Urinary System I Flashcards by Kim Martin

Although a great deal of waste material is discarded by the intestines, most was never
truly within the body. Almost all of the waste products originating from within the body itself
are removed and discarded by the _____.

kidneys

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The kidneys play a major role in _____ by sorting useful and necessary molecules from
those that are toxic or unneeded.

waste removal

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Urine is usually _____ but the pH can vary from ~4.5 to ~8.0 in response to changes in
metabolism or diet.

slightly acidic

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Urine composition is complex, but includes ions, _____ from catabolism of amino acids,
_____ from catabolism of dietary nucleic acids and RNA, _____ from decomposition of
creatine in the muscles and the yellow _____ from heme breakdown.

urea; urate OR uric acid;
creatinine; urobilins OR
urochrome

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Excessive plasma concentrations of organic molecules (such as glucose) can overwhelm
the kidney’s transport proteins and result in _____.

the presence of organic

molecules in the urine

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Damage to the structures of the urinary system from injury or infection can result in the
presence of _____, _____ or _____ in the urine.

large molecules; formed

elements; cells

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In a healthy individual, urine is a(n) _____ liquid until it leaves the body, at which time
bacteria present on the external genitalia may contaminate it.

sterile

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Kidneys regulate blood _____ and _____ by altering the concentration of the urine (and
thus, the amount of water lost or conserved) and by releasing _____.

volume; pressure; renin

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By changing the amount of each ion which is conserved or discarded, the kidneys
indirectly regulate the concentrations of solutes in the _____.

blood OR body

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By alternating between direct disposal of urea and disposal of ammonia, and also by
selectively secreting hydrogen or bicarbonate ions, the kidneys have a major influence on
the body’s _____.

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By monitoring their own oxygen supply and responding (if low) by releasing _____, a
hormone, the kidneys regulate _____.

erythropoietin; red blood cell

synthesis

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The kidneys help to control bone density by regulating the disposal of, or conservation of,
_____ in response to _____.

calcium; parathyroid hormone

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The kidneys help to control calcium absorption by regulating the conversion of vitamin D
to _____, which is done in response to _____.

its active form; parathyroid

hormone

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Urine is formed by each of two _____. From each, a muscular tube called the _____
propels urine to the _____ where it is stored until its release is convenient, at which time it
flows out of the body through the _____.

kidneys; ureter; bladder; urethra

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The kidneys are _____ to the peritoneum. Each lies in the _____ region, anterior to the
_____, but the right is slightly lower than the left to make room for the _____.

posterior; upper lumbar; 12th

rib; liver

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The kidneys are encased in a fibrous layer of connective tissue called the _____.

renal capsule

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The kidneys are surrounded by an outer fibrous layer called the _____ which _____. This
layer surrounds the adrenal glands as well.

renal fascia; fastens the kidney

to surrounding structures

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A dense layer of adipose tissue called the _____ lies between the renal capsule and the
renal fascia. Its function is to _____ and _____ the kidneys.

adipose capsule; support;

cushion

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The medial surface is concave and has a(n) _____, where the ureters, blood vessels,
nerves, and lymphatics enter or leave the kidney.

hilus OR hilum

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The hilus is continuous with the _____, a much deeper indentation filled with fat which
cushions the structures which enter and leave the kidney.

renal sinus

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The outer layer of the kidney, just deep to the renal capsule, is the _____. Columns of
tissue from this region called _____ extend toward the hilus; it is within these columns that
those renal blood vessels having the largest diameter lie.

renal cortex; renal columns

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The renal cortex surrounds the _____; columns of cortical tissue extend toward the hilus,
separating it into distinct regions called _____.

medulla; renal pyramids

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Each renal pyramid and the cortical tissue surrounding it is called a(n) _____. The term
‘_____’ refers to these units.

renal lobe; lobar

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Each renal pyramid is striated. The striations extend from the hilus toward the cortex and
are called _____. (They are actually _____.)

medullary rays; collecting ducts

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Each renal pyramid projects into a tube within the renal sinus which conducts urine away from the kidney. The projection itself is called the _____; the tube which it enters is called a(n) _____ (the plural is ':_____').

renal papilla; minor calyx; minor | calyces

Several minor calyces merge to form a(n) _____

major calyx

Each kidney contains roughly _____ minor calyces and _____ major calyces.

