Urinary Flashcards
Final exam prep
What does the urinary system consist of?
- 2 kidneys
- 2 ureters
- urinary bladder
- urethra
A major part of __________ is maintaining the composition, pH, and volume of body fluids within normal limits.
homeostasis
The urinary system maintains homeostasis in what type of fluids
extracellular fluids (ECF).
What is the primary role of the kidneys?
excretion
A __________ is any substance that is useless or present in excess of the body’s needs;
waste
What is more toxic metabolic or nitrogenous waste?
- metabolic: produced thru bodily processes
- nitrogenous: toxic
How are wastes excreted
thru the urine
Urine is excreted from each kidney through its ______ and is stored in the ______ ________until it is expelled from the body through the ________
ureter
urinary bladder
urethra
The specialized branch of medicine that deals with structure, function, and diseases of the male and female urinary systems and the male reproductive system is known as ___________
nephrology
The branch of surgery related to male and female urinary systems and the male reproductive system is called ________
urology
The paired kidneys lie against the posterior abdominal wall at the level of vertebrae T12 to L3. The ______ kidney is slightly lower than the left because of the space occupied by the large right lobe of the liver.
right
The kidneys are retroperitoneal, what does this mean?
they lie between the peritoneum and the back wall of the abdominal cavity, thus making them retroperitoneal organs.
What is in the external anatomy of the kidney
- hilum
- renal (fibrous) capsule
- adipose (fat) capsule
renal fascia
1._________: where the vessels, ureters, and nerves enter and leave the kidney
Hilum
- _______ (______) ________: A thin, tough layer of dense connective tissue that adheres directly to the kidney’s surface, maintaining its shape and forming a barrier that can inhibit the spread of infection from the surrounding regions
renal (fibrous) capsule
- ________(______)_________: Just external to the renal capsule “around the kidney”
adipose (fat) capsule
________ ________: external to the fat capsule, is an envelope that contains an external layer of fat that acts as a cushion and holds it in place
renal fascia
What are the 2 main divisions fo the internal kidney
- renal cortex
- renal medulla
what is the distinction between the renal cortex and the renal medulla
- renal cortex: outer layer (lighter)
- renal medulla: inner layer (darker)
Structure of the renal cortex: inward extensions of the renal cortex, they separate adjacent pyramids
renal columns
_________: cone shaped masses (collect and transport urine)
pyramid
_______: a single renal pyramid plus the cortical tissue that surrounds the pyramid
lobe
_________: It is composed of the renal corpuscle and a renal tubule
nephrons
why are nephrons considered the functional unit of the kidney
functional unit: smallest working part of kidney responsible for filtering blood and producing urine
Each pyramid is conical, with the base facing the cortex and a blunt point called the renal papilla facing the ______
sinus
_____ ________: A small cup-shaped structure in the kidney that collects urine from the renal papillae (at the tip of the renal pyramids) and funnels it into the major calyces.
minor calyx
_______ _________: Larger, funnel-shaped structures formed by the union of several minor calyces, which collect urine from the minor calyces and drain it into the renal pelvis
major calyx
_______ _________: The central, funnel-shaped cavity of the kidney that receives urine from the major calyces and channels it into the ureter for transport to the bladder.
renal pelvis
______ ________: The blood vessel that carries oxygenated blood and waste products from the heart to the kidneys for filtration.
renal artery
_______ __________: small blood vessels that carry blood to the glomerulus, where filtration of the blood occurs
afferent arterioles
__________: A network of tiny capillaries in the nephron where blood is filtered to remove waste, excess fluids, and electrolytes.
glomerulus
________ ___________: A cup-like structure surrounding the glomerulus that collects the filtrate from the blood after it passes through the glomerular capillaries.
glomerular capsule
_________ _________: The blood vessel that carries filtered blood away from the glomerulus after the filtration process.
efferent arteriole
what are the 2 structures associated with the efferent arterioles?
- juxtaglomerular complex
- macula densa
________ _________: A structure that functions in the regulation of blood pressure, is an area of specialized contact between the terminal end of the thick ascending limb of the nephron loop and the afferent arteriole
juxtaglomerular complex
________ ________: terminal portion of the nephron loop adjacent to the granular cells, consists of tall, closely packed epithelial cells that act as chemoreceptors for monitoring sodium conc in the filate
macula densa
________ _________: surround the proximal and distal convoluted tubules; active in resoprtion
peritubular capillaries
a. The renal tubule reabsorbs most of the water and solutes that filtered out of the blood at the ___________ and returns these to the blood via the peritubular capillaries.
glomerulus
______ ________: exits from the kidney at the hilum and empties into the IVC
renal vein
Wrapped around each renal artery is a renal _______ of nerves and ganglia.
plexus
The renal plexus carries __________ innervation to blood vessels and convoluted tubules. Stimulation by sympathetic fibers tends to reduce glomerular blood flow and slow the rate of urine production. They also respond to falling blood pressure by stimulating the kidneys to secrete renin.
sympathetic
Is the number of nephrons constant from birth?
