Urinary pt. 1 Flashcards
Most obvious function of kidneys
produce urine to facilitate elimination of metabolic wastes
Kidneys maintain homeostasis by manipulating ____________
manipulating composition of blood plasma
Kidneys also help regulate __________
regulates acid-bas balance and fluid-electrolyte balances
The kidneys must filter enough water and electrolytes out of the blood to equal ___________
to equal the amount that is being put into the blood from other sources
levels of NA, K, Cl, and N waste (urea from protein breakdown) in plasma must be maintained within specific, narrow concentration limits. Needs to do this for health and life to continue. What happens if kidneys fail to do this
concentrations can rise to toxic levels. Leads to illness and death
What is the most important function of the kidneys
Maintaining homeostasis
Main processes of maintaining homeostasis are:
Blood filtration, reabsorption, and secretion as well as fluid balance and regulation, Acid-base regulation, hormone production, and blood pressure regulation
During blood filtration, useful substances are _________, and waste products are ______
useful substances are returned to circulation, and waste products are secreted from the bloodstream, into a fluid that eventually becomes urine
The amount of urine produced depends on ________, this helps ensure ________
depends on the amount of water it contains, this helps ensure that the body contains the right amount of water to maintain a healthy internal environment
If the body has excess water and it needs to get rid of it, what happens
more urine is formed (diuresis)
if the body needs to conserve water, what happens
less urine is produced, and pass little (oliguria) or no urine at all (anuria)
The amount of water contained in the urine is under the control of the hormones ___________ and _____________
antidiuretic hormone (ADH) and aldosterone
Acid-base balance regulation is maintained by the ability to
remove acidic hydrogen and basic bicarbonate ions from the blood and excrete them in urine. By eliminating these ions in the appropriate amounts, blood pH can be maintained in the proper range
Kidneys have a close association with the endocrine system -> hormones that help regulate body functions. The kidneys do three things with hormones
Kidneys produce hormones, regulate the release of hormones from other organs, and are influenced by hormones themselves
Kidneys can influence the rate of release of ______ from the posterior pituitary gland and __________, secreted from the cortex of the adrenal gland
ADH from the posterior pituitary gland
aldosterone form the cortex of the adrenal gland
Specialized cells in kidney produce ______________, the hormone necessary for RBC production, and some __________
Erythropoietin
prostaglandins
Kidneys contain internal receptors that monitor blood pressure. When blood pressure fails, kidneys secrete
renin
the release of renin results in
vasoconstriction and the retention of Na and H2O. By increasing fluid volume of the blood, blood pressure will also be increased
Where are the kidneys located
Dorsal part of the abdomen, just ventral to and on either side of the first few lumbar vertebrae
In common domestic animals, except the pig, the right kidney is more cranial than the left
What surrounds the kidneys and helps protect them from pressure exerted by surrounding organs
A thick layer of fat (perirenal)
Kidneys are located ______ to the abdomen
retroperitoneal
They are outside the parietal peritoneum (more or less they are outside the abdomen)
To an extent, kidneys move with the diaphragm. As it contracts, what happens
-kidneys are pushed cranially (by half a vertebra)
-Right kidney doesn’t move as much as the left kidney
-Right kidney fits into a depression in the liver that stabilizes it
-Left kidney doesn’t have this stabilization
In most animals, what shape is the kidney and what is it covered by
kidneys are bean-shaped and covered by a fibrous connective tissue capsule
Horses: right kidney is compressed, so it becomes somewhat heart-shaped
Cattle: is multilobulated, about 12 lobes
The indented area on the medial aspect of the kidney is called the
hilus
This is where blood and lymph vessels, nerves, and the ureters enter and leave the kidney
If you cut the kidneys of most animals in half longitudinally through the hilus, you’ll find a funnel-shaped area inside the hilus. This is known as
the renal pelvis
the renal pelvis is a urine collection chamber the forms ____
The beginning of the ureter
The renal pelvis is lined with
transitional epithelium
what animal don’t have a distinct chamber that can be called a renal pelvis
cattle
