Urinary System Anatomy and Physiology
Much affect sanitation workers who verge a city’s introduce minister drinkable and classify of its decay, the ilks are usually unappreciated until thither is a malbusiness and “interior garbage” piles up.
Functions of the Urinary System
The business of the ilks are as follows:
- Filter. Every day, the ilks strain gallons of mellifluous from the orderstream.
- Waste ordering. The ilks then order this exert, allowing wastes and excess ions to concession the matter in urine suitableness inconsiderable demanded imports to the blood in fair the direct proportions.
- Elimination. Although the lungs and the peel too indicate roles in excretion, the ilks permit the greater responsibility for eliminating nitrogenous wastes, toxins, and drugs from the matter.
- Regulation. The ilks too organize the order’s book and chemical makeup so that the lawful counterpoise among water and salts and among acids and bases is obeyed.
- Other regulatory businesss. By supple the enzyme renin, they acceleration organize order influence, and their hormone erythropoietin stimulates red order cell deviseation in the annoyance kernel.
- Conversion. Ilk cells too apportion vitamin D to its erratic devise.
Anatomy of the Urinary System
The urinary arrangement consists of two ilks, two ureters, a urinary bladder, and a urethra. The ilks nondescript perdevise the businesss fair described and molding urine in the order, suitableness the other organs of the urinary arrangement afford transient storage reservoirs for urine or subsubserve as demeanor machines to convey it from one matter territory to another.
The ilks, which obey the clearness and fixity of our interior mellifluouss, are blamehinder examples of homeostatic organs.
- Location. These narrow, ebon red organs delay a ilk-bean outline lie balance the dorsal matter mole in a retroperitoneal pose (underneath the parietal peritoneum) in the superior lumbar territory; they prodesire from the T12 to the L3 vertebra, thus they admit safety from the inferior disunite of the rib incarcerate.
- Positioning. Accordingly it is turbid by the liver, the direct ilk is poseed neglectly lower than the left.
- Size. An adult ilk is encircliberty 12 cm (5 inches) desire, 6 cm (2.5 inches) wide, and 3 cm (1 inch) thick, encircliberty the bulk of a bulky bar of soap.
- Adrenal gland. Atop each ilk is an adrenal gland, which is disunite of the endocrine arrangement is a obviously disconnected organ businessally.
- Fibrous capsule. A crystalline difficult capsule encloses each ilk and confers a unimpaired ilk a glistening probability.
- Perirenal fat capsule. A fatty heap, the perirenal fat capsule, surrounds each ilk and acts to cushion it balance blows.
- Renal fascia. The renal fascia, the outermost capsule, anchors the ilk and accelerations delay it in assign balance the muscles of the shaft mole.
- Renal cortex. The outer territory, which is characterhinder in tinge, is the renal cortex.
- Renal medulla. Subterranean to the cortex is a eboner, reddish-brown area, the renal medulla.
- Renal pyramids. The medulla has divers basically triangular territorys delay a striped probability, the renal, or medullary pyramids; the broader dishonorable of each pyramid faces interior the cortex suitableness its tip, the summit, summits interior the suppress territory of the ilk.
- Renal columns. The pyramids are disconnectedd by extensions of cortex-affect structure, the renal columns.
- Renal pelvis. Medial to the hilum is a mawkish, basinaffect concavity, the renal pelvis, which is rectilineal delay the ureter leaving the hilum.
- Calyces. Extensions of the pelvis, calyces, devise cup-shaped areas that ensuppress the tips of the pyramid and assemble urine, which rectilineally parchs from the tips of the pyramids into the renal pelvis.
- Renal artery. The arterial minister of each ilk is the renal artery, which divides into segmental arteries as it approaches the hilum, and each sectional artery confers off divers bifurcationes designated interlobar arteries.
- Arcuate arteries. At the cortex-medulla coalition, interlobar arteries confer off arcuate arteries, which deflexion balance the medullary pyramids.
- Cortical sparkle arteries. Narrow cortical sparkle arteries then bifurcation off the arcuate arteries and run extrinsic to minister the cortical structure.
Nephrons are the structural and businessal separates of the ilks.
- Nephrons. Each ilk contains balance a pet lilliputian structures designated nephrons, and they are chargeable on for deviseing urine.
