Human Physio Ch. 19 Kidney

1.glomerular capillary endothelium 2. basal lamina 3. Bowman's capsule epithelium

Filtered solutes must pass first through ___, then through a ___, and finally through ___ before reaching the lumen of Bowman's capsule

blood cells and most plasma proteins

Filtration allows most components of plasma to enter the tubule but excludes

distal

Finely regulated reabsorption takes place in the more ___ segments of the nephron

proximal tubule, loop of Henle, distal tubule, and collecting duct, then drains into the renal pelvis.

Fluid filters from the glomerulus into Bowman's capsule. From there, it flows through the

Filtration

GFR - filter plasma into Bowman's capsule

Why is inulin administration an effective way of measuring renal clearance rates?

Inulin is neither secreted nor reabsorbed.

What is the most important function of the kidneys (in the sense that loss of this function results in serious medical problems before loss of other functions become problems)?

Regulation of water and ion content of the blood

afferent arteriole to glomerulus to ef- ferent arteriole to peritubular capillaries

Renal blood flow goes from

urea and other solutes

The active transport of Na+ and other solutes creates concentration gradients for passive reabsorption of ____

the amount filtered minus the amount reabsorbed plus the amount secreted

The amount of a solute excreted equals

The segment of the nephron between the proximal and distal tubules that loops down into the medulla of the kidney and returns back to the cortex is called the ________. ANSWER: minor calyx Bowman's capsule collecting duct loop of Henle vasa recta

loop of henle

The ________ cells lie between and around the glomerular capillaries. ANSWER: mesangial granular juxtaglomerular macula densa

mesangial

Urine is carried to the urinary bladder by ANSWER: the urethra. blood vessels. lymphatics. the ureters. All of the answers are corre

The ureters.

retroperitoneal

pertaining to the region behind the peritoneal membrane; used to refer to the kidneys because of their location outside and behind the peritoneum.

renal threshold

plasma concentration at which a substance first appears in the urine

Which structure is NOT part of the blood circulation through the kidney? ANSWER: loop of Henle renal corpuscle vasa recta glomerulus

loop of Henle

The excretion rate of a solute depends on

(1) its filtered load and (2) whether it is reabsorbed or secreted as it passes through the nephron.

Match each of the following substances with its mode(s) of transport in proximal tubule reabsorption. (a) Na+ (b) glucose (c) urea (d) plasma proteins (e) water 1. simple diffusion 2. primary active transport 3. indirect active transport 4. facilitated diffusion 5. movement through open channels 6. endocytosis 7. paracellular movement

(a) 2, 3, 5; (b) 3, 4; (c) 4, 7; (d) 6; (e) 5, 7

Identify the following structures, then explain their significance in renal physiology: (a) juxtaglomerular apparatus (b) macula densa (c) mesangial cells (d) podocytes (e) sphincters in the bladder (f) renal cortex

(a) Found where distal tubule passes between afferent and efferent arterioles. Composed of macula densa cells in the distal tubule and granular cells in arteriole wall. (b) Macula densa paracrine signals control autoregulation of GFR and renin secretion. (c) Alter the size of filtration slits. (d) Specialized epithelial cells that surround glomerular capillaries. Changes in slit size alter GFR. (e) An internal smooth muscle sphincter that is passively contracted and an external skeletal muscle sphincter that is tonically (actively) contracted. (f) Outer layer of the kidney that contains renal corpuscles, proximal and distal tubules, and parts of the loop of Henle and collecting ducts.

Arrange the following structures in the order that a drop of water entering the nephron would encounter them: (a) afferent arteriole (b) Bowman's capsule (c) collecting duct (d) distal tubule (e) glomerulus (f) loop of Henle (g) proximal tubule (h) renal pelvis

(a), (e), (b), (g), (f), (d), (c), (h)

Place the following blood vessels that carry blood to and within the kidney in the order in which blood passes through them. 1. afferent arteriole 2. efferent arteriole 3. glomerulus 4. peritubular capillary ANSWER: 1, 2, 3, 4 4, 3, 2, 1 3, 4, 2, 1 4, 2, 3, 1 1, 3, 2, 4

