Respiratory Physiology 1 Flashcards
1
Q
Define respiration
A
the process by which oxygen is taken in and
carbon dioxide is given out.
2
Q
The first breath takes place only after…
A
….birth
3
Q
Respiration is the process by which oxygen is taken in and
carbon dioxide is given out.
* The first breath takes place only after birth
This is cus fetal lungs are…
A
…non functional
4
Q
During intrauterine life the exchange of gases
between fetal blood and mother’s blood
occurs through…
A
…placenta.
5
Q
What are the two types of respiration?
A
external and internal respiration
6
Q
What is external respiration?
A
involves exchange
of respiratory gases, i.e. oxygen and
carbon dioxide between lungs and blood
7
Q
What is internal respiration?
A
involves exchange
of gases between blood and tissues
8
Q
internal and external respiration take place at the same…
A
…time
9
Q
where does external respiration take place?
A
between environment and lungs
10
Q
where does internal respiration take place?
A
between blood and cell.
11
Q
Describe the process of respiration
A
1) Ventilation of gas exchange between the atmosphere and alveoli in the lungs
2) Exchange of O2 and CO2 between air in the alveoli and the blood in the pulmonary capilleries
3) Transport of o2 and co2 by the blood between the lungs and the tissues
4) Exchange of o2 and co2 between the blood in the systemic capilleries and the tissue cells.
12
Q
A
13
Q
why do we breathe?
A
1 Take in oxygen
2 remove carbon dioxide
14
Q
other roles of the respiratory system?
A
- Allows speech
- Acid-base balance
- Water balance
- Maintain body temperature
15
Q
Respiration occurs in two
phases which are …
A
… inspiration adne expiration
16
Q
whats inspiration?
A
air
enters the lungs from
atmosphere
17
Q
whats expiration?
A
air leaves the lungs
18
Q
The respiratory system is an …
A
arrangement of spaces and passageways that conduct air into
the lungs.
19
Q
the entire respiratory system is though of as a…
A
pathway for air between the atmosphere and
the blood
20
Q
what is respiratory system divided into?
A
upper and lower respiratory system .
21
Q
what makes up the upper respiratory system?
A
nose
nasal cavity
sinuses
pharynx
22
Q
what makes up lower respiratory system?
A
larynx
trachea
bronchus
bronchioles
alveoli
23
Q
how does air first enter the body?
A
Air makes its initial entrance into
the body through the openings in
the nose called the nostrils.
24
Q
what is found inside the nostrils?
A
inside the nostrils, are the two
spaces known as the nasal
cavities.
25
nasal vestibule is lined with...
... hairs
26
function of hairs in the nose?
filter large particles from inhaled air.
27
what is nasal cavity divided into?
left and right chambers with folds.
28
what are conchae also known as?
turbinates.
29
function of nasal conchae?
increased surface area.
30
the lining of the nasal cavity is a ...
... mucous membrane
31
what does the nasal cavity contain?
...many blnlood vessels that bring heat and moisture to it.
32
what do the cells of the nasal cavities membrane secrete?
a large amount of fluid.
33
what do the nasal cavities filter?
Foreign bodies, such as dust
particles and pathogens,
* are filtered out by the hairs of the
nostrils or caught in the surface
mucus.
34
how does nasal cavity moisten air?
moistened by the liquid secretion.
35
what are sinuses ?
Air-filled spaces within the bones of
the skull that connect to the nasal
cavity
36
what do sinuses produce?
mucus
37
sinuses functions?
Produce mucus to clean the air
you breathe
Reduce the relative weight of the
skull
Act as resonating chambers to
modify sounds
Provide a cushion against impact
38
What is the nasal cavity, sinuses, and conchae lined with?
all are lined with a mucous membrane.
39
Describe the nasal epithelium?
* highly vascularised
* Has ciliated epithelium
* Warm and humidify inhaled air
40
where is nasal epithelium present?
Nasal cavity, sinuses & conchae
41
what is the nasal epithelium?
Nasal cavity, sinuses & conchae are lined with a
mucous membrane
42
nasal mucous is the noses...
... first line of defense
43
what does mucous trap?
traps noxious substances (bacteria, viruses, pollen, dust.).
44
what does the pharynx do?
The pharynx (throat) carries
air into the respiratory tract
* and foods and liquids into the
digestive system.
45
The pharynx is divided into...
