Physiology Exam 3 Flashcards
(401 cards)
1
Q
How do kidneys regulate osmolarity of fluids?
A
Urine, water and solute concentrations
2
Q
What ions does the kidney regulate plasma concentrations of?
A
Na+, K+, CA2+, Mg2+, Cl-, HCO3-, Phosphate and sulfate
3
Q
What are commonly used treatments of end stage kidney failure?
A
Transplant and dialysis
4
Q
What can the kidney remove?
A
Many drugs, drug metabolites, foreign or toxic substances
5
Q
What hormones dos the kidney degrade?
A
Insulin, glucagon, parathyroid hormone
6
Q
Where is ammonia synthtesized?
A
The kidney, where it plays a role in acid base homestasis
7
Q
Where is Vitamin D3 synthesized?
A
Kidney
8
Q
Where is EPO synthesized?
A
Kidney
9
Q
How does the kidney playa role in regulating acid bas balance?
A
By altering renal H+ excretion and HCO3- reabsorption
10
Q
How does the kideny regulate the volume of extracellular fluid?
A
By controlling Na+ and water excretion
11
Q
How does the kidney help regulate arterial blood pressure?
A
By adjusting Na+ excretion and producing various substances such as renin that can affect the blood pressure.
12
Q
What waste products of metabolism are elminated by the kidney?
A
Urea, uric acid, and creatinine
13
Q
What is the main nitrogen containing end product of protein metabolism?
A
Urea
14
Q
WHat is the end product of muscle metabolism?
A
Creatinine
15
Q
What is the end product of purine metabolism?
A
Uric Acid
16
Q
Where does the O2 ultimately go?
A
Mitochondria (ATP)
17
Q
Where does gas exchange occur?
A
Alveolia and capillary
18
Q
3 Factors that affect gas exchange
A
Surface area
respiratory membrane
blood supply (amount)
19
Q
Trace the airway tree all the way to capillary
A
Oral cavity Oropharnyx larnyx trachea carina primary secondary tertiary smaller bronchioles bronchioles terminal bronchioles respiratory bronchioles Alveolar sacs Alveoli
20
Q
WHere do the respiratory bronchiles start?
A
when you start to see alveoli
21
Q
What about alveoli make it goor for gas exchange
A
good blod supply
thin membrane
22
Q
How do bronchioles shange their radius?
A
they use smooth muscle
23
Q
At what size do the bronchioles start?
A
1mm
24
Q
what are the 2 functional zones of ventilation?
A
respiratory
conducting
25
How many total generations of ther ventilatory functional zones are there?
23 brnaches
16 in the conducting
7 in the respiratory
26
Describe conducting zone
Anatomical dead space (150ml)
16 branches
upper zone
conducts air to the respiratory zone
27
Describe respiratory zone
Respiration through bronchioles and alveoli
350ml normal value of participating air space
7 branches
this is where gas exchange occurs
28
Describe dead space
where no respiration occurs
| 150ml normal value
29
normal tidal volume
500ml
30
What secretes mucous in lungs?
goblet cells
31
WHat are cilia extensions of?
plasma membrane
32
Describe mucous elevator
cilia brings mucous and particles up airway to oral cavity where they are swalloed
similar to mexican wave
33
Is there mucous and cilia in respiratory zone
no, only in the conducting zone
| Macrophages are in respiratory zone
34
What is used to help keep respiratory zone clean
macrophages
35
Where is cartilage distribution in airway?
Cartilage gets less and less as you go down the conducting zone
none in respiratory zone
Cartilage is C shaped
36
Where is the smooth muscle distribution in the airway?
none at the top
| lots in the bronchioles
37
What does smooth muscle do in the airway
Bronchoconstriction
| bronchodilation
38
Where is there no goble cells, mucous, cilia, cartilage
Respiratory zone
39
What are muscles for inspiration
Diaphram
sternocleidomastoid
scalenes
external intercostal
40
Is inspiration active or passive?
active
41
Is expiration active or passive
passive (unless forced)
42
Describe expiration at rest
normal
passive
no energy expended
diaphragm relaxes recoil of lungs (which have elastic properties)
43
Describe forced expiration
```
Cough, sneeze, balloon
Abdominal muscles
rectus abdominus
external obliques
internal intercostals
```
44
Describe the rib movement on respiration
Like a bucket handle
on inspiration they go up and out
on exhalation they go down and in
45
Describe pressure gradient fro inspiration vs expiration
Gas moves from high pressure to low pressure
46
How do we change pressure in the lungs
we change the volume which changes the pressure
47
how does pressure change on inspiration
the volume increases and the pressure drops which allows air to flow in
48
How does pressure change on expiration
teh volume decreases, the pressure then increases which expels air
49
What is the complete process for inspiration
```
the inspiratory muscle contract
the diaphragm decends
the rib cage rises
THoracic cavity volume increases
the lungs are stretched
the intrapulmonary volume increases
the intrpulmonary pressure decreases
Air then flows into the lungs down the pressure gradient
The air continnues until pressure equalizes at 0 atm
```
50
What is the complete process for expiration
```
inspiratory muscles relax
diaphragm rises
rib cage descends
thoracic cavity volume decreases
intrpulmonary pressure increases
air flows out of lungs
down pressure gradient until 0 ATM
```
51
WHat shape is the diaphragm
concave when relaxed
| flattens out when it contracts
52
What do muscles do on inspiration
diaphragm moves inferiorly and flattens out
intercostals increase latteraly
sternocleidomastoid and scalene help superiorly
53
what is the P in PO2and PCO2
partial pressure
54
What is the total pressure at sea level
760mmhg
55
what is percentage of oxygen on earth regardless of altitude
21% o2
79% nitrogen
1% everything else
56
What is PO2 when inhaled
160mmhg
57
What is PO2 in alveoli
104mmhg
58
what is PO2 in arterial blood?
95mmhg
59
What is the PO2 in the tissues/capillary
40mmhg
60
WHat happens when the arterial blood at 95mmhg reaches the capillaries at 40mmhg?
the O2 in the blood will go down the pressure gradient and into the tissue
61
What is the PO2 of the venous blood
40mmhg
62
Trace PO2 pressure through circulation
```
inhaled 160mmhg
lungs 104
arterials 95
capillaries 40
venous 40
lungs 104
```
63
What happens to the deoxgenated blood when it gets back to the lungs in regards to pressure
the O2 inhaled at 160mmhg travels down the pressure gradient and oxygenates the blood returning to the lungs at 40mmg to restart the cycle.
64
What is the nitrogen air percentage inhaled and exhaled
79% for both, doesn't change
65
What is O2 percentage in haled and exhaled
21% inhaled
15-18% back out
the more intense the exercise, the less the %
66
What is the CO2 percentage inhaled and exhaled
0.04% inhaled
3-5% back out
HIgher instenisty activity, higher percentage
67
What is H2O percentage in haled and exhaled
.46% in
.46% out
No change
68
WHat is co2 pressure in arterials
40%
69
What is CO2 pressure in capillaries
46%
70
Why don't we need as much of a pressure gradient for CO2
it is more soluble
71
How does CO2 get back into blood i the tissue
```
travels down pressure gradient
46% in tissue
40% in blood
travels through venous system
and exhaled
```
72
What prevents natrual airway collapse
the intrapleural sac
a negative pressure between the two pleurae
suction force
causes chest wall and lung to move together
73
with a pneumothroax, what does the loss of negative pressure allow?
it allows the recoil of the lungs to happen and the lungs collapse
lung pulls away from chest wall
lung becomes inefficeint due to loss of surface area
74
What does the alveolar cycle mimic?
the lung cycle
| inhalation and exhalation
75
Trace alveolar cycle
```
Inspiratory muscles contract
thoracic cavity expands
pleural pressure becomes more negative
transpulmonary pressure increases
lungs inflate
alveolar pressure becomes subatmospheric
air flows into the lungs until alveolar pressure equals atmospheric pressure
```
76
What does spirometry measure
lung volume
77
On a PFT report, what does a downward deflection represent?
expiration
78
On a PFT report, what does a upward deflection represent?