Yes, they may increase in size but not in #
What are the 2 principle components of each nephron
- renal corpuscle
- renal tubule
What are the 2 main parts of the renal corpuscle
- parietal (outer) layer of the capsule
- visceral (inner) layer
i. The _________ (outer) layer of the capsule : simple squamous epithelium and contribrutes to the structure of the capsule but plays no part in the formation of filtrate
parietal
ii. The _________ (inner) layer : clings to the glomerulus and consists of unusual, branching epithelial cells
visceral
a. (part of visceral layer) __________: octopus shaped epithelial cells that surround the glomerular capillaries; they help produce and maintain the basement membrane
podocytes
Which arteriole is bigger than carries blood to the glomerulus
The significantly larger afferent arteriole enters the capsule, bringing blood to the glomerulus. The smaller efferent arteriole leaves the capsule carrying blood away from the glomerulus
Fluid filtered from the glomerular capillaries enters the _________ space, the space between the two layers of the glomerular capsule.
capsular
The parietal wall turns away from the corpuscle and gives rise to the renal tubule. The simple squamous epithelium of the capsule becomes ______ __________ in the tubule.
simple cuboidal
The _______ _________ is a duct that leads away from the glomerular capsule and ends at the tip of a medullary pyramid. It is about 3 cm long and divided into 4 regions.
renal tubule
(PCT, ascending limb, descending limb, DCT)
_______ ________ __________(______) : Confined entirely to the renal cortex, is most active in resorption and secretion. Their walls contain microvilli which increase SA and reabs ability
proximal convoluted tubule (PCT)
ii. The nephron loop (aka the….) : consists of the descending and ascending limb that forms a U shape that extends from the renal cortex into the renal medulla and back, playing a crucial role in creating a concentration gradient in the kidney, which aids in the reabsorption of water and salts, contributing to the formation of concentrated urine.
loop of Henle
_______ _______ ________ (____) : is also confined to the renal cortex, it is involved in the further reabsorption of water, sodium, and calcium, as well as the secretion of potassium and hydrogen ions, regulated by hormones like aldosterone and parathyroid hormone to maintain homeostasis.
distal convoluted tubule (DCT)
________ ________: each of which receives urine from several nephrons and runs straight through the cortex into the deep medulla
collecting duct
collecting duct -> then what are the next structures
minor calyx, major calyx, renal pelvis, ureters
__________: slender tubes, that carry urine from the kidneys to the bladder
ureters
The flow of urine is as follows: renal corpuscle ->
proximal convoluted tubule → nephron loop → distal convoluted tubule → collecting duct → papillary duct → minor calyx → major calyx → renal pelvis → ureter → urinary bladder → urethra→ outside body.
The main function of the nephrons and collecting ducts
control the composition of body fluids and remove wastes from the blood, the end product being urine.
What does urine excrete?
- wastes
- excess water
- electrolytes
Nephrons and collecting ducts perform three basic processes while producing urine:
- glomerular filtration
- tubular secretion
- tubular reabsorption
- The fluid that enters the capsular space is termed ________ __________. It is similar to blood plasma except that it has almost no protein and contains no RBCs and very little WBCs.
glomerular filtrate
- Glomerular filtration is a special case of the capillary exchange process and takes place across three barriers that constitute the filtration membrane. what 3?
fenestrated endothelium of the capillary, basement membrane, filtration slits
The ___________ endothelium of the capillary. Endothelial cells of the glomerular capillaries are honeycombed with filtration pore. Like fenestrated capillaries elsewhere, these are highly permeable although blood cells do not pass through the pores.
fenestrated
______ ________: This membrane consists of a proteoglycan gel that holds back larger particles and anions.
basement membrane
_________ ________: The filtrate passes into the capsular space through thin clefts between the foot (podocytes) processes
filtration slits
Almost any molecule smaller than ___ nm can pass through the filtration membrane and into the capsular space.
3 nm
What is proteinuria/hematuria
Kidney infections and trauma can damage the filtration membrane and allow albumin or blood cells to filter through. Distance runners and swimmers often experience temporary proteinuria and hematuria (coca-cola colored urine). Strenuous exercise reduces perfusion of the kidneys, and the glomerulus deteriorates under prolonged hypoxia, thus leaking components into the filtrate.
The principle of filtration
to force fluids and solutes through a membrane by pressure - is the same in glomerular capillaries as in capillaries elsewhere in the body.