...3 sections
46
What are the three sections of the pharynx?
1) Nasopharynx - located posterior to the nasal cavity
2) Oropharynx - posterior to the oral cavity
3) Laryngopharynx - located close to the vocal chords and trachea
47
48
Function of nasopharynx?
Receives air from the nasal cavity
and conduct air to the lower
sections of the respiratory tract
49
functon of oropharynx?
receives air from the nose and mouth (and food).
50
function of laryngopharynx?
Continuous with the larynx and the
oesophagus
* Conducts air into the trachea.
51
what closes over the larynx during swallowing?
During swallowing, the epiglottis closes over
the larynx to prevent food or liquids from
entering the lungs.
52
the larynx has a framework of...
... cartilage that protrudes in
the front of the neck.
53
the largest cartilage of the larynx is the ...
... thyroid cartilage.
54
males have a more prominent...
...thyroid cartilage (laryngeal prominence, adams apple).
55
what are the vocal chords?
two v shaped bands of muscle.
56
in vocal cords, air flow =
air flow = vibration
57
vibration produces...
...sound
58
when brreathing, the vocal cords...
...open, allowing air to move in and out.
59
when do vocal chords close?
They close when we talk and vibrate
to allow us to produce sounds
60
The nasal cavity and sinus acts as a ...
... resonating chamber to help form the
sound
61
why do males have deeper voices than females?
Testosterone in males produces
thicker/longer folds that vibrate
slower
- Producing the deeper voice
62
what is the larynx lined with...
...ciliated mucous membrane
63
function of cilia?
trap dust and other
particles, moving them upward to the pharynx to be expelled by coughing, sneezing, or blowing the nose.
64
mucous secreting cells in the body are referred to as?
goblet cells.
65
function of ciliated cells?
sweep debris
66
function of clara cells?
divide, differentiate, metabolize toxic chemicals.
67
what is the trachea (windpipe)?
a tube that extends from
the lower edge of the
larynx to the bronchi
68
trachea has a framework of...
...cartilages to keep it open
69
The purpose of the
trachea is to...
...conduct air between the larynx and the lungs.
70
what cells do trachea contain?
Numerous cilia cells & goblet cells
71
trachea contains numerous cilia cells and goblet cells. What is the function of this?
- produce mucus
- mucus-cilia elevsator/escalator
- pushes mucus up
72
what does the trachea divide into?
divide into left and right primary bronchi.
73
the trachea divides into...
...two bronchi which enter the lungs.
74
the right bronchus is considerably larger in ...
... diameter than the left and extends downward in a more vertical direction
75
the trachea divides into the bronchi, which is further divided into the ...
... bronchioles
76
What is the wall of the thorax abundant with?
abundant
connective
tissue with
elastic
properties
77
The thorax is a ...
... closed compartment.
78
the lungs are found in a ...
... closed compartment.
79
Black sections on a scan are...
...air
80
the white secitons on a scan are...
... the heart or diaphragm.
81
Function of the oblique and horizontal fissures?
allow lungs to slide over eachother.
82
In the lungs are cluster of air sacs,
resembling a...
.... bunch of grapes.
83
In the lungs are cluster of air sacs,
resembling a bunch of grapes. These sacs are known as...
alveoli
84
These sacs are known as alveoli.
* This very thin wall provides easy
passage for ...
... the gases entering and leaving the blood.
85
look at slide 58
86
THe lungs lie in...
... the pleural cavity
87
Two pleural cavities (pleurae) filled with...
...intrapleural fluid
88
Each lung occupies a single...
...pleura
89
Intrapleural fluid enables...
...efficient lung ventilation.
90
Pleura consists of ...
... 2 layers
91
What are the two layers of pleura?
Parietal pleura
Visceral pleura
92
Function of parietal pleura...
covers inner surface of thoracic wall.
93
Function of visceral pleura...
covers outer surfaces of lungs.
94
What do both layers of pleura secrete?
Both secrete pleural fluid
95
In some pathological conditions, the pleural
cavity ....
expands with accumulation of:
* air (pneumothorax),
* water (hydrothorax),
* blood (hemothorax) or
* pus (pyothorax)
96
What is surfactant...
a mixture of lipids, proteins, and carbohydrates that
coats the air sacs (alveoli).
97
Where is surfactant produced?
produced by Type II Pneumocytes (or alveolar type II cells) in the alveoli.