Inspiration
79
PFT Inspiration categories
IRV Inspiratory reserve volume 3.1 liters
80
PFT expiratory categories
ERV expiratory reserve volume 1.2 liters
RV Residual volume 1.2 liters
FRC functional residual capacity 2.4 liters
81
PFT Both inspiratory and expiratory categories
VT tidal volume (500ml)
IC inspiratory capacity 3.6 liters
VC Vital capacity 4.8 Liters
TLC total lung capacity 6 liters
82
What is FVC?
Forced vital capacity
maximum amount of air forcibly exhaled at a maximum inhalation
4.8L
83
What is FEV1/FVC
Forced expired volume / forced vital capacity ratio
Percentage of FVC exhaled in 1 sec
80% is normal
84
What is FEV1
forced expiratory volume
Maximum volume of air forcibly exhaled in 1 second
4.0L
85
What is TLC
```
Total lung capacity
The volume of air in the lungs at the end of maximum inspiration
Everything on graph combined
IRV+VT+ERV+RV=TLC
6L
```
86
WHat is VC
Vital capacity
Maximum volume of air that can be exhaled
IRV+VT+ERV=VC
4.8L
87
WHat is IC
Inspiratory capacity
Maximum amount of air inhaled at end of normal inspiration
VT+IRV=IC
3.6L
88
What is VT
Tidal volume
Volume of air inhaled and exhaled with each normal breath
500ml
89
What is FRC
```
Funtional residual capacity
Volume of air remaining in lungs at the end of normal tidal volume
ERV+RV=FRC
2.4L
(Expiration)
```
90
WHat is RV
Residual Volume
Volume of air remaining in lungs after maximum exhalation
1.2L
(Exhalation)
91
What is ERV
Expiratory reserve volume
Maximum volume of air exhaled at end of tidal volume
1.2L
(exhalation)
92
What is IRV
Inspiratory reserv volume
Maximum volume of air inhaled at the end of normal inspiration
1.2L
(Inspiration)
93
Wha tis normal percentage for FEV1/FVC ratio
80%
94
WHat is normal FEF
25-75
95
In obstructive disorder what does FEV1/FVC ratio do
decrease
96
In obstructive disorder what does FVC do
Decrease or could be normal
97
In obstructive disorder what does FEV1 do
Decrease
98
In restrictive disorder what does FEV1/FVC do
Normal or increases
99
In restrictive disorder what does FEV1 do
decrease
100
In restrictive disorder what does FVC do
decrease
101
Examples of obstructive disorders
Emphysema
Chronic bronchitis
bronchiectasis
asthma
102
Examples of restrictive disorders
```
intersitual lung disease
idiopathic pulmonary fibrosis
pneumoconiosis
sarcoidosis
chestwall neurmuscular disease
```
103
Why dont lung disease spread to the other lung typically
lungs are seperatate and comparmentalized
104
Describe the restrictive disorder
Reduced expansion of lung parenchyma accompanied by decreased lung total capcacity
105
Describe obstructive disorder
Limitation of airflow due to partial or compele obstruction
106
WHat is minute ventilation
```
tidal volume times respiration rate
ve=vt x f
example
500 x 12 = 6000
not really important compared to alveolar ventilation
```
107
What is alveolar ventilation
```
subtract the dead space from the tidal volume
then multiply times respiration rate
example
500-150 =350
350 x 12 = 4200
```
108
How is alveolar vetilation calculated
by measuing a persons expired CO2
109
What happens to CO2 in hypoventilation?
retain more CO2
| more CO2 in blood
110
What happens to CO2 in hyperventilation?
Blow off more CO2
| Blood becomes more basic
111
What is hypernea
INcreased breathing and metaboic rate due to exercise
112
what is the relationship between PAco2 and alveolar ventilation
they are inversely related
113
What does lung compliance measure
distensibilty
114
Will it be harder or easier to breath if lung compliance is low
harder
| it will be more difficult to inhale due to a stiffer lung
115
Will it be harder or easier to breath if lung compliance is high
it will be easier
| less work to inflate the lung
116
how does gravity affect the alveoli in the lung
The weight of the lung compress the alveoli in the base of the lung
117
contrast the alveoli in the base of the lung verse the apex
at the base, they are small alveolus that can expand greatly and have high comliance
at the apex, alveolus are larger, respiration is poorer, they change very little in size and the compliance is low
118
WHat does surfactant do?
lowrs the surface tension and stabalizes alveoli at low lung volumes
it is like dish soap
reduces the tendency of alveoli to stick together
keeps alveoli from collapsing
119
What cells secrete surfactant
Type 2 endothelial cells
120
What kind of cells are type 1 endothelial cells
simple squamous
121
How does alveolar surface tension affect lung compliance
Increased surfactant = increased compliance
less surfactant = less compliance
increased comliance = increased volume at a givn pressure
122
Is ther more surfactnat in smaller or larger alveoli
Smaller alveoli have more surfactant
larger alveoli have less surfactant
this negates any pressure gradient and keeps the alveoli from collapsing
123
What are the cells of the alveoli
simple squamous epithlial
1 layer
flat squashed cells
124
Are the majority of the alveoulus type 1 or type 2 cells
type 1 cells make up majority
125
Are alveoli seperate or connected
they are all connected via pores
126
Why do alveoli have macrophages
they have no cilia or mucous
127
Select the correct statement about the physical factors influencing pulmonary ventilation.
A. A decrease in compliance causes an increase in ventilation.
B. B. A lung that is less elastic will require less muscle action to perform adequate ventilation.
C. C. As alveolar surface tension increases, additional muscle action will be required.
D. D. Surfactant helps increase alveolar surface tension
C. C. As alveolar surface tension increases, additional muscle action will be required.
128
Which of the following would best characterize pulmonary function in a patient with asthma?
A. Maximal expiratory airflow is increased from normal.
B. B. Residual volume is decreased from normal.
C. C. Forced vital capacity is increased from normal.
D. D. Resistance to airflow is increased from normal.
E. E. The FEV1/FVC ratio is increased.
D. D. Resistance to airflow is increased from normal.
129
```
An individual has an alveolar ventilation of 6,000 mL/minute, a tidal volume of 600 mL, and a breathing rate of 12 breaths/minute. What is this individual’s anatomic dead space?
A. 100 mL
B. B. 120 mL
C. C.150 mL
D. D. 200 mL
```
A. 100 mL
```
6000 = (600 - X)12 solve for X
6000 /12 = 500
500 = 600 - X
500 – 600 = -100
-100 = -X
X= 100
```
130
pressure at sea level vs alitutde
Sea level 760mmhg = PO2 = 160
| Mt everest 253 mmhg = PO2 = 53
131
FIO2
21% O2
132
Whenis partial presure of O2 highest?
when it leaves the lungs
133
When is Partial pressure of CO2 highest
when it enters the lungs
134
How are distance and diffusion related
distance reduces efficiency of diffusion
135
What is lung diffusion capacity
the ability of the lungs to transfer gases
136
How does diffusion relate to hematocrit and blood volume
If you decrease hematocrit you will decrease diffusion capacity
if you decrease blood volume, you will decrease diffusion capacity
low cardiac output, anemia, blood loss
137
How much O2 does arterial blood carry?
20ml of O2 per Deciliter
138
What is O2 bound hemoglobin called
oxyhemoglobin
139
What is no O2 bound to hemoglobin called
deoxyhemoglobin
140
What is CO2 bound hemoglobin called
carboxyhemoglobin
141
How is oxgen transported % wise
98. 5 % is bound in hemoglobin
| 1. 5% dissolved in plasam
142
WHere does the O2 bind to hemoglobin
it binds to the iron that is in the Heme
143
Where does the CO2 bind in hemoglobin
it binds to the globin
144
What happens as more and more O2 binds to Hemoglobin
it causes more and more CO2 unbinding
145
What happens as more and more CO2 binds to hemoglobin
it causes more and more O2 to unbind
146
What is the plateua phas ein the oxyhemoglobin dissociation curve
```
Loading phase (lungs)
where there is a high affinity for hemoglobin in the lungs
```
147
What is the steep phase of the hemoglobin dissociation curve
```
unloading phase (tissues / capillaries)
Low affnity for hemoglobin in tissues
```
148
What causes sigmoidal shape in hemoglobin dissociation curve graph
The cooperative binding
149
What does a right shift on the graph represent
increases oxygen unloading
150
What does a left shift on the graph represent
increased oxygen loading
151
What is p50 for hemoglobin
the 50% saturation rate of hemoglobin
152
What are factors that can cause right shift on the hemoglobin dissocation graph (increased unloading)
```
INcreased Temperature
INcreased CO2
INcreased H+
INcreased BPG
increased workload
```
153
How is most of the CO2 in the blood transported
in the plasma as bicarbonate
60-70%
30% is bound to hemglobin as carbamino
10% is dissolved in the plasma
154
What is carbonic anhydrase reaction
```
CO2 + H2O ←CA→ H2CO3 ↔ H+ + HCO3-
CO2 combines with H2O
and using carbonic anhydrase
makes carbonic acid
Carbonic acid then dissociates into H+ and bicarbonate
Occurs in the Red blood cells
This equation occurs in the tissues/capillaries
the reverse occurs in thelungs
```
155
What happens t the charge when HCO3- leaves the red blood cell
a Cl- ion enters to balance the charge
| KNown as chloride shift
156
What is chloride shift
when a HCO3 leaves a red blood cell and a cl- enters in oreder to balance the charge
157
where does this equation occur?
