Respiratory system Flashcards
1
Q
State the functions of respiratory system
A
- Warming and humidifying air
- Olfaction (smell)
- Phonation (speaking)
- Filtering particulate matter
- Pulmonary ventilation
- Metabolism of potentially damaging chemicals
- Endocrine functions
- Site of immune defence
- Gas exchange between lung and blood which supports gas exchange between blood and tissue
2
Q
State components of upper respiratory system
A
Nasal cavity, nostril, oral cavity, pharynx, larynx
3
Q
State components of lower respiratory system
A
Trachea, primary bronchi, lungs (right and left), pleura, bronchus (left and right primary), diaphragm, carina of trachea(split airflow into bronchus)
4
Q
Whats between the upper and lower respiratory system?
A
Base of larynx or the cricoid cartilage (circle of cartilage stopping people vomiting when being intubated)
5
Q
What are the sections of the pharynx?
A
Throat
1. Nasopharynx (nasal cavity)
2. Oropharynx (mouth)
3. Laryngopharynx (larynx/ voise box)
6
Q
What are lungs asymmetrical?
A
Due to mediastinum and heart positions accommodated for
7
Q
Whats the trachea?
A
- Wind pipe (after cricoid cartilage and thyroid cartilage)
- About 12cm
- Split into left(more acute) and right(more obtuse so when something stuck in lungs its most likely to be in the right lung) primary bronchi
- Made of hyaline cartilage – keep the airway open
8
Q
Whats the carina of trachea?
A
- particularly concentrated nerve endings and chemo sensory and mechanical sensory nerve endings
- helping with cough and gag reflex
9
Q
What are trachealis muscles?
A
- on edge of lumen of trachea and oesophagus
- contracts to make lumen smaller diameter
- when coughing this is good as increases the pressure and forces foreign bodies out of the trachea
- also as oesophagus expands the lumen can relax and get smaller
10
Q
What is adventitia?
A
- simple endelthium surrounding outsides of trachea to partition off from other organs and body parts
11
Q
Whats mucosa?
A
- pseudostratified ciliated columnar epithelium
- have cilia on the surface of the columnar epithelium
- associated with goblet cells (which produces mucus)
- mucus to trap dust, bacteria cells
12
Q
Whats submucosa?
A
- containing seromucous gland in submucosa
- pump mucus up to lubricate the trachea
13
Q
Whats cilia?
A
walls of trachea
- mucociliary escalator – system of mucus and cilia that moves mucus up and out of the longs expelled by coughing or swallowing
- moves in coordinated organised fashion
14
Q
Whats the hilum?
A
- root of lungs – connecting the carina to bronchi joining to bronchioles
- contain blood vessels of pulmonary artery and veins from and too the heart
- bronchial veins and arteries – to supply blood to lungs themselves
- pulmonary nerve plexus involved in broncho dilation, broncho constriction
15
Q
What are the divisons of the lungs lobes by fissures?
A
Right lung:
1. horizontal fissure
2. oblique fissure
left lung:
1. cardiac notch (allowing space for heart so no horizontal fissure)
2. oblique fissure
16
Q
Whats the costal surface of lungs?
A
Surface nearest to the ribcage
17
Q
Whats the thorasic surface of the lungs?
A
Orientated towards the heart on inside of the lungs
Further from the ribcage
18
Q
Whats lobar?
A
(secondary) bronchi – supply’s one of the lobes
3 right and 2 on left
19
Q
What are segmental bronchus?
A
Tertiary as each segment of lung is supplied by segmental bronchus
Left – 4/5 segments
Right – superior lobe – 3, middle lobe – 2 and inferior lobe 5
20
Q
What are bronchioles?
A
- cartilage rings disappear
- smooth muscle increases
- cilia and goblet cells decrease
21
Q
Whats the passage from bronchioles to alveoli?
A
- bronchiole
- pulmonary arteriole - deoxygenated
- terminal bronchiole
- respiratory bronchiole
- alveoli
- capillary network – gasous exchange
- pulmonary venule – oxygenated to heart
22
Q
Whats the respiratory zone?
