Chapter 14: Urinary System Flashcards
1
Q
the kidneys are primarily responsible for
A
- maintaining the stability of the ECF volume
- water and electrolyte composition
- blood pressure
- osmolarity
2
Q
kidneys are the main route for
A
- eliminating potentially harmful substances
- metabolic wastes
- foreign compounds in the body
3
Q
the outer surface of the kidney is called
A
the renal cortex
4
Q
the inner surface of the kidney is called
A
renal medulla
5
Q
function of the ureters
A
carry urine from the kidneys to the urinary bladder
6
Q
function of the urinary bladder
A
- temporarily stores urine
- excretion
7
Q
urethra function
A
- provides route for eliminating urine from the bladder
- provides a route for semen in males
8
Q
in which gender is the urethra longer
A
males
9
Q
how many nephrons are there in a kidney
A
1 million
10
Q
the renal medulla is made up of
A
striated triangles called renal pyramids
11
Q
what structures are apart of the vascular component
A
- afferent arteriole
- glomerulus
- efferent arteriole
- peritubular cappilaries
12
Q
afferent arteriole
A
carries blood to the glomerolus
13
Q
glomerulus
A
a tuft of capillaries that filters a protein free plasma into the tubular component
14
Q
efferent arteriole
A
carries filtered blood from the glomerulus
15
Q
peritubular capillaries
A
supply the renal tissue; involved in exchange within the fluid in the tubular lumen
16
Q
what structures are apart of the tubular component
A
- bowmans capsule
- proximal tubule
- loop of henle
- distal tubule and collecting duct
17
Q
bowmans capsule
A
- collects the glomerolar filtrate
18
Q
proximal tubule
A
uncontrolled reabsortion and secretion of selected substances occur here
19
Q
loop of henle
A
establishes an osmotic gradient in the renal medulla that is important in the kidneys ability to produce urine of varying concentrations
20
Q
distal tubule and collecting duct
A
- variable, controlled reabsorption of sodium and water, and secretion of potassium and hydrogen occur here
- fluid leaving thr collecting duct is urine which enters the renal pelvis
21
Q
what structure is apart of the combined tubular/vascular component
A
- Juxtaglomerular apparatus
22
Q
Juxaglomerular apperatus
A
produces substances involved in the control of kidney function
23
Q
cortical nephrons
A
- lie in the outer layer of the cortex
24
Q
what percentage of nephrons are cortical
A
80
25
juxtamedullary nephrons
- lie in the inner layer of the cortex
- performs most urine concentrations
26
glomerular filtration
filtrate protein free plasma
27
what structures are involved in glomerular filtration
- glomerulus
- bowmans capsule
28
tubular reabsorption
- absorbs nutrients, ions, and electrolyte
29
what structures are involved in tubular secretion
- kidney tubules
- peritubular capillaries
30
tubular secretion
- movement of non filtered substances
31
structures involved in tubular secretion
- peritubular capillaries
- kidney tubules
32
glomerular capillary wall
- a single layer of endothelial cells
- more permeable to water and solutes than capillaries elsewhere in the body
- filtration
33
basement membrane
- acellular gelatinous layer
- composed of collagen and glycoproteins (discourage filtration of small proteins)
- do not filter plasma proteins
34
inner layer of the bowmans capsule is made up of
podocytes foot processes that encircle the glomerolar tuft
- connective tissue
35
what are the barriers to the substances that are filtered
- endothelial cells
- basement membrane
- podocyte foot proceeses with filtration slips
36
what do podocytes contain
filtration slips
37
which structure within the glomerolus discourages that plasma protein filtration
basement membrane
38
pressure excreted by the blood within the glomerular capillaries depends on (3 things)
- contration of the heart
- resistance to blood flow offered by afferent and efferent arterioles
- the smaller diameter of the efferent arteriole
39
what is the major force producing glomerular filtration
Glomerular capillary blood pressure
40
Glomerular capillary blood pressure effect
favours filtration
41
Glomerular capillary blood pressure magnitude
55
42
Plasma colloid osmotic pressure is caused by
the unequal distribution of plasma proteins across the glomerular membrane (by osmosis)
43
Plasma colloid osmotic pressure effect
opposes filtration
44
Plasma colloid osmotic pressure magnitude
30
45
the pressure excreted by fluid in the initial part of the tubule
Bowmans Capsule Hydrostatic pressure
46
Bowmans Capsule Hydrostatic pressure effect
opposes filtration
47
Bowmans Capsule Hydrostatic pressure magnitude
15
48
Differnece between force favouring filtration and forces opposing filtration
Net filtration pressure
49
Net filtration pressure effect
favours filtration
50
Net filtration pressure magnitude
10
51
How to calculate glomerular filtration rate
Glomerular capillary blood pressure - (plasma colloid pressure + bowmans capsule hydrostatic pressure)
52
Glomerular filtration rate depends on (3 things)
- net filtration pressure
- glomerular surface area avaliable for penetration