| CO2 + H2O ←CA→ H2CO3 ↔ H+ + HCO3-
in the tissue/capillaries
Forward in lungs,
backwards in tissues
the reverse equation occurs in the lungs
158
Where does this equation occur?
| H+ + HCO3- ↔ H2CO3 ←CA→ H2O + CO2
In the lungs
Forward in lungs,
backwards in tissues
the reverse occurs in the tissus/capillaries
159
What is reverse chloride shift
the HCO3 enters the red blood cell while a cl ion leaves
160
Which of the following increases oxygen unloading from hemoglobin?
A. increased carbon dioxide in the tissue
B. increased oxygen levels in the tissue
C. increased blood pH
D. decreased metabolism
E. decreased temperature
A. increased carbon dioxide in the tissue
161
Which of the following will most likely lead to decreased oxygen exchange at the respiratory membrane in a healthy individual?
A. Increased cardiac output, low atmospheric PO2
B. Increased pulmonary capillary recruitment, exercise
C. Decreased O2 diffusion distance in the alveolar–capillary membrane
D. Decreased alveolar PO2
D. Decreased alveolar PO2
162
```
If alveolar ventilation is held constant, which of the following predicted changes in alveolar oxygen and carbon dioxide tensions would occur when metabolic rate is increased?
PACO2 PAO2
A Increases Increases
B Increases Decreases
C Increases No change
D Decreases Decreases
```
B Increases Decreases
163
What is the differnec betweent he bronchiole circulation and the pulmonary circulation
they are seperate
Bronchial circulation is to nourish the conducting airways
Pulmonary circulation is gas exchange
164
What is the primary function of bronchiole circulation
to nourish conducting zone
165
What is the primary function of pulmonary circultion
```
Primary is gas exchange
Secondary are
flitering (thrombi)
Metabolic organ (ACE)
Blood source (10% volume)
```
166
What are secondary functions of pumonary circulation
```
Primary is gas exchange
Secondary are
flitering (thrombi)
Metabolic organ (ACE)
Blood source (10% volume)
```
167
as cardiac output decreases, what happens to resistance in the vascular system
it is inverse
| it increases
168
as cardiac output increases, what happens to resistance in the vascular system
it is inverse
| it decreases
169
is the pulomnary circuit high pressure or low pressure
unlike systemic circuit
| the pulmonary ciruit is low pressure
170
is pulmonary circuit normally dialated or constricted
Pulmonary circuit is normally dialated
| systemic circuit is normally constricted
171
which side has greater cardic output, the left or the right
Neither, they are equal
Pressures differ
volumes are the same
172
What can increase capillary recruitment in the lungs
increased cardiac output
173
How does pulmonary circulation help decrease resistance when arterial pressure rises
```
Capillary recruitment
Capillary distention
Due to more capillaries
capillaries in parallel
more distented capillaries
```
174
What does capillary recruitment do in the lungs
```
when cardiac output increases, capillary recruitment can effect a marked decrease in pulmonary vascular resistance
Due to more capillaries
capillaries in parallel
more distented capillaries
helps decrease pulmonary edema
```
175
What does capillary distetion do in lungs?
increases capillary surface area
increase gas exchange
helps decrease pulmonary edema
176
When does pulmonary vascular resistance increase?
```
At hig and low lung volumes
At low volumes
extra alveolar compress
at high lung volumes
alveolar vessles compress
```
177
What are factors that can effect fluid exchange in the capillaries
alveolar surface tension which enhances filtration
| Alveolar pressure which opposes filtration
178
Which enhances filtration?
Alveolar surface tension
or
Alveolar pressure
Alveolar surface tension
179
Which opposes filtration?
Alveolar surface tension
or
Alveolar pressure
Alveolar pressure
180
WHat helps to keep the alveoli dry and avoid edema
a low pulmonary capillary hydrostatic pressure
181
what is the most frequent cause of pulmonary edema
increased capillary hydrostatic pressure
| this is due to abnormally high pulmonary venous pressure
182
what is the second major cause of pulmonary edema
First is increased capillary hydorstatic pressure
| second is noncardiogenic and is due to increasd alveolar tension
183
How is blood flow distributed in the lungs
Blood flow is more copius at the base and dimishes towards the apex
184
How many zones are there for blood flow in the lungs
```
3 zones
zone 1 is at top (apex)
no perfusion, no gas exchange
Zone 2 is in middle
a little, but not a lot of gas exchange
Zone 3 is at base
Largest rate of blood flow
Best gas exchange occurs here
```
185
How does gravity affect the the perfusion, and ventilation ratio in the lung
In the apex, there is hig ventilation but poor perfusion
this gives a high number for ratio
in the base there is low ventilation but good perfusion
gives a low number for ratio
186
What does low oxygen tension in the lungs cause
pulmonary vasoconstriction
187
what does regional hypoxia in the lungs cause
regional vasoconstriction which isolates poorly ventilated areas
188
What dos general hypoxia cause in the lungs
General hypoxia causes vasoconstriction thoughout the lungs,
| in other vessels outsod eof the lungs, hypoxia causes vasodialation
189
WHen you have hypoxia why do the lungs vasoconstrict
This increases resistance and pilmonary artery pressure
190
When do the lungs change ventilation to match changes in perfusion
decreased blood flow and less co2 in the Alveoli is the stimulus for the bronchioles to constrict.
this reduces the air flow so tht it matches the blood flow
191
When do the lungs change perfusion to match changes in ventilation
decreased airflow which reduces PO2 in blood vessels which causes vasoconstriction
this results in decreased bloodflow to match the decreased air flow
192
What happens to ventilation perfusion ratio if there is an airway Obstruction
In normal airway, airway is open, capillaries are open, there is good gas exchange, minimal shunting of air or blood (wasted air/blood)
In obstruction
this causes low ventilation / perfusoin ratio
we are underventilated compared to ou blood flow
increases wasted blood (shunting)
increases venous admixture
193
What happens to ventilation perfusion ratio if there is an capillary obstruction
In normal airway, airway is open, capillaries are open, there is good gas exchange, minimal shunting of air or blood (wasted air/blood)
This will cause a high ventilation / perfusion ratio
over ventilated compared to blood flow
this will increase wasted air (psyiological dead space)
194
Which of the following would be predicted to occur in a healthy individual, who has a 50% increase in his cardiac output?
```
Pulm Blood Flow Cap Recruitt PulmVasc Resist
A Increases Increases Decreases
B Increases Increases Increases
C Increases No Change Decreases
D No change Increases No change
```
A Increases Increases Decreases
195
Which of the following best characterizes alveoli that are well ventilated but are poorly perfused?
A. They are most likely to occur with a partially plugged airway.
B. They are most likely to occur at the base of the lung.
C. PO2 is high in these alveoli, while PCO2 is low.
D. PO2 is low in these alveoli, while PCO2 is high.
E. Both PO2 and PCO2 are normal.
C. PO2 is high in these alveoli, while PCO2 is low.
196
Most of the oxygen in the pulmonary capillaries is delivered to the heart from the base rather than from the apex of the lungs. This is primarily due to the fact that
A. the high V/Q ratio occurs at the base of the lungs.
B. the base of the lungs receives more ventilation than the apex.
C. the base of the lungs has a higher blood flow than the apex.
D. more shunted blood occurs at the lung apex.
E. the PO2 is lower in capillary blood leaving the lung apex than at the base.
C. the base of the lungs has a higher blood flow than the apex.
197
WHere are the respiratory centers?