A
respiratory bronchioles
alveolar ducts
alveoli
23
Q
Explain the microscopic structure of alveoli
A
- capillary covering
- alveoli respiratory surface made of type 1 alveolar cells – simple squamous epithelial cells
-** type 2 alveolus cells** - can differentiate into type 1 but also produce surfactant - macrophages – cleaning the lungs
24
Q
Whats parenchyma?
A
lung tissue
25
Whats the surfactant?
Created by type two alveoli cells to stop alveoli collapsing.
Destroys the surface tension on alveoli to stop them collapsing
Contain substances like phospholipids and acts as a detergent covering surface in moist layer for gas transfer
26
What is macrophages?
Move around inside surface of nanoparticles, phagocytosing ingesting and destroying leukocyte particles, viral particles, dying cells, debris and bacteria
Helping orchestrate an immune defence and inflammatory response
27
What are alveolar pores?
Allow air to equalise in pressure between the alveoli
Acting as an alternative air route
28
How do different sized particles filter debris from lungs?
large particles
1. nasal hairs
2. mucus of upper respiratory tract
medium particles
1. mucus of bronchi and bronchioles
2. mucociliary escalator
smaller particles
1. alveolar macrophages
2. and type 1 alveoli which can take up smallest dust cells
29
What effects gas trasnfer at the respiratory membrane?
1. partial pressure
2. thickness of respiratory surface
3. area of respiratory surface
4. ventilation/perfusion coupling
5. temperature of fluids/tissue – solubility (and gases)
30
Whats partial pressure?
(gas diffuses from high partial pressure to low partial pressure) eg. Across alveolar wall more O2 out and CO2
Pressure exerted by an individual gas in a mixture
31
Whats daltons law?
Total pressure in a mixture of gasses equals the sum of the partial pressures of each individual gas
Pressure exerted by each gas independently depends on the amount of that gas in the mixture
P total = P N2 + P O2 + P CO2
32
Whats the partial pressure of air?
Total atmospheric pressure at sea level
~101 kPa (760mmHg)
N2 = 79%(kPa) O2 = 21%(kPa) and CO2 – 0.04%(kPa) = makes that 101.
33
Whats ficks law of diffusion?
Rate of diffusion is the tissue area multiplied by the diffusion coefficient of gas multiplied by the difference in partial pressure each side of membrane. Divided by the tissue thickness of the membrane.
Rate of gas transfer is inversely proportional to the thickness of the membrane
V gas = A x D x (P1-P2) / T
34
Whats the V/Q coupling ratio?
Alveolar ventilation over perfusion
Balanced the two to get an optimal gas exchnage
V/Q is morning ~0.8 at rest
35
Whats alveolar ventilation?
Volume of air which takes part in gas exchange
36
Whats perfusion?
The blood that reachs the alveoli via the capillaries
37
Whats local autoregulation?
In blood vessels and bronchioles
- all areas of the lungs have slightly different V/Q rates
- ventilation in apex is lower and purfusion is much lower (V/Q about 3) – stretched alveloi and blood against gravity
- in base high ventilation and much higgher perfusion of V/Q about 0.6
38
Whats ventilation perfusion mismatch?
The effect of gravity
- all areas of the lungs have slightly different V/Q rates
- ventilation in apex is lower and purfusion is much lower (V/Q about 3) – stretched alveloi and blood against gravity
- in base high ventilation and much higgher perfusion of V/Q about 0.6
39
Whats the causes of V/Q mismatch?
- gravity
- chest trauma – broken rib and pneumothorax
- blockage of bronchiole
- posture
- pulmonory oedema
- asthma
- bronchitis
- TB
- Emphysema
- Pulmonary embolism
40
Whats haemoglobins struction?
Deoxyghaemoglobin
- 4- haem groups
- 4 – iron atoms
Oxyhaemoglobin
- 4 – hame groups
- 4 – iron atoms
- 4 – O2 molecules
Binding oxygen producing hygrogen
41
Whats cooperatuve bings loading?
As more oxygen Is binded to haemoglobin its easier to bidn the next oxygen molecule
42
Whats cooperative unbinding or unloading?
Takes hydrogen and releases oxygen easier to unload as each oxygen is released.
43
What affectes loading and unloading?
1. Molecular conformation
2. pH – availibility of H+ ions
3. P02 – availiability of oxygen
4. PCO2 – availibility of CO2
5. Temperature
44
Whats the oxyhaemoglobin dissociation curve?