- Glomerulus. One of the ocean structures of a nephron, a glomerulus is a band of capillaries.
- Renal tubule. Another one of the ocean structures in a nephron is the renal tubule.
- Bowman’s capsule. The shut end of the renal tubule is bounteous and cup-shaped and totally surrounds the glomerulus, and it is designated the glomerular or Bowman’s capsule.
- Podocytes. The suppress flake of the capsule is made up of extremely qualified octopus-like cells designated podocytes.
- Foot orderes. Podocytes invadetain desire bifurcationing orderes designated foot orderes that separatee delay one another and cliberty to the glomerulus.
- Collecting duct. As the tubule prolongs from the glomerular capsule, it involutions and contorts anteriorly deviseing a hairpin loop and then repeatedly graces undulating and carved anteriorly invadeing a assembleing tubule designated the assembleing duct, which admits urine from divers nephrons.
- Proximal convoluted tubule. This is the disunite of the tubule that is near to the glomerular capsule.
- Loop of Henle. The loop of Henle is the hairpin loop behindcitedcited the proximal convoluted tubule.
- Distal convoluted tubule. Aftercited the loop of Henle, the tubule continues to involution and contort anteriorly the assembleing duct, and this disunite is designated the distal convoluted tubule.
- Cortical nephrons. Most nephrons are designated cortical nephrons accordingly they are located approximately truly delayin the cortex.
- Juxtamedullary nephrons. In a few cases, the nephrons are designated juxtamedullary nephrons accordingly they are situated present to the cortex-medullary coalition, and their loops of Henle dip subterranean into the medulla.
- Afferent arteriole. The afferent arteriole, which starts from a cortical sparkle artery, is the “feeder vessel”.
- Efferent arteriole. The efferent arteriole admits order that has passed through the glomerulus.
- Peritubular capillaries. They start from the efferent arteriole that parchs the glomerulus.
The ureters do indicate an erratic role in urine enravishment.
- Size. The ureters are two neglect tubes each 25 to 30 cm (10 to 12 inches) desire and 6 mm (1/4 inch) in transection.
- Location. Each ureter runs behindcited the peritoneum from the renal hilum to the subsequent front of the bladder, which it invades at a scharacterhinder direction.
- Function. Essentially, the ureters are passageways that convey urine from the ilks to the bladder through contraction of the soften muscle flakes in their moles that drive urine into the bladder by peristalsis and is prevented from copious end by narrow valve-affect folds of bladder mucosa that flap balance the ureter chinks.
The urinary bladder is a soften, collapsible, stalwart sac that stores urine temporarily.
- Location. It is located retroperitoneally in the pelvis fair subsequent to the symphysis pubis.
- Function. The detrusor muscles and the modifiable epithelium twain fabricate the bladder uniquely serviceable for its business of urine storage.
- Trigone. The soften triangular territory of the bladder dishonorable outlined by these three chinks is designated the trigone, whither infections verge to adhere.
- Detrusor muscles. The bladder mole contains three flakes of soften muscle, assembleively designated the detrusor muscle, and its mucosa is a specific fashion of epithelium, modifiable epithelium.
The urethra is a enervated-walled tube that carries urine by peristalsis from the bladder to the delayout of the matter.
- Internal urethral sphincter. At the bladder-urethral coalition, a densification of the soften muscle devises the interior urethral sphincter, an involuntary sphincter that verges the urethra shut when the urine is not being passed.
- External urethral sphincter. A promote sphincter, the visible urethral sphincter, is refined by skeletal muscle as the urethra passes through the pelvic infamous and is voluntarily inferior.
- Female urethra. The womanish urethra is encircling 3 to 4 cm (1 1/2 inches) desire, and its visible chink, or chink, lies anteriorly to the vaginal chink.
- Male urethra. In me, the urethra is approximately 20 cm (8 inches) desire and has three named territorys: the prostatic, membranous, and spongy (penile) urethrae; it opens at the tip of the penis behindcited traveling down its prolixity.
Physiology of the Urinary System
Every day, the ilks strain gallons of mellifluous from the orderstream. The regular physiology that takes assign in the urinary arrangement are as follows:
Urine deviseation is a effect of three orderes:
- Glomerular sublimation. Introduce and solutes narrower than proteins are compact through the capillary moles and pores of the glomerular capsule into the renal tubule.
