Chapter 15 - Urinary System/lab
How many ureters are found in a healthy animal?
2
Approximately what percentage of plasma is removed form the blood circulation every minute?
25%
What percentage of reabsorption occurs in the proximal convoluted tubule (PCT)?
65%
In the PCT, what substances are reabsorbed?
80% water, Na, Cl, and bicarb; 100% glucose and amino acids
What is used as an indicator of glomerular damage?
abnormal amounts of protein in urine
Are the blood vessels that carry blood into the glomeruli afferent or efferent arterioles?
afferent
Which arteriole carries blood into the glomerulus of the renal corpuscle.
afferent arteriole
The fluid balance regulation function refers to
amount of urine produced is controlled primary by antidiuretic hormone (ADH) and aldosterone
Urine volume is determined by what?
amount of water in tubular filtrate when it reaches renal pelvis
What two hormones are responsible for the majority of urine volume regulation?
antidiuretic hormone (ADH) and aldosterone
What is sodium cotransport?
as sodium facilitated diffuses and is transported passively into cytoplasm of PCT epithelial cells, glucose and amino acids "hitch a ride" on same carrier protein and are also transported into PCT epithelial cells
What are the homeostatic functions?
blood filtration, fluid balance regulation, acid-base regulation, hormone production
part of renal corpuscle, surrounds the glomerus; made of two layers: inner (visceral) layer that lies directly on glomerular capillaries and outer (parietal) layer
bowman's capsule
How does urine production maintain homeostasis?
by manipulating the composition of blood plasma; regulates acid base and fluid-electrolyte balances in blood so that toxic concentrations of substances (sodium, potassium, chloride, urea, etc) do not build up
What is the function of the urinary bladder?
collect and sotre urine as it is produced and released from body
Tubule system that collects fluid form distal convoluted tubules and carries it to renal pelvis
collecting ducts
What structures are responsible for carrying urine from nephrons to the renal pelvis?
collecting ducts
What is the function of the urinary bladder?
collects and stores urine
How do the ureters move urine?
continuously move urine form kidneys to urinary bladder via peristaltic contractions of smooth muscle in ureteral walls
What is the outer portion of the kidney?
cortex
Reabsorption occurs via what?
diffusion and osmosis for some substances; others need to be actively transported across cell membranes
Last tubular part of nephron before it enters the collecting duct.
distal convoluted tubule
What is the last tubular portion of the nephron?
distal convoluted tubule
Most secretion takes place where?
distal convoluted tubule (DCT)
Which arteriole that carries blood out of the glomerulus of the renal corpuscle?
efferent arterioles
Arterioles that carry blood away form glomerus after it has been filtered in renal corpuscle.
efferent glomerular arterioles
The kidneys have a close association with what other system and why?
endocrine system, kidneys produce hormones, regulate release of hormones from other hormones and are themselves influenced by hormones
What is uresis?
expulsion of urine from urinary bladder into urethra for elimination from the body
Name the three main mechanisms for renal waste elimination:
filtration - of blood, reabsorption- of useful substances into the blood stream, secretion - of waste products form the blood into the renal tubules and out of the body in the urine
Why does urine not backup into kidneys?
full bladder collapses ureteral openings so urine cannot back up to kidneys
"Tuft" of capillaries at center of renal corpuscle. Urine production begins when plasma is filtered out of capillaries and into Bowman's space
glomerular capillaries
"Tuft" of capillaries at the center of renal corpuscle, AKA glomerular capillaries
glomerulus
The tuft of capillaries found in the renal corpuscle.
glomerus or glomerular capillaries
This is the indented area of the kidney where blood and lymph vessels, nerves, and the ureter enter and leave the organ.
hilus
Indented area on medial sides of kidneys where blood, lymph vessles, enrves, and ureters enter and leave kidney
hilus of kidney
Why is erythropoietin needed?
hormone needed for RBC production
What is glomerular filtration rate (GFR)?
how fast blood plasma is filtered as it passes through the glomorulus
The acid-base regulation function refers to
hydrogen and bicarbonate ions are removed form blood and excreted in urine
What three substances are eliminated by secretion?
hydrogen, potassium, and ammonia
What is the function of aldosterones?
