1
Q
What is the function of the respiratory system?
A
Provides oxygen to the body, disposes of carbon dioxide and helps regulate blood pH.
2
Q
Where does gas exchange occur?
A
Respiratory membrane - In the alveoli in the lungs, and at capillary beds around the body.
3
Q
What is the normal breathing rate for adults?
A
12-20 breaths per minute. PBM
4
Q
Normal oxygen saturations in healthy adult?
A
94 - 98% SpO2.
5
Q
What is respiratory arrest?
A
When respiration has ‘arrested’ or stopped.
Caused by anything that prevents effective respiration. - causes respiratory failure.
eg, choking, airway trauma.
6
Q
What is cardiac arrest?
A
When the heart ‘arrests’ or stops its function
7
Q
What is a symptom?
A
Something the patient feels or is aware of.
8
Q
What is a sign?
A
Something the clinician can establish through clinical observations and examination. eg, reduced oxygen levels.
9
Q
-itis meaning
A
Inflammation.
10
Q
Function of respiratory system (longer)
A
-Respiration
-Homeostasis
-Role in blood pH control
-Gas exchange - 02 taken up and C02 released
-CO2 is acidic, so to help lose excess acidity, patient will breathe faster to exhale CO2
-Purify, dampen, and warms incoming air
-Cardiovascular system works closely with RS.
11
Q
Two parts of respiratory system?
A
Upper respiratory tract – Nose to larynx
Lower respiratory tract – trachea to alveoli
12
Q
Conducting zones?
A
All respiratory passageways that carry air to the terminal bronchioles and beyond
13
Q
Respiratory zones
A
Part of the lung that leads into the alveoli and is involved in gas exchange) - respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli.
14
Q
Nose info?
A
- Air enters nose by nostrils
- Interior = nasal cavity, divided by midline nasal septum.
- Olfactory receptors for smell are in muscosa in superior art of nasal cavity, beneath ethmoid bone.
- Respiratory mucosa lines nasal cavity.
- Veins warm the air as it flows past.
- The mucus produced by mucosa’s glands moisten the air and traps pathogens and debris.
- Lysozyme enzymes in the mucus destroy bacteria chemically.
- The ciliated cells of the nasal mucosa create a gentle current that moves the contaminated mucus toward the pharynx, where it’s swallowed and digested by stomach juices.
15
Q
What happens in the nose when it’s very cold.
A
the cilia allow mucus to accumulate in the nasal cavity.
The lateral walls of the nasal cavity are uneven due to lobes called conchae – projections from the walls of the nasal cavity that increase the air turbulence and SA of mucosa exposed to air.
16
Q
Why is air turbulence needed in the nasal cavity?
A
As the air swirls more, inhaled particles are deflected onto the mucosa, and are trapped, so don’t reach the lungs.
The nasal cavity is separated from the oral cavity by a partition, the palate. There is a hard (supported by bone) and soft palate. (Unsupported by bone)
17
Q
Sinuses info?
A
The nasal cavity is surrounded by a ring of paranasal sinuses in the frontal, sphenoid, ethmoid and maxillary bones. The sinuses lighten the skull and act as resonance chambers for speech. They also produce mucus, which drains into the nasal cavities.
18
Q
Pharynx info?
A
- Muscular tube extending from the posterior of the nasal cavities to the oesophagus.
- Passageway for food and air
- Three regions: nasopharynx, oropharynx, laryngopharynx.
- Food passes through the pharynx and the three regions, and into the oesophagus through the flap called the epiglottis.
- Lined with mucous membrane
- Site of tonsils
- Chamber for speech resonation
- The pharyngotympanic tubes that drain the middle ears, open into the nasopharynx.
- The mucosae are continuous so ear infections may follow a pharyngeal infection.
19
Q
Larynx info?
A
- The cartilaginous organ located between the trachea and the pharynx: voice box.
- Passageway for air only.
- Connects laryngopharynx to trachea.
- Formed by 8 rigid hyaline cartilages and elastic cartilages called the epiglottis.
- The largest of the hyaline cartilage is the thyroid cartilage, which protrudes anteriorly - Adams apple
- Cricoid cartilage attaches to first ring cartilage of trachea.
- Mucous membrane folds into vocal cords.
20
Q
Epiglottis info?
A
Epiglottis – the elastic cartilage at the back of the throat that covers the glottis during swallowing. It allows the passage of air into the lower respiratory passages.
- It diverts food into oesophagus and protects the superior opening of the larynx
When swallow:
- Larynx is pulled upward
- Epiglottis tips, forming lid over larynx’s opening, and leading food into the oesophagus.
- If anything other than air enters larynx, cough reflux to stop It entering lungs. Reflex doesn’t work when unconscious.
21
Q
Vocal cords info?
A
Part of the mucous membrane of the larynx forms a pair of folds called vocal folds, or true vocal cords.
They vibrate with expelled air to produce sound
22
Q
Vocal cords info?
A
Part of the mucous membrane of the larynx forms a pair of folds called vocal folds, or true vocal cords.
They vibrate with expelled air to produce sound
23
Q
Glottis info?