10-20; 2-3

The major calyces in each kidney merge to form a funnel-like chamber called the _____, which later narrows to form the _____, which conducts urine to the urinary bladder.

renal pelvis; ureter

Blood (1/4 of the blood pumped by the heart, when one is resting) reaches the kidneys via the _____, which branch to form _____ which branch again within the renal sinus to form the _____.

renal arteries; segmental | arteries; lobar arteries

Most of the blood reaching the kidney flows to the _____, where it will be filtered.

renal cortex

Blood flows to the renal cortex through the _____ arteries, then arches around the renal lobes just below the cortex via the _____ arteries. Many small arteries called the _____ arteries arise here: these supply blood to the _____ arterioles and _____.

interlobar; arcuate; interlobular; | afferent; glomerulus

Blood leaves the glomerulus via the _____, which take it to a second capillary bed, the _____.

efferent arterioles; peritubular | capillaries

Juxtamedullary nephrons are supplied with a special type of peritubular capillary, the _____, whose long straight vessels travel directly into and out of the renal pyramids.

vasa recta

From the peritubular capillaries, blood leaves the kidneys by flowing through veins whose paths and names are identical to those of the _____.

arteries that delivered the blood | to the kidney

The blood flow within the kidneys is controlled by the _____, which is supplied by fibers of the sympathetic nervous system originating in the least thoracic and first lumbar splanchnic nerves.

renal plexus

_____ are the structures within the kidney that actually sort the substances which should be kept or discarded.

Nephrons

Each kidney contains _____ nephrons.

over a million

Each nephron has two major parts: the _____ in the cortex and a thin _____, U-shaped at the center, which extends from the cortex into the medulla and back.

renal corpuscle; tubule

There are two types of nephron: the glomerulus of _____ nephrons is near the medulla, and the tubule of these nephrons _____ into a renal pyramid. These nephrons are very important in the production of _____ urine.

juxtamedullary; travels deep; | concentrated

There are two types of nephron: most are _____ nephrons. Each of these has a glomerulus which is near the outer surface of the cortex, and a short tubule which _____ into a renal pyramid.

cortical; does not extend far

The function of the renal corpuscle is to _____ in the first step of urine formation.

filter the blood

The renal corpuscle has two parts: the central portion is a tangled ball of capillaries called the _____. This is surrounded by the outer portion, a double-walled, cup-like chamber called the _____.

glomerulus; Bowman's capsule

The _____ is the interior of the Bowman's capsule, and is continuous with the _____.

capsular space; proximal tubule

The inner wall of the Bowman's capsule is permeable to liquid and is called the _____ layer. Liquid cannot pass, however, through the outer wall, the _____ layer.

visceral; parietal

Glomerular capillaries contain many _____ through which liquid can pass.

fenestrations

_____ forces liquid to leave the capillaries in the glomerulus, while formed elements and large molecules are left behind. The fluid passes through the visceral layer of the Bowman's capsule to enter the capsular space.

Blood pressure

The visceral layer of the Bowman's capsule is formed by specialized cells called _____. Fingerlike extensions of these cells wrap the capillaries of the glomerulus; between these are gaps called _____ which allow liquid to pass into the proximal tubule.

podocytes; filtration slits

Between the capillary walls and the visceral layer of the Bowman's capsule is a thin basement membrane through which liquid easily passes. Together, these three structures form the _____.

filtration membrane

Blood to the glomerulus is supplied by the _____ and leaves by the _____.

afferent arteriole; efferent | arteriole

The tubule consists of simple epithelium: the _____ or _____ surface of the epithelial cells contacts the filtrate in the lumen, while the _____ or _____ surface contacts the interstitial fluid surrounding the tubule.

apical; lumenal; basal; | basolateral

The tubular portion of the nephron is divided into several sections both functionally and conceptually: the portion of the tube closest to the renal corpuscle is the _____. Its primary function is _____.

proximal convoluted tubule (PCT); resorption of solutes and water

The tubular portion of the nephron is divided into several sections both functionally and conceptually: the portion of the tube farthest from the renal corpuscle is the _____. Its primary function is resorption of water, but this is varied depending on _____.

distal convoluted tubule (DCT); | the body's needs

Both the proximal and distal tubules are very _____.

convoluted OR twisted

The proximal and distal tubules of the nephron are connected by a hairpin-like loop called the _____, which extends toward or into the renal pyramids. Its primary function is _____

loop of Henle; resorption of | water and salt

The loop of Henle in _____ nephrons extends deep into the renal medulla.

juxtamedullary

The region of the loop of Henle in which fluid is traveling toward the hilus is called the _____; the region where fluid is flowing toward the outer surface of the kidney is the _____.

descending limb; ascending | limb

. Each limb of the loop of Henle has a(n) _____ and a(n) _____ portion.

thick; thin

The tubule of the nephron twists in such a way that the beginning of the DCT and the afferent and efferent arterioles contact one another. Cells in this region (the _____) are specialized to sense blood pressure, filtration rate, and oxygen availability.