The main force that moves substances by filtration through the glomerular capillary wall is _________ pressure of the blood inside.
hydrostatic
The glomerular hydrostatic pressure (GHP) is much higher here than elsewhere because the afferent arteriole is so much _______ than the efferent arteriole.
larger
The glomerular filtrate is normally almost protein-free and has no significant _____
COP (colloid osmotic pressure = proteins)
d. The high blood pressure in the glomeruli makes the kidneys especially vulnerable to __________
hypertension
. Hypertension ruptures glomerular capillaries and leads to scarring of the kidneys called __________ which can lead eventually to renal failure
nephrosclerosis
The normal rate of glomerular filtration is so high that the volume of fluid entering the proximal convoluted tubule in half an hour is greater than the total plasma _______
volume, VERY HIGH
____________ is the process of reclaiming water and solutes from the tubular fluid and returning them to the blood using both active and passive transport processes
reabsorption
_________ ________, the transfer of materials from the blood and tubule cells into tubular fluid, helps control blood pH and helps eliminate other substances from the body.
tubular secretion
How much of the reabsorption occurs in the proximal convoluted tubule
MAJORITY of solute and water reabsorption from filtered fluid occurs in the proximal convoluted tubules (70%).
What is the primary function of the nephron loop (loop of henle)
generation of a salinity gradient that enables the collecting duct to concentrate the urine and conserve water.
The distal convoluted tubule is adapted for _________ _________, the active transport of materials from the blood into the filtrate. Substances not filtered in glomerulus, are secreted from peritubular capillaries into renal tubules here at the DCT.
tubular secretion
_______ _________ receives tubular fluid from numerous nephrons. It usually reabsorbs water and concentrates the urine
Collecting duct (CD)
What receptors do the cells within the collecting ducts have?
ADH
An analysis of the volume and physical, chemical, and microscopic properties of urine, called ________, reveals much about the state of the body.
urinalysis
About how much of the urine is water and how much is solutes
About 95% water and 5% solutes by volume
What is the most abundant solute in urine
The most abundant solute is urea, followed by sodium chloride, potassium chloride, and lesser amounts of creatinine, uric acid, phosphates, and other ions.
What would be abnormal to see in the liver
Proteins, Glucose, and Blood cells.
From the renal pelvis, urine drains into the muscular ureters and then into the urinary bladder, and finally, out of the body by way of the _______
urethra
___________: slender tubes, about 25 cm long, that carry urine from the kidneys to the bladder
ureters
What are the 4 main components of the urinary bladder
- trigone
- detrusor muscle
- internal urethral sphincter
- external urethral sphincter
- _________ : In the interior of the bladder, openings for both ureters and the urethra define a triangular region on the posterior wall (infections can exist in this area)
trigone
- _______ ________: this forms the middle layer, includes smooth muscle fibers, contraction of this muscle squeezes urine from the bladder during urination
detrusor muscle
- _________ ________ _________: invol sphincter of smooth muscle that keeps the urethra closed when urine is not being passed and precents dribbling of urine between voiding
internal urethral sphincter
______ ________ _________: surrounds the urethra within the sheet of muscle called the urogenital diaphragm, used to inhibit urination voluntarily until the proper time
external urethral sphincter
____________: (voiding) is the act of emptying the bladder
micturition
b. When the volume of urine in the bladder reaches a certain amount (usually _____-____ ml), stretch receptors in the urinary bladder wall transmit impulses that initiate a spinal micturition reflex. Urination results when returning parasympathetic nerve impulses cause the sphincters to relax and the detrusor muscle in the bladder to contract.
200-400 mL
c. A lack of voluntary control over micturition is referred to as ____________
incontinence
- The ________ is a tube leading from the floor of the urinary bladder to the exterior.
urethra
- Histologically, the wall of the urethra consists of either _____ coats in females or _____ coats in males. It has a thick layer of longitudinal smooth muscle
females = 3
males = 2
What is the function of the urethra
discharge urine from the body
what does the male urethra also serve as
serves as the duct for ejaculation of semen (reproductive fluid).
What is the difference between the male and female urethras
- In a female: 3-4 cm long (shorter and just for urination – opens to the outside at the external urethral orifice)
- In a male: 20 cm long (longer and for reproduction and urination) carries sperm
Explain what a UTI is and who is most likely to get one
common infections that affect any part of the urinary system, including the kidneys, ureters, bladder, and urethra, and most commonly occur in sexually active young women due to factors such as anatomical differences and sexual activity that facilitate the introduction of bacteria into the urinary tract.
What are renal calculi and how might they be a problem (what might they obstruct?)
(aka Kidney stones) 12% men, 5% women, most are small (5 mm, crystallizations) and can pass thru the urinary tract but calculi cause pain when they obstruct ureter, blocking the drainage of urine and increasing intrarenal pressure
