Lesson 18-19 - Urinary System Flashcards
(165 cards)
1
Q
the urinary system contains four principal organs
A
- two kidneys
- two ureters
- urinary bladder
- urethra
2
Q
functions of the kidney (4)
A
- filer blood and excrete toxic metabolic wastes
- regulate blood volume/pressure/osmolarity
- regulate electrolytes
- regulate acid-base balance
3
Q
the kidneys secrete _____, which stimulates production of RBCs
A
erythropoietin
4
Q
the kidneys help regulate _____ levels by participating in _____ synthesis
A
calcium; calcitriol
5
Q
the kidneys clear _____ from blood
A
hormones
6
Q
the kidneys detoxify…
A
free radicals
7
Q
in starvation, the kidneys synthesize what from what?
A
glucose from amino acids
8
Q
waste
A
any substance that is useless to the body or present in excess of the body’s needs
9
Q
metabolic waste
A
waste substance produced by the body
10
Q
among the most toxic are _____ waste
A
nitrogenous
11
Q
nitrogenous wastes (3)
A
- urea
- uric acid
- creatinine
12
Q
urea comes from the breakdown of…
A
protein
13
Q
uric acid comes from the breakdown of…
A
nucleic acid
14
Q
creatinine comes from the breakdown of…
A
creatine phosphate
15
Q
blood urea nitrogen (BUN)
A
level of nitrogenous waste in the blood
16
Q
azotemia
A
elevated BUN (blood urea nitrogen)
17
Q
azotemia may indicate..
A
renal insufficiency
18
Q
azotemia may progress into _____
A
uremia
19
Q
uremia is characterized by…(4)
A
diarrhea, vomiting, dyspnea, and cardiac arrhythmia stemming from the toxicity of nitrogenous wastes
20
Q
excretion
A
separating wastes from body fluids and eliminating them; carried out by four body system
21
Q
four systems of excretion
A
- respiratory
- integumentary
- digestive
- urinary
22
Q
four systems of excretion: respiratory
A
expels CO2, water, and small amounts of other gases
23
Q
four systems of excretion: integumentary
A
expels water, inorganic salts, lactate, and urea in sweat
24
Q
four systems of excretion: digestive system
A
expels water, salts, CO2, lipids, bile pigments, cholesterol, and other metabolic wastes
25
four systems of excretion: urinary system
expels many metabolic wastes, toxins, drugs, hormones, salts, H+, and water
26
each kidney weighs about
150g
27
renal hilum
receives renal nerves, blood vessels, lymphatics, and ureter
28
the kidneys lie against the _____ abdominal wall at the level of what vertebrae?
posterior; T12-L3
29
why is the right kidney slightly lower than the left?
large right lobe of the liver
30
the kidneys are _____peritoneal, along with what other renal organs?(4)
retro; ureters, urinary bladder, renal artery/vein, and adrenal glands
31
renal fascia
immediately deep to parietal peritoneum
32
function of the renal fascia
binds kidney to the abdominal wall
33
perirenal fat capsule
cushions kidney and holds it in place
34
fibrous capsule
encloses the kidney protecting it from trauma and infection
35
_____ fibers extend from the fibrous capsule to the renal fascia
collagen
36
renal parenchyma
glandular tissue that forms urine
37
renal sinua
medial cavity that contains blood and lymphatics vessels, nerves, and urine-collecting structures
38
two zones of renal parenchyma
- renal cortex
- renal medulla
39
the boundary between the renal cortex and medulla is called...
