Respiratory System Flashcards
1
Q
What gas moves from air into blood?
A
Oxygen
2
Q
What is the process by which gas moves from the blood to the air?
A
Diffusion
3
Q
Type 2 Alveolar cells are also known as this
A
Septal cells
4
Q
What muscle is involved in breathing?
A
Diaphragm
5
Q
What is the cartilage portion at the top of the trachea?
A
Larynx
6
Q
What type of epithelium is in the upper respiratory passages?
A
Pseudo stratified
7
Q
What is the name of an air sack?
A
Alveolus
8
Q
What structures move trapped particles out of airways?
A
Cilia
9
Q
What is the top portion of the lung?
A
Apex
10
Q
What type of cartilage is found in tracheal rings?
A
Hyaline
11
Q
What type of epithelium lines air sacks?
A
Squamous
12
Q
What blood vessels are associated with air?
A
Pulmonary capillaries
13
Q
What are the different segments of the lungs?
A
Lobes
14
Q
What is the outer membrane of the lungs?
A
Pleural
15
Q
What gas moves from blood into air?
A
Carbon dioxide
16
Q
What shape is tracheal rings?
A
C
17
Q
What does the trachea divide into?
A
Primary bronchi
18
Q
What type of cells secrete mucus in the trachea?
A
Goblet cells
19
Q
What lowers surface tension?
A
Surfactant
20
Q
What is the passage conducting air from the mouth to the trachea called?
A
Pharynx
21
Q
What is the last of the bronchioles?
A
Terminal bronchioles
22
Q
What is the shape of the cells lining the trachea?
A
Columnar
23
Q
What is the passage of air into the lungs? (Bronchial tree)
A
24
Q
What is an alveoli?
A
Small spherical air sacks lined by simple squamous epithelium
25
What are type one alveolar cells?
It’s the continuous lining of alveolar wall and the main sites of gas exchange in alveoli
26
What are type two alveolar cells?
They are known as septal cells
There are a fewer in number
They secrete alveolar fluid
Includes surfactant
Lower surface tension and prevent alveolar collapse
27
28
What is ventilation?
The process of breathing
29
What is inhalation?
Air moves from the atmosphere into the lungs
30
What is exhalation?
And moves from the lungs to the atmosphere
31
How do we achieve this movement of air?
Due to pressure differences between the atmosphere and the lungs.
These pressure differences are caused by the contraction and relaxation of the respiratory muscles
32
33
Muscles of exhalation
34
What happens as the volume of the thoracic cavity increases?
The pressure in the cavity drops
35
What is Boyle law?
This states that for a gas at a constant temperature (pressure x volume) is a constant
PV = k
36
What happens if the volume goes down and what happens if the volume goes up?
If volume goes down, pressure must go up
If volume goes up, pressure must go down
37
What happens during ventilation?
1.Inspiratory muscles increase the volume of the thoracic cavity
2. Pressure and thoracic cavity decreases.
3. Pressure drops below atmospheric pressure - alveola pressure drops to ~758mmHg
4. Air moves from atmosphere into lungs.
38
What happens at the end of inhalation?
1. Inspiratory muscles relax.
2. Chest wall and lungs return to normal size under elastic recoil - no muscle activity.
3. Volume of thoracic cavity decreases.
4. Pressure increases above atmospheric pressure (our pressure increases to ~762mmHg)
5. Air moves from the lungs. (High p) to the atmosphere (low p)
6. Exhalation/expiration
39
When do expiratory muscles come into action?
During forceful breathing - shouting, singing, coughing, exercise.
40
At rest is atmospheric pressure higher or lower than alveolar pressure?
It’s the same
41
During inhalation is atmospheric pressure higher or lower than alveolar pressure?
Atmospheric pressure is higher
42
During exhalation is atmospheric pressure higher or lower than alveolar pressure?
It is lower
43
What do the differences in pressure change?
The depth of breathing in different circumstances
44
What is three factors can affect ventilation?
1. Alveola surface tension.
2. Lung compliance.
3. Airway resistance.
45
What is alveolar surface tension?
Alveoli are small vertical structures lined with fluid
They have high surface tension
It is reduced by surfactant - making it easier to inflate the alveoli .
46
What is lung compliance?
The measure of how easy or difficult is to expand the lungs or chest wall
47
What is high compliance?
Easy expansion - normal high elasticity in lungs means that high lung compliance is the norm
48
What is low compliance?
Difficult expansion - this becomes a apparent in lung disease
49
What is airway resistance?
It’s related to airway diameter
Reduced diameter > increased resistance to airflow > decreased ventilation
50
What disease conditions result in a reduced airway diameter?
1. Asthma - airways narrowed due to smooth muscle contraction.
2. Chronic bronchitis - airways narrowed due to inflammation and secretion of excess mucus.
3. Emphysema. - airways collapsed due to loss of elastic tissue
51
At rest normal ventilation is about ________ per breath
500 ML (tidal volume)
52
How much of the 500 ML makes it to the alveoli to participate in gas exchange?
