Chapter 23 Flashcards
1
Q
__ take urine from kidneys to urinary bladder to be stored
A
Ureters
2
Q
what are the functions of the kidneys
A
- Filter blood and excrete toxic metabolic wastes
- Regulate blood volume, pressure, and osmolarity
- Regulate electrolytes and acid-base balance
- Secrete erythropoietin, which stimulates the production of red blood cells
- Help regulate calcium levels by participating in calcitriol synthesis
- Clear hormones from blood
- Detoxify free radicals
- In starvation, they synthesize glucose from amino acids
3
Q
what is the definition of waste
A
any substance that is useless to the body or present in excess of the body’s needs
4
Q
what is the definition of metabolic waste
A
waste substance produced by the body
5
Q
ammonia is produced by __ and is then converted to
A
the catabolism of proteins, urea
6
Q
Creatinine comes from __which is made from certain amino acids which come from proteins
A
creatine
7
Q
Uric acid comes from
A
nucleic acids
8
Q
urea makes up about __% of nitrogenous wastes
A
50
9
Q
what does BUN stand for
A
blood urea nitrogen
10
Q
what is blood urea nitrogen
A
level of nitrogenous waste in blood
11
Q
Normal concentration of blood urea is
A
10 to 20 mg/dL
12
Q
what is azotemia
A
elevated BUN
May indicate renal insufficiency due to nephron destruction
13
Q
what is uremia
A
syndrome of diarrhea, vomiting, dyspnea, and cardiac arrhythmia stemming from the toxicity of nitrogenous waste
Develops at 90% loss of renal function
14
Q
what is the treatment for uremia
A
hemodialysis or organ transplant
15
Q
__can tell you if the blood is being cleared of nitrogenous waste
A
BUN
16
Q
what is the definition of excretion
A
separating wastes from body fluids and eliminating them
17
Q
what are the four body systems that carry out excretion
A
respiratory, integumentary, digestive, and urinary
18
Q
what is excreted from the respiratory system
A
CO2, small amounts of other gases, and water
19
Q
what is excreted from the integumentary system
A
water, inorganic salts, lactic acid, urea in sweat
20
Q
what is excreted from the digestive system
A
water, salts, CO2, lipids, bile pigments, cholesterol, and other metabolic waste
21
Q
what is excreted from the urinary system
A
many metabolic wastes, toxins, drugs, hormones, salts, H+, and water
22
Q
where are the kidneys located
A
at the level of T12 to L3
23
Q
the __ kidney is slightly lower due to th large lobe of the liver
A
right
24
Q
how big are the kidneys
A
about the size of a bar of soap
25
what is the slit in the kidneys called
the hilum
26
what are the protective connective tissue coverings
renal fascia, perirenal fat capsule, and the fibrous capsule
27
where is the renal fascia located
Immediately deep to parietal peritoneum
| Binds it to abdominal wall
28
what does the perineal fat capsule do
cushions kidney and holds it into place
29
what does the fibrous capsule of the kidneys do
encloses kidney protecting it from trauma and infection
30
what is renal parenchyma
glandular tissue that forms urine, encircles the renal sinus
31
what is the renal sinus
cavity that contains blood and lymphatic vessels, nerves, and urine-collecting structures. Adipose fills the remaining cavity and holds structures in place
32
what are the renal columns
extensions of the cortex that project inward toward sinus
33
what are the renal pyramids
6 to 10 with broad base facing cortex and renal papilla facing sinus
34
what are the lobes of the kidneys
one pyramid and its overlying cortex
35
what is a minor calyx
cup that nestles the papilla of each pyramid; collects its urine
36
what are the three major calyces
formed by convergence of 2 or 3 minor calyces
37
what is the renal pelvis
formed by convergence of 2 or 3 major calyces
38
what are the ureters
a tubular continuation of the pelvis that drains urine down to the urinary bladder
39
Kidneys are only __% of body weight, but receive about __% of cardiac output
0.4, 21
40
In the cortex, efferent arterioles give rise to __supplying the tissue near the glomerulus- the proximal and distal convoluted tubules
peritubular capillaries
41