corticomedullary junction
40
renal columns
extensions of the cortex that project inward toward the sinus
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renal pyramids
triangular shaped structures in the renal medulla
42
the base of renal pyramids is adjacent to the _____, while the apex projects towards the _____ _____
cortex, renal sinus
43
renal papilla
the apex of a renal pyramid
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lobe of kidney
one pyramid and its overlying cortex separated from other lobes by the renal column
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minor calyx
little cup that surrounds the papilla of each pyramid collecting its urine
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major calyx
formed by convergence of 2-3 minor calyces
47
renal pelvis
formed by convergence of 2-3 major calyces
48
ureter
a tubular continuation of the renal pelvis that drains urine to the urinary bladder
49
each nephron is composed of two principal parts
- renal corpuscle
- renal tubule
50
renal corpuscle
filters the blood plasma
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renal tubule
long, coiled tube that converts that filtrate into urine
52
the portions of the renal tubule (4)
- proximal convoluted tubule (PCT)
- loop of henle (nephron loop)
- distal convoluted tubule (DCT)
- collecting duct (CD)
53
the renal corpuscle consists of..(2)
the glomerulus and a two-layered glomerular capsule
54
structure of the glomerular capsule
- parietal (outer) layer
- visceral (inner) layer
55
glomerular capsule: parietal layer is composed of...
simple squamous epithelium
56
glomerular capsule: visceral layer consists of...
podocytes that wrap around the capillaries of the glomerulus
57
capsular space
separates the two layers of the glomerular capsule
58
mesangial cells
pack the spaces amount the glomerular capillaries
59
mesangial cells regulate
blood flow and phagocytize debris
60
renal tubule
duct leading away from the glomerular capsule and ending at the tip of the medullary pyramid
61
the renal tubule is divided into four regions
1. proximal convoluted tubule
2. nephron loop
3. distal convoluted tubule
4. collecting duct
62
which portion of the renal tubule is the longest and most coiled region?
proximal convoluted tubule
63
which portion of the renal tubule absorbs 99% of all glucose, amino acids, etc?
proximal convoluted tubule
64
the proximal convoluted tubule is lined with...(2)
- simple cuboidal epithelium
- with prominent mircovilli
65
the descending limb of the nephron loop absorbs...
water
66
the ascending limb of the nephron loop absorbs...
Na+ and Cl-
67
the thick segment of the nephron loop is composed of...
simple cuboidal epitheloum
68
the thin segment of the nephron loop is composed of...
simple squamous epithelium
69
the thick segment of the nephron loop is impermeable to...
water
70
the thin segment of the nephron loop is VERY permeable to...
water
71
the thick/thin segment of the nephron loop has many mitochondria
thick
72
the distal convoluted tubule begins...
shortly after the ascending limb re-enter the cortex
73
the distal convoluted tubule is composed of...
cuboidal epithelium without the microvilli
74
collecting duct
receives fluid from the DCTs of several nephrons as it passes back into the medulla
75
numerous collecting ducts converge where?
toward the tip of the medullary pyramid
76
papillary duct
formed by merging of several collecting ducts
77
where are juxtamedullary nephrons positioned?
close to the medulla
78
juxtamedullary nephrons loop can extend as far as...
the apex of a renal pyramid
79
which type of nephron sometimes has no nephron loop at all?
cortical
80
what type of nephron is the majority of them?
cortical
81
renal plexus
nerves and ganglia wrapped around each renal artery
82
what nephrons are almost solely responsible for maintaining the osmotic gradient in the medulla?
juxtamedullary
83
what does the renal plexus issue?
nerve fibers to blood vessels and convoluted tubules of the nephron
84
the renal plexus carries what kind of innervation?
sympathetic innervation from the abdominal aorta
85
stimulation from the renal plexus reduces/increases glomerular blood flow and rate of urine production
reduces
86
how does the renal plexus responds to falling blood pressure?
stimulating the kidneys to release renin
87
renin
an enzyme that activates hormonal mechanisms to restore blood pressure to trigger the renin-angiotensin system
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four stages of blood plasma to urine
1. glomerular filtration
2. tubular reabsorption
3. tubular secretion
4. water conservation
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fluid has three different names as it passes through the nephron
- glomerular filtrate
- tubular filtrate
- urine
90
fluid has three different names as it passes through the nephron: glomerular filtrate
fluid in the capsular space
91
what is the difference between blood plasma and glomerular filtrate?