1,3,2,4 afferent arterioles glomerulus efferent arteriole peritubular capillary

List the 6 functions of the kidneys

1. Regulation of Extracellular fluid volume & Blood Pressure 2. Regulation of osmolarity 3. Maintenance of Ion Balance (electrolytes) 4. Homeostatic regulation of pH (acid/base) 5. Excretion of wastes 6. Production of Hormones (erythropoietin, E = renin)

Name the 3 sets of filters:

1. fenestrated capillary 2. basal lamina - negative charge repels protein 3. epithelium of Bowman's capsule - podocyte

General principle of urine formation:

1. filter all blood and collect a lot of plasma. 2. selective (& massive) Reabsorption important stuff. 3. fine tune by: a. additional selective secretion. b. concentration of remaining waste (urine) to conserve water. c. monitor actual [Na+] & [K+] to regulate body fluid content.

Autoregulation consists of two local control components:

1. myogenic response a. afferent arteriole is similar to systemic system 2. Tubuloglomerular FeedBack a. juxtaglomerular apparatus

The amount of plasma that filters into the nephrons is approximately ________ of the total volume. ANSWER: 4/5 3/4 90% 1/2 1/5

1/5

Approximately how much plasma moves through the kidneys of an adult during a 24-hour period?

180L

Measurements in a nephron reveal a glomerular hydraulic pressure of 69 mm Hg, and a fluid pressure in the Bowman's capsule of 15 mm Hg. Assuming that the plasma osmotic pressure is 30 mm Hg, and that essentially no plasma proteins are filtered by the glomerulus, what is the net glomerular filtration pressure in this case? ANSWER: 114 mm Hg -6 mm Hg 54 mm Hg 84 mm Hg 24 mm Hg

24 mm Hg

Put the following in order from where urine is produced to where it exits the body: 1. Urethra 2. Urinary bladder 3. Nephron 4. Ureter

3,4,2,1

Put the following in order from where urine is produced to where it exits the body: 1..Urethra 2. Urinary bladder 3. Nephron 4. Ureter 2, 3, 4, 1 3, 4, 2, 1 1, 2, 3, 4 4, 2, 1, 3

3,4,2,1 Nephron, Ureter, Urinary Bladder, Urethra

In which segment of the nephron does most reabsorption take place? When a molecule or ion is reabsorbed from the lumen of the nephron, where does it go? If a solute is filtered and not reabsorbed from the tubule, where does it go?

70% occurs in the proximal tubule. Reabsorbed molecules go into the peritubular capillaries and the systemic venous circulation. If filtered and not reabsorbed, a molecule is excreted in the urine.

What dictates filtration?

A competition between hydrostatic and oncotic pressure

Match each step in urine formation to its description. A. excretion B. filtration C. reabsorption D. secretion movement from the nephron lumen to the external environment

A. excretion

Secretion into the nephron is a/an ________ process because the direction is ________ the concentration gradient.

Active, against

If the afferent arteriole of a nephron constricts, what happens to GFR in that nephron? If the efferent arteriole of a nephron constricts, what happens to GFR in that nephron? Assume that no autoregulation takes place.

Afferent arteriole constricts, GFR decreases. Efferent arteriole constricts, GFR increases.

Net handling of a solute & thus excretion by kidney determined by:

Amount filtered - Amount reabsorbed + Amount secreted = Amount of solute excreted

myogenic response; tubuloglomerular feedback

Autoregulation of glomerular filtration is accomplished by a ___ of vascular smooth muscle in response to pressure changes and by ____

125 mL/min, or 180 L/day

Average GFR is

Match each substance with its primary mode of transport across the kidney epithelium. A. transcytosis B. active transport C. symport with a cation D. passive reabsorption/diffusion sodium

B. active transport

glomerulus

Blood flows from the afferent arteriole into a ball-like network of capillaries

The nephron begins with a hollow, ball-like structure called ANSWER: Bowmans capsule. macula densa. vasa recta. glomerulus.

Bowman's Capsule

podocytes; filtration slits

Bowman's capsule epithelium has specialized cells called ____ that wrap around the glomerular capillaries and create ____

Match each step in urine formation to its description. A. excretion B. filtration C. reabsorption D. secretion movement from the nephron lumen to the blood

C. reabsorption

What force(s) promote(s) glomerular filtration? What force(s) oppose(s) it? What is meant by the term net driving force?

