A&P of Kidneys Flashcards
DESCRIBE the components of the urinary system
Two kidneys (left and right)
Two ureters (left and right)
One urinary bladder
One urethra
What do the kidneys help maintain throughout the body?
The kidneys help maintain homeostasis throughout the body by performing certain functions.
The kidneys maintain homeostasis throughout the body by performing what functions?
Regulation of ion levels in the blood.
Regulation of blood volume and blood pressure.
Regulation of blood pH.
Production of hormones.
Excretion of wastes.
The kidneys help regulate the blood level of several ions. What are these ions?
What function of the kidney does this fall under?
Sodium Ions
Potassium Ions
Calcium Ions
Chloride Ions
Phosphate Ions
Regulation of ion levels in the blood
Kidney’s help regulate blood pressure by secreting what enzyme?
What function of the kidney does this fall under?
Renin
Renin activates the angiotensin-aldosterone pathway by adjusting blood flow in and out of the kidneys, and by adjusting blood volume.
Regulation of blood volume and blood pressure.
How do kidneys adjust the volume of blood in the body?
By returning water to the blood or eliminating it in the urine.
How do the kidneys regulate the PH of blood?
By regulating the concentration of H+ in the blood. Excreting a variable amount of H+ in the urine.
Kidneys produce what hormones?
What function of the kidney is this?
The kidney produces Calcitriol and EPO.
Production of Hormones.
What is the active form of vitamin D, that also helps regulate calcium homeostasis?
Calcitriol
What hormone stimulates the production of red blood cells?
Erythropoietin (EPO)
Kidneys excrete what things as waste?
Ammonia/Urea: breakdown of amino acids
Bilirubin: breakdown of hemoglobin
Creatinine: breakdown of creatine phosphate in muscle fibers
Uric Acid: breakdown of nucleic acids
Drugs. Environmental Toxins, Foreign Substance from Diet.
What is a substance that has no useful function in the body?
Waste
Give a general description of the kidneys.
Pair of reddish organs shaped like kidney beans
Lie on either side of the vertebral column, between the peritoneum and back wall of abdominal cavity
At level of T12-L3.
11th and 12th ribs provide protection for superior parts of the kidneys.
Right kidney is lower than left kidney due to liver occupying large area above kidney on the right side.
Adult kidney is about size of a bar of soap.
The center of the medial border of the kidney is an indentation known as what?
Renal Hilum
What enters and exits the Renal Hilum?
Ureter leaves the kidney and blood vessels.
Lymphatic Vessels and Nerves enter and exit the renal hilum
What is the renal capsule?
A connective tissue sheath that helps maintain SHAPE of the kidney and serves as a BARRIER against trauma.
What is anchors the kidney the posterior abdominal wall?
Adipose tissue surrounds the renal capsule and cushions the kidney.
What are the two main regions of the kidney (internally)
Renal Cortex
Renal Medulla
What is the outer lighter region of the internal portion of the kidney?
Renal Cortex
What are within the renal medulla?
What are extensions of the renal cortex? And what do they do?
Cone Shaped Renal Pyramids
Renal columns, fill the spaces between renal pyramids.
What is the flow of urine through the body?
Minor Calyces, Major Calyces, Renal Pelvis, Ureters, Urinary Bladder, Urethra, Ocean
How many minor calyces are there?
8-12 Minor Calyces
How many Major Calyces are there?
2-3 Major Calyces
How much of resting cardiac output (1200 milliliters of blood per minute) flows
into the kidneys through the right and left renal arteries?
About 20–25% of the resting cardiac output.
Each afferent arteriole divides into a tangled capillary network called a what?
GLOMERULUS
The capillaries of the glomerulus reunite to form what?
Efferent Arteriole.
Within each kidney, the renal artery divides into smaller and smaller vessels (segmental,
interlobar, arcuate, interlobular arteries) that eventually deliver blood to what?
Afferent arterioles.
Upon leaving the glomerulus, each efferent arteriole divides to form a network of
what?
Capillaries around the kidney tubules.
The functional units of the kidney is what?
Nephrons,
A nephron consists of how many parts and what are they?
Two parts
(a) Renal corpuscle, where blood plasma is filtered.
(b) Renal tubule into which the filtered fluid, called glomerular filtrate, passes
What are the two parts that make up the renal corpuscle?
The two parts that make up a renal corpuscle are the glomerulus and the glomerular
(Bowman’s) capsule,
What is the order that fluid passes through the renal tubule?
In the order that fluid passes through them, the three main sections of the renal tubule
are the proximal convoluted tubule, the loop of Henle, and the distal convoluted
tubule.
The basic functions performed by the nephron.
Glomerular filtration, tubular reabsorption, and tubular secretion
What is filtration?
Filtration is the forcing of fluids and dissolved substances smaller than a certain size
through a membrane by pressure.
What is the first step of urine production?
Glomerular filtration is the first step of urine production. Blood pressure forces water
and most solutes in blood plasma across the wall of glomerular capillaries, forming
glomerular filtrate
What is happening during tubular reabsorption?
Filtered fluid flows along the renal tubule and through the collecting duct:
Tubule and duct cells return about 99% of the filtered water and many useful solutes
to the blood flowing through peritubular capillaries.
What is taking place during tubular secretion?
Tubular secretion also takes place as fluid flows along the tubule and through the collecting duct:
The tubule and duct cells remove substances, such as wastes, drugs, and excess ions,
from blood in the peritubular capillaries and transport them into the fluid in the renal
tubules.
When can something be called urine?
By the time the filtered fluid has undergone tubular reabsorption and tublar secretion and
enters the minor and major calyx it is called urine.
As nephrons perform their functions, what are they helping to maintain?
They help maintain homeostasis of the blood’s
volume and composition.
The cells that make up the inner wall of the glomerular capsule are called what?
Podocytes,
Blood cells and most plasma proteins remain in the blood because of what reason?
They are too large
to pass through the filtration membrane.
What is the pressure that causes filtration?
Blood pressure in the glomerular capillaries
What are the two pressures that oppose glomerular filtration?
Blood Colloid Osmotic Pressure
Glomerular capsule pressure
What is the equation for Net filtration pressure?
Glomerular capillary blood pressure - two opposing pressures. (blood colloidal + glomerular capsule pressure)
Constriction of the afferent arteriole decreases blood flow into the glomerulus, which
increases or decreases net filtration pressure?
Decreases
Constriction of the efferent arteriole slows outflow of blood and increases or decreases net
filtration pressure?
Increases
What is Glomerular Filtration Rate
The amount of filtrate that forms in both kidneys every minute is called the glomerular
filtration rate (GFR)
What is the GFR for females per minute?
105mL/min in females
What is the GFR for males per minute?
125mL/min in males
What is a hormone that promotes loss of sodium ions and water in
the urine in part because it increases glomerular filtration rate?
Atrial natriuretic peptide (ANP)
If the GFR is too high what happens?
Needed substances pass so quickly through the renal tubules
that they are unable to be reabsorbed and pass out of the body as part of urine
If the GFR is too low what happens?
Nearly all the filtrate is reabsorbed and waste
products are not adequately excreted
How does ANP act on the kidneys?
ANP then acts on the kidneys to increase loss of sodium ions and water in urine,
which reduces the blood volume back to normal.
The blood vessels of the kidneys are controlled by what?
By sympathetic neurons of the autonomic nervous
system