Diagram to explain how its easier to load oxygen two and three over 1.
45
Whats venous O2 reserve?
Access of extra oxyegn in emergency – done due to BPG
46
Whats BPG?
A byproduct of areobic respiration
Promoting the unloading of oxygen from haemoglobin within cells – due to conformational change
47
Whats Bohr effect?
- Higher PCO2 in respiring tissue
- Means more H+ ions so low pH
- H+ ions enhance the release of O2
So Bohr effect facilitates the use of the venous reserve
48
How is gas exchange adjust to metabolic needs?
- PCO2 – Bohr effect
- BPG
- PO2
- Temperature
49
How's CO2 transported through the blood?
1. Plasma – very soluble so 7-10% is dissoved in plasma
2. 20-23% binds to haemoglobin becoming cardaminohaemaglobin
3. ~70% converted to bicarbonate – due to this reaction – helped bu carbonic carbohydrates enzyme
CO2 and H2O -. H2CO3 -> H+ and HCO3-
50
Whats the Haldane effect?
Gas exchange adjusted to local conditions
In Lungs
- Higher partial pressure of oxygen
- Lower tempertaure
- Lower partial pressure of carbo dioxide
- Higher pH
This means:
- Haemoglobin binds to oxygen
- And prmotes the carbon dioxide release
51
What are the components of the nasal cavity?
- Nasal conchae
- Nasal meatuses
- Tubal tonsil
- Olfactory epithelium layer
- Olfactory nerves
- Opening of pharyngotympanic (auditory) tube
- Uvala
- Soft palate
- Hard palate
- Nasal vestibule particles
52
Whats nasal conchae?
- superior, middle and inferior
- supported by turbulant bones holding cavity open
- Supporting mucus membrane
- highly vascularised so structures are warming the air to clean and humidify
53
Whats nasal meatuses?
- superior, middle and inferior
- collection points of mucus to be swallowed
- the mucus containing antibacterial microbes and immunogloblins to control virses and pathogens which damageding cell wall of bacteria
54
What are tubal tonsils?
- accosiated with pharynx to observe pathogens trying to enter
- immunologucally active tissue.
55
Whats the epithelial layer in nasal cavity?
- humidifying air coming through cavity and catching particles of dust and small insects to clean air and sweep back across nasal conchae to be swallowed
56
Whats the nasal vestibule?
- nostil
- full of hairs to filter out particles
57
Whats the pleurae of the lungs?
pressure of pleura on each otherr stopping lungs collapsing due to elastic recoil of the lung (lower than air pressure)
- large surface covered by visceral pleura
- thoracic cavity lined by parietal pleura
- pleural cavity contains pleural fluid
58
Whats endothoracic fascia?
- lines the ribcage
- cheat of connective tissue
- adds to structural integrety of the intercoastal muscle
59
Whats costal pleura?
- plural membrane
- sits up against the endothoracic fascia and bonded too it
- part of parietal pleura which lines the pulmonary cavity – which is continuously developed around the lining of the plural cavity
60
Whats are the components of the plural cavity?
- costal (costal pleura)
- mediastial (mediastinal pleura)
- diaphramatic (diaphragmatic pleura)
- cervial (cervical pleura)
- containing pleural fluid
61
What is pleura?
Membranes linining the thorax and enveloping the lungs in humans and other mammals
62
Whats visceral pleura?
- lining the surface of the lung itself
63
Whats the location of the plural cavity?
sandwiched between the parietal pleura and the visceral pleura
64
Whats the purpose of plural cavity?
* Containing pleural fluid
* Which is a capillary layer to lubricate and allow the partietal and visceral pleura to slide over each other during inhalation and exhalation
65
What are the two types of breathing?
relaxed and forced
66
Whats the breathing musculature in forced breathing?
Intercostal muscles
- external – relaxed and forced breathing
- Internal – only used in forced exhalation
Diaphragm
- Contracting – increased volume inside thorax
- Relaxtion – decreased volume
67
What nerves are involved in breathing?
- Phrenic nerve
- Intercostal nerves
- Both branches of thoracic spinal nerves
68
Whats the process of relaexed inhalation?