Capillary hydrostatic pressure promotes filtration. Fluid pressure in Bowman's capsule and colloid osmotic (oncotic) pressure of plasma oppose it. Net driving force is the sum of these pressures.

nephrons

Each kidney has about 1 million microscopic

An obstruction in a glomerulus would affect the flow of blood into the ANSWER: efferent arteriole. afferent arteriole. renal vein. renal artery.

Efferent arteriole

Blood leaves the glomerulus via which vessel? ANSWER: efferent arteriole afferent arteriole vasa recta peritubular capillaries

Efferent arterioles

Cysts on the kidney can press upon nephrons, raising the pressure inside the nephrons. How will this affect glomerular filtration rate and blood pressure? ANSWER: GFR increases and blood pressure decreases GFR increases and blood pressure increases GFR decreases and blood pressure increases GFR decreases and blood pressure decreases

GFR decreases and blood pressure increases

Where does all filtration take place in the kidneys?

Glomerulus

secondary active transport

Glucose, amino acids, ions, and various organic metabolites are reabsorbed by Na+-linked ____

1/5

How much of renal plasma flow filters into the tubule lumen

55 mm Hg

Hydrostatic pressure in glomerular capillaries averages ___, favoring filtration

afferent and efferent arterioles

Hydrostatic pressure in glomerular capillaries can be altered by changing resistance in the

creatinine

In clinical settings, ___ is used to measure GFR

outer cortex and inner medulla

In cross section, a kidney is arranged into an

Vasa recta

In juxtamedullary nephrons, the long peritubular capillaries that dip into the medulla

What causes the internal urethral sphincter to open?

Increasing urine pressure due to contraction of the full bladder

Clearance

Measure GFR with; RATE a solute disappears from body per unit time (by excretion or metabolism). In PSL: volume of plasma passing through kidney that has been totally cleared of solute

paracellular

Most reabsorption involves transepithelial transport, but some solutes and water are reabsorbed by the ___pathway

proximal tubule

Most reabsorption takes place in the

transport maximum Tm

Most renal transport is mediated by membrane proteins and exhibits saturation, specificity, and competition. The ___ is the transport rate at saturation.

The functional unit of the kidney is the ________. ANSWER: juxtaglomerular apparatus loop of Henle renal corpuscle nephron

Nephron

Clearance of X is less than inulin clearance

Net reabsorption of X

Filteration is greater than excretion

Net reabsorption of X

Clearance of X is more than inulin clearance

Net secretion of X

Excretion is greater than filtration

Net secretion of X

30 mm Hg; 15 mm Hg.

Opposing filtration are colloid osmotic pressure of ___ and hydrostatic capsule fluid pressure averaging ____.

Why is the osmotic pressure of plasma in efferent arterioles higher than that in afferent arterioles?

Osmotic pressure is higher in efferent arterioles because fluid volume is decreased there, leaving the same amount of protein in a smaller volume

Glomerular Filtration Pressure

PH - pi - PF = net filtration pressure

__________ neurons cause contraction of the smooth muscle in the bladder wall._________ motor neurons leading to the external sphincter are simultaneously inhibited

Parasympathetic; somatic

hormones; autonomic nervous system

Reflex control of GFR is mediated through systemic signals, such as ___, and through the ___

_______ reabsorption drives the rest of reabsorption at the kidney.

Sodium

1. its filtered load 2. whether it is reabsorbed or secreted as it passes through the nephron

The excretion rate of a solute depends on

10 mm Hg

The net driving force is ___, favoring filtration.

peritubular capillaries

The network of tiny blood vessels that surrounds the proximal and distal tubules in the kidney

filtration fraction

The percentage of total plasma volume that filters is called the

ALL reabsorption is iso-osmotically achieved.

True

One substance has no membrane transporters to move it but can diffuse freely through open leak channels if there is a concentration gradient. Initially, this substance's concentrations in the filtrate and extracellular fluid are equal. Later, however, the active transport of Na+ and other solutes creates a gradient by removing water from the lumen of the tubule where it is located. What substance is this? ANSWER: glucose, calcium, and urea glucose and calcium glucose calcium urea

Urea

ureter to the urinary bladder

Urine flows through the

macula densa cells

When fluid flow through the distal tubule increases, the ___ send a paracrine signal to the afferent arteriole, which constricts

If net filtration out of glomerular capillaries occurs, then you know that capillary hydrostatic pressure must be (greater than/less than/equal to) capillary colloid osmotic pressure.

