Urinary Tract Flashcards
superior pole of kidney
this is the most superior part of the kidney and is where the adrenal glands sit on top of the kidneys
fibrous capsule
- this covers the outer surface of the entire organ
- it is a layer of collagen fibers
- important for preventing things from entering the kidneys that are not supposed to and preventing the spread of infection
perirenal fat
- this is a fat capsule that surrounds the fibrous capsule
- good for cushioning the kidneys and providing insulation
- this is a layer between the fibrous capsule and the renal fascia and there is a layer surrounding the the renal fascia called the pararenal fat
renal fascia
this is a dense outer layer that this acts to anchor the kidney to the posterior abdominal wall
hilum
this is on the medial surface
- this is an indentation where the renal blood and lymph vessels enter and leave, where the nerves enter and leave and where the ureter leaves
renal cortex
- this is deep to the renal capsule
- this is along the outer rim of the organ and extends into the medulla in the form of renal columns
renal medulla
this is made up of renal pyramids
- this is the site of the ducts and the tubules of the nephrons that drain urine into the minor calyx
renal papilla
this is the apex of the renal pyramid and this is the site that urine flows into the minor calyx
corticomedullary junction
- this is the region between the cortex and the medulla(right at the base of the pyramids)
- this is where the vast majority of nephrons are located and you can see blood vessels traveling here in many diagrams
minor calyx
this is the area right outside of the apex of the renal pyramid where urine first drains out of the collecting ducts
major calyx
this is where a couple minor calices merge and their contents merge
renal pelvis
- this is where the major calices all merge and drain the urine into the ureter
- it is a large funnel shaped chamber
renal arteries
- these supply oxygenated blood to the kidneys and branch from the descending aorta
- enter the kidney at the hilum
segmental arteries
- these are the first branches after the renal arteries enter the hilum
interlobar arteries
these are branches off of the segmental arteries and they travel between the renal pyramids and the renal column
arcuate arteries
- these branch off the interlobar arteries and they are the vessels that run along the base of the renal pyramid
cortical radiate arteries
these branch off of the arcuate arteries and they extend up into the cortex away from the base of the pyramid
afferent arterioles
- these branch off of the cortical radiate arteries
- these enter the glomerulus
- have a larger diameter than the efferent arterioles
efferent arterioles
- these exit the glomerulus
- significant because they are still containing oxygen rich blood after traveling though a capillary bed
- have a smaller diameter than the afferent arteriole that enters the glomerulus
cortical radiate veins
after the efferent arterioles, the blood travels into a secondary capillary bed around the capillary and this is where the blood becomes deoxygenated
- the venuoles after the capillary bed drain into the cortical radiate veins
- these then drain the blood from the renal cortex into the arcuate veins
arcuate veins
these are what the cortical radiate veins drain into
- these are along the base of the renal pyramid
interlobar veins
- the arcuate veins drain into these and they run in between the pyramid and the renal column
describe the pathway of blood through the kidney
- enters through the renal artery
- branches into the segmental artery
- which branches into the interlobar arteries
- then the arcuate arteries
- then the cortical radiate arteries
- then the afferent arterioles
- which enter the glomerulus
- then exit that at the efferent arteriole
- which travels to the peritubular capillaries
- merge into venules
- which drain into the cortical radiate veins
- and these drain into the arcuate veins
- which go into the interlobar veins
- which merge into the renal vein which leaves the kidney at the hilum and drains into the inferior vena cava
retroperitoneal
situated behind the peritoneum
- the kidneys are retroperitoneal
transitional epithelium
- epithelial cells which can contract and expand in order to adapt to the degree of distension (enlargment) needed
- prevent leakage
- this is found in everywhere the urinary tract after the renal pelvis
micturition
the action of urinating
what are the functions of the urinary system
- storage of urine
- excretion of urine
- regulation of blood volume
- regulation of ion balance/ acid base balance
- regulation of erythrocyte production
what part of the kidney is subject to the most potential damage
- the base of the kidney because it isn’t protected by the ribs
what has the primary control of the kidneys when it comes to innervation
- the sympathetic nervous system
- most fibers are post ganglionic sympathetic fibers
- this adjusts the rate of urine production by changing blood flow at the nephron
what are the three renal processes to form urine
- filtration at the glomerulus
- resorption of the essential items at the tubules
- secretion of undesired molecules at the tubules
nephron
the structural unit of the kidney
- this is where filtration, resorption, and secretion occur
- contains the renal corpuscle
- the proximal convoluted tubule
- the loop of henle (descending and ascending)
- distal convoluted tubule
- collecting ducts
cortical nephron
- this is 85% of nephrons
- these are primarily in the cortex and only the tip of the loop of henle may enter the medulla
- they have short loops of henle
- glomerulus is further from the cortex-medulla junction
juxtamedullary nephron
- 15 % of nephrons
- these have long loops of henle that travel deep into the medulla
- these are used for the concentration of urine
- glomerulus is closer to the corticomedullary junction
renal corpuscle
-this contains the glomerulus and the colmerular capsule
glomerulus
this is a group of fenestrated capillaries
- the afferent arteriole feeds this and they drain into the efferent arteriole
what is the importance of the difference in the size of the afferent and efferent arteriole
- with the efferent having a smaller diameter and lumen, a bottle neck is created which increases the pressure within the capillaries
- this causes more filtrate to be pushed out of the fenestrated capillaries into the proximal tubule and it requires no energy
glomerular capsule
- this has two layers