increases reabsorption of sodium in the DCT and collceting ducts back into the blood, this causes an osmotic imbalance that causes water to flow back into the blood along with sodium
What is chloride's role in sodium reabsorption?
it passively follows sodium to balance out the positive charge in the interstitium caused by positive sodium ions being pumped into the interstitial fluid
Organ responsible for removing soluble waste from body through urine production
kidney
What urinary system structure is located retroperitoneal?
kidney
Which kidney is located more caudal in the abdomen than the other kidney?
left
Narrowest part of the tubular part of nephron; dips medulla of kidney and makes a U-turn to return to cortex
loop of henle
This is the part of the nephron that dips into the renal medulla.
loop of henle
Is the hilus of kidney in the body located on the lateral or medial side of the kidney?
medial
What is the inner portion of the kidney?
medulla
Aldosterone is also known as a
mineralcorticoid
What are antidiuretic hormones?
most important for urine volume regulation, acts on the DCT and collecting ducts to promote water reabsorption, prevents water loss from body, without ADH water will no be reabsorbed
Structural/functional unit of the kidney
nephron
What is the basic functional unit of the kidney?
nephron
Explain the process of reabsorption/
occurs from the tubules of nephron into peritubular capillaries. glomerular filtrate leaves bowman's capsule and enters proximal convoluted tubule (PCT), fluid is now known as tubular filtrate and moved from PCT to loop of Henle and distal convoluted tubule (DCT) where additional reabsorption takes place.
Explain the process filtration of blood throughout the urinary system
occurs in renal corpuscle; glomerular capillaries have high blood pressure which forces plasma out of capillaries and into capsular space of bowman's capsule, this fluid is glomerular filtrate.Process is aided by fenestration (pores) in capillary endothelium and both blood cells and plasma protein molecules are too big to pass through
What structures does the urinary system consist of?
paired kidneys, paired ureters, urinary bladder, and urethra
For any substance to be reabsorbed it must what?
pass out of tubular lumen, go through/between the tubular epithelial cells, into interstitial fluid, and pass through the endothelium into peritubular capillaries
What is the function of the kidneys?
produce urine, specialized cells produce erythropoietin and some prostaglandins, influence release rate of antidiuretic hormone from posterior pituitary gland and aldosterone from the cortex of the adrenal gland, and maintain acid base regulation by removing hydrogen and bicarbs ions from blood and into urine
What happens if the endothelium of the glomerular capillaries are damaged?
proteins and cells leak into the glomerular filtrate and there is no mechanism to reabsorb them so they will show up as abnormal constituents of urine
What is the first part of the tubular nephron?
proximal convoluted tubule
What reduces the volume of glomerular filtrate (urine) produced?
reabsorption
The blood filtration function refers to
reabsorption of useful substance and secretion of wastes
What is the primary function of the urinary system?
remove soluble waste products (urea, salt, water, etc) from the blood and transports them out of the body
What artery is the major arterial blood supply to the kidney?
renal artery
What is the first part of the nephron?
renal corpuscle
Filtration of the blood occurs where?
renal corpusucle
Where are the renal corpuscle and the proximal convoluted tubule located?
renal cortex
Where is distal convoluted tubule located?
renal cortex
Where is the glomerulus located?
renal cortex
What structure carries purified blood out of the kidney?
renal vein
Which kidney is usually located more cranial than the other kidney?
right
Where are the loops of Henle located?
the medulla
To get rid of waste products what does the kidney have to do?
transfer them to peritubular capillaries, into interstitial fluid, into tubular epithelial cells, into tubular filtrate in tubules- out as urine, aka secretion
What is the function of the urethra?
transports urine out of the body
What is the function of the ureters?
transports urine to urinary bladder
This is the process by which some substances that were filtered out of the blood in the renal corpuscle, but are still needed in the body, are returned form the tubules of the nephron to the blood in the peritubular capillaries.
tubular resorption`
This is the process by which substances that the body needs to eliminate in greater amounts than were filtered in the renal corpuscle are moved form the blood in the peritubular capillaries into the tubules of the nephron.
tubular secretion
This is the muscular tube that moves urine form the kidneys to the urinary bladder.
ureter
What tubes take the newly formed urine from the kidneys to the unrinary bladder?
ureters
The tubular structure that leaves the urinary bladder and carries urine out of the body.
urethra
The urinary system is the most important single route of -
waste removal