350ml
53
What happens to the remaining 150 ML?
It is contained in the conducting airways - dead space
54
What is tidal volume?
The volume breathed in and out in a single normal breath
55
What is inspiratory reserve volume?
The additional volume that could be breathed in with a maximum inhalation
56
What is the inspiratory capacity?
Total volume that can be inhaled after a normal exhalation (Vt + IRV)
57
What is the expiratory reserve volume?
The additional volume that can be breathed out with a maximum exhalation
58
What is vital capacity?
The amount of air that can be breathed in and out in a single maximum breath
59
What is residual volume?
The amount of air left in the lungs after a maximum exhalation - remaining in the alveoli and non-collapsible airways
60
What is the functional residual capacity?
The total volume of air in the lungs after a normal exhalation (ERV+RV)
61
What is total lung capacity?
Total amount of air present in the lungs after a single maximum inhalation (VC + RV)
62
63
How did the gases move from the air in the alveoli into into the blood?
Diffusion
64
Is carbon dioxide in the blood of alveolar capillaries higher than the alveolar air?
Yes
65
Concentration of gases is given by their _____________
Partial pressure
66
If the total pressure of all the gases is 760mmHg and 21% of it is accounted for by oxygen. What is the partial pressure of oxygen?
21% x by 760mmHg = 160mmHg
67
What does the partial pressure differences of gases in alveoli and in the blood determine?
The direction of movement of the gases
68
What is atmospheric PO2?
160mmHg
69
What is alveolar PO2 and PCO2
PO2 = 100-105 mmHg
PCO2 = 40mmHg
70
When starting venous blood PO2 and PCO2is?
PO2 = 40mmHg
PCO2 = 46mmHg
71
When moving into arterial blood PO2 and PCO2is?
PO2 = 100mmHg
PCO2 = 40mmHg
72
Blood blood leaving the lungs to return to the heart is known as ________________. It has _________ CO2. It has _______________ O2.
Arterial blood
Lost
Picked up
73
In each litre of arterial blood, how much oxygen is there?
200 ML
74
Out of 200 ML per litre how much oxygen is dissolved in water of the blood?
3ML/L
75
Of the 200 ML/L of oxygen how much oxygen is bound to haemoglobin in RBCs?
About 197ML/L
76
What is the average haemoglobin concentration in the blood?
150g/l (15%)
77
What does the centre of each heam molecule contain?
An iron ion
78
How many molecules of oxygen can combine with an iron ion?
One
79
How many molecules of oxygen can each haemoglobin molecule carry?
Four
80
What name is given when haemoglobin is combined with oxygen?
Oxyhaemoglobin
81
If haemoglobin is completely converted to Oxyhemoglobin, it is said to be…
Fully saturated
82
If haemoglobin is not completely converted to Oxyhemoglobin, it is said to be…
Partially saturated
83
What is the main factor determining level of saturation?
PO2 of the blood
84
What does the oxygen-haemoglobin dissociation curve show when PO2 is high?
It shows that most of the oxygen is bound to the haemoglobin
85
What does the oxygen haemoglobin curve show when PO2 is low?
It shows the oxygen is not bound to haemoglobin - it is released from haemoglobin
86
Where is PO2?
At the lungs - therefore oxygen is picked up by haemoglobin
87
Where is PO2 low?
At the tissues - therefore oxygen is released from haemoglobin and delivered to the tissues
88
Is the shape of the dissociation curve fixed?
No, it can be influenced by several factors, including pH, temperature, metabolites
89
If the dissociation curve shift to the left, would the pH be more or less acidic?
Shift to the left makes it less acidic
90
It’s the dissociation curve shifts to the right with the pH be more or less acidic
More acidic
91
When pH is more acidic is more or less oxygen bound to haemoglobin
Less oxygen
92
Where in the body is pH more acidic and why?
The tissues
The tissues are metabolically active and are producing carbon dioxide
93
Where in the body will the pH be less acidic?
At the lungs - at the lungs more oxygen is picked up at lower PO2.
94
What are the shifts in the dissociation curve known as?
The Bohr effect
95
Give examples of a left shift
1. Alkalosis.
2. Decreased PCO2.
3. Hypothermia.
4. Decreased metabolites.
5. Fetal haemoglobin.
96
Give examples of a right shift
1. Acidosis.
2. Increased PCO2.
3. Increased metabolites.
4. Hyperthermia.
97
What are the three main mechanisms of carbon dioxide transport?
1. Dissolved in the water of the plasma. (~8%)
2. Bound to haemoglobin (carbaminohaemoglobin) (25%)
3. Transported as bicarbonate in the plasma (67%)
98
What enzyme speeds up the reaction in red blood cells?
CARBONIC ANHYDRASE
99
Why are the hydrogen ions produced buffered?
They are buffered by combining with haemoglobin in RBCs
100
Where do the bicarbonate ions diffuse from and what do they contribute to?
Red blood cells
Plasma