98
surfactant is not produced until?
late in foetal life (8 months)
99
What is the purpose of surfactant?
to reduce surface tension and prevent alveoli from
collapsing
100
What does surfactant deficiency lead to?
Deficiency leads to respiratory distress syndrome in
premature infants
101
Most Premature babies' lungs lack...
... sufficient surfactant
102
As a result of deficient surfactant, alveoli collapses... Which is called...
Infant Respiratory Distress Syndrome (IRDS)
103
What is the diaphragm?
The diaphragm is a large, dome-shaped muscle that contracts and relaxes to move air into and out of the lungs
104
Pressure of a gas is inversely proportional to ...
... its volume
105
contraction and relaxation of the diaphragm ensures...
...inspiration and expiration.
106
What is Boyles law?
‘Pressure of a gas is inversely proportional to its volume
107
As volume increases...
...pressure decreases
108
As volume decreases....
...pressure increases.
109
An increase in volume of lungs decreases...
...pressure of gas; allows air to move in.
110
Pressure changes result from ...
changes in thorax volume
111
Palv < Patm =
Air flows inward - INSPIRATION
112
Palv > Patm =
Air flows outward - EXPIRATION
113
Air flows from areas of ...
...higher pressure to areas of lower pressure.
114
What are the two phases of ventilation?
Inhalation and Expiration.
115
What is inhalation?
the drawing of
air into the lungs.
116
What is exhalation?
Exhalation is the expulsion of
air from the lungs.
117
Describe process of inhalation?
1. During inhalation, the diaphragm contracts and is drawn
downwards
2. The intercostal muscles between the ribs contract and raise ribcage
up and outward
3. The chest cavity expands, and intra-alveolar (lung) pressure is
reduced
4. The lungs are pulled outwards and expand, drawing air into them
118
Describe process of exhalation?
1. The diaphragm relaxes and moves upwards
2. The intercostal muscles relax and the ribcage moves inward and
downward
3. The volume of the chest cavity is reduced and pressure increases
4. The lungs contract, forcing air out of them
119
What are pulmonary volumes and capacities?
These are the different amounts of air in the
lungs during different phases of breathing
120
what is inspiratory reserve volume (IRV)?
the amount of air that you can breathe in over and above the tidal volume
121
what is the resting tidal volume (Vt) ?
the amount of air you move into or out of your lungs during a single respiratory cycle under resting conditions
122
what is the expiratory reserve volume (ERV) ?
the amount of air that you can voluntarily expel after you have completed a normal, quiet respiratory cycle.
123
whats the minimal volume?
a component of the residual volume, the amount of air that would remain in your lungs if they were allowed to collapse. The minimal volume ranges from 30 to 120 mL, but cannot be measured in a healthy person.
124
what is the total lung capacity?
the total volume of your lungs calculted by adding the vital capacity and the residual volume. This averages around 6000 mL in males and 4200 mL in females.
125
whats the residual volume?
the amount of air that remains in your lungs even after a maximal exhalation
126
whats the functional residual capacity (FRC)?
the amount of air reminaing in ur lungs after u have completed a quiet respiratory cycle. The FRC is the sum of the expiratory reserve volume and the residual volume.
127
what is The vital capacity ?
the maximal amount of air that you can move into or out of your lungs in a single respirsotry cycle. The vital capacity is the sum of the expiratory reserve volume, the tidal volume, and the inspiratory reserve volume.
128
What is the inspiratory capacity?
is the amount of air that you can draw into your lungs after you have completed a quiet respiratory cycle. The inspiratory capacity is the sum of the tidal volume and the inspiratory reserve.
129
Alveoli adaptations?
large surface area,
short diffusion distance
moist surface
130
The capiillaries lining the alveoli have high concentration of ...
...oxygen
131
oxygen from the air easily
diffuses from the alveoli into the blood
through the...
...thin barrier of
the alveolus wall.
132
How does carbon dioxide leave the lungs?
1) the concentration
of carbon dioxide
is quite high in the
blood,
2) the gas easily
diffuses out into
the alveolar
space.
3) from here, the
air that has
comparatively
more
concentration of
carbon dioxide
leaves the lungs
133
What are the cells of the alveoli?