- permeable golmerolar membrane
53
GFR in males
125ml/min
54
GFR females
115ml/min
55
When the plasma colloid pressure and Bowmans Capsule hydrostatic pressure is constant, the glomerular capillary goes up, and the net filtration pressure increases what is the effect of the GFR
increases
56
effect of increasing the arterial blood pressure on GFR
increases GFR
57
what are the two mechanisms that control GFR
- auto regulation
- Extrinsic sympathetic NS
58
autoregulation
prevents spontaneous changes in GFR
- myogenic mechanism (effects smooth muscles)
- tubuloglomerular feedback (TGF)
59
Extrinsic sympathetic control
- regulates long term blood pressure regulation
- mediated by the sympathetic nervous system input to the afferent arterioles
- baroreceptor reflex
60
mechanisms effect on GFR
- regulates caliber / diameter
- resistance in the afferent arterioles
61
vasoconstriction in the afferent arterioles effect on GFR
decreases GFR
62
vasodilation in the afferent arterioles effect on the GFR
increase GFR
63
smooth muscle cells within the wall of the afferent arteriole contains
granular cells
64
specialized tubular cells in the juxtaglomerular region contains
macula densa cells
65
function of the macula densa cells
converts ATP to adenosine
66
effect of adenosine on the afferent arterioles
vasodilates them, increasing the GFR
67
extrinsic control of the GFR is perpetrated by
- sympathetic nervous system
- baroreceptors
- filtration coefficent
68
paprasympathic effect on kidneys
there is no parasympathetic effect on the kidneys
69
which mechanisms is stronger
extrinsic controls can override the auto regulatory responses
70
where are the barorecpetors located
- aprtic arch
- carotid sinus
71
decreased GFR effect on urine production
decreases urine production
72
reduced urine output effect on GFR
decreases
73
the rate of glomerular filtration depends on,
- filtration coefficent
- net filtration pressure
74
the KF depends on
- surface area
- the permeability of the glomerular membrane
75
what determines the permeability of the glomerular membrane
- the number of flitration slips in the podocytes open
76
purpose of tubular reabsorption
maintain the proper composition & volume of the ECF
77
the tubules have a ____ _______ ______. for substances needed by the body
high absorpative capacity
78
excess amounts of essential electrolytes are
excreted in the urine
79
the rate at which substances are reabsorbed depends upon
- deficency
- absorbative capacity
80
tubular reabsorption involves ________ transport
transepithelial
81
what is the sequence of transepithelial transport in tubular reabsorption
1. luminal cell membrane
2. the cytosol
3. the basolateral cell membrane
4. the interstitial fluid
5. the peritubular capillary wall
82
what is the sequence of transepithelial transport in tubular secretion
1. the peritubular capillary wall
2. the interstitial fluid
3. the basolateral cell membrane
4. the cytosol
5. the luminal cell membrane
83
ways of transport
- active
- passive
84
passive transport
- no energy required
- substances move down the electrochemical and osmotic gradients
84
active transport
- requires ATP use
- substances move against the electrochemical gradient
84
examples of active transport
- glucose
- Na / K
- Cl
- electrolytes
- PO4/3
85
average percentage of filtered water reabsorbed
99
86
average percentage of sodium reabsorbed
99.5
87
average percentage of glucose reabsorbed
100
88
average percentage of urea reabsorbed
50
89
average percentage of phenol reabsorbed
0
90
average percentage of filtered water excreted
1
91
average percentage of filtered sodium excreted
0.5
92
average percentage of glucose excreted
0
93
avergae percentage of filtered urea excreted
50
94
average percentage of filtered phenol excreted
100
95
phenol is a _____
toxin
96
what percentage of Na si reabsorbed in the proximal tubule
67
97
proximal tubule plays a role in reabsorbing
- glucose
- amino acids
- h2o
- cl
- urea
98
percentage of Na reabsorbed in the ascending limb of the loop of henle
25
99
the ascending loop of henle plays a critical role in the kidneys ability to
produce urine of varying concentration
100
percentage of Na reabsorbed in the distal and collecting tubules
8
101
what part of the kidney is effected by ADH during dehydration
distal and collecting tubules
102
of the total energy spent by the kidneys what percentage is used for Na transportation
80
103
glucose and amino acids are reabsorbed by which part of the nephron
proximal tubules
104
how are amino acids and glucose reabsorbed
co-transport carrier molecules
105
filtered load of glucose
quantity of any substance filtered per minute
106
what is the normal plasma concentration of glucose
100mg/100ml
107
formula for filtered load
plamsa concentration x GFR
108
at constant GFR, the filtered load of glucose is __________ proportional to the plasma glucose concentration
directly
109
what is the tubular maximum for glucose
375mg/min
110
what happens if the glucose level is above the TM
1. TM will exceed 375
2. plasma glucose concetration must not exceed more than 375
