HES week 9 Flashcards
What is the urinary tract composed of and what does each thing do
ureters, urinary bladder, and urethra
Ureters- transport filtrate from the kidneys to the bladder
urinary bladder- stores urine
urethra- where urine exits the bladder through
What is the kidney divided into
Renal Cortex, Renal medulla, and renal pelvis
What happens in the renal cortex and renal medulla
it is where filtrate is collected and turned into urine
What happens in the renal pelvis
collects and drains the urine produced from the nephrons
What is the functional unit of the kidney
nephron
what does each nephron consist of
consists of a renal corpuscle and renal tubule
what is the order of how substrates flow through
renal corpuscle
proximal tubule
nephron loop
distal tubule
collecting duct
What happens in the renal corpuscle and what are the two parts of it
Where the blood filtrate enters into the kidney. Contains glomerulus and glomeruler capsule
What is the glomeruls
Group of looping fenestrated capillaries (very leaky capillaries)
what is glomerulus capsule
double layered sheath of epithelial tissue with capsular space in the middle that receives all the filtrate from capillaries. has inner visceral layer made up of modified epithelial cells (podocytes)
Where does newly formed filtrate enter
enters renal tubule where it can be further modified in three structurally and functionally distinct regions
What are the three regions that newly entered filtrate enters
proximal tubule, nephron loop and distal tubule
what does the collecting duct collect
collects filtrate from distal tubules of multiple nephrons and further modifies it before it exits the kidneys
What is the juxtagolmerular apparatus made up of
made up of juxtagolmerular cells found in walls of afferent and efferent arterioles and macula densa cells that are found in nephron tubule.
what does the juxtagolmerular apparatus regulate
regulates blood pressure and glomerular filtration rate
What is the glomerular filtration rate and what is a normal rate of it
amount of filtrate entering into both kidneys in one minute. (125mL/minute)
What are the the three physiological processes carried out by nephrons
glomerular filtration, tubular reabsoprtion, tubular secretion
describe golmerular filtration and where does it take place
substances from blood entered into renal capsule based on size. Takes place in renal corpsucle
describe golmerular reabsorption
filtrate is modified based on the bodies needs and most water, glucose, AA, and electrolytes returned into the blood.
What is the glomerular hydrostatic pressure
the force of the blood against the filtration membrane. Pushes plasma into the capsule
What is capsular hydrostatic pressure
The force of the filtrate pushing back against the filtration membrane. Pushes filtrate back into the glomerular capillaries
Describe glomerular colloid osmotic pressure
the force created by the presence of proteins in the plasma.
Describe tubular secretion
more substances are added into the filtrate for secretion if needed.
what is the three layers of filtration
- fenestrated glomerular capillary endothelial cells
- Basal Lamina (collagen fibers)
- Podocytes
What percent of substrate can pass through the glomerular 3 ply membrane to become filtrate
20%
What are the three forces that determine GFR
- Glomerular hydrostatic pressure
- Capsular Hydrostatic pressure
- Glomerular colloid osmotic pressure
describe GHP
Force of blood against the filtration membrane (determined by BP)
Pushes plasma into capsule
describe CHP
The force of filtrate pushing back against the filtration membrane (pushes filtrate back into glomerular capillaries)
describe GCOP
The force created by the presence of proteins in the plasma. Protein concentration is higher in capillary plasma than filtrate.
What are the two auto regulations for GFR
Myogenic and tubuloglomerular feedback
what are the two hormonal mechanisms for GFR
The RAAS system
Atrial natriuretic peptide
Describe the myogenic mechanism
Enables GFR to remain relatively stable even when BP fluctuates
smooth muscle found in afferent and efferent arterioles can vasoconstrict or vasodilate in response to change in BP to maintain constant GFR
Describe tubuloglomerular feedback
Enables GFR to remain relatively stable even when BP fluctuates
as GFR increases, volume of filtrate flowing through renal tubule and macula densa cells increase
what is the primary goal of the RAAS system.
maintain systemic BP
what are the three possible stimuli for renin release
- stimulation for sympathetic NS
- Low Glomerular hydrostatic pressure
- stimulation for the macula densa cells
where is the atrial natriuretic peptide released from and when is it released
hormone released by cells in the atria of the heart. released in response to increased blood volume.
what does the release of ANP do
increases GFR by causing vasodilation of afferent arterioles and vasoconstriction of efferent arterioles
does it increase or decrease excretion of urine
increased excretion of urine
does blood volume( and BP) increase or decrease
decrease