When net filtration out of the glomerular capillaries occurs, the capillary hydrostatic pressure must be greater than the capillary colloid osmotic pressure.

If net reabsorption into peritubular capillaries occurs, then capillary hydrostatic pressure must be (greater than/less than/ equal to) the capillary colloid osmotic pressure.

When net reabsorption into the peritubular capillaries occurs, the capillary hydrostatic pressure must be less than the capillary colloid osmotic pressure.

Renal Corpuscle

Where filtration occurs within the Bowman's capsule. structure of corpuscle creates filtration barrier two different epithelial like cells (endothelial and podocye) as well as basal lamina

Clearance of X is equal to inulin clearance

X is neither reabsorbed or secreted.

Match each step in urine formation to its description. A. excretion B. filtration C. reabsorption D. secretion movement from the glomerulus to the nephron lumen

filtration

A glomerulus is

a "knot" of capillaries that lies within the Bowman's capsule.

A glomerulus is ANSWER: -the portion of the nephron that attaches to the collecting duct. -the portion of the nephron closest to the renal corpuscle -the hairpin-shaped segment of the nephron. -the expanded end of a nephron. -a "knot" of capillaries that lies within the Bowman's capsule.

a "knot" of capillaries that lies within the Bowman's capsule.

Functions of the kidneys include all but one of the following. Identify the exception: -regulation of blood protein levels -regulation of extracellular fluid volume -maintenance of ion balance in body fluids -homeostatic regulation of blood pH -regulation of blood osmolarity

a. regulation of blood protein levels

Match each substance with its primary mode of transport across the kidney epithelium. A. transcytosis B. active transport C. symport with a cation D. passive reabsorption/diffusion glucose

active transport

Match each substance with its primary mode of transport across the kidney epithelium. A. transcytosis B. active transport C. symport with a cation D. passive reabsorption/diffusion sodium

active transport

The percentage of total plasma volume that filters is called the ANSWER: glomerular filtration rate. excretion rate. filtration fraction. clearance rate.

filtration fraction

glomerular filtration rate (GFR)

amount of fluid filtered through Bowman's capsule per unit time

glomerular filtration rate (GFR)

amount of fluid that filters into Bowman's capsule per unit time

basal lamina

an acellular layer of extracellular matrix that separates the capillary endothelium from the epithelial lining of Bowman's capsule. The basal lamina consists of negatively charged glycoproteins, collagen, and other proteins. The lamina acts like a coarse sieve, excluding most plasma proteins from the fluid that filters through it.

Active transport in the kidney is on the ________ side

basal

Technically, the kidneys are located ANSWER: behind the peritoneal membrane. in the pelvic cavity. in the thoracic cavity. in the abdominal cavity. behind the pleural membranes.

behind the peritoneal membrane

The force for glomerular filtration is the ANSWER: -osmotic pressure in the glomerular capillaries. -fluid pressure produced by the displacement of the fluid in the lumen of the tubules. -blood pressure in the glomerular capillaries. -ATP-dependent processes in the nephron. -None of the answers are correct.

blood pressure in the glomerular capillaries

Which statement is NOT true? ANSWER: a Women are more likely to develop urinary tract infections than men. b The urinary bladder is filled by two ducts, called ureters, and emptied by the single urethra. c The kidneys do not reabsorb filtered waste products. d The blood supply to the kidneys comes through the renal arteries. e As much as one fourth of the cardiac output may flow to the kidneys at any given moment.

c The kidneys do not reabsorb filtered waste products.

The characteristic yellow color of urine is attributed to the presence of: a. bile. b. urea. c. urobilinogen. d. uric acid. e. renin.

c. urobilinogen

inulin

clearance is equal to GFR.