glomerular filtrate has almost no protein
92
fluid has three different names as it passes through the nephron: tubular fluid
fluid from the proximal convoluted tubule through the distal convoluted tubule
93
fluid has three different names as it passes through the nephron: urine
fluid within the collecting duct and beyond (no real changes minus water content)
94
glomerular filtration
water and some solutes pass from blood within the glomerulus into the capsular space of the nephron
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filtration membrane
barrier through which filtered fluid passes
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three portions of the filtration membrane
- fenestrated endothelium of the capillary
- the basement membrane
- filtration slits
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three portions of the filtration membrane: fenestrated endothelium of the capillary
contains large filtration pores that are highly permeable but small enough to exclude RBCs
98
three portions of the filtration membrane: basement membrane
proteoglycan gel with a negative charge, excluding molecules greater than 8nm
99
three portions of the filtration membrane: filtration slits
podocyte foot processes (pedicles) wrap around the capillaries creating negatively charged filtration slits between them
100
almost any molecules smaller than _____ nm can pass freely through the filtration membrane
3
101
things that can pass through the filtration membrane (8)
water, electrolytes, glucose, fatty acids, amino acids, nitrogenous wastes, vitamins
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Some substances of low molecular weight are bound to plasma proteins and cannot get through the membrane (3)
calcium, iron, thyroid hormone
103
proteinuria (albuminuria)
albumin in urine
104
hematuria
blood in urine
105
blood hydrostatic pressure (BHP)
60 mmHg
106
why is BHP high in the glomerular capillaries?
because afferent arteriole is larger than the efferent
107
hydrostatic pressure in the capsular space
18 mmHg
108
why is the hydrostatic pressure so low in the capsular space?
due to high filtration rate and accumulation of fluid in the capsule
109
colloid osmotic pressure (COP) of bloos
32 mmHg
110
net filtration pressure (NFP)
BHP - (HP of capsular space) - COP
111
glomerular filtration rate (GFR)
amount of filtrate formed per minute by the two kidneys combined
112
filtration coefficient (Kf)
depends on permeability and surface area of filtration barrier
113
what happens if GFR is too high? (2)
- fluid flows through the renal tubules too rapidly for them to reabsorb the usual amount of water and solute
- urine output rises, increasing chance of dehydration and electrolyte depletion
114
what happens if GFR is too low?
wastes are reabsorbed and azotemia may occur
115
what is the only way to adjust GFR from moment to moment?
change glomerular blood pressure
116
changes in glomerular blood pressure occur through three mechanisms
- renal autoregulation
- sympathetic control
- hormonal control
117
renal autoregulation
the ability of the nephrons to adjust their own blood flow and GFR without external control
118
what does renal autoregulation enable the kidneys to do?
maintain relatively stable GFR
119
renal autoregulation happens in two ways
- myogenic mechanism
- tubuloglomerular feedback
120
myogenic mechanism
if arterial blood pressure increases, the afferent arteriole is stretched which leads to afferent arteriole constriction which reduced blood flow into the glomerulus
121
tubuloglomerular feedback
when GFR is high, the macula densa secretes ATP which ultimately stimulates nearby granular cells to constrict the afferent arteriole to reduce GFR
122
granular cells secrete _____ if blood pressure is low to trigger what pathway?
renin; renin-angiotensin-aldosterone system
123
_____ nerve fibers richly innervated the renal blood vessels
sympathetic
124
these two things constrict the afferent arteriole in strenuous exercise
- sympathetic nervous system
- adrenal epinephrine
125
sympathetic nervous system's effect on the afferent arteriole (2)
- reduces GFR and urine output
- redirects blood from the kidneys to other organs
126
renin-angiotensin-aldosterone mechanism: in response to a drop in BP, _____ (type of receptor) in the _____ and ____ stimulate the _____ nervous system
baroreceptors; carotid, aorta, sympathetic
127
renin-angiotensin-aldosterone mechanism: _____ fibers trigger release of _____ by kidney's _____ cells
sympathetic, renin, granular
128
renin converts....