The medulla and the Pons
198
What are the two respiratory cneters in the medulla
DRG and VRG
DRG or dorsal respiratory group
is in nucleus of the tractus solitirus
primarily for inspiration
VRG or ventilatory respiratory group
is in the nucleus ambiguos and nucleus retroambiguos
it has both inspiratory and expiraotry neurons
VRG expiration is active, unlike normal expiration which is passive
VRG is larger
199
WHat is the DRG
DRG or dorsal respiratory group
is in nucleus of the tractus solitirus
primarily for inspiration
200
What is VRG
VRG or ventilatory respiratory group
is in the nucleus ambiguos and nucleus retroambiguos
it has both inspiratory and expiraotry neurons
VRG expiration is active, unlike normal expiration which is passive
VRG is larger
201
Describe role of phrenic nerve
Somatic nerve in charge of respiration
Controls diaphragm
c3,4,5, keep the diaphragm alive
202
WHat are the two types of chemo receptors
central and peripheral
THese are not sensitive to changes in O2
dont detect O2 changes until around 40mmhg
Very sensitive to CO2
203
Describe peripheral chemoreceptors
Carotid sinus
aortic arch
Receptors for CO2, H+ and O2
204
Describe Central chemoreceptors
IN lungs
Receptors for CO2 mainly
but also H+
205
What are the three types of receptors in the lungs
Chemoreceptors
mechanoreceptors
muscle propioceptors
206
What do muscle proprioceptors do in the lung
They are used for the feed forward mechanism
207
Describe the mechanoreceptors in the lung
Stretch receptors
J receptors (juxtaposed)
activated by engourgment of pulmonary capillaries
Irritant receptors
Typically stimulate respiratory cneter but can
depress it
208
Where does voluntary control of respiration come from
cerebrum
hold breath
breath faster or slower
209
How is everything relayed to the respiratory centers in pons and medulla
```
signals are relayed to spinal motor nerves
ie the phrenic nerve
then they are relayed to
diaphragm
intercostals
acessory muscles
muscles of respiration
```
210
describe neural reflexes in the control of breathing
as CO2 goes up, minute vetilation goes up
(linear relationship, straight line)
CO2 is powerful stimulus for ventilation
O2 is not the same, it needs to drop a really long ways to have any changes in ventilation
(to around 40mmhg)
Central and peripheral chemoreceptors detect the changes
they respond to changes in arterial blood gases
and
H+ ion concentrations
211
Talk about the blood brain barriers role in ventilation
The BBB is impermeable to H+ and HCO3
It is permeable to CO2
this can cause rapid changes in acid base status
The more CO2, the more ventilation
212
CO2 in relation to ventilation
the more CO2 the more ventilation
213
The increase in ventilation from moderate exercise in a healthy individual is caused by:
A. an increase in lactic acid production.
B. an increase in arterial PCO2.
C. a decrease in arterial PO2.
D. a decrease in the pH of brain extracellular fluid.
E. an increase in limb joint and muscle receptor excitation.
E. an increase in limb joint and muscle receptor excitation.
214
A patient suddenly has a decrease in her arteriolar PO2. Which of the following statements best describe the ventilatory response to the decreased arteriolar PO2?
A. The response is mediated by both peripheral and central O2 chemoreceptors.
B. The response is mediated by peripheral O2 chemoreceptors.
C. The response is mediated by O2-sensitive chemoreceptors in skeletal muscle.
D. The response is mediated by O2-sensitive chemoreceptors in the alveolar capillary membrane.
B. The response is mediated by peripheral O2 chemoreceptors.
215
A newborn inhales and stimulates the stretch receptors in the airway smooth muscle.
This will:
A. inhibit inspiration and stimulate expiration.
B. stimulate depth of breathing and oxygen uptake in the lung. C. inhibit depth of breathing and stimulate shallow breathing.
D. stimulate depth and rate of breathing.
A. inhibit inspiration and stimulate expiration.
216
A 50-year-old man with a persistent cough and difficulty breathing is referred
by his family physician for pulmonary function tests. The test results show
that the forced vital capacity (FVC), forced expired volume in 1 s (FEV1), and
functional residual capacity (PRC) are all significantly below normal. Which
of the following diagnosis is consistent with these pulmonary function test
results?
A. Asthma
B. Chronic bronchitis
C. Emphysema
D. Pulmonary fibrosis
D. Pulmonary fibrosis
217
2. A 19-year-old man is taken to the emergency department after being stabbed
in the right side of the chest. 'Ihe entry of air through the wound resulted in a
pneumothorax on the right side of his chest What difference between the right
and left sides of the chest would be apparent on a plain chest x-ray?
A. 'Ihe lung volume on the right would be larger
B. The position of the diaphragm on the right would be higher
C. The thoracic volume on the right would be larger
D. There would be no dllferences in thoracic geometry
C. The thoracic volume on the right would be larger
218
A 28-year-old man is involved in a high-speed motor vehicle accident in which
he suifers multiple rib fractures. On arrival at the emergency department. he
is conscious but in severe pain. His respiratory rate is 34 breaths/min, and his
breathing is labored. His blood pressure is 110/95 mm Hg, and his pulse is 140
beats/min. His arterial Po2 is 50 mm Hg, and he is unresponsive to supplemental 0 1
• His arterial Pco2 is 28 mm Hg. What is the most likely cause of this
patient's hypoxemia?
```
A. Alveolar hypoventilation
B. High ventilation/perfusion (V / Q) ratio
C. Increased dead space ventilation
D. Intrapulmonary shunt
E. Low V/Q ratio
```
D. Intrapulmonary shunt
219
A 16-year-old girl is found unconscious in the street. She has no visible injuries
but is cold and is taking shallow breaths at a rate of 6-8 per minute. An arterial blood gas analysis recorded in the emergency department shows that her
Po2 is 55 mm Hg and her Pco2 is 75 mm Hg. What is the most likely cause of
hypoxemia in this patient?
```
A. Alveolar hypoventilation
B. High ventilation/perfusion (V / Q ) ratio
C. Increased dead space ventilation
D. Intrapulmonary shunt
E. Low V/ Q ratio
```
A. Alveolar hypoventilation
220
A 62-year-old man with a history of COPD is admitted to the hospital due to
acute deterioration in lung function as a result of a viral chest infection. An
anal}'5is of arterial blood gases shows that his Po2 is 60 mm Hg and his Pco1 is
70 mm Hg. His exhaled minute ventilation rate is two times higher than that of
a normal individual of the same age and body size. He has hypercapnea. despite
having an increased exhaled minute ventilation rate because his
```
A. alveolar ventilation is increased
B. dead space ventilation is increased
C. VT is increased
D. ventilation/perfusion (V / Q) ratio is decreased
E. intrapulmonary shunt is increased
```
B. dead space ventilation is increased
221
A 40-year-old woman presented with dyspnea, hematuria, and right flank pain.
CT scans revealed a renal tumor, with an extensive venous thrombus that hadnvaded the inferior vena cava. Fragments of the thrombus had entered the
lungs and were blocking several major branches of the pulmonary arteries.
Aasuming that there was no change in VT or respiratory rate, what effect would
these pulmonary emboli have on arterial blood gases within the first few minutes of their occurrence?
```
A. Decreased Pco2 and decreased Po2
B. Decreased Pco2 and increased Po2
C. Increased Pco2 and decreased Po2
D. Increased Pco2 and increased Po2
E. No change in Pco2 or Po2
```
C. Increased Pco2 and decreased Po2
222
A 9-ycar-old boy decided to find out for how long he could continue to breathe
into and out of a paper bag. After approximately 2 minutes, his friends noticed
that he was breathing very rapidly so they forced him to stop the experbnent.
What change in arterial blood gas composition was the most potent stimulus
for this boy's hyperventilation?