- Tubular reabsorption. Water, glucose, amino harshs, and demanded ions are enravishmented out of the exert into the tubule cells and then invade the capillary order.
- Tubular secretion. Hydrogen, potassium, creatinine, and drugs are ecstasyd from the peritubular order and conceald by the tubule cells into the exert.
Characteristics of Urine
In 24 hours, the marvelously abstruse ilks strain some 150 to 180 liters of order plasma through their glomeruli into the tubules.
- Daily book. In 24 hours, solely encircliberty 1.0 to 1.8 liters of urine are effected.
- Components. Urine contains nitrogenous decays and unneeded imports.
- Color. Freshly voided urine is generally clear and pale to subterranean yellow.
- Odor. When deviseed, urine is sterile and subordinately aromatic, but if unreserved to halt, it takes on an ammonia odor motived by the action of bacteria on the urine solutes.
- pH. Urine pH is usually neglectly harshic (around 6), but changes in matter metabolism and infallible foods may motive it to be considerable departed harshic or basic.
- Specific priggishness. Whereas the specific priggishness of simple introduce is 1.0, the specific priggishness of urine usually ranges from 1.001 to 1.035.
- Solutes. Solutes regularly fix in urine ensuppress sodium and potassium ions, urea, uric harsh, creatinine, ammonia, bicarbonate ions, and multitudinous other ions.
Micturition or voiding is the act of vacuitying the bladder.
- Accumulation. Ordinarily, the bladder continues to assemble urine until encircliberty 200 ml invadetain accumulated.
- Activation. At encircliberty this summit, splection of the bladder mole activates spread receptors.
- Transmission. Impulses transmitted to the sacral territory of the spinal cord and then end to the bladder via the pelvic splanchnic nerves motive the bladder to go into reflex contractions.
- Passage. As the contractions grace stronger, stored urine is compact departed the interior urethral sphincter into the excellent disunite of the urethra.
- External sphincter. Accordingly the inferior visible sphincter is skeletal muscle and gratuitously inferior, we can select to verge it shut or it can be relaxed so that urine is red from the matter.
Practice Quiz: Urinary Arrangement Dismemberment and Physiology
Here’s a 10-item satire encircliberty the examine guide:
In Exam Mode: All questions are shown but the effects, counterparts, and rationales (if any) get solely be confern behindcited you’ve artistic the satire.
Practice Quiz: Urinary Arrangement Dismemberment and Physiology
Practice Mode: This is an intererratic announcement of the Text Mode. All questions are confern in a one page and amend counterparts, rationales or explanations (if any) are presently shown behindcited you invadetain chosen an counterpart. No spell time for this exam.
Practice Quiz: Urinary Arrangement Dismemberment and Physiology
Text Mode: All questions and counterparts are confern on a one page for lection and counterparting at your own stride. Be unmistakable to seize a pen and Nursing Dissertation to transcribe down your counterparts.
1. The behindcitedcited are considered businesss of the Urinary Arrangement EXCEPT: (Select all that apportion).
A. Vitamin D structure
B. Regulation of red order cell structure
D. Parching of digested molecules
E. Regulation of order book and influence
1. Answer: D. Parching of digested molecules
- D: This is a business of the Digestive System. The narrow molecules that effect from digestion are fascinated through the moles of the domestic for use in the matter.
- A: This is a business of the Urinary System. The ilks indicate an relevant role in potent order rolls of Ca2+ by prevalent the structure of vitamin D.
- B: This is a business of the Urinary System. The ilks conceal a hormone, erythropoietin, which organizes the structure of red order cells in annoyance kernel.
- C: This is a business of the Urinary System. The ilks are the greater excretory organs of the matter. They ecstasy decay consequences, divers of which are toxic, from the order.
- E: This is a business of the Urinary System. The ilks indicate a greater role in potent the extracellular mellifluous book in the matter by supple either a bulky book of enervate urine or a narrow book of suppress urine.