Type I Pneumocyte/ Type I alveolar cells
Type II Pneumocyte/Type II alveolar cells
Alveolar Macrophages
134
Describe Type I Pneumocyte/ Type I alveolar cells
* Flat squamous epithelial cells
* Thin & delicate
* 95% alveolar surface
* Allow for rapid gas diffusion
135
Describe Type II Pneumocyte/Type II alveolar cells
Cuboidal septal cells
Thick and narrow
Scattered between type I cells
5% alveolar surface
2 main functions:
Produce surfactant
Repair alveolar epithelium
136
Describe alveolar macrophages.
(dust cells)
- present in the alveoli lumen
- preserve alveoli integrity
- last lime of defence - removes pathogens.
137
How many binding sites does haemoglobin have?
Hemoglobin has four binding
sites for oxygen molecules,
138
Where are the binding sites of hemoglobin located?
each located in an iron atom
in a heme group
139
Hb -> HbO2 -> HbO4 -> HbO6 -> HbO8
increase in oxygen binding affinity from left to right, and a decrease in oxygen binding affinity from right to left.
140
The amount of oxygen that can bind to hemoglobin
is known as ...
...t he oxygen-binding capacity
141
Factors affecting binding from oxygen to hemoglobin
✓pH
✓carbon dioxide
✓temperature
✓2,3-Bisphosphoglycerate
142
The amount of oxygen bound to the
hemoglobin at any time is related to the...
... partial pressure of oxygen.
143
How much oxygen is carried by haemoglobin (Hb) in RBC?
98.5%
144
How much oxygen is dissolved in plasna?
1.5%
145
If PO2 increases...
* Reaction above shifts to right
* More O2 gets bound to haem
* Saturation increases
146
If PO2 decreases...
* Reaction above shifts to left
* More O2 released
* Saturation decreases
147
What is the average resting PO2 at systemic capillaries?
40mmHg
148
What is the normal PO2 at pulmonary capillaries ?
100mmHg
149
Whats the Bohr effect?
- Increased CO2 levels
lowers blood pH
- Hb molecule shape
changes
- Lower pH causes Hb to
release more O2
- Higher pH causes Hb to
hold onto more O2
150
As temperature rises Hb releases
more...
O2
151
As temperature rises Hb releases
more O2.
These effects are important for...
... active tissues where large
amounts of heat are being
generated.
152
Where is 2,3-Diphosphoglycerate (2,3-DPG) produced?
Produced in erythrocytes
153
What does 2,3-Diphosphoglycerate (2,3-DPG) reduce?
Reduces Hb affinity for O2
154
WHat does 2,3-Diphosphoglycerate (2,3-DPG)
facillitate?
Facilitates the release of O2
155
89
156
what is high altitude?
High altitude is the region of earth located
at an altitude of above 8,000 feet from
mean sea level.
People can ascend up to this level, without
any adverse effect.
157
Air Composition does not...
... vary with altitude
158
Characteristic feature of high altitude
is the...
...low barometric pressure.
159
Characteristic feature of high altitude
is the low barometric pressure.
Climb
However, amount of oxygen is...
...is same as that of sea level.
160
Due to low barometric pressure, partial pressure of
gases, particularly oxygen ...
... proportionally decreases.
161
Due to low barometric pressure, partial pressure of
gases, particularly oxygen proportionally decreases.
What does this lead to?
...* It leads to hypoxia.
162
At what attitude does altitude sickness occur?
occurs above 2,500 metres in
average
163
What are the symptoms of altitude sickness?
Collection of nonspecific symptoms: flu, carbon monoxide poisoning, hangover, headache, nausea, vomiting, anorexia.
164
what is the amount of o2 in the air at high altitude?
The amount of O2 in the air remains at 21% but the barometric
pressure decreases with altitude
165
what stays the same and what decreases with altitude?
The amount of O2 in the air remains at 21% but the barometric
pressure decreases with altitude
166
What falls with increasing elevation?
the partial pressure of oxygen falls with increasing elevation
167
how high up is the DEATH ZONE 🤯🥶😱 ???
26,000 ft 😎😤🤪
168
po2 of venous blood at 26,000 feet?
40 mmHg - incompatible with life
169
As one ascends, PO2 start to ...
... drop exponentially with altitude,
reaching dangerous values at 50 mmHg
170
po2 at sea level?
160 mmHg
171
po2 at lake titcaca?
95mmHg
172
po2 at lake mt everest?
