Urinary System (Renal Exam 1) Flashcards
Maintaining homeostasis requires the regulation of the composition, pH, and volume of body fluids within…..
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normal limits
The urinary system removes and excretes metabolic wastes and substances in excess, __________ containing compounds from protein metabolism, and foreign substances such as pharmaceuticals and their metabolites
N and S
The kidneys assist in regulation of RBC production via ______ and regulation of blood pressure via _____, and calcium ion absorption
EPO, RAAS
What are some of the many functions of the renal system?
-excretion of metabolic wastes and foreign chemicals
-regulation of water and electrolyte balances
-regulation of body fluids through osmolality/osmolarity and electrolyte conc.
-regulation of arterial pressure
-regulation of acid-base balance
-secretion, metabolism, and excretion of hormones
-control rate of RBC production with EPO
-gluconeogenesis
What organs are involved in the renal system?
-2 kidneys
-2 ureters
-1 urinary bladder
-1 urethra
The kidneys lie on either side of the vertebral column high in a depression on the posterior abdominal wall. Kidneys are retroperitoneal (behind the peritoneum). The L kidney is higher than the R kidney. Why?
R kidney is lower bc of the liver
What is the other name for adrenal gland?
suprarenal gland
The right adrenal gland drains into the….
IVC directly
***note: this is bc the R adrenal gland needs direct access to major circulation for hormone delivery to target organ. The right side is closer to the IVC for direct access
The left adrenal gland drains into the….
renal vein and then IVC
What is secreted by the adrenal medulla?
NE and epi
What are the features of the kidney structure?
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-convex lateral surface
-concave medial surface w/ hilum
-renal sinus
-renal pelvis (major and minor calyces)
-renal medulla (composed of renal pyramids)
-renal cortex (renal columns)
-renal capsule
The papillary/collecting duct drains urine into the….
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minor calyx
The minor calyx drains urine into major calyx. Where does urine go after major calyx?
renal pelvis
What is the most common type of nephron?
cortical nephrons
The aorta branches into the renal artery which goes into kidneys. What is the blood flow through here?
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renal a. > segmental a.> interlobar a.> arcuate a.> interlobular a. (also known as cortical radiate a.)> afferent arteriole> glomerular capillaries > efferent arteriole> peritubular capillaries associated with convoluted tubules OR vasa recta associated with loop of henle
The capillary bed filters….
plasma
What is the venous blood flow starting from the vasa recta and peritubular capillaries of the kidneys?
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peritubular capillaries and vasa recta> interlobular v. (also known as cortical radiate v.)> arcuate v.> interlobar v.> renal v.> IVC
Which arteriole leaves the capillary bed?
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efferent arteriole
What captures the filtrate from plasma?
glomerular capsule
What is the first capillary bed in the nephron?
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glomerulus
A renal a. enters each kidney through the _______ and continues to branch to the nephrons (functional units)
hilum
What is another name for interlobular arteries or veins?
cortical radiate arteries or veins
What is another name for the glomerular capsule?
Bowman’s capsule
T/F: the descending and ascending limb of the loop of henle have a differential regulation of water and ions
true, they have different permeability for water and ions
What are the 2 types of nephrons?
1) cortical nephrons (short)
2) juxtamedullary nephrons (long, go to medulla)
Which nephrons are important for regulating water balance?
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juxtamedullary nephrons bc they’re long and sit low in the cortex
What are the 2 parts of a nephron?
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1) renal corpuscle
2) renal tubule
What are the 2 parts of a renal corpuscle?
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1) glomerulus (capillaries)
2) glomerular (Bowman’s) capsule
What are the 2 portions of the glomerular/Bowman’s capsule and what cells are here?
-parietal and visceral portions
-podocytes are in the visceral layer
The renal tubule extends from the glomerular capsule to the….
collecting duct
What are the parts of the renal tubule in order?
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1) PCT
2) nephron loop/loop of henle
-descending limb
-ascending limb thin segment
-ascending limb thick segment
3) DCT
4) connecting tubule
5) cortical-medullary collecting tubule
6) collecting duct
The DCT of several nephrons empty into the….
collecting ducts (which will continue to the medulla and join other collecting ducts to drain through the renal papillae into a minor calyx)
Where does the majority of filtration and absorption occur?
PCT
For cortical nephrons, they have a short loop of henle and glomerulus further from the corticomedullary junction but has the vascular bed around the PCT and DCT. The efferent arterioles supply the….
peritubular capillaries
For juxtamedullary nephrons, they have a long loop of henle and glomerulus closer to the corticomedullary junction. The efferent arterioles supplies the….
vasa recta
T/F: there is temporary storage in the urinary bladder and then it is emptied through the urethra
true
Substances move from the glomerular capillary blood into the glomerular capsule. What molecules can/are filtered through glomerulus?
water and small dissolvable molecules or ions
(large molecules such as large proteins and cells remain in the blood because they are too large to pass through the glomerular filtration membrane)
Glomerular capillaries are way more permeable than other capillaries. Why?
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because glomerular capillaries are fenestrated
What should not be in urine?
-blood
-glucose
-protein
Filtrate is formed as substances and ________ filter from the glomerulus into the glomerular capsule
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plasma
T/F: initial filtrate has different composition from plasma and tissue fluid
FALSE, its the same composition
What acts like a barrier for fenestrations in sinusoidal caps?
basement membrane
In the first capillary bed of the nephron, filtration will not occur without….
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the specific fenestrated type of capillary
What does filtrate include?
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-water
-glucose
-AAs
-ions
-urea
-hormones
-vitamin B and C
-ketones
-small amounts of protein
basically- anything small
(for a normal person, most of this needs to be absorbed)
What are the 3 parts of the filtration membrane?
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1) fenestrated capillary endothelium
2) basement membrane fused basal lamina
3) podocytes of visceral membrane of capsule - slit pore
The top of each nephron’s ascending limb passes next to its afferent arteriole. At this location, cells are specialized to form the….
juxtaglomerular (JG) apparatus
What 2 cell types that make up the JG apparatus?
1) macula densa (in the ascending limb)
2) JG cells (vascular smooth muscle cells of the afferent arteriole)
What cells synthesize/secrete renin?
granular cells
What triggers renin to be secreted when BP needs to be increased?
afferent arteriole
The JG apparatus has what receptors?
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mechanoreceptors (check BP) and osmoreceptors (Check osmolality)
How do cells communicate in JG apparatus?
through gap junctions
The main function of the nephrons and collecting ducts is to control the composition of body fluids and remove wastes from the blood, the product being urine. What does urine contain?
-wastes
-excess water
-electrolytes
Urine is the final product of what 4 processes?
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1) glomerular filtration
2) tubular reabsorption
3) tubular secretion (from 1st pass effect, will be secreted into urine)
4) excretion/ concentration and dilution (how concentrated urine is)
How much cardiac output is brought to the kidneys?
25%
filtration - reabsorption + secretion = ?
excretion
If theres only filtrate, will anything be absorbed or secreted?
no
What causes filtration with only partial reabsorption?
glucose overload (diabetic patients will have this)
What is normal urine formation?
filtration with complete reabsorption
In most systemic capillaries, filtration predominates at the ________ end and osmotic reabsorption predominates at the ___________ end
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arteriole, venular
Where does most tubular reabsorption occur?
PCT
Which substance makes up most of the plasma contents?
sodium