```
A. Dcacased Pco2
B. Decreased Po2
C. Decreased pH
D. Increased Pco2
E. Increased Po2
F. lncrcaacd pH
```
D. Increased Pco2
223
A 54-ycar-old woman with advanced emphysema due to many years of cigarette smoking is admitted to the hospital because of severe peripheral edema
and shortness of breath. On physical examination, there is jugular venous distension and a widely split second heart sound with a loud pulmonic sound. A
differential diagnosis of right heart failure and pulmonary hyperte1U1ion is confirmed by cardiac cathetmzation. The results of her arterial blood gas analpiis
show Po2 = 55 mm Hg, Pco2 = 75 mm Hg, and pH = 7.30. What is the most
lilccly cause of pulmonary hypertension in this patient?
```
A. Decreased alveolar Po2
B. Decreased lung compliance
C. Decreased parasympathetic neural tone
D. Increased alveolar Pco2
E. Increased thoracic volume
F. Increased sympathetic neural tone
```
A. Decreased alveolar Po2
224
A group of medical students is experimenting with a peak flow meter in the
respiratory phy&iology laboratory. Two students decide to compete to see which
of them can blow the hardest into the device. Which of the following mwcles is
most effective at producing a maximal expiratory effort such as this?
```
A. Diaphragm
B. External intercostal muscles
C. Internal intercostal muscles
D. Rectus abdominus
E. Sternocleidomastoid
```
D. Rectus abdominus
225
A 22-year-old man was involved in a :6.ght in which he received a severe blow
to the head. On arrival at the emergency department. he was unconscious and
initially received assisted ventilation via a manual bag-valve device. An analysis
of his arterial blood gases shows:
Po2 =45mmHg
Pco2 = 80 mm Hg
pH=7.05
HC0,-=27 mM
In what form was most col being transported in his arterial blood?
A. Bicarbonate ions
B. Carbaminohemoglobin comp
A. Bicarbonate ions
226
A 67-year-old woman involved in a motor vehicle accident lost 1 L of blood
became of an open fracture of her left femur. Paramedics were able to prevent
further bleeding. What changes to her intracellular fluid (ICF) and extracellular
fluid (ECF) volumes would be observed 15 minutes after this blood loss?
A. ECF volume smaller; ICP volume unchanged
B. ECF volume smaller; ICF volume smaller
C. ECF volume unchanged; ICF volume unchanged
D. ECF volume unchanged; ICF volume smaller
A. ECF volume smaller; ICP volume unchanged
227
1he following pressure measurements were obtained from within the glomerulus of an experimental animal:
Glomerular capillary hydrostatic pressure = 50 mm Hg
Glomerular capillary oncotic pressure = 26 mm Hg
Bowman's space hydrostatic pressure = 8 mm Hg
Bowman's space oncotic pressure = 0 mm Hg
Calculate the glomerular net ultrafiltration pressure (positive pressure favors
filtration; negative pressure opposes filtration).
```
A. +16mmHg
B. +68mmHg
C. + 84mmHg
D. Omm.Hg
E. -16mmHg
F. -68mmHg
G. -84mmHg
```
A. +16mmHg
228
A novel drug aimed at treating heart failure was tested in experimental animals.
The drug was rejected for testing in humans because it caused an unacceptable
decrease in the glome.rular filtration rate (GFR). Further analysis showed that
the drug caused no change in mean arterial blood pressure but renal blood 1low
(RBF) wu increased. The filtration fraction wu decreased. What mechanism is
most likely to explain the observed decrease in GFR?
A. Afferent arteriole constriction
B. Afferent arteriole dilation
C. Efferent arteriole constriction
D. Efferent arteriole dilation
D. Efferent arteriole dilation
229
A healthy 25-year-old woman was a subject in an approved research study. Her
average urinary urea excretion rate was 12 mglmin, measured over a 24-hour
period. Her average plasma urea concentration during the same period was
0.25 mg/mL. What is her calculated urea clearance?
A. 0.25 mL/min
B. 3mUmin
C. 48mUmin
D. 288 mLlmin
C. 48mUmin
230
A 54-year-old woman received. a life-saving kidney transplant 6 months ago
and had been well until the p8$1 few days. She now reports severe fatigue and
dizziness upon standing. Urinalysis is positive for glucose, and there is excessive excretion of HC03 - and phosphate. In which segment of the nephron is
function most likely to be abnormal?
A. Proximal tubule
B. Loop of Henle
C. Distal tubule
D. Collecting duct
A. Proximal tubule
231
A resident in internal medicine was called to the hospital room of an 85-yearold patient in the middle of night. The man was sitting up in bed coughing. and
was severely short of breath. Crackles heard in both lungs suggested pulmonary
ed.ema. Which diuretic is most appropriate for this patient?
A. Carbonic anhydrase inhibitor
B. Loop diuretic
C. Thiazide diuretic
D. Potassium-sparing diuretic
B. Loop diuretic
232
A 46-year-old. woman visited her family physician because she was urinating
many times a day and was constantly thirsty. She was evaluated in the hospital to find out the cause of her severe polydipsia and polyuria. She was not
given any :6.uids for 6 hours before testing, and no change in urine osmolarity
was measured during this period. A nonpressor ADH agonist was then given,
which produced a rapid increase in urine osmolarity. Which diagnosis is most
likely to account for this patient's polydipsia and polyuria?
```
A. Central. diabetes insipidus
B. Compulsive overconsumption of water
C. Nephrogenic diabetes insipidus
D. 'fype 1 diabetes mellitus
E. 'fype 2 diabetes mellitus
```
A. Central. diabetes insipidus
233
A 61-year-old woman with moderate renal insufficiency ate a large amount of
prunes in an effort to treat chronic constipation. She was unaware that prunes
have high potassium content and the meal caused her serum potassium concentration to double. Which of the following short-term intravenous infusions
would be most effective at reducing her serum pot&.S5ium concentration?
```
A. or.-Adrenoceptor agonist
B. Aldosterone antagonist
C. Dilute hydrochloric acid
D. Insulin/glucose
E. Parathyroid hormone
```
D. Insulin/glucose
234
A 3-month-old infant presented with persistent vomiting and was lethargic.
Arterial blood gas analysis shomd the following results:
Pao2 = 88 mm Hg
Pacoi = 44 mm Hg
pH = 7.60
[HCO,-J = 36 mEq/L
Base excess = + 12 mEq/L
Which of the following primary acid-base disturbances is present?
A. Respiratory alkalosiJ
B. Respiratory acidosis
C. Metabolic alkalosis
D. Metabolic acidosill
C. Metabolic alkalosis
235
```
The results of an arterial blood gas analysis of a 56-year-old man with a history
of heavy smoking are as follows:
Pao2 = 60 mm Hg
Paco2 = 60 mm Hg
pH = 7.33
[HCO,-J = 32mEq/L
Base excess = + 8 mEq/L
The patient has a partially compensated
```
A. mpiratory alkalosis
B. respiratory acidosis
C. metabolic alkalosiJ
D. metabolic acidosiJ
B. respiratory acidosis
236
How much Cardiac output does kidney receive
about 20% of cardiac output at rest
| Kidney is highly vascular
237
How is the kidney innervated
Sympathetic nerve fibers
cause constriction of renal vessels and decres reanl blood flow
Play a role in increasing sodium reabsorption
play a role in renin release
Also has afferent sensors that help drtermine stretch of vessels
mechano, chemical, baro help determine BP
238
Trace blood supply through kidney
```
Heart
aorta
renal artery
segmetnal artery
lobar artery
interlobar artery
arcuate artery
cortical radiate artery
afferent artery
Glomeulus
Efferent artery
peritubular capillary
(juxtamedullary nephron) vasa recta
cortical radiate vein
arcuate vein
interlobar vein
renal vein
inferior vena cava
```
239
What are the two nephrons
cortical
| juxtamedullary
240
Describe the cortical nephron
Majority of this nephron is in cortex
has a short loop of Henle
glomerulus is in out cortex
241
Describe juxtamedullary nephron
```
Majority of nephron is in medulla
top is cortec
glomerulus is in deep cortex
has long loop of henle
salt conserving nephron
important in urine concentration
has a vasa recta
when blood flow is reduced, more blood is sent to these nephrons to help conserve extracellular fluids
```
242
where do the collecting ducts come out
they exit the medullary pyramid at the papilla
243
What is the functional unit of the kidney
the nephron
244
How many nephrons in a kidney
approx 1 million
245
how are arid animals different than humans
they have a greater concentration of juxtamedullary nephrons to help them reclaim more water
246
Where is renin porduced
the juxtaglomerular apparatus
247
Wherer is the juxtaglomerular apparatus
where the afferent arteriole meets the glomerulus
248
What types of cells are in the juxtaglomerulus apparatus
Macula densa cells
monitor fluid composition in tubule
mesangial cells
transmit inromation from macula densa cells to granular cells
granular cells
these ar modified smooth muscle cells
They synthesize and release renin (hypotension)
249
What are mesangial cells
Located in the juxtaglomerulus apparatus
mesangial cells
transmit inromation from macula densa cells to granular cells
250
What aremacula densa cells
Located in the juxtaglomerulus apparatus
Macula densa cells
monitor fluid composition in tubule
251
What are granular cells
Located in the juxtaglomerulus apparatus
granular cells
these ar modified smooth muscle cells
They synthesize and release renin (hypotension)
252
What are the three basic processes in urine formation
glomerular filtration
Tubular reabsoption
Tubular secretion
253
Describe glomerular filtration
20% of plasma is filtered while other 80@ flows through efferent arteriole into peritubular capillaries
approx 180 liters a day
body plasma is filtered about 65 times per day
Primarily a physical process and does not require pumps
254
Describe tubular reabsorption
of the 180 liters that is filtered i glemerulus
178.5 is reabsorbed
the other 1.5 liters is excreted as urine
255
Describe tubular secretion
Route of substance to enter the renal tubules
| mechanisms for selectively eliminating substances from the plasma
256
Excreted = ???