53 mmHg
173
Symptoms deteriorate with...
... increasing altitude
174
How does the cardiorespiratory system adapt to high altitudes initially?
1) Increased cardiac output
2) Hyperventilation:
- increase respiration and tidal volume as the body tries to extract O2 from the air
175
What does hyperventilation (becus of high altitudes) result in?
Respiratory alkalosis: increased respiration
elevates blood pH beyond the normal range
(7.35-7.45) as result of reduction in arterial CO2 levels
176
Long-term compensation for low PO2?
✓ Increased haematocrit and blood volume (weeks)
✓Increased diffusion capacity of lungs
✓Increased capillarity in tissues
✓O2 carrying capacity of blood – Polycythaemia
✓O2 diffusion from blood to tissues
* Capillary density
* Increase in myoglobin concentration
* Tissue utilisation of O2
177
why does low po2 from high altitudes cause increased haematocrit?
* RBC production increases via erythropoietin – PO2 sensed– produced in kidneys– acts on hematopoietic stem cells
* Blood volume under hormonal control of kidneys
178
describe increased capaicty of lungs?
✓Increased capillary volume
✓Increased lung volume
✓Increased pulmonary pressure
179
describe Increased capillarity in tissues
✓Stimulate angiogenesis – growth of new capillaries
✓Feedback control in local tissue beds
✓More effective in young people
180
describe O2 diffusion from blood to tissues
Concentration of 2,3-diphosphoglycerate (DPG) in red blood cells increases within 24h of ascending in altitude.
DPG reduces the affinity of haemoglobin for oxygen thus facilitating oxygen release to the tissues.
181
why changes in capillary density in high altitudes?
reduces the diffusion distance for oxygen between the blood and the tissues
182
describe Increase in myoglobin concentration at high alts?
There is an increase in the concentration of myoglobin that facilitates diffusion of O2 to the tissues.
183
describe Tissue utilisation of O2?
Muscle biopsies in acclimatized men show an increase in mitochondria and enzymes, associated with aerobic pathways.
184
define Acclimatization
refers to the adaptations or the adjustments
by the body in high altitude.
185
While staying at high altitudes for several days
to several weeks, a person slowly gets...
...adapted or adjusted to the low oxygen tension, so that hypoxic effects are reduced
186
describe Native adaptation to high altitude
– All the same compensations of acclimatization
plus:
* Larger chest cavity
* Larger heart, especially right side
* Increased cellular efficiency to use O2
187
High Altitude Disorders?
* Acute Mountain Sickness
* High Altitude Cerebral Oedema (HACE)
* High Altitude Pulmonary Oedema (HAPO)
188
what are symptoms of Acute Mountain Sickness (AMS)?
* Headache
* Nausea & Dizziness
* Loss of appetite
* Fatigue
* Shortness of breath
* Disturbed sleep
* General feeling of malaise
189
Symptoms of
mountain sickness can
be partially eliminated
by...
...breathing pure O2,
which is why most
climbers making
ascents of peaks like
Mt Everest use
supplementary O2
190
what is HACE?
a medical condition in which the brain swells
because of the physiological effects of traveling to a high altitude.
191
In who does HACE usually appear?
in patients who have acute mountain
sickness and involves disorientation, lethargy, and nausea among other symptoms.
192
When does HACE occur?
It occurs when the body fails to acclimatize while ascending to a high altitude.
193
HACE generally does not occur until...
...an individual has spent 48 hours at an altitude of 4,000 metres.
194
hace rarity?
Rare: 0.5-1% above 4km
195
symptoms of HACE?
- Hypoxia-induced vasodilatation, high
capillary pressure and oedema
- Damage to BBB, causing microhemorrhages
✓ Fever
✓ Ataxia
✓ Photophobia
✓ rapid heart beat
✓ Lassitude
✓ Confusion, Altered mental state
✓ Sufferers cease physical activities regardless of their necessity for survival
✓ Loss of consciousness
196
mortality of rate of HAPE?
✓ High mortality rate
197
how does HAPE occur?
Vasoconstriction in pulmonary
capillaries leads to increased blood
pressure in open capillaries leading
to oedema
198
What r the effects of HAPE?
a) Increased pulmonary hypertension secondary to hypoxic pulmonary
vasoconstriction.
b) Idiopathic non-inflammatory increase in the permeability of the vascular endothelium.