In the medulla, efferent arterioles give rise to the __, supplying the nephron loop portion of the nephron
vasa recta
42
each kidney has about __ nephrons
1.2 million
43
each nephron is composed of two principal parts
the renal corpuscle and the renal tubule
44
what does the renal corpuscle do
filters blood plasma
45
what does the renal tubule do
long, coiled tube that converts the filtrate into urine
46
Renal corpuscle consists of the __ and a two-layered __ that encloses glomerulus
glomerulus, glomerular capsule
47
the parietal layer of the glomerular capsule is made of
simple squamous epithelium
48
the visceral layer of glomerular capsule consists of __ that wrap around the capillaries of the glomerulus
podocytes
49
what is the vascular pole
the side where the afferent arterial enters and the efferent arteriole leaves the corpuscle
50
what is the urinary (tubular) pole
where the renal tubule begins
51
what is the renal tubule
the duct leading away from the glomerular capsule and ending at the tip of the medullary pyramid
52
what are the four regions of the renal tubule
proximal convoluted tubule, nephron loop, distal convoluted tubules and the collecting duct
53
what regions of the renal tubule are parts of a single nephron
proximal convoluted tubule, nephron loop, and the distal convoluted tubules
54
Glomerular filtrate goes into glomerular capsule then becomes
tubular fluid
55
what is the proximal convoluted tubule made out of and what is it known for
simple cuboidal epithelium and it is the longest and most coiled region of a nephron
56
the nephron loop has a __ limb and a __ limb
descending and ascending
57
thick segments of the nephron loop have__ while thin segments have__
simple cuboidal epithelium, simple squamous epithelium
58
the distal convoluted tubule is made of __ and is special because
simple cuboidal epithelium, it is the end of the nephron
59
___ nephrons consist of 15% of all nephron
juxtamedullary
60
what do juxtamedullary do
maintain salinity gradient in the medulla and help conserve water
61
cortical nephrons consists of __% of nephrons
85
62
are cortical nephrons short or long
short
63
where are cortical nephrons found
in the cortex of the kidney but very few will extend into the medulla
64
what does the collecting duct do
receives fluid from the DCTs of several nephrons as it passes back into the medulla
65
Numerous collecting ducts converge toward the
tip of the medullary pyramid
66
the papillary duct is formed by
merger of several collecting ducts
67
The collecting duct receives tubular filtrate, then the fluid continues down to the papillary duct and is then considered
urine
68
what is the flow of fluid from the point where the glomerular filtrate is formed to the point where urine leaves the body
glomerular capsule → proximal convoluted tubule → nephron loop → distal convoluted tubule → collecting duct → papillary duct → minor calyx → major calyx → renal pelvis → ureter → urinary bladder → urethra
69
what is the renal plexus
nerves and ganglia wrapped around each renal artery
70
what are the functions of the renal plexus
1. Follows branches of renal artery into the parenchyma of the kidney
2. Issues nerve fibers to blood vessels and convoluted tubules of the nephron
3. Carries sympathetic innervation from the abdominal aortic plexus
- Stimulation reduces glomerular blood flow and rate of urine production
- Respond to falling blood pressure by stimulating the kidneys to secrete renin, an enzyme that activates hormonal mechanisms to restore blood pressure
71
the kidneys receive __ innervation of an unknown function
parasympathetic
72
kidneys convert blood plasma to urine in what four stages
1. Glomerular filtration
2. Tubular reabsorption
3. Tubular secretion
4. Water conservation
73
what is glomerular filtrate
the fluid in the capsular space
74
glomerular filtrate is similar to blood plasma except that is has almost no
protein
75
what is tubular fluid
fluid from the PCT through the DCT
76
what is urine
fluid that enters the collecting duct
77
The collecting tubules are a little passage way from the __ to the
distal convoluted tubule, collecting duct