1. Diaphragm and external intercostals contract and ribcage rises
2. Thoracic cavity volume increases
3. Lungs volume increases
4. Intrapulmonary pressure drops
5. Air flow into lungs down its pressurw gradient
69
How is inspiration an active process?
Costal cartilage stores energy as they are deformed
70
Changes in anterior-posterior and superior-inferior dimensions - inspiration
- Ribs are elevated and sternum flares as external intercostals contract
- Diaphragm moves inferiorly during contraction
71
Process of relaxed expiration?
1. Inspratory muscle relax, rib cage descends due to recoil of costal cartilages
2. Thoracic cavity volume decreases
3. Elastic recoil of lungs intrapulmonary volume decreases
4. Intrapulonary pressure rises
5. Air flow out the lungs down its pressure gradient
Passive process
72
Changes in anterior-posterior and superior-inferior dimensions – expiration
- Ribs and sternum are depressed as external intercoastals relax
- Diaphrgm moves superiorly as it relaxes
- Returning to original shape – releasing
73
Neck muscles in forced inhalation
- Sternocleiomastoids
- Scalenes
Helps to lift the ribcage assisting the intercostal muscles
74
Chest muscles in forced inhalation
- Pectoralis major
- Pectoralis minor
Rapidly lifting ribcage when we need to inhale rapidly or deeply
75
Spine muscles in forced inhalation
- Erector spinae – spinal muscles
76
Muscles used in forced exhalation
- Transverse abdominals
- Rectus abdominis
- Latissimus dorsi
Pulls ribcage down rapidly to expel air pushing internal organs against diaphragm so it relaxes more rapidly and reduces the volume of the thoracic cavity.
77
Whats the intercostal intimus?
- Innermost intercostal – a third layer of intercostal muscles
- role – stiffen chest wall during breathing and forced exhalation (with internal intercostal)
78
Whats the effect of altitude on partial pressure?
- at altitude the partial pressure of oxygen is reduced
- additionally under water (each 10m is one atmosphere added pressure) - higher partial pressure more oxygen than other gases
79
Whats henry's law?
The amount of dissolved gas in a liquid is proportional to the partial pressure in the gas above
So if theres a high partial pressure of oxygen in the alveolus then oxygen will easily dissolve into the blood liquid.
Additionally if theres a low partial pressure of carbon dioxide in alveolus the carbon dioxide will easily dissolve out the blood and into the alveoli
80
Whats the comparable solubility of gases?
CO2 > O2 >> N2
Gas solubilities decreases with increased temperture
81
What affects the work of breathing?
- the resistance of the airways
- the elasticity of the lung tissue
- obstruction to flow (physical blockage or inflammation of airways (edema from pneumonia)
- chest wall compliance (abilkity of thorax to change volume of lung)
82
What are some factors effecting airflow?
1. pulomnary compliance
2. airway resistance
3. alveolar surface tension
83
Whats compliance?
Measure of the ease of expansion of the lungs determined by pulmonary volume and elasticity
84
What affects pulmonary compliance?
Decreased compliance (restrictive as more elastic recoil)
1. pulmonary TB (causing pulmonary fibrosis and large elastic recoil)
2. Pneumonia (Edema due to excess fluid)
Increased compliance (obstructive loss of elastic recoil)
1. Emphysema (confluent alveoli and loss of elastic fibres amd tissue)
2. Nromal ageing (loss of elastic recoil)
85
How does bronchial diameter effect airway resistance?
- Any network of the tubes has air resistance
- Conducting division/zone – upper respiratory tract, bronchi, bronchioles and terminal bronchioles
- Respiratory division/zone – respiratory bronchioles and alveoli
86
Whats bronchoconrtiction and dilation?
- Changing the size of the lumen of bronchi to increases or decreases airway resistance
- Helped by mucus and the lining of the bronchi
87
Whats activated in bronchoconstriction?
- Parasympathetic nervous system activated
- Eg. Asthma due to airborne irrantas, cold air and histamine
88
Whats activated in bronchodilation?
- Adrenaline, B2 adrenergic agonists
- Sympathetic nervous system is activated
- In the fight or flight system
89
Whats activated in bronchodilation?