What part of the nephron is responsible for the greatest possible increase in urine concentration? ANSWER: Bowman's capsule collecting duct loop of Henle proximal convoluted tubule

collecting duct

Damage to the renal medulla would interfere first with the functioning of the ANSWER: collecting ducts. Bowman's capsule. proximal tubule. distal tubule. glomerulus.

collecting ducts

During the micturition reflex, what does activation of parasympathetic efferent neurons cause the bladder to do?

contract

Eighty percent of the nephrons in a kidney are contained within the ________, but the other 20%, called the ________ nephrons, dip down into the ________.

cortex, juxtamedullary, medulla

Eighty percent of the nephrons in a kidney are contained within the ________, but the other 20%, called the ________ nephrons, dip down into the ________. ANSWER: medulla, cortical, cortex renal pelvis, juxtamedullary, vasa recta cortex, juxtamedullary, medulla vasa recta, cortical, cortex

cortex, juxtamedullary, medulla

What solute that is normally present in the body is used to estimate GFR in humans?

creatinine

Which of the following statements about autoregulation is TRUE? ANSWER: -Myogenic response is a paracrine signaling mechanism. -In tubuloglomerular feedback, stretch-sensitive ion channels open, resulting in depolarization of smooth muscle cells. -In myogenic response, the macula densa cells send a paracrine message to the neighboring afferent arteriole. -Myogenic response is the intrinsic ability of vascular smooth muscle to respond to pressure changes.

d Myogenic response is the intrinsic ability of vascular smooth muscle to respond to pressure changes.

Myogenic Response

decreasing resistance in AFFERENT (brings blood) can in theory increase GFR, but it is normally fairly relaxed so plays only minor role (Also have to worry about the EFFERENT arteriole - takes blood away)

clearance

describes how many milliliters of plasma passing through the kidneys have been totally cleared of a solute in a given period of time

Presence of glucose in the urine is evidence of what condition?

diabetes mellitus

The portion of the nephron that attaches to the collecting duct is the ANSWER: proximal tubule. loop of Henle. collecting duct. minor calyx. distal tubule.

distal tubule

Ions directly regulated by the kidney include all EXCEPT which of the following? a. Ca2+ b. HCO3- c. K+ d. Na+ e. OH-

e. OH-

Blood leaves the glomerulus via which vessel?

efferent arteriole

secretion

enhances excretion by removing solutes from the peritubular capillaries. K+, H+, and a variety of organic compounds are secreted.

All of the following will normally be found in the filtrate EXCEPT ANSWER: urobilinogen glucose potassium erythrocytes

erythrocytes

When the plasma concentration of a substance exceeds its renal concentration, more of the substance will be ANSWER: excreted. secreted. reabsorbed. filtered. None of the answers are correct.

excreted

Match each step in urine formation to its description. A. excretion B. filtration C. reabsorption D. secretion movement from the nephron lumen to the external environment

excretion

Which equation correctly describes the relationship between excretion, filtration, reabsorption, and secretion?

excretion = filtration - reabsorption + secretion

Urine is produced by the ANSWER: urinary bladder. urethra. kidney. ureter. gallbladder.

kidney

The amount of filtrate entering the proximal tubules of the kidneys each minute is the ________ rate. ANSWER: glomerular filtration excretion clearance collecting

glormerular filtration rate

The excretion of glucose in the urine is called ANSWER: hypoglycemia. micturation. glucosuria. glucose secretion.

glucosuria

Renal Blood Flow

goes from afferent arteriole to glomerulus to efferent arteriole to peritubular capillaries. The vasa recta capillaries dip into the medulla

Approximately what percent of the total filtered volume is excreted as urine each day?

less than 1%

Approximately what percent of the total filtered volume is excreted as urine each day? ANSWER: 30% 100% 10% less than 1%

less than 1%

sympathetic nervous system in kidneys

innervate BOTH afferent & efferent arterioles; induces vasoconstriction ONLY if severe drop in Blood pressure, i.e. conserve fluid

In the lumen of the proximal tubule, Na+ concentration ________ the Na+ concentration inside the cells of the tubule wall. ANSWER: is much higher than is slightly lower than is slightly higher than is much lower than is about the same as

is much higher than

mesengial cells

lie between and around the glomerular capillaries. They have cytoplasmic bundles of actin-like filaments that enable them to contract and alter blood flow through the capillaries. In addition,they secrete cytokines associated with immune and inflammatory processes.

