Chapter 24 the Urinary system
Organs of the urinary system
- Kidneys • Ureters • Urinary bladder • Urethra
What is the renal corpuscle
- glomerulus and glomerular capsule
Where is an empty bladder located
- lies entirely within the pelvis
Macula densa do what and where are they located
- portion of distal convoluted tubule • Tall, closely packed epithelial cells • Act as chemoreceptors
WHat is the glomerulus
-tuft of capillaries -capillaries are fenestrated
How much of the fluid filtered by the kidney actually becomes urine? 10% 99% 50% 1%
1%
What is the average kidney size
12 cm tall, 6 cm wide, 3 cm thick
Juxtamedullary nephrons make up what percentage of nephrons
15% of nephrons, mostly in the medulla
Urethra in men
20 sm in length
Cortical nephrons make up how much of nephrons
85%, they are mostly in the cortex
What do the ureters do
Carry urine from the kidneys to the urinary bladder • Oblique entry into bladder prevents backflow of urine
Where does a full bladder go
Expands into the abdominal cavity
What arteriole feeds and drains the glomerulus
Fed by afferent arterioles • Drained by efferent arterioles
Juxtaglomerular apparatus
Functions in the regulation of blood pressure
Which of the following statements about the urinary bladder is false? Two ureteral openings and the internal urethral orifice bound the trigone of the bladder. When empty, the bladder lies inferior to the abdominal cavity. The ureters attach to the bladder through oblique posterolateral orifices. In females, the bladder lies posterior to the uterus but anterior to the rectum.
In females, the bladder lies posterior to the uterus but anterior to the rectum.
Where is the kidney located
Located retroperitoneally • Lateral to T12-L 3 vertebrae
What do the kidneys do in relation to the urinary system
Maintain the chemical consistency of the blood • Filter many liters of fluid from blood • Send toxins, metabolic wastes, and excess water out of the body • Main waste products • Urea, uric acid, and creatinine
What happens in tubular resorption? Undesirable molecules are moved into the tubule from surrounding renal capillaries. Some waste compounds are returned to the blood of renal capillaries for further processing. The urine becomes more dilute because of the addition of water from surrounding renal capillaries. Most nutrients, water, and essential ions are returned to the blood renal capillaries.
Most nutrients, water, and essential ions are returned to the blood renal capillaries.
Layers of the ureters
Mucosa - transitional epithelium • Muscularis - two layers • Inner longitudinal layer • Outer circular layer • Adventitia - typical connective tissue
Bowmans capsule contains 2 layers what are those and what are they made of
Parietal layer - simple squamous epithelium • Visceral layer - consists of podocytes
What is the order the filtrate proceeds through
Proximal convoluted tubule • Loop of Henle • Descending limb • Thin segment • Thick segment • Distal convoluted tubule
What typ of tissue is at the mid urethra and near the distal end
Stratified and pseudostratified columnar - mid urethra • Stratified squamous epithelium - near the distal end
Which structure(s) is/are confined to the renal medulla? only the renal corpuscle only cortical nephrons The renal corpuscle, proximal convoluted tubule, and distal convoluted tubule The thin segments of the nephron loop (loop of Henle.) the juxtaglomerular apparatus
The thin segments of the nephron loop (loop of Henle.)
In what way is the histology of the ureters the same as that of the urinary bladder? The muscularis of the ureters is comprised of inner longitudinal, middle circular, and outer longitudinal for its entire length and the muscularis of the urinary bladder is comprised of the same three layers. Their muscularis is composed of smooth muscle and skeletal muscle. Both the ureters and the urinary bladder contain the detrusor muscle. Their luminal epithelium is transitional epithelium.
Their luminal epithelium is transitional epithelium.
What is the function of the macula densa? These are modified smooth muscle cells with secretory granules that contain renin, which is secreted in response to falling blood pressure in the afferent arteriole. These are specialized cells of the DCT that act as chemoreceptors for monitoring ion concentrations in the filtrate. These are urine-concentrating cells, similar to those of the collecting ducts. These are cells that show contractile properties that regulate blood flow within the glomerulus.
