Renal I Flashcards
What are the 4 functions of the kidneys?
- Regulation of water, inorganic ion balance, and acid-base balance
- Removal of metabolic waste products from the blood and their excretion in the urine
- Removal of foreign chemicals from the blood and their excretion in urine
- Production of hormones/enzymes
What is the function of erythropoietin?
It is the hormone that controls erythrocyte production
What is the function of renin?
It is the enzyme that controls the formation of angiotension and enfluences blood pressure and sodium balance
What are the 3 main hormones/enzymes produced by the kidneys?
Erythropoeitin, renin, and 1,25-dihydroxyvitamin D
Where are the kidneys located?
Behind the peritoneum of the abdominal cavity on either side of the vertebral column against the posterior abdominal wall.
The kidneys are connected to the […] by the […]
The kidneys are connected to the bladder by the ureter
Urine leaves the bladder via the […]
Urine leaves the bladder via the urethra
How does the length of the urethra compare between males and female
Males have a longer urethra than females.
Name the sequence of structures that blood passes through beginning when it arrives via the renal artery all the way to the glomerulus
Renal artery -> interlobar artery -> arcuate artery -> interlobular artery -> afferent arteriole -> glomerulus
What is the functional unit of the kidney? How many are there in each kidney?
The nephron. There are about 1 million per kidney.
Each nephron consists of what two components?
Renal corpuscle (glomerulus + Bowman’s capsule)
Tubule
At what structure in the nephron does urine formation begin?
The glomerulus.
What is the function of the collecting duct? What are the two parts of it
Its function is to merge the urine of that nephron with that of other surrounding nephrons. Its two sections are the cortical collecting duct and the medullary collecting duct.
What are the three sections of Bowman’s capsule? Describe where they are located.
Paterial layer: outside layer
Bowman’s space: space between patietal layer and visceral layer
Viscerial layer/podocytes: inside layer that touches the glomerulus
Where is the juxtaglomerular apparatus located and what is its function
It surrounds the afferent arteriole of the glomerulus. Its function is to secrete renin.
Foot processes are found on what renal structure?
The glomerular capillary wall
Describe the structure from bottom to top of the glomerular capillary wall.
Endothelial cells with fenestra
GBM
Visceral glomerular epithelial cells (podocytes)
Describe the process by which substances get filtered at the glomerular capillary wall.
The filtrate first passes through the fenestrae (windows) of the endothelial cells, then the basement membrane, then through the filtration slides between the foot processes.
The glomerulus structure is comprised of […]
The glomerulus structure is comprised of entangled capillary loops surrounded by Bowman’s capsule
Beginning in the glomerulus, name the consecutive structures through which urine passes as it gets processed. For each structure, include whether it is situated in the renal cortex or medulla.
Glomerulus: cortex
Bowman’s capsule: cortex
Proximal convoluted tubule: cortex
Proximal straight tubule: cortex and medulla
Descending thin limb of Henle’s loop: medulla
Ascending thin limb of Henle’s loop: medulla
Ascending thick limb of Henle’s loop (macula densa at the end): medulla and cortex
Distal convoluted tubule: cortex
Cortical collecting duct: cortex
Medullary collecting duct: medulla
The blood vessel surrounding the nephron tubule is called the […]
peritubular capillaries
What part of the peributubular capillary is oxygenated vs deoxygenated?
It is oxygenated when it enters and leaves the glomerulus all the way until it reaches the descending limb of Henle’s loop in the medulla. The descending limb of the loop of Henle is surrounded by deoxygenated blood.
What are the three processes of urine formation?
- Glomerular filtration
- Tubular secretion
- Tubular reabsorption
Describe the composition of glomerular filtrate, including what is and is not in it compared to the plasma.
Glomerular filtrate is cell-free and except for proteins, contains all the substances in plasma in virtually the same concentrations as in plasma.
What is the difference between reabsorption and secretion?
Tubules -> peritubular capillaries = reabsorption
Peritubular capillaries -> tubules = secretion
What is the formula for the amount of urine excreted?
Amount excreted = amount filtered + amount secreted - amount reabsorbed
Give an example of a substance that gets completely eliminated in the urine.
Para-amino-hippurate (PAH)
Explain how para-amino hippurate undergoes the 3 processes of urine formation.
- Filtration: a small amount will filter into Bowman’s space but most will not.
- Reabsorption: none
- Secretion: everything in the capillary will be secreted into the tubule
End result: 100% elimination
Describe how water undergoes the 3 processes of urine formation.
- Filtration: most does not get filtered into the tubule but a small amount does.
- Reabsorption: most gets reabsorbed into the capillaries
- Secretion: none is secreted
End result: near 100% elimination
Describe how sodium undergoes the 3 processes of urine formation.
- Filtration: most does not get filtered into the tubule but a small amount does.
- Reabsorption: most gets reabsorbed into the capillaries
- Secretion: none is secreted
End result: near 100% elimination
Describe how glucose undergoes the 3 processes of urine formation.
- Filtration: most does not get filtered into the tubule but a small amount does
- Reabsorption: everything that was filtered gets reabsorbed
- Secretion: none
End result: 0% elimination (none ends up in urine)
Where are the macula densal located?
At the end of the thick ascending limb of the loop of Henle, in the cortex.
Urine leaves the tubule via the […]
Renal pelvis