Excreted = filtered - reabsorbed +secreted
257
What is reabsorption
movement of solutes from the tubule back into the blood
| you are reabsorbing solutes into the blood
258
What is seceretion
Secretion is the movement of solutes from the peritubular capillary inthe the tubule
259
In glomerular filtration, what is ultra filtrate
small moelcules but restricts passage of larger molecules
260
In glomerular filtration, what is filtered
```
low molecular weight substances that are dissolved in plasma
various polar molecules like
glucose
amino acids
ions
peptides
drugs
waste products like urea and creatinine
```
261
In glomerular filtration, what is non filtered
Large proteins
blood cells
proteinuria is hallmark of glomerular filtration barrier disorder
262
What does proteinuria signify
hallmark of glomerular filtration barrier disorder
263
What are the three layers of gloermular filtration
endothelium (bottom layer)
fenestrated
```
Basment layer (middle)
negatively charged proteins get repelled
```
visceral layer of bowman capsule (top)
podocytes, filtratin slit, filtration of small proteins
264
Trace filtration pathway in glomerulus
```
Capillary
endothelium
basement membrane
visceral layer of bowmans capsule (between podocytes)
into bowmans capsule
```
265
What happens to large moleules and negatively charge proetins in glomerular filtration
theyt cannot get across filtration barrier
266
What is the dominant force that influences filtration
capillary hydrostatic pressure
| the pressure of blood i the capillaries will force molecules across
267
Where is filtration and absorbption in a skeletal muscle capillary
filtration occurs at the arterial end and absorption occurs at the venous end
268
WHat is the dominant force in the glomerulus
Filtration
Filtration occurs along the entire length of capillary
filtration rate is highest at the afferent end and lowest at the effernet end
this is due to colloid osmostic pressure
an increase in solutes helps keep fluids in the nephron
269
What affects renal blood flow
hormones
extrinsic neural stimulation
local regulatory factors
270
how is optimal renal blood flow maintained
autoregulation (intrinsic / local)
| THis maintains a constant blood flow to renal system despite changes in MAP
271
What happens to renal arteries when perfusion is low
renal arteries dilate
272
what happens to renal arteries when perfusion is raised
renal arteries constrict
273
What is pressure of renal blood lfow
80-180
274
When map is 80 -180, what will GFR be
125 ml/min
275
At what MAP pressure does GFR cease
50 and below
276
Trace pressure through renal system in descending order
```
Renal artery
affernet arteriole
glomerular capsule
effernet arteriole
peritubular capilary
intrarenal vein
renal vein
```
277
Where is the greatest slow down of blood in teh renal system
The afferent and effernet arteriole is where the greatest vascular resistance is
this is the greatest slowdown of blood
278
Why is glomerular resistance greater than other systems
prescence of efferent arteriole as oppossed to a veinule
| this helps to facilitate glomerular filtration
279
What is the major forces that determines glomerular filtration
glomerular capillary pressure
280
what are the forces involved in glomerular filtration
Favor
glomerular capillary pressure 55mmhg
oppose
plasma colloidal osmotic pressure 35mmhg
bowman capsule hydrostatic pressure 15mmhg
35 +10 =45
55-45 = 10
difference in filtration pressures
net filtration pressure 10mmhg in favor
281
what happens to filtration when we get hypo tensive
filtration drops off
this helps to keep fluid in the blood to maintain volume and pressure
This is under extrinsic control
282
what happens to filtration when we get hypertensive
filtration increases
this helps to reduce volume by trying to pull more fluid out and reduce pressure
This is under extrinsic control
283
what are the two intrinsic mechanisms of renal autoregulation
myogenic mechanism
| tubuloglomerular feedback
284
Describe the process of the intrinsic mechanism for renal autoregulation : myogenic mechanism
When BP is elevated
increase in pressure stretches affrent arteriole walls
this activates stretch cation channels in smooth muscle
this causes intrcellular calcium to rise
this results in smooth muscle contraction
reducing lumen and diameter
increasing resistance and decreasing flow
this all helps counteract increase in BP
285
Describe the process of the intrinsic mechanism for renal autoregulation : tubuloglomerular feedback
When GFR is increased due to increased arterial pressure
more NaCl is absorbed by the macula densa
macula densa cells then secrete ATP to the mesangial cells
mesangial cells metabolize ATP to adenosine
Adenosine stimulate granular cells
Granular cells stimulation cause constriction
this causes constriction of nearby affernet arteriole
this reduces GFR
(negative feedback system)
286
Does renal autoregulation affect eh afferent or effernet arteriole
the afferent
287
What are the renal extrinsic regulation mechanisms
Sympathetic nerve stimulation
| Hormones and chemicals
288
Describe the sympathetic nerve stimulation in renal extrinsic regulation
vasoconstriction of eitehr afferent or effernet arteriole
this decreases blood flow
this can be activated under stressful conditions like cold, hemmorhage, pain, etc
this is an emergency mechanism to help increase
total peripheral resistance
MAP
cardiac output
289
Describe the chemicals and hormones that vasoconstrict in renal extrinsic regulation
```
adenosine
angiotensin II
enothelium
epi
norepi
ADH
```
290
Describe the chemicals and hormones that vasodialate in renal extrinsic regulation
```
ANP
Dopamine
HIstamine
Kinins
Nitric oxide
prostaglandins
```
291
what are the renal prtective measures
sustained release of renal vasodialators
these prostaglandins oppose the constrictor effect from sympathetic nerve stimulation
this prevents too severe of a reduction in renal blood flow
292
Changes in the glomerular capillary hydrostatic pressure profoundly affect the GFR
What happens with
constriction of afferent arteriole
reduced renal blood flow
reduced glomerular capillary pressure
reduced GFR filtration rate
293
Changes in the glomerular capillary hydrostatic pressure profoundly affect the GFR
What happens with
Constriction of efferent arteriole
reduced renal blood flow
increased glomerular capillary pressure
increased GFR filtration rate
294
Changes in the glomerular capillary hydrostatic pressure profoundly affect the GFR
What happens with
Afferent arteriole Dialation
increased renal blood flow
increased glomerular capillary pressure
increased GFR filtration rate
295
Changes in the glomerular capillary hydrostatic pressure profoundly affect the GFR
What happens with
Efferent arteriole Dialation
INcreased renal blood flow
decreased GFR capillary pressure
decreased glomerular filtration rate
296
WHat is reabsorption
Goes from tubules back into blood
297
What is secretion
goes from blood into tubules
298
What is reabsorbed in the proximal convoluted tubule,
| what is secreted
resabosrption (tube to blood)
everything except nh4+
```
Secretion (blood to tube)
urea
uric acid
creatinine
H+
NH4+
some drugs
```
299
What is reabsorbed in the Distal convoluted tubule,
| what is secreted
Reabsorbed (tube to blood)
H+, K+, NH4+
Secreted (blood to tube)
Na+, Cl-, HCO3-, H2O
300
What is reabsorbed in the Ascending limb (FAT)(goes to collecting duct)
what is secreted
nothing is reabsorbed, is impermeable to H2O
Secreted
Na+, K+, Cl-
301
What is reabsorbed in the descending limb (skinny)
| what is secreted
Reabsorbed
Urea
Secreted
H2O
302
What is reabsorbed in the Collecting Duct,
| what is secreted
nothing is reabsorbed
unless there is ADH or aldosterone
Secretion
Urea, H2O
303
Where in tubular reabsorption is water reabsorbed
all regions of tubule
except the Ascending limb
The DCT and collecting duct only when ADH and aldosterone is present
99% of all water is reabsorbed
304
Where in tubular reabsorption is sodium reabsorbed
65% is reabsorbed in the PCT
25% in the ascending limb
some in DCT and collecting duct
99% of sodiumis reabsorbed
305
Where in tubular reabsorption is glucose reabsorbed
100% of glucose is reabsorbed in the PCT
| Zero in urine
306
Where in tubular reabsorption is urea reabsorbed
in the PCT
50% is reabsorbed
50% is excreted
307
Where in tubular reabsorption is phenol reabsorbed
100% is excreted
308
what is load dependence or glomerulotubular balance
when we increase the filter load of sodium
