaries then flows into ….
peritubular capillaries (vasa recta)
during filtration, solutes (and water they are dissolved in) pass from the blood into the … in the …
tubular fluid
renal capsule (Bowmans space)
during secretion, substances are transported from the … in the peritubular capillaries into the ….
blood
tubular fluid
during reabsorption, substances are transported from the … into the … in the peritubular capillaries
tubular fluis
blood
what remains in the tubular fluid at the end of the collecting ducts is….
excreted
a … is a dense capillary bed where filtration occurs surrounded by renal capsule (bowmans capsule) which collects the filtrate from the blood entering via the afferent arterioles
glomerulus
filtered blood leaves via …. and flows into peritubular capillaries
efferent
blood flow through the glomerulus is regulated by several mechanisms:
smooth muscle contraction in afferent and efferent arterioles
response of juxtaglomerular apparatus (JGA)
sympathetic nervous system
the …. is located at the intersection of the macula densa of distal tubule with afferent and efferent arterioles – the … secretes the hormone renin which regulates systemic BP and therefore glomerular blood flow
juxtaglomerular apparatus
the … drains the renal caosule
proximal tubule
the proximal tubule reabsorbs …. of filtered salt and water
2/3
the proximal tubule reabsorbs all filtered … and …
glucose
amino acids
will diuretics work in the proximal tubule?
yes, some will
the loop of henle can be divide into these 3 segments
thin descending limb
thin ascending limb
thick ascending limb (TAL)
the loop of henle is the site of …. needed to produce concentrated urine but the loop itself produces a …. filtrate
countercurrent multiplication
dilute
very powerful diuretics work in the ….
loop of henle
the … drains the loop of henle
distal tubule
functions of the distal tubule
continued reabsorption of solutes
regulation of calcium
site of action for some diuretics
the collecting duct extends from … through the …
cortex
medulla
the collecting duct regulates …., …, and …
Na, K, H2O
do diuretics act in the the collecting ducts?
yes, some
… is the rate of excretion of a solute through the kidney, expressed as amount per unit time
renal clearance
… represents the volume of plasma from which all of a particular substance is removed to the urine and is a clinically important concept for monitoring renal fxn
renal clearance
…. rate is the amount of blood filtered by the kidney, expressed as volume per unit time.
glomerular filtration rate
can renal clearance be used to measure GFR?
yes based on 3 criteria:
- substance is freely filtered in glomerulus
- substance is not secreted
- substance is not reabsorbed
in a normal kidney, GFR (for all nephrons) is …. or … in females and …. in males
125 ml/min
180 L/day
90-140 ml/min
… and … are substancces that can be used to measure renal clearance
inulin
creatinine
…. is a small polysacharride; freely filteres and not secreted or reabsorbed
inulin
…. is a product of muscle metabolism; freely filtered, not reabsorbed, almost no secretion
creatinine
normal creatinine levels?
less than 1 + or - .5 mg/dl
need dialysis if greater than 10
glomerular capillaries are fenestrated; …. cells around the capillaries form filtration slits
podocytes
filtrate is acellular and essentially … free
protein
glucose, salts and amino acids are freely….
filtered
size is a factor in filtration:
less than …. are free filtered
more than …. not filtered
20 A
42 A
charge is a factor in filtration because the basal lamina is …. charged so filtration of moderately sized …. charged solutes is limited
negatively
negatively
despite changes in BP, renal blood flow remains fairly …. which means GFR remains ….
constant
constant
autoregulation involves intrinsic mechanisms that adjust bloodflow through the glomerulus; it is achieved by these 2 mechanisms
- myogenic mechanism
2. tubuloglomerular feedback- feedback from the JGA adjusts afferent arteriole diameter and thus GFR
GFR equations
(Pgc-Pbs)- (Oncgc- Oncbs)
effect on renal blood flow and net ultrafiltration pressure:
increased afferent resistance
decrease in both
effect on renal blood flow and net ultrafiltration pressure:
decreased afferent resistance
increase both
effect on renal blood flow and net ultrafiltration pressure:
increased efferent resistance
decrease flow
increase filtration press
effect on renal blood flow and net ultrafiltration pressure:
decreased efferent resistance
increase flow
decrease filtration press
4 extrinsic factors that affect RBF and GFR
diet
dehydration
symp. NS
angiotensin 2, aldosterone, natriuretic peptide
tubuloglomerular feedback:
increase in GFR increases NaCl in tubular fluid which increases NaCl at the ….which causes an increase in …. in the afferent arterioles ultimately leading to a decrease in …
macula densa
resistance
GFR