These are specialized cells of the DCT that act as chemoreceptors for monitoring ion concentrations in the filtrate.
Which of these statements concerning peritubular capillaries is FALSE? They are continuous from efferent arterioles draining the cortical glomeruli. They are low-pressure porous capillaries. They are adapted for secretion. They absorb solutes and water from the tubule cells after these substances are resorbed from filtrate.
They are adapted for secretion.
What is secretion
active process of removing undesirable molecules, from the bloodstream to the tubule
Blood vessel that contains granular cells involved in blood pressure regulation. macula densa afferent arteriole extraglomerular mesangial segmental artery efferent arteriole
affarent arteriole
What doe Vasa recta do
allow us to form concentrated urine -thin-walled looping vessels • Part of the kidney's urine-concentrating mechanism
An increase in the permeability of collecting tubule cells to water is due to the presence of a salty urine in the bladder. an increase in the production of ADH. a decrease in the production of ADH. a decrease in the concentration of solutes in the blood plasma.
an increase in the production of ADH.
What is the path of blood from the heart to the kidneys
aorta renal artery affarent arteriole glomerulus efferent arteriole peritubular capillaries renal vein inferior vena cava
The micturition center is located in the pons of the brain stem. cerebellum. sacral spinal cord. detrusor muscle layer of the bladder wall.
pons of the brain
The epithelium lining the urinary bladder that permits distension is transitional. stratified squamous. simple squamous. pseudostratified columnar.
transitional
Which type of epithelium lines the lumen of the ureter (shown here), urinary bladder, and proximal portions of the urethra? columnar epithelium stratified cuboidal epithelium transitional epithelium stratified squamous epithelium
transitional epithelium Transitional epithelium allows the mucosal lining to stretch as the ureter and bladder fill with urine while still protecting the underlying connective tissue.
describe the external urethral sphincter
voluntarily inhibits urination
The uniferous tubules are composed of what
• Nephron - renal corpuscle plus renal tubules • Collecting duct - involved in concentrating urine
What is reabsorption
• most nutrients, water, and essential ions reclaimed, back into the blood stream
What is the urinary bladder
A collapsible muscular sac
Where do peritubular capillaries
Arise from efferent arterioles • Low-pressure, porous capillaries • Absorb solutes
Why is blood pressure in the glomerulus higher than in other capillary beds? Peritubular capillaries are less permeable than efferent arterioles, causing blood pressure to increase in the glomerulus. Arterioles are high-resistance blood vessels, and the efferent arteriole is narrower than the afferent arteriole. The afferent arteriole is more permeable than the efferent arteriole, causing blood leaving the glomerulus to retain most of the solutes and ions destined to be released in urine. The volume of blood passing through the glomerulus is higher per unit area than in other capillary beds. Arterioles are low-resistance blood vessels, and the afferent arteriole is narrower than the efferent arteriole.
Arterioles are high-resistance blood vessels, and the efferent arteriole is narrower than the afferent arteriole.
The visceral layer of the glomerular capsule __________. is a simple squamous epithelium that contributes to the structure of the capsule plays no role in formation of filtrate is a fenestrated endothelium, like the glomerular capillaries clings to the glomerulus, consists of branching cells call podocytes, and plays an important role in the formation of filtrate
clings to the glomerulus, consists of branching cells call podocytes, and plays an important role in the formation of filtrate
Renal corpuscles __________. contain the afferent and efferent arterioles are the final portion of the nephron before the collecting duct consist of a glomerulus and a glomerular capsule are located in the cortex and medulla of the kidney
consist of a glomerulus and a glomerular capsule
During urination what does the detrusor muscle do
contract
The most superficial layer of the kidney is the medulla. cortex. renal pyramids. renal papilla.
cortex
85% of nephrons are described by this term that relates to their location in the kidney. cortical trabecular medullary extrinsic sinusoidal
cortical
The function of the collecting duct is to contract its muscular walls to expel urine from the cortex. drain blood from the kidney and deliver it to the renal vein. transport resorbed water back into the cardiovascular system. determine the final volume and concentration of urine.
determine the final volume and concentration of urine.