78
When fluid hits the __that is when it is formally called urine
papillary duct
79
glomerular filtration creates a __like filtrate of the blood during urine formation
plasma
80
___ removes useful solutes from the filtrate returns them to the blood during urine formation
tubular reabsorption
81
__ removes additional wastes from the blood, adds them to the filtrate during urine formation
tubular secretion
82
__ removes water from the urine and returns it to the blood and concentrates wastes
water conservation
83
what is globular filtration
the movement of substances from the blood within the glomerulus into the capsular space
84
what is tubular reabsorption
the movement of substances from the tubular fluid back into the blood
85
what is tubular secretion
the movement of substances from the blood into the tubular fluid
86
what are the three barriers of the filtration membrane
fenestrated endothelium, basement membrane, and the filtration slits
87
how large are the filtration pores and why
70-90 nm, they are small enough to exclude blood cells
88
T?F fenestrated endothelium are highly permeable
true
89
the proteoglycan gel of the basement membrane excludes molecules greater than
8nm
90
albumin is repelled by
negative charge
91
Blood plasma is __% protein, the filtrate is only __% protein
7, 0.03
92
Podocyte cell extensions wrap around the capillaries to form a barrier layer with __ nm filtration slits
30
93
filtration slits are negatively/positively
negatively
94
what are fenestrations
types of pores or spaces that are of a certain size
95
Kidney infections and trauma can damage the __and allow albumin or blood cells to filter
filtration membrane
96
what is proteinuria
the presence of protein in urine
97
what is hematuria
the presence of blood in the urine
98
Distance runners and swimmers often experience temporary __ or__
proteinuria, hematuria
99
__ reduces profusion of kidney
Prolonged, strenuous exercise
100
Glomerulus deteriorates under
prolonged hypoxia
101
Filtration pressure depends on
hydrostatic and osmotic pressures on each side of the filtration membrane
102
why is blood hydrostatic pressure high in the glomerular capillaries than elsewhere
Due to afferent arteriole being substantially larger than efferent arteriole
103
what is the hydrostatic pressure in the capsular space and why
18 mm Hg due to high filtration rate and continual accumulation of fluid in the capsule
104
what is usual colloid osmotic pressure
32 mm Hg
105
T/F: Glomerular filtrate is almost protein-free and has no significant COP
true
106
what does filtration pressure do
Pushes blood from out into capsular space
107
High BP in glomerulus makes kidneys vulnerable to
hypertension
108
what can be a result of Hugh BP in the glomerulus
to rupture of glomerular capillaries, produce scarring of the kidneys (nephrosclerosis), and atherosclerosis of renal blood vessels, ultimately leading to renal failure
109
what is the clinical term for scarring of the kidneys
nephrosclerosis
110
what is glomerular filtration rate
the amount of filtrate formed per minute by the two kidneys combined
111
what is the average glomerular filtration rate for men and women
men: 125 mL/min. or 180 L/day
women: 105 mL/min. or 150 L/day
112
Filtration coefficient depends on __ and __ of filtration barrier
permeability, surface area
113
Total amount of filtrate produced per day equals __ times the amount of blood in the body
50 to 60
114
__% of filtrate is reabsorbed since only 1 to 2 L urine excreted per day
99
115
what happens if the glomerular filtration rate is too high
1. Fluid flows through renal tubules too rapidly for them to reabsorb the usual amount of water and solutes
2. Urine output rises
3. Chance of dehydration and electrolyte depletion
116
what happens if GFR is too low
1. Wastes are reabsorbed
| 2. Azotemia may occur
117
by what three homeostatic mechanisms does regulation of glomerular filtration occur
renal auto regulation, sympathetic control, and hormonal control
118
what is renal autoregulation of GF
The ability of the nephrons to adjust their own blood flow and GFR without external control.
