Renal I Flashcards
Historically, what are the 4 characteristics of urine that have been used as an indicator of health and functioning of the body?
Colour, clarity, odor, and taste
What is the cause of Blackwater fever?
Severe hemolysis, seen by black urine
What is the most prevalent pathology that used to be determined based on the taste of urine?
Diabetes
What is the overall function of the kidneys?
Homeostatic regulation of water and ion content of the blood (salt-water balance or fluid-electrolyte balance)
Here are the 6 more specific functions of the kidneys:
1. Regulation of extracellular ____ ____ and ____ ______
2. Regulation of ______: kidneys + behaviour
3. Maintenance of ___ balance: ___, ___, and ____
4. Homeostatic regulation of ___
5. Excretion of _____ : metabolic and xenobiotics
6. Production of _______: erythropoietin, renin
- fluid volume, blood pressure
- osmolarity
- ion, Na+, K+, Ca2+
- pH
- wastes
- hormones
You can lose up to ___ kidney function before affecting homeostasis
¾
What are xenobiotics?
Not naturally occurring in the body (preservatives, medications, etc)
___-___% of CO is directed towards the kidneys
20-25
What are the 4 main components of the urinary system?
Kidney, ureter, urinary bladder, urethra
The kidneys are located ________ at the level of the lower ribs
retroperitoneally
_______ are the functional unit of the kidneys
Nephrons
Of the nephrons in the kidney, 80% are _____ nephrons, and 20% are _______ nephrons
cortical, juxtamedullary
Cortical nephrons are located in the _______ while juxtamedullary nephrons are located within the ______
cortex, medulla
______ _______ : important for maintaining normal functioning within the nephrons
Juxtaglomerular apparatus
The region where the tubule passes the starting point again is the _______ ______
juxtaglomerular apparatus
The _____ contains all Bowman’s capsules, proximal and distal tubules. The ______ contains loops of Henle and collecting ducts
cortex, medulla
Kidneys are a ____ portal system
3rd
In juxtamedullary nephrons, they have a different name for the peritubular capillaries, they call it the _____ ____. This is specifically the portion of the capillaries that extends along the very long loop
vasa recta
Order these components according to “vascular components:”
efferent arterioles
afferent arterioles
renal vein
renal artery
peritubular capillaries
glomerulus (capillaries)
Renal artery ➞ afferent arterioles ➞ glomerulus (capillaries) ➞ efferent arterioles ➞ peritubular capillaries ➞ renal vein
_______ ____ take blood to the cortex
Renal arteries
One nephron has ___ arterioles and ___ sets of capillaries that form a portal system
2, 2
What are the 4 main steps of the kidney?
Filtration, reabsorption, secretion, and excretion
Where is the Bowman’s capsule?
The bulb portion
_______ _____: where the glomerulus makes contact with the nephron itself
Bowman’s capsule
The loop of Henle is divided into 2 sections: ?
ascending limb and descending limb
Order these components according to “tubular components:”
collecting duct
Bowman’s Capsule
descending loop of Henle
distal tubule
proximal tubule
ascending loop of Henle
Bowman’s Capsule ➞ proximal tubule ➞ descending loop of Henle ➞ ascending loop of Henle ➞ distal tubule ➞ collecting duct
The tubular component of the kidneys have a single layer of ______ cells
epithelial
________ : movement from blood to lumen in bulk flow
Filtration
______: from the blood to the lumen of the tubule
Secretion
________ : from the lumen into the blood
Reabsorption
_______ : from the lumen to outside the body
Excretion
What are the 3 processes that occur in the nephron?
Glomerular filtration, Tubular secretion, Tubular reabsorption
Approximately ___L of plasma is filtered at the glomeruli each day, >___% is reabsorbed, ~___L/day is excreted
180, 99, 1.5
~70% of reabsorption occurs in the ________ _____
proximal tubule
? : responsible for creating dilute urine
Loop of Henle
Distal tubule and collecting duct finely regulate salt and water balance under the control of _______
hormones
Glomerulus is generally ___-osmotic
iso
Reabsorption at the proximal tubule is ___-osmotic
iso
In the descending limb, water is being reabsorbed (___-osmotic)
hyper
In the ascending limb, way more solute to water is being reabsorbed (___-osmotic)
hypo
Solution entering the distal tubule is ___-osmotic
hypo
Final volume and osmolarity of urine excreted ______
varies
True or False: not all substances in plasma undergo filtration and/or reabsorption and/or secretion
true
How would you calculate the amount excreted?
Amount filtered - amount reabsorbed + amount secreted = amount excreted
A person filters 720 millimoles of K+ in a day and secretes 43 millimoles. She excretes 79 millimoles in her urine. What happened to the rest of the K+ and how much was it?
Filtered:720
Secreted: 43
Excreted: 79
Reabsorbed:?
720mmol-amount reabsorbed+43mmol=79mmol
Amount reabsorbed=684mmol
In filtration, RBC’s and plasma proteins remain in the _____, while plasma and dissolved solutes make up the ______
blood, filtrate
Of all the plasma that enters into the Bowman’s capsule, only ___% is filtered (filtration fraction), ___% continues on to the peritubular capillaries
20, 80
If 120mL of plasma filter each minute and the filtration fraction is 20%, what is the daily renal plasma flow?
Cardiac output is 5L/min
Kidneys receive ~20% of CO (1 L/min)
60% of blood is plasma (.6L/min)
20% of the plasma is filtered (0.12L/min)
0.12L/min x 60min/hour x 24 hour/day
~173 (180)L plasma filtered/day
125ml/min
_____ _____ : bowman’s capsule and the glomerular capillary
Renal corpuscle
______ : specialized epithetical cells that are found within the renal corpuscle that wrap around the glomerular capillary
Podocyte
________ : found in the middle and around the glomerular capillary tuft, and they can influence filtration itself by changing the amount of surface area that’s available for filtration. They are contractile cells
Mesangial
The renal corpuscle has a ______ filtration barrier
triple
What are the 3 components of the triple filtration barrier?
- capillary endothelial cells (fenestrated)
- basal lamina (extracellular matrix)
- podocyte endfeet
Podocyte foot processes surround each capillary, leaving _____ through which filtration takes place. Mesangial cells between the capillaries ______ to alter blood flow
slits, contract
Three pressures govern filtration from glomerular capillaries into the renal tubules: ?
Hydrostatic, colloid osmotic (oncotic), and Bowman’s capsule hydrostatic
______ pressure: of blood in the glomerular capillaries favors filtration (~55 mm Hg)
Hydrostatic
? pressure: of the blood is the pressure gradient due to the presence of plasma proteins and opposes filtration (~30 mm Hg)
Colloid osmotic (oncotic)
? pressure: the fluid that’s already been filtered that’s sitting in the nephron, opposes filtration (~15 mm Hg)
Bowman’s capsule hydrostatic
? : the volume of fluid that filters from the glomerular capillaries into the Bowman’s capsules per unit time
Glomerular filtration rate (GFR)