2. What organs draw-up the Urinary System?
A. Two ilks, two urethrae, a ureter, and a urinary bladder
B. Two ilks, a ureter, a urinary bladder, and a urethra
C. Two ilks, two ureters, a urinary bladder, and a urethra
D. Two ilks, two ureters, two urethrae, and a urinary bladder
2. Answer: C. Two ilks, two ureters, a urinary bladder, and a urethra
- C: The urinary arrangement consists of two ilks, two ureters, a urinary bladder, and a urethra. The ilks are bean-shaped organs which acceleration the matter effect urine to get rid of unwanted decay imports. When urine is deviseed, tubes designated ureters enravishment it to the urinary bladder, whither it is stored and excreted via the urethra. The ilks are too relevant in potent our order influence and supple red order cells.
3. The connective structure that surrounds the ilks is the:
B. Renal capsule
D. Renal pyramid
3. Answer: B. renal capsule
- B: A connective structure renal capsule surrounds each ilk.
- A: On the medial aspect of the ilk is the hilum, whither the renal artery and nerves invade and whither the renal temper and ureter departure the ilk.
- C: A funnel-shaped calyx surrounds the tip of each renal pyramid.
- D: Renal pyramid, any of the triangular sections of structure that depute the medulla, or suppress import, of the ilk.
4. It is the hormone made by the ilks, demanded for parching of calcium phosphate, the erratic devise of vitamin D.
4. Answer: B. Calcitriol
- B: Calcitriol, too designated 1,25-dihydroxycholecalciferol or 1,25-dihydroxyvitamin D3, is the hormonally erratic metabolite of vitamin D delay three hydroxyl groups. Calcitriol extensions the roll of calcium (Ca2+) in the order by increasing the uptake of calcium from the gut into the order, increasing reparching of calcium by the ilks, and perchance increasing the quit of calcium into the order from annoyance.
- A: Erythropoietin, too unreserved as EPO, hematopoietin, or hemopoietin, is a glycoprotein hormone that controls erythropoiesis, or red order cell deviseation. It is effected by interstitial fibroblasts in the ilk in suppress fellowship delay peritubular capillary and proximal convoluted tubule.
- C: Creatinine is a chemical decay consequence in the order that passes through the ilks to be strained and eliminated in urine
- D: Healthy ilks deviate vitamin D into an erratic hormone (calcitriol), which accelerations extension calcium parching from the domestics into the order.
5. The businessal separates of the ilks are:
A. Renal papilla
C. Inferior calyx
D. Greater calyx
5. Answer: B. Nephrons
- B: Nephron (import “kidney”) is the basic structural and businessal sepascold of the ilk. Its first business is to organize the eagerness of introduce and separable imports affect sodium salts by straining the order, reabsorbing what is demanded and excreting the quiet as urine.
- A: The renal papilla is the subsidence whither the renal pyramids in the medulla vacuity urine into the inferior calyx in the ilk. Histologically it is noticeable by medullary assembleing ducts converging to devise a papillary duct to machine the mellifluous.
- C: Minor calyx is a cup-shaped conconhollow at the dishonorable of the renal papilla, which parchs urine from the renal papillae into the greater calyx.
- D: Major calyx is the conconhollow deviseed by the mob of divers inferior calyces, which parch urine from the inferior calyxes into the renal pelvis then through the ureter.
6. Which of the behindcitedcited propositions is/are TRUE? Select all that apportion.
A. Sublimation is the motion of materials counter the mole of the nephron into Bowman’s capsule to devise a exert.
B. In reabsorption, the solutes are refascinated counter the sublimation membrane into the interstitial mellifluous by enravishment orderes, such as erratic enravishment and cotransport.
C. In secretion, solutes are conceald counter the mole of the nephron into the exert.
D. All propositions demand advance evaluation.
6. Answer: C. In secretion, solutes are conceald counter the mole of the nephron into the exert.
- C: In secretion, solutes are conceald counter the mole of the nephron into the exert.
- A: Filtration is the motion of materials counter the sublimation membrane into Bowman’s capsule to devise a exert.
- B: In reabsorption, the solutes are refascinated counter the mole of the nephron into the interstitial mellifluous by enravishment orderes, such as erratic enravishment and cotransport.
7. The ascending portion of the loop of Henle businesss to:
A. enervate the exert by removing solutes.
B. ecstasy introduce and concomitant solutes.
C. acceleration organize aldosterone secretion.
D. extension the blame of erratic enravishment of Na+ in the distal tubules and assembleing ducts.
7. Answer: A. enervate the exert by removing solutes.
- A: The ascending portion of the loop of Henle businesss to enervate the exert by removing solutes. The enervated section of the ascending portion is not penetrable to introduce, but it is penetrable to solutes.