119
what is sympathetic control of GF
Nervous innervation of renal blood vessels (and adrenal epinephrine) constrict afferent arterioles redirecting blood from kidneys to heart, brain, and skeletal muscles where urgently needed
120
what is hormonal control of GF
Renin-Angiotensin-Aldosterone Mechanism
121
Conversion of glomerular filtrate to urine involves the
removal and addition of chemicals by tubular reabsorption and secretion
122
what does PCT stand for
Proximal Convoluted Tubule
123
PCT reabsorbs about 65% of glomerular filtrate, while it also removes some substances from __, and secretes them into tubular fluid for disposal in urine
blood
124
what are some characteristics of the PCT
1. Prominent microvilli and great length
2. Abundant mitochondria provide ATP for active transport
3. PCTs alone account for about 6% of one’s resting ATP and calorie consumption
125
what are the two routes of reabsorption
transcellular route and paracellular route
126
what happens the transcellular route
Substances pass through cytoplasm of PCT epithelial cells and out their base
127
what happens the paracellular route
1. Substances pass between PCT cells
2. Junctions between epithelial cells are leaky and allow significant amounts of water to pass through
3. Solvent drag—water carries a variety of dissolved solutes with it
128
reabsorbed fluid during tubular reabsorption is taken up by
peritubular capillaries
129
nephrons reabsorb about half of what nitrogenous waste
urea
130
the PCT reabsorbs what nitrogenous waste
uric acid, but later portions of the nephron secrete it
131
is creatinine reabsorbed
no, it is passed in the urine
132
where can creatinine levels be looked at
in the urine and the blood
133
Each day, kidneys reduce __ L of glomerular filtrate to 1 or 2 L of urine
180
134
__% of water in filtrate is reabsorbed in PCT
65
135
Reabsorption of solutes makes the tubule cells and tissue fluid __tonic to tubular fluid
hyper
136
Water follows solutes by osmosis through what two routes
both paracellular and transcellular routes
137
Transcellularly, water uses channels called
aquaporins
138
In PCT, water is reabsorbed at constant rate called
obligatory water reabsorption
139
what three factors promote osmosis into the capillaries
high interstitial fluid pressure, low blood hydrostatic pressure, and high colloid osmotic pressure
140
what causes high interstitial pressure
due to accumulation of reabsorbed fluid in extracellular space
141
what causes low blood hydrostatic pressure in the peritubular capillaries
due to narrowness of efferent arterioles
142
what causes high colloid osmotic pressure in blood
due to presence of proteins that were not filtered
143
The amount of solute that renal tubules can reabsorb is limited by
the number of transport proteins in tubule cells’ membranes
144
If all transporters are occupied, any excess solute
passes by and appears in urine
145
Transport maximum is reached when
transporters are saturated
146
Any blood glucose level above 220 mg/dL results in
glycosuria
147
purposes of secretion in PCT and nephron loop include
acid-base balance, waste removal, and clearance of drugs and contaminants
148
in acid-base balance, secretion of hydrogen and bicarbonate ions helps
regulate pH of body fluids
149
during waste removal in tubular secretion, what wastes are removed
Urea, uric acid, bile acids, ammonia, and a little creatinine are secreted
150
what are some examples of clearance drugs and contaminants
morphine, penicillin, and aspirin
151
what is the primary function of the nephron loop
to generate salinity gradient that enables collecting duct to concentrate the urine and conserve water
152
during electrolyte reabsorption from filtrate, Thick segment reabsorbs 25% of __ and
Na+, K+, and Cl−, Tubular fluid is very dilute as it enters distal convoluted tubule
153
DCT and CD reabsorb variable amounts of __
water and salts
154
by what hormones are DCT and CD regulated
1. Aldosterone,
2. Atrial natriuretic peptide,
3. ADH, and
4. Parathyroid hormone
155
what are the two types of cells the DCT and collecting duct
principal cells and intercalated cells
156
what are some characteristics of principal cells
1. Have receptors for hormones
| 2. Involved in salt and water balance
157
what are some characteristics of intercalated cells
Involved in acid–base balance by secreting H+ into tubule lumen and reabsorbing K+
158
what is the salt-retaining hormone
aldosterone
159
what is the steroid secreted by the adrenal cortex
aldosterone
160
what are the triggers for aldosterone secretion
1. When blood Na+ concentration falls or
2. When K+ concentration rises or
3. There is a drop in blood pressure-->renin release-->angiotensin II formation--> stimulates adrenal cortex to secrete aldosterone