The hairpin-shaped segment of the nephron is the

loop of Henle

The hairpin-shaped segment of the nephron is the ANSWER: vasa recta. distal tubule. loop of Henle. proximal tubule. minor calyx.

loop of Henle

Which is NOT a kidney filtration barrier? ANSWER: glomerular capillary endothelium juxtaglomerular apparatus Bowman's capsule epithelium basal lamina

juxtaglomerular apparatus

reabsorption

movement of filtered materials from tubule to blood

filtration

movement of fluid from plasma into Bowman's capsule

secretion

movement of selected molecules from blood to tubule

The functional unit of the kidney is the ________.

nephron

Filtration and secretion are the same

no net reabsorption/secretion

In normal kidneys, blood cells and plasma proteins are ANSWER: secreted then reabsorbed. filtered and secreted. filtered then reabsorbed. not filtered.

not filtered

Match each substance with its primary mode of transport across the kidney epithelium. A. transcytosis B. active transport C. symport with a cation D. passive reabsorption/diffusion urea

passive reabsorption/diffusion

Urea is ANSWER: -actively reabsorbed in the proximal tubule. -actively secreted in the distal tubule. -actively transported into the filtrate by the cells of the collecting duct. -completely eliminated in the urine. -passively reabsorbed in the proximal tubule.

passively reabsorbed in the proximal tubule.

List three solutes secreted into the tubule lumen.

penicillin, K+, and H+

Which word means to selectively move molecules from the blood and add them to the tubule lumen?

secretion

The specialized cells found in the capsule epithelium are called ________. These cells have long cytoplasmic extensions called ________. ANSWER: juxtaglomerular cells, loops of Henle mesangial cells, cilia podocytes, foot processes granular cells, flagella

podocytes, foot processes

Inulin

polysaccharide that is filtered & excreted, not resorbed, not secreted

Blood flow through the kidney includes a feature seen in only a few organs. What is it? ANSWER: arterial shunts veins containing highly oxygenated blood anastomoses vascular sinuses portal system

portal system

angiotensin II

potent vasoconstrictor

prostaglandins

potent vasodialator

Reabsorption utilizes these types of transport:

primary active, secondary active, and passive diffusion.

Most reabsorption takes place in the_________ _________. Finely regulated reabsorption takes place in the more distal segments of the nephron.

proximal tubule

The portion of the nephron closest to the renal corpuscle is the ANSWER: collecting duct. proximal tubule. distal tubule. minor calyx. loop of Henle.

proximal tubule

Secretion

selective removal of a compound from plasma to lumen - active process. active removal of solute from (usually) peritubular capillaries/ECF to lumen of nephron

Renal clearance

rate of excretion of a solute relative to plasma concentration

Peritubular capillaries

reabsorb fluid along their entire length.

Match each step in urine formation to its description. A. excretion B. filtration C. reabsorption D. secretion movement from the nephron lumen to the blood

reabsorption

The primary function of the proximal tubule is ANSWER: -secretion of acids and ammonia. -reabsorption of ions, organic molecules, and water. -adjusting the urine volume. -filtration. -secretion of drugs.

reabsorption of ions, organic molecules, and water.

The kidneys function to produce hormones, excrete wastes, regulate blood pressure, and maintain ion balance. Which of the following is another function of the kidneys?

regulation of osmolarity

The process of filtration in the kidney is most accurately described as

relatively nonspecific

The process of filtration in the kidney is most accurately described as ANSWER: relatively nonspecific. completely nonspecific. highly specific.

relatively nonspecific

Excretion

remove from the body

The ________ branch off the ________ and supply blood to the kidneys. ANSWER: afferent arteries, abdominal aorta renal arteries, inferior vena cava arcuate arteries, inferior vena cava renal arteries, abdominal aorta

renal arteries, abdominal aorta

The Bowman's capsule and glomerulus make up the ANSWER: renal corpuscle. renal papilla. loop of Henle. collecting system. renal pyramid.

renal corpuscle.