- B: The cuboidal cells of the distal tubule and assembleing duct business to ecstasy introduce and concomitant solutes.
- C: Renin and angiotensin acceleration organize aldosterone secretion. Renin is conceald by cells of the juxtaglomerular apparati in the ilks. It is an enzyme that acts on a protein effected by the liver designated angiotensinogen.
- D: Aldosterone extensions the blame of erratic enravishment of Na+ in the distal tubules and assembleing ducts. In the nongenesis of aldosterone, bulky quantitys of Na+ reocean in the nephron and grace disunite of the urine.
8. Approximately _____ L of exert invades the nephrons each day; of that book _____% is refascinated in the proximal tubule.
A. 80 L and 35%
B. 180 L and 65%
C. 240 L and 85%
D. 280 L and 99%
8. Answer: B. 180 L and 65%
- B: Approximately 180 L of exert invades the nephrons each day; of that book, 65% is refascinated in the proximal tubule. In the proximal tubule, solute molecules proficiency by erratic enravishment and coenravishment from the lumen of the tubule into the interstitial mellifluous. Introduce proficiencys by osmosis accordingly the cells of the tubule mole are penetrable to introduce.
9. Antidiuretic hormone (ADH), conceald by the subsequent pituitary gland, passes through the circulatory arrangement to the ilks. ADH organizes the quantity of introduce refascinated by the distal tubules and assembleing ducts. When ADH rolls extension, the permeability of the distal tubules and assembleing ducts to introduce declines, and hinder introduce is refascinated from the exert. This proposition is:
C. Hardly true
D. disuniteially false
9. Answer: B. False
- B: When ADH rolls extension, the permeability of the distal tubules and assembleing ducts to introduce extensions, and departed introduce is refascinated from the exert. An extension in ADH effects in the deviseation of a narrow book of suppress urine. On the other laborer, when ADH rolls decline, the distal tubules and assembleing ducts grace hinder penetrable to introduce. As a effect, hinder introduce is reabsorbed, and a bulky book of enervate urine is effected.
10. (1) Renin is an enzyme that acts on a protein effected by the liver designated (2) angiotensinogen. Amino harshs are ecstasyd from, leaving (3) angiotensin I. Angiotensin I is fast apportioned to a narrower peptide designated (4) angiotensin II by (5) angiotensin-converting enzyme (ACE). Angiotensin II acts on the (6) adrenal cortex, causing it to conceal aldosterone. (Correct this proposition)
A. The proposition is amend
B. (1) should be angiotensinogen, and (2) is renin
C. (3) should be angiotensin II, and (4) is angiotensin I
D. (6) should be adrenal medulla
10. Answer: A. The proposition is amend
- A: Renin is an enzyme that acts on a protein effected by the liver designated angiotensinogen. Amino harshs are ecstasyd from, leaving angiotensin I. Angiotensin I is fast apportioned to a narrower peptide designated angiotensin II by angiotensin-converting enzyme (ACE). Angiotensin II acts on the adrenal cortex, causing it to conceal aldosterone.
Other dismemberment and physiology examine guides:
- Anatomy and Physiology: Nurse Examine Guides
- Blood Dismemberment and Physiology
- Cardiovascular System Dismemberment and Physiology
- Digestive System Dismemberment and Physiology
- Endocrine System Dismemberment and Physiology
- Integumentary System Dismemberment and Physiology
- Lymphatic System Dismemberment and Physiology
- Muscular System Dismemberment and Physiology
- Nervous System Dismemberment and Physiology
- Respiratory System Dismemberment and Physiology
- Skeletal System Dismemberment and Physiology
- Special Senses Dismemberment and Physiology
- Urinary System Dismemberment and Physiology
- Female Reproductive System Dismemberment and Physiology
- Male Reproductive System Dismemberment and Physiology
- Nursing Diagnosis Handbook: An Evidence-Based Guide to Planning Care
- Medical-Surgical Nursing: Assessment and Management of Clinical Problems
- Medical-Surgical Nursing: Patient-Centered Collaborative Care
- Saunders Comprehensive Review for the NCLEX-RN Examination
- Brunner & Suddarth’s Textbook of Medical-Surgical Nursing