Contraction of this muscle forces urine from the bladder. detrusor vesicular diaphragm dartos cremaster
detrusor
What is filtration in urine production
filtrate of blood leaves kidney capillaries -glomerulus
Knot of capillaries that directs blood into the efferent arteriole. peritubular capillaries arcuate arteries afferent arterioles glomerulus cortical radiate arteries
glomerulus
Which of the following is not normally found in urine? urea uric acid glucose creatinine
glucose
Renin is produced in the glomerulus. the renal medulla. the granular cells. glomerular capsules.
granular cells
Which of the following is not part of the filtration membrane? basement membrane capillary endothelium filtration slit diaphragm granular cells
granular cells
The mucosal folds in the bladder (rugae) are not present in life, only in cadavers. have the same basic function as transitional epithelium accommodating stretch as the bladder fills. act to increase the surface area for absorption. thicken the bladder wall so that it does not burst.
have the same basic function as transitional epithelium accommodating stretch as the bladder fills.
The medial concave cleft in which vessels, ureters, and nerves enter/leave the kidney. sinus renal corpuscle hilum renal capsule cortex
hilum
What does the prostate gland do
in males • Lies directly inferior to the bladder • Surrounds the urethra
Where is the micturition center located
in the pons
The name of the inferior of the three openings in the trigone of the bladder is the detrusor. ureteric orifice. urachus opening. internal urethral orifice.
internal urethral orifice.
Describe the internal urethral sphincter
involuntary smooth muscle
Urethra in females
length is 3-4 cm
Region of the distal tubule that monitors concentration of the filtrate. macula densa extraglomerular vasa recta mesangial collecting duct
macula densa
Where is transitional epithelium in the urethra
near the bladder
What is the hilus
on concave surface • Vessels and nerves enter and exit
Where is the spongy (penile) urethra
passes through the length of the penis
Where is the prostatic urethra located
passes through the prostate gland
The oblique entry of the ureters into the bladder __________. prevents entry of fecal material into the urinary bladder prevents backflow of urine into the ureters from the urinary bladder is one of the little-recognized but important factors leading to kidney cancer sometimes leads to hydronephrosis is one of the reasons why many more women develop urinary tract infections than men
prevents backflow of urine into the ureters from the urinary bladder
What do the collecting tubules do
receive urine from distal convoluted tubules
What surrounds the kidney
renal capsule
Before it enters the ureter, urine collects in the renal cortex. renal pelvis. renal pyramids. renal sinus.
renal pelvis
What do juxtaglomerular cells secrete and what do they do
renin sense stretch renin is released when it is not stretched -surround afferent and efferent arterioles
The descriptive term for the location of the kidneys relative to the abdominal cavity. supraperitoneal extraabdominal subcapsular retroperitoneal intraperitoneal
retroperitoneal
Which of these sequences correctly traces arterial blood as it flows from the renal artery to the renal cortex? interlobar artery, segmental artery, cortical radiate artery, peritubular capillary, afferent arteriole, efferent arteriole, glomerulus, arcuate artery segmental artery, interlobar artery, arcuate artery, cortical radiate artery, afferent arteriole, glomerulus, efferent arteriole, peritubular capillary segmental artery, arcuate artery, interlobar artery, cortical radiate artery, efferent arteriole, peritubular capillary, afferent arteriole, glomerulus arcuate artery, interlobar artery, segmental artery, cortical radiate artery, peritubular capillary, efferent arteriole, afferent arteriole, glomerulus None of the listed choices is correct.
segmental artery, interlobar artery, arcuate artery, cortical radiate artery, afferent arteriole, glomerulus, efferent arteriole, peritubular capillary
The longest of the three parts of the male urethra is the spongy urethra. neck. prostatic. membranous.
spongy urethra
In the juxtaglomerular apparatus, the macula densa belongs to the glomerulus. visceral layer of the glomerular capsule (podocytes). terminal nephron loop. efferent arteriole.
terminal nephron loop
What is the nerve supply to the kidneys
the renal plexus • A network of autonomic fibers • An offshoot of the celiac plexus
where is the membranous urethra
through the urogenital diaphragm