161
what are the functions of aldosterone
1. Stimulates reabsorption of Na+ and secretion of K+
2. Water and Cl− follow the Na+
3. Body retains NaCl and water (blood pressure ↑)
4. Urine volume is reduced
5. Urine has an elevated K+ concentration
162
what are atrial natriuretic peptides
secreted by atrial myocardium of the heart in response to high blood pressure
163
what are the four actions that result n the excretion of more salt and water in the urine, thus reducing blood volume and pressure
1. Dilates afferent arteriole, constricts efferent arteriole: GFR
2. Inhibits renin and aldosterone secretion
3. Inhibits secretion of ADH
4. Inhibits NaCl reabsorption by collecting duct
164
ADH is secreted by
the posterior pituitary gland
165
what are the triggers for ADH secretion
1. Dehydration
2. Loss of blood volume
3. Rising blood osmolarity
166
ADH makes the collecting duct more __ to water
permeable
167
Water in the tubular fluid __ rather than being lost in urine
reenters the tissue fluid and bloodstream
168
what hormone is secreted in response to low blood calcium
Parathyroid hormone (PTH)
169
what is the clinical term for low blood calcium
hypocalcemia
170
PTH acts on PCT to
increase phosphate excretion
171
PTH Acts on the thick segment of the ascending limb of the nephron loop, and on the DCT to
increase calcium reabsorption
172
PTH Increases phosphate content and lowers __content in urine
calcium
173
what is the kidneys role in water conservation
The kidney eliminates metabolic wastes from the body, but prevents excessive water loss
174
where does the collecting duct begin
in the cortex where it receives tubular fluid from several nephrons
175
how does the CD make urine more concentrated
CD runs through medulla, and reabsorbs water
176
Medullary portion of CD is more permeable to water than to
NaCl
177
what is water diuresis
hypotonic urine
Cortical portion of CD reabsorbs NaCl, but it is impermeable to water
Salt is removed from the urine but water stays in
178
Dehydration leads to
production of hypertonic urine
179
If BP is low in a dehydrated person, GFR will be
low
180
The ability of kidney to concentrate urine depends on
salinity gradient in renal medulla
181
Nephron loop acts as a
countercurrent multiplier
182
what does a multiplier do
continually recaptures salt and returns it to extracellular fluid of medulla which multiplies the osmolarity of adrenal medulla
183
the higher the osmolarity of the ECF, the more water leaves the __ limb by osmosis
descending
184
the more water that leaves the descending limb, the __ the fluid is that remains in the tubule
slatier
185
the saltier the fluid in the ascending limb, the more __ the tubule pumps into the ECF
salt
186
how is the countercurrent exchange formed
by blood flowing in opposite directions in adjacent parallel capillaries
187
what do the descending capillaries of the casa recta do
Exchanges water for salt
| Water diffuses out of capillaries and salt diffuses in
188
what doe the ascending capillaries of the vasa rect do
1. Exchanges salt for water
2. Water diffuses into and NaCl diffuses out of blood
3. Vasa recta gives the salt back and does not subtract from the osmotic gradient of the medulla
189
what is a urinalysis
examination of physical and chemical properties of urine
190
why is urine yellow
due to urochrome pigment from breakdown of hemoglobin
191
why would urine be cloudy or have blood in it
suggest urinary tract infection, trauma, or stones; or might just be contamination with other fluids
192
what is pyuria
pus in the urine
193
what is hematuria
blood in urine due to urinary tract infection, trauma, or kidney stones
194
what is specific gravity of urine
compares urine sample’s density to that of distilled water
| Density of urine ranges from 1.001 to1.028 g/mL
195
what is osmolarity of urine
Ranges from 50 mOsm/L to 1,200 mOsm/L in dehydrated person
196
what is urine pH
4.5 to 8.2, usually 6.0
197
what is the chemical composition of urine
95% water and 5% solutes
198
what is normal to and in urine
urea, NaCl, KCl, creatinine, uric acid, phosphates, sulfates, traces of calcium, magnesium, and sometimes bicarbonate, urochrome, and a trace of bilirubin
199
what is abnormal to find in urine
glucose, free hemoglobin, albumin, ketones, bile pigments
200
what is normal urine volume for adults
1 to 2 L/day
201
what is polyuria
output excess of 2 L/day
202
what is oliguria
output less than 500mL/day
203
what is anura
0-100mL/day
204
what can cause anuria
Low output from kidney disease, dehydration, circulatory shock, prostate enlargement
205
what is the definition of diabetes
any metabolic disorder resulting in chronic polyuria; usually as a result of high concentrations of glucose in the renal tubule.