this stimulates the increase in sodium reabsorption
helps us from losing too much sodium
309
Describe the promixal convoluted tubule
nonregulated reabsorption (no hormones)
70% on sodium and H2O
all glucose
many microvilli
many mitochondriA
Leaky tight junctions
sodium potassium pump works to reabsorb sodium
glucose, amino acids, phosphate are transported by their carriers
310
Describe the collecting ducts
tight junctions
less mitochondria
smaller fewer microvilli
more regulated than PCT
311
Which parts of nephron have hormone recptors
DCT and collecting ducts
this allows aldosterone and ADH to bind
ADH allows for more water reabsorption
aldosterone increases sodium reabsorption
Aldosterone increases potassium and H+ ion secretion
312
What are the two cells in the late part of the DCT
Principle cells
these reabsorb sodium and cause potassium secretion
aldosterone increases these
alpha intercalated cells
important for potassium reabsorption and acid base balance
313
What are the most importatn things that are secreted (blood to tubule)
H+ ions
K+
CL-
314
what is the primary site for potassium excretion
DCT
| collecting duct
315
Where are many durgs and toxins secreted and eliminated from teh blood
PCT
316
Descibe Ascending limb
```
Fat
goes to collecting duct
impermeable to water
permeable to slats
vasa recta
```
317
Descibe descending limb
skinny
permeable to water
impermeable to salts
318
Which limb has more concentration of solutes
the Descending limb
water is pulled out in descendin limb leaving salts behind
more concentration at bottom
319
How do we get water out of the collecting duct
ADH binds to receptors on collecting duct
there is a secondary messenger cascade
cAMP is secondary messenger
this intiates the synthesis of aqua porins
aquaporins increase
more water moves across and is reabsorbed
Without ADH, the collecting ducts are more or less water impermeable
320
WHat is used to assess renal clearance
inulin
| used to figure out GFR
321
Describe renal titration curve
```
Every substance has a threshold
as concentration of glucose increases, there comes a point where you start to excrete glucose
all transporters ar ebeing used (TM)
all other glucose gets excreted
IE diabetes
```
322
Describe involutary micutrition reflex
stertch receptors
detect filling of bladder
affernet signal is sent to spinal cord
signal returns to bladder from spinal cord via parsympathetic nerve fibers
efferent signal excite the detrusor muscle
efferent signla relaxes internal urethral sphincter
urin is involuntarily voided if not inhibited by the brain
323
Describe voluntary micturition control
Stretch receptors detect filling of the bladder
the pons receives signals from the stretch receptors
```
if it is ok to urinate,
pins sends signals to spinal interneurons
thi then excites detrusor muscle,
relaxes internal urethral sphincter
urine is voided
```
if it is not ok to urinate yet
signals from the cerebrum excite spinal interneurons
this keeps the urethral sphincter contracted
urine is retained in the bladder
324
What is the skeletal muscle involved in the bladder
External urethral sphinter
325
Is internal urethral sphincter voluntary or involuntary
involuntary
| smooth muscle
326
what is the somatic nerve fiber that relaxes the external sphincter
pudendal nerve
327
Dilation of efferent arterioles results in
A. an increase in glomerular blood flow.
B. an increase in glomerular capillary pressure.
C. an increase in GFR.
D. an increase in hydrostatic pressure in the urinary space of the Bowman capsule.
A. an increase in glomerular blood flow.
328
The main driving force for water reabsorption by the proximal tubule epithelium is
A. active reabsorption of amino acids and glucose.
B. active reabsorption of Na+.
C. active reabsorption of water.
D. the high colloid osmotic pressure in the peritubular capillaries.
B. active reabsorption of Na+.
329
According to the tubuloglomerular feedback mechanism, an increase in tubular fluid NaCl delivery to the macula densa will result in
A. a decrease in glomerular filtration rate in the same nephron.
B. an increase in glomerular blood flow of the same nephron.
C. an increase in proximal tubular sodium and water reabsorption.
D. an increase in renin secretion.
A. a decrease in glomerular filtration rate in the same nephron.
330
describe fluid compartmetns of the body (%)
60% water in males
33% is ICF (2/3)
27% is ECF (1/3)
Third space fluid or intersitual fluid
CSF, lymph, vitreous,aqueous, synovial, peritoneal, pericardial
slow to adapt
as we age we lose muscel and gain fat
this causes us to lose water as we age
331
What are cations
(+)
332
What are anions
(-)
333
What happens when you add hypotonic solution to body
ICF and ECF increase evenly
334
WHat happens when you add Hypertonic solution tothe body
ICF decreases
| ECF increases
335
What happens when you add isotonic solution to the body
ECF increases
| ICF remains the same
336
What is the normal intake of fluids
60% drink
30% food
10% metabolism
337
What is the normal loss of fluid
Sweat 8%
Urine 60%
Feces 4%
Swet and expiration 28%
338
What is minmum urine output daily
400ml
minimu we need to rid the body of nitrogenous waste
339
What are the two neuron secretory cells in the anterior hypothalamus
Supraoptic nucleus
Oxytocin
Paraventricular nucleus
ADH
340
Where is ADH made
In the anterior hypothalamus in the paraventricular cells,
| it is then sent ot he posterier pituitary via the hypothalmicneurohypophyseal tract where it is stored until needed
341
What is the main mechanism controlling ht release of ADH
plasma osmolarity
342
How does plasma osmolarity control the release of ADH
when plsama osmolarity rises, neurons called osmoreceptor cells located in the anterior hypothalamus shrink
this stimulates production of ADH
343
What is normal osmolarity
```
280 mOsm
above 280 ADH increase proportionally
The thirst threshold is 290
but only when there is appreciable water deficit
it is a negative feedback loop
```
344
describe the negative feedback loop of ADH and dehydration
```
Dehydration occurs
elevates blood osmolarity
stimulates hypothalmic osmoreceptors
stimulates ADH release fromposterior pituitary
then either A or B
```
A= this triggers thrist mechanism, water is ingested, H2O increases, dehydration ceases (negative feedback loop)
```
B= stimulates DCT and collecting duct
increases water reabsorption
reduces urine volume
at same time increases ratio of sodium to water in urine
sodium decreases
dehydration decreases
(negative feedback loop)
```
345
What are the two mechanisms for thrist
increased osmolarity
Stimulate hypothalmic osmoreceptors
reduced blood pressure
Renin
angiotensin II
stimulates hypothalmic receptors
Both trigger thirst
346
What does an increase in blood volume do to ADH
it inhibts ADH
a decrease would stimulate ADH
347
What does an decrease in blood volume do to ADH
it stimulates ADH
severe blood loss cause a large increase in ADH
this causes vasoconstriction which helps counteract low BP
348
Where are the two blood volume receptors at
stretch receptors in the right atrium
| pulmonary veins in the pericardium
349
What are the effects of angiotensin II
stimulates thirst
cuases vasoconstriction
stimulates adrenal cortex to produce aldostreone
Sodium reabsorbtion
stimulates hypothalamus to porduce ADH
water reabsorbtion
350
Renin angiotensin aldosterone pathway
Decrease in arterial blood volume
kidneys porduce renin
liver produces angitensinogen
renin and angiotensinogin combin to form
angiotensin I, which then travels to the lungs
in the lungs it combines with angiotensin converting enzyme (ACE)
creating angiotensin II
351
where is ACE made
ACE is made in the lungs
| in the pleural epithelial cells
352
WHat is ANP
Atrial natiuretic peptide
released form atria
release is stimulated by blood volume expansion
(atrial stretch)
increases sodium excretion
helps bring blood volume back down to normal
353
What is ANP mechanism
```
Volume increases
atria stretches
triggers ANP release
ANP causes vasodilation
inhibts aldosterone production
inhibits renin production
increases sodiumexcretion
increases water excretion
```
354
Where is most of our potassium
within the cells
| ICF
355
what effect does insulin have on potassium
it can cause it to enter the cells
356
What can cause potassium to leave thecells
digitalis
truama
infection
357
What is the major cause of potassium imbalance
abnormal renal potassium secertion
358
Which of the following results in thirst?