- a parietal layer of simple squamous epithelium
- a visceral layer containing podocytes and pedicles
podocytes
cells in the Bowman’s capsule that wrap around capillaries of the glomerulus
- these, along with the filtration slits and the basement membrane, work to form a filtration barrier in front of the fenestrated capillaries
what are pedicels
these are foot processes that extend off of the podocytes and wrap around the capillaries and contribute to the selective permeability function of the podocytes
filtration slites
these are thin spaces that separate the pedicles where the water, glucose, amino acids, and other chemicals pass as they become renal filtrate
filtration membrane
- this is the membrane that works to have selective permeability of the fenestrated capillaries in the glomerulus
- consistes of the fenestrated endothelium
- the foot processes and slit diaphragm
- and the basement membrane
what does the slit diaphragm and the basement membrane do
- these work together to hold back everything but small proteins, water, ions, glucose, amino acids, and urea through
- the slit diaphragm is a thin sheet that covers the filtration slit
tubular fluid
this is the fluid within the tubules of the nephron
filtrate
this is the fluid that is filtered from the blood at the glomerular capillaries into the tubules of the kidney
proximal convoluted tubule
this is lined with simple cuboidal epithelium with tall microvilli
- this makes sense because they want to increase surface area to allow for the reabsorption of the nutrients and water that we want to save
- this is the site were almost all of the good things are reabsorbed
- this is directly after the renal corpuscle
nephron loop (loop of henle)
-this projects into the medulla and has two parts
-ascending and descending
-both parts of the loop facilitate reabsorbtion of water and solutes
(primarily sodium and chloride ions
thin portion of the loop of henle
this is made of simple squamous
-things diffuse across easily and allows for the reabsorption of water
thick portion of the loop of henle
- this is most of the ascending tubule
- this is more cuboidal and it takes work to move things in or out of this part of the loop
distal convoluted tubule
- this is found in the renal cortex
- it is made of simple cuboidal epithelium with some sparse microvilli (very similar to the ascending limb)
- specialized for selective secretion and resorption of ions
- this is the site of active transport of ions, acids, drugs, toxins and a little water into the tubular fluid
collecting tubule
this is where the distal convoluted tubule travels into and then multiple collecting tubules from multiple nephrons merge into a collecting duct
the collecting tubule and duct
- this is the last place where water and sodium are reabsorbed
- this is the location that is key in conserving body fluid when we need to store water (like depends on how hydrated we are)
peritubular capillaries
- these are a second capillary bed that wrap around the proximal and distal tubules and this is where things that are reabsorbed from the filtrate re enter the blood stream to be saved in the body
- these have low pressure and they are porous capillaries
- the vasa recta is the capillary bed that wraps around the long loop of henle in the juxtamedullary nephron
juxtaglomerular complex/apparatus
this is an important site of regulation of blood pressure
- this is located where the distal convoluted tubule comes back and passes the afferent and efferent arteries at the glomerular capsule
ureters
these are the tubes that the renal pelvis drains into and these travel down to the bladder
- these have transitional epithelium
- two layers of smooth muscle that are used to cause peristaltic contractions to propel urine down to the bladder
- enter the bladder on the posterolateral wall at the base of the bladder
how does the bladder fill with urine
the bladder fills superiorly which is important because as it fills it places pressure on the ureters and prevent back flow of urine into the ureters
pelvic kidney
this is when a kidney fails to migrate superiorly during body formation
supranumerary kidney
this is extra kidneys
bifid ureter
this is when there are two ureters traveling down from one kidney
horseshoe kidney
this is when the inferior aspects of the kidneys fuse together and they try to ascend into the abdominal cavity but end up getting stopped by the inferior mesenteric artery so they are more situated in the pelvic region
renal failure
this is diminished or absent renal function
perironeal dialysis
this is less commone
- allows people to walk around and move and be less trapped in a sense but it requires the implantation of a port
- people use a highly concentrated solution back to cause water and particles within the blood to diffuse down a concentration gradient into a collection bag because the solution is so concentrated
(allows for filtration of blood)
hemodialysis
this is the more common form of dialysis
- this is when people are connected to a machine, their blood is pumped into the machine and the machine filters the blood before pumping it back into the person
- has to be done multiple times a week and can take multiple hours
- not ideal
renal caliculi
kidney stones
- this is a calcium build up
- commonly caused by dehydration
urinary bladder
this is where urine is stored and then this expels the urine
- it can expand as it fills
- has rugae, similar to the stomach to allow for expansion when necessary
detrusor muscle
this is three layers of smooth muscle that is responsible for contracting the bladder in response to the autonomic nervous system
tigone
this is an area that guides the urine toward the urethra
- the tops of the triangular area are the two ureteral openings and the tip is the urethral opening
internal urethral sphincter
this is the muscle at the opening of the urethra and it is made of smooth muscle
- this gets relaxed by the parasympathetic nervous system when the stretch receptors signal the brain that the bladder is full
external urethral sphincter
this is made of skeletal muscle
- this is under voluntary control
- this is part of the pelvic floor muscles
prostatic urethra
this is the portion of the urethra that travels through the prostate in a male
membranous urethra
this is the portion of the urethra that is not in the prostate or the corpus spongiosum in a male
spongy urethra
- the last portion of the male urethra
- this is traveling through the corpus spongiosum