the outer portion of the kidney is called
the renal cortex
it is reddish brown and has a rough granular appearance
The inner portion around the renal pelvis is the
renal medulla
it has a smooth appearance with a dark purple outer area that sends rays up into the cortex and a pale grey-red inner area that extends down the renal pelvis
The shapes of the cortex and medulla and how they relate to each other vary among species
Cattle and pigs:
medulla is made of numerous, pyramid-shaped areas with the apex pointing to the renal pelvis (pigs) or directly to the ureter (cattle)
This gives the medulla a scalloped appearance
The cortex fills in around the scallops
Kidneys with the structure like the cattle and pigs have is called
multipyramidal or multilobular
In other species the medullary pyramids fuse to occupy the entire medulla, and the cortex is pushed to the outside area only. This is known as
unipyramidal or unilobar
The basic functional unit of the kidney is the
Nephron
4 parts of the nephron:
- Renal corpuscle
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
The renal corpuscle is located where
in the cortex of the kidney
The renal corpuscle is made up of
glomerulus and Bowman’s capsule
The glomerulus is
a tuft of glomerular capillaries
Bowman’s capsule
double walled capsule that surrounds the glomerulus
Bowman’s capsule has two layers
a visceral and a parietal
The visceral layer of the Bowman’s capsule has ________
podocytes (“foot cells”)
Cover capillaries and make a permeable layer that allows fluid and dissolved substance to pass through during filtration
fluid filtered out of the blood is called
glomerular filtrate
Proximal convoluted tubule (twisty turn) is a continuation of
the capsular space of the bowman’s capsule
What is the longest part of the tubular system of the nephron
the proximal convoluted tubule (PCT)
What type of epi cells line the PCT
cuboidal and have a brush border (important for resorption)
filtered fluid in the pct is known as
tubular filtrate
The loop of Henle continues from
the PCT and descends into the medulla of the kidney, makes a U turn and heads back up to the cortex
The descending loop portion is made of what kind of cells
simple cuboidal with a Brush border like the PCT
as the loop of henle maks the u turnin the medulla of the kidney, what happens?
it becomes thinner. The epi cells transition to simple squamous and it loses the BB
As the loop of henle ascends to the cortex, what happens
it becomes thicker again, but it doesn’t regain the BB
Distal convoluted tubule (DCT) is a continuation od
the ascending loop of Henle. it follows twisting path through the cortex
DCT from all the nephrons in the kidney empty into a series of tubules called
collecting ducts
the collecting ducts carry tubular filtrate through __________ into
through the medulla into the calyces —> renal pelvis
The DCT is also the primary site of action for ____
ADH
and K and acid-base regulation occur here
where does the nerve supply to the kidney come from
primarily from the sympathetic nervous system
Each kidney has a massive blood supply because it is _________________________ for blood
It is a filter organ for blood
How much of the blood pumped by the heart goes to the kidneys
25%
Meaning that every 4-5 min, all circulating blood in the body passes through the kidneys
What artery does the blood come from into the kidneys
the renal artery
branches off the abdominal artery
enters at the hilus
divides/subdivides until becoming a series of afferent glomerular arterioles
The afferent glomerular arterioles carry blood where
into the glomerular capillaries of the renal corpuscle
The glomerular capillaries are a continuation of the afferent arterioles. What do the filter
they filter some of the plasma out of the blood
not all plasma is filtered out, if so, blood flow would stop
When the blood is in the glomerular capillaries, the blood is still arterial blood at this point, which means what?
This is the only place the blood entering AND leaving the capillaries is oxygenated blood
efferent glomerular arterioles are capillaries that surround what
the rest of the nephron
what is the efferent glomerular arterioles is known as
peritubular capillaries
what happens in the efferent glomerular arterioles
oxygen transfer
substances are also taken out of the tubular filtrate and put back in the blood (AKA tubular reabsorption)
Peritubular capillaries surround ______________ and converge to form __________________
surround the nephron and converge to form venules
The renal vein leaves the kidney at ____
at the hilus and joins the abdominal portion of the Caudal vena cava (cleanest blood in the body)
