Urinary system Ch 28
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Urinary system Ch 28
Nursing A&P ch 28
What are kidneys responsible for?
What are the principal organ of the urinary system?
What are the accessory organs of the urinary system?
Ureters, urinary bladder, and urethra
What does the urinary system do?
regulate the content of the blood plasma to maintain "dynamic constancy"
What does dynamic constancy mean?
Where do the kidneys lie?
beneath the diaphragm in the back portion of the body
What surrounds the kidneys?
Fat pads to protect from injury
What does a kidney look like?
roughly oval with a medial indentation
Are the kidneys evenly shaped and sized?
No. The left kidney is often larger than the right and sits a little higher that the right
What is the hilum?
Concave notch on the medial surface where vessels and tubes enter kidney
What is the filtering process?
Enter along capsule, filters through medullary pyramid, and all unused waste moves thru to hilum which turns into the ureter
Where is the papilla and what does it do?
Located at the top of each pyramid and releases urine thru multiple ducts
What are the renal columns?
space where cortical tissue dips between pyramids
What is the calyx?
cuplike structure at each renal papilla to collect urine
What forms when minor calyces join together?
Major calcyces which in turn join to form the renal pelvis
Why does the renal pelvis narrow?
It narrows as it exits the kidney to become the ureter
What is the renal artery?
Direct connection to the aorta. It brings blood into each kidney
What is the ureter?
tube running from each kidney to the urinary bladder
What are the three layers of the ureter?
Mucous lining, muscular middle layer, fibrous outer layer
Ureter is made up of...
...smooth muscle that pushes waste into bladder.
What is the star shaped opening in the ureter called?
What is the urinary bladder and what does it do?
Collapsible bag made mostly of smooth muscle located behind pubic symphysis. Lining forms rugae. Can distend considerably.
Reservoir for urine before it exits body. Aided by the urethra, it expels urine from the body
How many openings does the bladder have?
3. 2 ureters and 1 urethra
What sits beneath the bladder in men?
What does the small mucous membrane in the urethra do?
Lines tube extending from the trigone to the exterior of the body
Where does the urethra lie in females?
posterior to the pubic symphysis and anterior to the vagina
3 cm long
Where does the urethra lie in males?
Passes through prostate and extends to the base of the penis.
20 cm long
What dies micturition mean?
What is the process of voiding?
Bladder volume increases causing contractions and the internal urethral sphincter relaxes.
External urethral sphincter muscle contracts at first, then relaxes to release urine.
Nephrons comprise the bulk of the...
The microscopic functional units of the kidneys are called...
How many regions make up each nephron?
2. Renal corpuscle and renal tubule
What is the Bowman (glomerular) capsule?
cup-shaped mouth of the nephron
What does all the work when it comes to filtering?
How many nephrons are in each kidney?
What is the filtering process thru the nephron?
Proximal convoluted Tubule
down and then up Henle loop
Papilla of renal pyramid
If glomeruler filtration system slows down what causes will it have on certain drugs?
Drugs will stay in system longer and be more potent because it is not being filtered out correctly.
What are the dots on the renal corpuscle called?
What is the Proximal convoluted tubule?
First part of the renal tubule nearest to Bowman capsule
What is the Henle loop?
Renal tubule segment just beyond the proximal tubule
Looks like the letter U
What is the Distal convoluted tubule?
Convoluted tubule beyond the Henle loop
What is the collecting duct?
Straight duct joined by the renal tubules of several nephrons
What do the afferent arteriole of the nephron enter?
Glomerular capillary network
What do the efferent arterioles of the nephron leave?
Glomerulus and extends to the peritubular blood supply
What are Vasae rectae?
straight arterioles that run alongside Henle loop
What are Peritubular capillaries?
Capillaries that surround the tubule
What happens if nephrons die?
Filtering won't be as effective and you don't get more because they don't reproduce.
What is the chief function of the kidneys?
To process blood and form urine
What are the three processes the nephron performs to make urine?
What does filtration do?
Movement of water and protein-free solutes from plasma in the glomerulus into the capsular space of Bowman capsule
What is tubular reabsorption?
Movement of molecules out of the tubule and into peritubular blood
What is tubular secretion?
Movement of molecules out of peritubular blood and into tubule for excretion
How many liters of water and solutes filter thru the Bowman'[s capsule each day?
Filtration occurs as a result of...
a pressure gradient
Glomerular capillary filtration occurs rapidly because...
The increased number of fenestrations
What is the glomerular filtration rate (GFR) is determined mainly by...
glomerular hydrostatic pressure and therefore directly related to systemic blood pressure.
Reabsorption occurs as a result of...
passive and active transport mechanisms from all parts of the renal tubules
Where does the majority of reabsorption occur?
Proximal convoluted tubules
What does High BP destroy?
Nephrons in bowman capsule
What is recovered by the blood during the reabsorption process?
Most water and solutes in the proximal convoluted tubule, leaving only a small volume of tubule fluid left to move on the Henle loop.
What is diuresis?
increase in urine production beyond normal
less voiding which means more fluid in blood system, increasing BP
ADH is secreted by
posterior pituitary gland
What does Aldosterone do?
Reabsorbs salt into blood system
What is Aldosteron?
Hormone that targets the cells of the distal tubule and collecting duct.
Causes increased activity of the sodium-potassium pump
Raises the sodium concentration of blood and thus promoting reabsorption of water
Any drug that increases diuresis is causing...
ADH and Aldosterone work opposite of...
Atrial natriuretic hormone
What is atrial natriuretic hormone (ANH)?
Hormone secreted by atrial muscle fibers that keeps sodium in nephrons
What is the urine composed of?
95% water with several substances dissolved in it. Most important include:
If a lot of glucose is found in a patient's urine, what can you deduce?
That the patient is an out of control diabetic