The ________ carries blood from the kidneys back to the ________. ANSWER: renal vein, inferior vena cava efferent arteriole, abdominal aorta vasa recta, renal artery arcuate vein, inferior vena cava

renal vein, inferior vena cava

Tubuloglomerular FeedBack

salt detector; The juxtaglomerular apparatus is involved. Increases in renal arterial perfusion pressure increase GFR. Cells of the macula densa sense the increased flow by detecting changes in tubular sodium chloride concentration/transport. They respond by increasing production and secretion of a vasoconstrictor substance which acts locally to increase afferent arteriolar resistance. modified tubular epithelium = macula densa granular cells = modified sm muscle cells contain granules of E= RENIN

Contents in the peritubular capillaries are actively transported into proximal and distal convoluted tubules in a process known as: ANSWER: excretion filtration reabsorption secretion

secretion

Match each step in urine formation to its description. A. excretion B. filtration C. reabsorption D. secretion movement from the peritubular capillaries to the nephron lumen

secretion

Which of the following kidney processes is always active and always requires energy to occur? ANSWER: secretion reabsorption filtration excretion

secretion

The internal sphincter of the bladder is controlled by ______ muscle while the external sphincter is controlled by _______ muscle

smooth; skeletal

If blood flow through the afferent arterioles increases, ANSWER: -the stretch triggers further relaxation of the arteriolar wall, lessening blood pressure. -stretch reflexes trigger vasoconstriction to reduce the flow. -the smooth muscle in the vessel walls stretches to accommodate the increased flow and the stretch triggers further relaxation of the arteriolar wall, lessening blood pressure. -the smooth muscle in the vessel walls stretches to accommodate the increased flow.

stretch reflexes trigger vasocontriction to reduce the flow.

Neural control of GFR is mediated by ________ that innervate ________ receptors on vascular smooth muscle causing ________. ANSWER: sympathetic neurons, alpha, vasoconstriction somatic neurons, nicotinic, vasodilation parasympathetic neurons, alpha, vasodilation parasympathetic neurons, beta, vasoconstriction

sympathetic neurons, alpha, vasoconstriction

SGLT protein

symport on the apical side of kidney cell that transport sodium down its gradient and glucose against its gradient. glucose is later transported out the other side by a uniporter and sodium by Na+-K+-ATPase.

The typical pattern for molecules absorbed by Na+-dependent transport involves this: an apical ________ and a basolateral ________. ANSWER: symport protein, osmotic gradient osmotic gradient, symport protein facilitated diffusion carrier, osmotic gradient symport protein, facilitated diffusion carrier facilitated diffusion carrier, symport protein

symport protein, facilitated diffusion carrier.

Glucose and amino acids are reabsorbed by ANSWER: symport with sodium. cotransport. countertransport. diffusion.

symport with sodium

Reabsorption

take back most of what is filtered - PCT does >80%

vasa recta

the ___ capillaries dip into the medulla

What part of the nephron forms the juxtaglomerular matrix?

the ascending limb joining the distal tubule

Renal threshold

the plasma concentration at which a substance first appears in the urine

transport maximum (Tm)

the transport rate at saturation.

The plasma concentration at which all of the renal carriers for a given substance are saturated is the renal ANSWER: handling. threshold. ceiling. permissiveness.

threshold

Match each substance with its primary mode of transport across the kidney epithelium. A. transcytosis B. active transport C. symport with a cation D. passive reabsorption/diffusion small plasma proteins

transcytosis

When fluid flow through the distal tubule increases as a result of increased GFR, the macula densa cells send a chemical message to the neighboring afferent arteriole. The afferent arteriole constricts, increasing resistance and decreasing GFR. This type of autoregulation involving both the kidney tubule and the arteriole is known as ________ feedback. ANSWER: tubuloglomerular positive neuroendocrine autonomic

tubuloglomerular

Urine is carried to the external environment by the ANSWER: glomerulus. collecting duct. ureter. urethra.

urethra

After it is formed, urine is temporarily stored in the ANSWER: urinary bladder. ureter. renal pelvis. nephron.

urinary bladder

two kidneys, two ureters, a bladder, and a urethra

urinary system is composed of

The ________ are the long peritubular capillaries that dip into the medulla. ANSWER: vasa recta renal pyramids Bowmans capsules glomerulus

vasa recta

Mesangial cells

what cells are associated with the glomerular capillaries