3. spill into the urine
111
TM
- when the moximum reabsorption rate is reached, and when all carriers specific for a particular substance is fully occupied, they cannot handle any additional glucose at this time, this is TM
112
what is one of the first characteristics identified in a patient with sever renal failure
elevated urea
113
TS provides
a socond route of entery to the tubule for selected substance
114
tubular secretion includes
- h
- k
- organic ions and cation
115
H
important in regulating the acid base balance
- secreted in the proximal, distal, and collecting tubules
116
k
- keeps the plasma concentration at an approprite level to maintain the normal membrane excitability in the muscles and nerves
- secreted only in the distal and collecting tubules under the control of aldosterone
117
organic ions
- accomplish more efficent elimination of foreign organic compounds from the body
- secreted only in the proximal tubule
118
h is secreted in
- proximal, distal and collectign tubules
119
k is secreted in
the distal and collecting tubules under the control of aldosterone
120
organic ions is secreted in
the proximal tubule
121
decrease in na / ECF volume / decreased arterial blood pressure
Activates RAAS
casues an increase in renin --> increased angiotension I --> concerts to angiotension II -->stimulates aldosterone
122
effect of aldosterone
- increases tubular k secretion (increased urinary k excretion)
- increased tubular Na reabsorption (decreased urinary Na excretion)
123
plasma clearance
the volume of plasma cleared of a particular substance / min
OR
the plasma volume completetely cleared of the substance ny kidney/min
124
plasma clearance ecpresses
the kidneys effectiveness in removing substances from the internal fluid enviorment
125
what percentage of insulin is excreted
100
126
what percentage of of urea is excreted
50
127
what percentage of glucose is excreted
0
128
what percentage of h are excreted
100
129
plasma clearance formula
urine concentration x urine flow rate
130
what are three diuretic substances
1. ANP
2. Alcohol
3. coffee
131
Atrial natriuretic peptide
where is it secreted?
when is it secreted?
- hormone secreted by the atria
- secreted is responce to increased salt, increased volume, or increased artrial pressure
132
Atrial natriuretic peptide effects
- decreased sodium reabsorption by the kidney tubules (increased sodium and water excretion in the urine)
- decreased salt conserving renin-angiotensin-aldosterone system (increased sodium and water excretion in the urine)
- smooth muscle of afferent arterioles vasodilation (increases GFR)
- sympathetic nervous system, decreases CO and TPR (decreases arterial blood pressure)
133
Isotonic
solute concentration is equal to the water concentration
134
hypotonic
if too much water is present than the solute load, the body fluid is said to be hypotonic / diluted
135
hypertonic
if less water is present than the solute load, the body fluid is too concentrated
136
what part of the nephron is involved in the formation of concentrated or diluted urine
loop of henle
137
decending loop of henle is only permeable to ______
water
138
what is the result of the filtrate once it is filtered through the descending loop of henle
- highly concentrated urine
- hypertonic solution
139
ascending loop of henle is only permeable to ______
salt
- impermeable to water
140
vasopressin is present during
dehydration
141
the countercurrent multiplication mechanism is established by the
medullary vertical osmotic gradient
142
countercurrent multiplication
the passive exchange of solutes and water between the two limbs of the loop of henle
143
obligatory is located in the
proximal tubule
144
secretion of vasopressin ______ cells permeability to water
increases
145
vasopressin runs on a _______ feedback loop
negative
146
what are the four functions of the renin-angiotensin-aldosterone system
1. aldosterone increases reabsorption in the distal and collecting tubules
2. promotes salt retention and resultant water retention and elevation of arterial blood pressure
3. angiotension -II is a potent constrictor of the systemic arterioles, thus increasing blood pressure and peripheral resistance
4. stimulates thirst and vasopressin release
147
angiotensinogen is secreted by the
liver
148
renin is secreted by the
kidneys
149
angitotensin-I converts to angiotension-II through what enzyme
angiotension converting enzyme
150
angiotension converting enzyme is secreted by the
lungs
151
the adrenal cortex is responsible for
- aldosterone
- thirst
152
angiotensin II causes the secretion of ______ form the _______
vasopressin / ADH
posterior pituitary
153
ADH is produced by the
hypothalmus
154
functions of angiotensin II
- cause the release of vasopressin
- stimulates thirst
- responsible for arteriolar vasoconstriction
155
the bladder is guarded by
two sphincters
- internal
- external
156
micturition 2 types of control
- reflex control
- voluntary control
157
external urethral spinchter opens when
motor neuron in INHIBITED
158
external urethral sphincter closes when
motor neuron is STIMULATED
