A&P Unit 3 Exam

What are the 3 functions of the Urinary System?

1. excretion - the removal of waste products from body fluids​

2. elimination - discharge of waste​

3. homeostatic regulation of volume & concentration of blood plasma​

What are the 5 Essential Homeostatic Functions of the Urinary system?

1. regulating blood volume & pressure- by adjusting volume of water lost in urine through the use of hormones EPO & Renin

2. regulating plasma concentrations of Na, K, Cl, and other ions- controls loss of ions in urine

3. helps to stabilize blood pH- controls loss of H ions & bicarbonate ions in urine​

4. conserves valuable nutrients - prevents their excreto in urine​

5. assists the liver - by detoxifying poisons & deaminating amino acids​

What are organs that produce urine​?

Kidneys

What sits on top of the kidney?

Adrenal Glands

What transports urine from kidney to bladder​?

(2) Ureters

What is the site of temporary storage of urine​?

Urinary bladder

What transports urine from bladder to outside the body?

Urethra

What part of the kidneys anchors kidney to surrounding structures, outer most structure​?

Renal fascia

What part of the kidneys is adipose tissue that surrounds the kidney​?

Adipose capsule

What part of the kidney covers the outer surface of the kidney​?

What is the point of entry for artery, & nerve, and exit for vein & ureter​?

Hilum

What is an internal cavity inside the kidney​?

Renal sinus

What is the outer portion of the kidney​?

Renal cortex

What is the inner portion of the kidney?

Renal medulla

What are 6 to 18 triangle-shaped structures in the medulla​?

Renal pyramids

What is the tip or point of pyramids, projects into the renal sinus​?

Renal papilla

What are the bands of tissue in between the pyramids​?

Renal columns

What collects urine from the papilla​?

Minor calyx

What collects urine from 4 to 5 minor calyx​?

Major calyx

What collects urine from 2 or 3 major calyx​?

Renal pelvis

What is the functional unit of the kidney?

Nephrons

What is renal blood flow?

Renal artery → Segmental arteries → Interlobar arteries → Arcuate arteries →​ Interlobular arteries → Afferent arterioles → Glomerulus → Efferent arteriole → Peritubular capillaries* → Interlobular veins → Arcuate veins → Interlobar veins → Renal vein ​

What is the Nephron portion of the Renal blood flow?

Glomerulus → Efferent arteriole → Peritubular capillaries

What are the 2 functions of a renal nerve?

1. adjusts the rate of urine formation by altering blood flow + pressure at nephron​

2. stimulates renin which stimulates water & salt reabsorption at nephron​

What percentage of a nephron are Cortical nephrons?

85%

What are located totally in the superficial cortex of the kidney​?

Cortical nephrons

What have long loops of henle that extend deep into the medulla + produce concentrated urine​?

Juxtamedullary nephrons

What are long capillaries that parallel loop of henle in juxtamedullary nephrons​?

Vasa Recta

What is a cup-shaped outer wall of renal corpuscle (parietal epithelium)​?

Bowman’s capsule

What is the space between parietal & visceral epithelium?

Capsular space

What are interconnected capillaries inside the renal corpuscle (visceral epithelium)​?

Glomerulus

What is blood into the glomerulus​?

Afferent arteriole

What is blood out of the glomerulus​?

Efferent arteriole

What contain feet known as Pedicels​?

Podocytes (cells in visceral epithelium)

What are gaps between pedicels called?

filtration slits ​

What is the first segment of the renal tubule ?

Proximal Convoluted Tubule (PCT)

What is fluid inside renal tubule​?

tubular fluid

What interstitial fluid surrounding renal tubule​?

peritubular fluid

What is the primary function of the PCT?

Reabsorption of nutrients, ions, water & plasma proteins

_________ limb connects to PCT​, _________ limb connects to DCT​

Descending, ascending

What refers to size of cells not the diameter of lumen, pumps sodium & chloride ions out of fluid​?

Thick segment

What segment is freely permeable to water

Thin segment

What are the 3 functions of Distal Convoluted Tubule?

• Passes between afferent and efferent arterioles ​

• Active secretions of ions, acids, drugs and toxins​

• Selective reabsorption of Na ions, Ca ions, & water​

What secretes hormones EPO & Renin?

The Juxtaglomerular Apparatus

What are cluster of cells along DCT​?

Macula Densa

What are smooth muscle fibers?

Juxtaglomerular Cells

What are the functions of the Collecting Duct?

• Transports tubular fluid from nephron to renal pelvis ​

• Adjusts the final composition, concentration,and volume of urine ​

• Several collecting ducts unite to form a papillary duct ​

• PAPILLARY DUCT → MINOR CALYX → MAJOR CALYX

What are the 3 organic waste products?

Urea, Creatinine, Uric Acid

What is the most abundant organic waste, most of it from breaking down amino acids, 21 g/day​?

Urea

What are generated in skeletal muscle from the breakdown of creatine phosphate, 1.8g/day, all is excreted?

Creatinine

What is formed from recycling nitrogenous bases RNA, 480mg/day?

Uric Acid

What occurs when blood pressure forces water & solutes across wall of the glomerulus?

Filtration

What is the removal of water & solutes from the filtrate, occurs after filtrate has left the renal corpuscle​?

Reabsorption

What is the transport of solutes into renal tubules, back up process to filtration in order to remove all undesirable materials from blood plasma​?

Secretion

Where is the only site of filtration​?