angiotensinogen into angiotensin 1
129
the lungs and kidneys have this enzyme that converts angiotensin 1 to angiotensin 2
angiotensin-converting enzyme (ACE)
130
angiotensin 2
a hormone that acts in several ways to restore fluid volume and blood pressure
131
angiotensin II is a potent _____
vasoconstrictor; raised blood pressure throughout the body
132
angiotensin II constricts _____ arterioles in the kidney's
efferent; raising GFR despite low BP
133
constriction of the efferent arteriole lowers BP where?
peritubular capillaries enhancing reabsorption of NaCl and water
134
angiotensin II stimulates the adrenal cortex to secrete _____
aldosterone
135
aldosterone
promotes Na+ and water reabsorption in the PCT
136
angiotensin II stimulates the posterior pituitary to release...
antidiuretic hormone
137
antidiuretic hormone
promotes water reabsorption by the collecting duct
138
what hormone stimulates third and encourages water intake?
angiotensin II
139
aminoaciduria
amino acids found in urine
140
tubular reabsorption
process of reclaiming water and solutes from tubular fluid and returning them to blood
141
glucose is cotransported with sodium during reabsorption by....
sodium-glucose transporters (SGLTs)
142
urea is reabsorbed with _____
water
143
nephrons reabsorbs about half of urea in ______ fluid
tubular
144
obligatory water reabsorption
in the PCT, water reabsorbed independent of hormones at a constant rate
145
two thirds of water in filtrate is reabsorbed where?
PCT
146
reabsorption of solutes makes the _____ cells and tissue fluid _____ to tubular fluid
tubule; hypertonic
147
peritubular capillaries reabsorb water and solutes that leave the _____ surface of the tubular epithelium
basal
148
reabsorption occurs by...(2)
- osmosis
- solvent drag
149
purposes of secretion of PCT and nephron loop include: acid-base balance
secretion of varying proportions of hydrogen and bicarbonate ions help regulate pH of body fluids
150
purposes of secretion of PCT and nephron loop include: waste removal
urea, uric acids, bile acids, ammonia, excess ions, and a little creatinine are secreted into the tubule
151
purposes of secretion of PCT and nephron loop include: clearance of drugs and contaminants
such as morphine, penicillin, and aspirin; some drugs must be taken multiple times per day to keep up with renal clearance
152
ions leave the nephron loop leave cells by....
active transport and diffusion
153
NaCl remains in tissue fluid of the ______ ______
renal medulla
154
tubular fluid is _____ as it enters the distal convoluted tubule
dilute (very dilute)
155
DCT and the collecting duct reabsorb variable amounts of _____ and _____ and are regulated by these hormone
water, salt
- aldosterone
- atrial natriuretic peptide
- ADH
- parathyroid hormone
156
aldosterone
steroid hormone that stimulates reabsorption of sodium and secretion of potassium
157
aldosterone is secreted by the adrenal cortex when... (2)
- blood Na+ concentration falls of K+ concentration rises
- drop in BP stimulates renin release, leading to aldosterone secretion
158
aldosterone acts on which portions of the nephron? (3)
- thick segment of the ascending loop of Henle
- DCT
- cortical portion of collecting ducts
159
antidiuretic hormone
stimulates water retention by the kidney
160
what does ADH do to the nephron?
makes the collecting duct more permeable to water to cause more water reabsorption
161
the collecting duct can produce a _____ urine
hypertonic
162
as urine passes through the increasingly _____ medulla, water leaves the CD by _____, ______ urine
salty, osmosis, concentrating
163
ADH stimulates an increase in ______ _____ in the collecting ducts to cause more water reabsorption
aquaporin channels
164
ureters are ______peritoneal
retro
165
wall of the bladder consists of (4)
- muscularis called the detrusor
- the trigone
- mucosa lined with urothelium (transitional epithelium)
- rugae