A. Decreased plasma levels of angiotensin II
B. Distension of the stomach
C. Heart failure
D. Hypotonic volume expansion
C. Heart failure
359
Which of the following will stimulate the release of ADH from the posterior pituitary?
A. A low plasma osmolality
B. Atrial natriuretic peptide
C. Decreased stretch of carotid sinus baroreceptors
D. Stretch of the left atrium of the heart
C. Decreased stretch of carotid sinus baroreceptors
360
A 45-year-old man has a disease that destroyed the outer part of his adrenal cortex. Which of the following would be expected in this patient?
A. Decreased sodium appetite
B. Hypertension
C. Increased extracellular fluid volume
D. Increased plasma potassium concentration
D. Increased plasma potassium concentration
361
What is an acid
any chemical that gives up a H+
362
What is a base
Any chemical that accepts a H+
363
What happens at ph of 6.8 and below
CNS depression
coma
death
364
What happens at ph of 8.0 or above
```
excitation of the nercous system
muscle tetany
convulsions
respiratory arresst
death
```
365
what are 2 sources of acid
Respiratory Acid
CO2
H2co3
Nonvolatile acid / nonrespiratory acid
Lacric acid
ketones
366
What are 2 major buffering systems
Chemical buffering system
Bicarbonate (CO2) most importatn
phosphate
protein
Physiological buffering system
Respiratory CO2 excretion (quick)
Renal hydrgogen ion excretion (slow)
367
How do chemical buffers maintain the normal blood ph
respiratory
disposes of CO2
if we start to get acidic, we blow off CO2
```
Kidneys
elimniates H+ ions
if we start to get acidic
we excrete H+ ions
form bicarb
put bicab bak into blood
```
Diet can effect ph
368
What do the kidneys excrete to help maintain acid base balance
acid
| H+ ions
369
What are alpha intercalated cells for
they secrete H+ to teh blood
| a for acid
370
What are Beta intercalated cells for
they secret bicarb
| b for bicarb
371
How do the kidneys play a general role in maintaining acid base homeostasis
the kidneys excrete excess acid
| the kidneys regulate blood ph by reabsorbing filtered bicarbonate
372
What does NH4+ do
gets rid of H+ ions in the urine
373
describe ammonium ions
they get rid of H+ ions in the urine
they are formed rom glutamate
they ae secreted into the tubular urine
374
What are factors that can lead to increased H+ secretion by the kidney tubule epithilium
```
Decreased intracellular pH
increased arterila blood pco2
CA activity
sodium reabsorption
K+ decrease
increased aldosterone
```
375
What is compensation mechanism for respiratory acidosis
kidneys increase H+ excretion
376
What is compensation mechanism for respiratory alkalosis
kidneys increase HCO3- excretion
377
What is compensation mechanism for metabolic acidosis
alveolar hyperventilation
| kidneys increase H+ excretion
378
What is compensation mechanism for metabolic alkalosis
Alveolar hypoventilation
| kidneys increase HCO3- excretion
379
Describe things that lead to metabolic acidosis
```
Kidney failure, cant excrete acid
excess keytones, diabetes
accumulation of non respiratory acid
prolonged diahrrea
prolonged vomiting
```
380
Describe things that lead to metabolic alkalosis
gastric drainage
vomiting
loss of acids
381
What is metabolic acidosis
a condition in which the tissue and blood ph is abnormally low due to an increase in non volatile acids
382
In the defense of acid-base balance, which of the following processes takes the longest time for completion?
A. Buffering by bone
B. Distribution and buffering in the extracellular fluid
C. Renal excretion of acid
D. Respiratory compensation
C. Renal excretion of acid
383
Mixed venous blood has a lower pH than arterial blood (e.g., 7.35 vs. 7.40). The main reason for the lower pH of venous blood is its
A. higher bicarbonate concentration.
B. higher carbonic acid concentration.
C. higher oxygen content.
D. lower oxygen content.
B. higher carbonic acid concentration.
384
You get your final exam result back and are over the moon with how well you did. To celebrate you gorge on lots of pizza and have a few too many alcoholic beverages. That night you throw up your stomach contents. As a result, you may be in a state of:
A. Respiratory acidosis
B. Respiratory alkalosis
C. Metabolic acidosis
D. Metabolic alkalosis
D. Metabolic alkalosis
385
How is intracellular ph regulated
cellular ph is maintained by extruding H+ ions
must take in HCO3- at the same rate as H+ going out
Same as at systemic level
386
What are respiratory acidosis and alkalosis caused by
altered levels of PaCO2
387
things that can cause respiratory acidosis
begin to accumulate CO2
decreased rate of breathing
aiway obstruction
decreased gas exchange
388
things that can cause respiratory alkalosis
Decrease in acids
```
decrease in CO2
anxiety
fever
poisoning
high altitude
hyperventilation
```
decrease in H2co3
Decrease in H+
389
pH PCO2 HCO3-
Metabolic Acidosis ↓ ↓ ↓↓
Metabolic Alkalosis ↑ ↑ ↑↑
Respiratory Acidosis ↓ ↑↑ ↑
Respiratory Alkalosis ↑ ↓↓ ↓
pH PCO2 HCO3-
Metabolic Acidosis ↓ ↓ ↓↓
Metabolic Alkalosis ↑ ↑ ↑↑
Respiratory Acidosis ↓ ↑↑ ↑
Respiratory Alkalosis ↑ ↓↓ ↓
390
What is the key physiological buffer
Bicarbonate carbon dioxide system
onley works in an open system
can remove CO2 through hyperventilation
kindeys excrete H+ ions
Kidneys put bicarb back into blood
391
What is the bicarbonate system based on
the strong buffering capacity of the respiratory system
392
Does the respiratory or chemical system neutralize more acid
Respiratory system neutralizes 2-3 times as much acid as chemical buffers can
393
What are 3 methods of compensation
metabolic - immediate
quick acid relase
pulmonary - minutes to hours
CO2 expelled or retained
renal - hours to days
H+ increased to form acids
H+ excreted trhough ammonium
394
Time period for respiratory compensation to a metabolic disorder
begins within 30 mintues
complete within 12 - 24 hours
PCO2 should move in same direction as bicarb
395
metabolic compensation for respiratory disorders
immediate small change in HCO3
if porblem persists
much larger change in HCO3
takes 3-5 days
396
What is delta ratio
Change in anion gap divided by change in bicarb
less than 1 normal metabolic acidosis
1 to 1 = uncompensated metabolic acidosis
1 to 2 or over 2 = metabolic alkalosis with metabolic acidosis
397
what is the acid that doesnt effect anion gap
HCL
398
What are causes of high anion gap over 30
```
lactic acidosis
ketoacidosis
uremia
toxic alcohol ingestion
slicylate lactic acid
acetaminophen
pyroglutamic acid
fromic acid
oaxlic acid
ethlene glycol
```
399
4 conditions that adversely effect anion gap
hypoalbuminemia
hypyerkalemia
hypermagneseia
hypercalcimeia
400
which acid base disorder is anion gap typically asociated with
metabolic acidosis
401
what is unmeasured but typically responsible for anion gap
albumin
use corrected anion gap whenalbumin is not normal
normal albumin is 4.5