206
what are some characteristics of diabetes mellitus type 1, 2 an dgeatational diabetes
High concentration of glucose in renal tubule
Glucose opposes the osmotic reabsorption of water
More water passes in urine (osmotic diuresis)
Glycosuria—glucose in the urine
207
what is glycosuria
glucose in the urine
208
what is diabetes insipidus
ADH hyposecretion causes not enough water to be reabsorbed in the collecting duct
More water passes in urine
209
inisipidus has __uria but not__uria
ply, glyco
210
what are diuretcs
any chemical that increase urine volume
211
some diuretics increase
GFR
212
what does caffeine do to effect urine volume
dilates the afferent arteriole
213
some diuretics reduce tubular reabsorption of water such as
alcohol which inhibits ADH secretion
214
some diuretics act on a nephron loop to inhibit
Na+–K+–Cl− symport
215
Diuretics are commonly used to treat _- by reducing the body’s fluid volume and blood pressure
hypertension
216
what is renal clearance
The volume of blood plasma from which a particular waste is completely removed in one minute. Clinically measured by blood and urine tests.
217
what is GFR estimated from
creatinine excretion
218
Urination is episodic—
occurring when we allow it
219
what are the ureters
retroperitoneal, muscular tubes that extend from each kidney to the urinary bladder
220
the ureters pass __ to the bladder and enter it from
posterior, below
221
what are the three layers of the ureter
adventitia, muscular, mucosa
222
what does the adventitia consist of
connective tissue layer that connects ureter to surrounding structures
223
what does the muscular consist of
two layers of smooth muscle with third layer in lower ureter
224
as the Urine enters the ureters, it stretches and contracts in
peristaltic wave
225
what is the mucosa consist of
transitional epithelium
226
are males or female more susceptible to UTIs and why
females because of their shorter urethra
227
where is the urinary bladder located
the pelvic floor
228
what are the three layers of the urinary bladder
parietal peritoneum, msucularis(three layers of smooth muscle), and mucosa (consisting of transitional epithelium)
229
Umbrella cells on surface of epithelium of the mucosa layer of the urinary bladder protect it from the
hypertonic, acidic urine
230
what is the capacity of the urinary bladder
moderate fullness is 500 mL, maximum fullness is 700 to 800 mL
231
what is another name for kidney stones
renal calculus
232
what are kidney stones made of
hard granule of calcium phosphate, calcium oxalate, uric acid, or a magnesium salt called struvite
233
where are kidney stones formed
the renal pelvis
234
what is hydronephrosis
pressure buildup in the kidney, can be caused by large kidney stones. this destroys nephrons
235
what is hematuria
damage to a ureter likely caused by jagged kidney stones
236
what are some causes of kidney stones
hypercalcemia, dehydration, pH imbalances, frequency UTIs, or enlarged prostate causing urine retention
237
what are treatments for kidney stones
stone-dissolving drugs, often surgery, or lithotripsy
238
what is lithotripsy
nonsurgical technique that pulverizes stones with ultrasound
239
what is cystitis
an infection of the urinary bladder
240
is cystitis more common in female or males and why
females because of the shorter urethra
241
what frequently triggers cystitis
sexual intercourse
242
cystitis can spread up the ureter causing
pyelitis
243
what is pyelitis
infection of the renal pelvis
244
what is pyelonephritis
infection that reaches the cortex and the nephrons
245
what can cause pyelonephritis
blood borne bacteria
246
what system controls the internal urethral sphincter
sympathetic
247
what system controls the external sphincter
somatic motor fibers
248
what is micturition
the act of urinating
249
what can cause urinary incontinence
spinal cord injuries, a number of diseases, and simple aging
250
stretch receptors detect the filling of the bladder and transmit __ signals to the spinal cord (Involuntary)
afferent
251
signals concerning bladder stretch return to the bladder from spinal cord segments __ and __ via ___ fibers in the pelvic nerve (involuntary)
S2, S3, parasympathetic
252
__ signals excite detrusor muscles (involuntary)
efferent
253
__ signals relax internal urethral sphincter. urine is involuntarily voided if not inhibited by brain (involuntary)
efferent
254
for voluntary control, micturition center in pons receives signals from
stretch receptors