Glomerulus/Renal Corpuscle

How much L/day of filtrate in the Glomerulus/Renal Corpuscle?

180

Can plasma proteins and RBCs leave the glomerulus?

They can not

What are the 3 Filtration Pressures? ​

Glomerular hydrostatic pressure (GHP)​

Capsular hydrostatic pressure (CsHP)

Blood colloid osmotic pressure (BCOP)

What type of pressure is the blood pressure in the glomerular capillaries, (about 50 mmHg)​?

Glomerular hydrostatic pressure (GHP)

Which filtration pressure tends to push water & solutes out of plasma​?

Glomerular hydrostatic pressure (GHP)

Which filtration pressure is inside the nephron & conducting system, (15mmHg)​?

Capsular hydrostatic pressure (CsHP)

Which filtration pressure wants to push water & solutes back into plasma – opposes GHP​?

Capsular hydrostatic pressure (CsHP)

What filtration pressure tends to pull water back into plasma due to plasma proteins in glomerulus, (25mmHg)?​

Blood colloid osmotic pressure (BCOP)

Which filtration pressure opposes GHP?

Blood colloid osmotic pressure (BCOP)

What equals sum of all three pressures, this is the pressure that forces water and dissolved materials out of the glomerulus and into the capsular space → into renal tubule​?

Filtration pressure (FP)

What is the Filtration pressure (FP) equation?

FP = (GHP - CsHP) - BCOP​

If blood pressure at the glomerulus drops by ___%, kidney filtration will stop​.

20%

Why are the kidneys sensitive to changes in blood pressure?

If blood pressure at the glomerulus drops by 20%, kidney filtration will stop​

What can a decline in GFR can lead to​?

acute renal failure

What is the amount of filtrate the kidneys produce each minute (125 ml/minute)?

Glomerular filtration rate (GFR)

What are the 3 steps of Autoregulation?

1. dilates afferent arterioles​

2. dilates glomerular capillaries​

3. constricts efferent arterioles ​

What elevates glomerular blood pressure​?

Autoregulation

What type of regulation is a decline in blood pressure triggers release of RENIN from juxtaglomerular apparatus?

Hormonal

What is the process of regulation in the glomerulus?

RENIN → angiotensin I → angiotensin II (lungs)

What causes constriction of efferent arteriole, directly stimulates PCT to reabsorb Na & water?​

Nephron

What causes secretion of aldosterone → increases Na reabsorption in DCT & collecting duct​?

Adrenal gland

What increases thirst, release of ADH → increases water absorption in DCT & collecting duct, increases cardiac output​?

CNS

What vasoconstricts arterioles → increases BP throughout body​?

Peripheral capillary beds

What is sympathetic activation that causes vasoconstriction of afferent arteriole causing a decrease in GFR (overrides local autoregulation), (do not urinate when running)?

Autonomic regulation

What term recovers useful materials that have left the bloodstream in the filtrate​?

Reabsorption

Which term ejects waste products and toxins that did not leave the bloodstream at the glomerulus?

Secretion

66% of the filtrate is reabsorbed at which location?

PROXIMAL CONVOLUTED TUBULE (PCT)​

Where are almost all of the glucose, amino acids and other organic nutrients in the filtrate reabsorbed​?

PROXIMAL CONVOLUTED TUBULE (PCT)​

What reabsorbs 15 %, about half of the remaining water and 2/3 of the Na & Cl ions?

Loop of Henle

What is the exchange between thin descending limb & thick ascending limb with tubular fluid moving in different directions?

countercurrent concentration

What limb is permeable to water but relatively impermeable to solutes​?

Thin limb

What limb is impermeable to water and to solutes, Pumps Na & Cl ions out of tubular fluid​ (Almost 2/3 of ions are pumped out) ?

Thick limb

What are the actions of the Loop of Henle?

• Pumping action elevates osmotic concentration of fluid around thin descending limb​

• This causes more water to flow out of the thin limb concentrating ions in the thick limb and so on​

• This also establishes the concentration gradient of the medulla (about 1200m Osm/L maximum)​

• 750 is due to countercurrent concentration​

• the rest (450) is from urea leakage at the end of the papillary duct ​

Only about 15-20% of the filtrate gets to which point?

DISTAL CONVOLUTED TUBULE (DCT)

Which fluid no longer resembles plasma​?

urea is now makes up a significant proportion​

What does aldosterone cause?

more Na to be reabsorbed → water follows salt​

___ is also site for Ca reabsorption​, regulated by ________ hormone​

DCT, parathyroid

What is secreted in exchange for Na ions​?

Potassium (K), Hydrogen ions (H)

What removal is coupled with bicarbonate ion production to help with blood pH?

H removal

What receives tubular fluid from many nephrons and carries it toward the renal sinus?

COLLECTING DUCT ​

_________ continues to cause Na reabsorption​; _________ are reabsorbed in exchange for chloride ions.

Aldosterone; Bicarbonate ions

What makes DCT & collecting ducts permeable to water (usually impermeable to water) and accounts for the reabsorption of the remaining 15% of water​?

COLLECTING DUCT ​

What carries both water and solutes out of the medulla at about the same rate as reabsorption and osmosis takes place in the medulla​?

vasa recta

A healthy adult typically produces how much urine a day?

1200ml

What are attributes of urine?

pH = 4.5 to 8 (average = 6)​

specific gravity = 1.003 to 1.030​

water content = 93% to 97%​

color = clear yellow​

urine is sterile (no bacterial content)​