- Adrenaline, B2 adrenergic agonists
- Sympathetic nervous system is activated
- In the fight or flight system
90
Whats alveolar surface tension?
- Force acting along an imaginary line In the surface of the liquid
- Arising from attractive forces between molecules
- High would cause alveoli to collapse, severely decreased compliance and very hard to inflate lungs
91
Whats minute volume?
Air drawn in per minute whilst at rest
Typically 12-16
92
Whats residual volume?
Air remaining in the lungs after expiration normally 1200-1100ml
93
Whats tidal volume?
Air taken in during one breath at rest normally 500ml
94
Whats vital capacity?
Maximum volume of inspired breath following maximum expiration
95
Why study lung volumes?
Assess or monitor respiratory diseases
96
Whats static lung volumes?
Relaxed ‘normal’ breathing
97
Whats dynamic lung volumes?
- Use a dynamic spirometry
- Useful to assess obstructive disorders like asthma or COPD
- Measure the forced expiratory volume in one second
- Also tests the forced vital capacity
- Ratio is forced expiratory / forced vital capicity
- Normally between 75-80%
- If lower than 40% a disease may be indicated
98
What are the three definitions of respiration?
1. Systematic
2. Tissue
3. Cellular
99
Whats systematic respiration?
The ventilation of the lungs – breathing
100
Whats tissue respiration?
Gas exchange between air/blood and blood/tissue fluid
101
Whats cellular respiration?
Use of oxygen in cellular metabolism
102
What is the conducting division of the respiratory system?
Passages involved in air flow only i.e. nostrils → bronchioles
103
What is the respiratory division of the respiratory system?
Parts involved in gas exchange: respiratory bronchioles and alveoli
104
How does the upper respiratory tract differ from the lower respiratory tract?
Structures comprising the upper respiratory tract are located in the head and neck, whereas structures comprising the lower respiratory tract are located in the thorax.
105
Write down, in order, the structures through which air flows on its journey from the nose to the pulmonary alveoli.
Nostril → nasal cavity → choanae → pharynx → larynx → trachea → primary bronchus → secondary bronchus → tertiary bronchus → bronchiole → terminal bronchiole → respiratory bronchiole → alveolar duct → alveoli
106
What are the functions of the nose?
1. warms, cleanses and humidifies inhaled air
2. detects odours
3. amplifies the voice
107
Whats the cardiac notch?
AKA cardiac impression
Accommodates the heart
108
What are the fissures of the left and right lung?
Left: oblique; right: oblique and horizontal.
109
Whats the number of lobes in the left and right lung?
left - 2
right - 3
110
What is a bronchopulmonary segment?
The portion of the lung supplied by each tertiary bronchus.
111
What are the two parts of bronchial tree?
Bronchiole
Terminal bronchiole
112
What are bronchioles?
Small airways (1mm or less in diameter) that lack supportive cartilage. Walls contain much smooth muscle
Conduct air to terminal bronchioles; can constrict or dilate in response to stimuli from the autonomic nervous system.
113
Whats the terminal bronchiole?
0.5 mm or less in diameter; contain cilia
Conduct air to respiratory bronchioles; cilia prevent mucus accumulation
114
Components of pulmonary alveoli
1. bronchiole
2. pulmonary arteriole
3. pulmonary venule
4. alveolus
5. alveolar space
6. capillaries
7. terminal bronchiole
8. respiratory bronchiole
115
State the three types of alveolar cell
Type 1 alveolar cell
Type 11 aveolar cells
Alevolar macorphages
116
Whats types one alveolar cell?
* Make up the alveolar wall; permit rapid gas exchange
117
Whats type 2 alveolar cell?
* Repair alveoli; secrete surfactant
118
What are alveolar macrophages?
* Phagocytosis of debris
119
Whats pleurae?
Serous membranes that cover the lung surfaces and line the thoracic cavity
120
Whats the function of pleurae?
They reduce friction, work with the plural fluid to transfer forces between the lungs and the chest wall, create a pressure gradient and compartmentalise the lungs.
121
What does trachealis muscle do?
Trachea
Adjusts air flow, allows for distention of the oesophagus during swallowing
122
What does the mucociliary escalator do?
Trachea, bronchi and bronchioles
Traps and removes debris from airways