Juxtaglomerular Apparatus | JGA

The Juxtaglomerular Apparatus (JGA) is a group of specialized cells which sense _____, _____, and _____.

blood pressure; filtration rate; | oxygen availability

The distal tubules of each nephron merge with _____; each of these carries urine from several nephrons to a(n) _____, where it drains via the _____ into a(n) _____ on its way out of the kidney.

collecting ducts; renal papilla; | papillary ducts; minor calyx

A(n) _____ is a region within a renal lobe which contains a group of nephrons connected to a common collecting duct.

renal lobule

There are three processes involved in urine formation: _____, _____ and _____.

filtration; resorption OR | reabsorption; secretion

In _____, the liquid components of the blood (including small molecules that are dissolved therein) are separated from the formed elements and large molecules.

filtration

In resorption, molecules which are _____ are allowed to remain in the filtrate, while glucose, amino acids, ions, and so on are reclaimed.

toxic, unneeded or | unrecognized

In the _____ and _____, several substances may be specifically secreted: these include ammonia, hydrogen ions, and some drugs.

proximal convoluted tubule (PCT); distal convoluted tubule (DCT)

Blood pressure in the glomerulus is controlled by _____ in the afferent and efferent arterioles so that it is maintained at levels that permit filtration.

smooth muscles

Glomerular blood pressure is higher than in other capillaries because the _____ arterioles have a larger diameter than the _____ arterioles.

afferent; efferent

The blood pressure in the glomerulus is often referred to as the _____.

glomerular hydrostatic pressure | HPg

The _____ is the sum of all of the forces which influence glomerular filtration rate.

net filtration pressure

Fluid leaves the glomerulus due to glomerular hydrostatic pressure (HPg). This is inhibited by two factors: _____ or _____ osmotic pressure, abbreviated _____, and back-pressure due to fluid already in the capsular space (_____, abbreviated _____).

blood colloidal; glomerular; OPg; capsular hydrostatic pressure; HPc

The _____ is the sum of all of the various forces influencing movement of fluid in the renal corpuscle during filtration. It is given by the formula: _____. (Note: be able to use the formula if given values!)

net filtration pressure (NFP); | HPg – (HPc + OPg)

A bit over one liter of blood passes through the kidneys and is filtered each minute: this is the _____.

renal blood flow rate

Since not all of the blood's volume is due to plasma, it is useful to calculate the _____, which is the amount of plasma filtered by the kidneys per minute.

plasma flow rate

The amount of filtrate formed by the kidneys per minute is the _____, and is usually about a fifth of the plasma flow rate.

glomerular filtration rate (GFR)

In a healthy kidney, two factors that affect GFR normally do not change: _____ and _____. (In disease states, these factors may change, however.)

the number of glomeruli; the permeability of the filtration membrane

To change the filtration rate, both local and systemic mechanisms are able to change the _____.

glomerular hydrostatic pressure | HPg

A '_____' is one in which the smooth muscles in a blood vessel respond to stretching by contracting, or to a decrease in resistance by relaxing.

myogenic response

In response to changes in systemic blood pressure, the afferent and efferent arterioles in the kidney dilate or contract to maintain _____; this is an example of a(n) _____. Note that this only works if the changes in systemic pressure are _____.

glomerular hydrostatic pressure (HPg); myogenic response; small

Both flow rate and filtrate concentration (osmolarity) are sensed by cells in the DCT, and signals are sent to the glomerulus in response. This is called _____.

tubuloglomerular feedback

When the filtrate flow in the DCT is too high, cells in the juxtaglomerular apparatus called _____ cells secrete a chemical signal which causes the _____, decreasing the GFR.

macula densa; afferent | arteriole to constrict

Urinary System I Flashcards

(80 cards)