A
Glottis is the opening between the vocal cords in the larynx. Air must pass through to enter the trachea.
24
Q
Trachea info?
A
- The windpipe, the respiratory tube extending from larynx to bronchi. (10-12cm)
- Walls are reinforced with C-shaped rings of hyaline cartilage.
- Open parts of the rings abut the oesophagus and allow the trachea to expand anteriorly when swallowing large bolus.
- Solid rings support the trachea walls and keep it open to withstand the pressure changes during breathing.
- Trachealis muscle lies next to the oesophagus and completes the wall of the trachea.
- Trachea is lined with a ciliated mucosa. Cilia are surrounded by goblet cells that produce mucus.
25
Cilia info?
Cilia – hairlike projections on cell surfaces that propel mucus (that traps dust and pathogens) to throat to be swallowed or coughed up.
If trachea is blocked, perform Heimlich manoeuvre, or in emergency, tracheostomy (surgical opening of trachea)
26
Lungs info?
- They occupy entire thoracic cavity except for mediastinum. – region of thoracic cavity between the lungs that houses the heart, great blood vessels, bronchi, oesophagus and other organs. .
- Pulmonary pleura – serous membrane layer covering the cavity in which the lung resides.
- Walls of thoracic cavity lined by parietal pleura.
- Pleural membranes produce pleural fluid, which allows the lungs to glide over the thorax wall during breathing to reduce friction and causes the two pleural layers to cling together.
- Made of elastic connective tissue that allows the lungs to stretch and recoil during breathing.
- Right – 3 lobes ; Left – 2 lobes (due to heart)
27
Pleurisy info?
Pleurisy – Inflammation of the pleurae – caused by insufficient secretion of pleural fluid. Two types – pleural surfaces become dry, resulting in friction OR pleurae produce excessive fluid, which exerts pressure on lungs.
28
Alveoli info?
- Air spaces
- Walls of alveoli made of single, thin layer of simple squamous epithelial cells.
- Alveolar pores connect neighbouring air sacs and provide alternative routes for air to reach alveoli whose feeder bronchioles are clogged by mucus or blocked.
- Part of the respiratory membrane, where gas exchange occurs.
- Contains alveolar macrophages that remove pathogens and debris.
- Contain specialised cells that produce surfactant, which prevents alveoli collapse.
- Highly vascular.
29
Respiratory membrane info?
- Effectively divides gas from fluid
- Site of external respiration
- Made up of 4 layers: - Alveolar walls & basement membrane - Capillary walls & basement membrane
- Huge surface area
- Very thin membrane - for diffusion
- O2 into bloodstream, CO2 into alveoli
30
Bronchi info?
The left and right primary bronchi are formed by division of trachea. They plunge into the hilum (medial depression of the lung)
Right bronchus is wider, shorter, and straighter than left. It is more common for inhaled objects to become lodged because it is easier to access.
The bronchial tree because of the branching and rebranching of respiratory passageways. All but the smallest branches have reinforcing cartilage in their walls.
31
Dalton's Law
The pressure exerted by a mix of gases is the sum of all the partial pressures exerted by each gas within that mix.
Px is the pressure of a specific gas in a mix of gases.
These partial pressures allow diffusion to occur in respiration.
O2 partial pressure measured in mmHg, millimetres of mercury.
32
Types of respiration?
Internal
- Gas exchange between the capillaries and the cells and tissues.
External
- Gas exchange between the alveoli and the bloodstream.
33
To supply body with O2 and remove CO2, what happens.
Pulmonary ventilation: air moves into and out of lungs. the exchange of air between the lung alveoli and external environment.
External respiration: Gas exchange between the alveoli and the bloodstream.
Respiratory gas transport: O2 + CO2 transported to and from lungs and cells of body via bloodstream
Internal respiration: Gas exchange between the capillaries and the cells and tissues.
34
Henry's Law
the quantity of gas that dissolved into a liquid is proportional to its partial pressure and its solubility.
Oxygen does not dissolve very easily into plasma. (the fluid component of the blood)
FiO2, Fraction of inspired Oxygen
35
Anaemia info?
- Aemia – in the blood.
- Lack of circulating oxygen due to:
- Insufficient red blood cells
- Poorly functioning haemoglobin – genetic protein mutation
- Lack of haemoglobin – due to low iron levels.
- Shortness of breath.
36
How is carbon dioxide transported in the plasma?
- Dissolving into plasma (7%)
- In carbamino compounds (23%)
- As bicarbonate ions HCO3 - (70%)
Co2 is more soluble than O2.
37
Carbon dioxide equation.
- Carbonic anhydrase (CA) catalyses carbon dioxide + water to form carbonic acid in RBCs:
- CO2 + H20 < carbonic anhydrase > H2CO3 <-> H+ + HCO3-
38
Normal blood pH
7.35 - 7.45
39
Carbon monoxide info?
odourless, colourless gas. Same binding site as oxygen on haemoglobin. Haemoglobin binds to CO more readily than to oxygen.
CO poisoning – kills softly and quietly. Victim becomes confused and headache. Given 100% oxygen until CO cleared.
40
Boyles Law
Volume of gas is inversely proportional to its pressure if mass and temp are constant.
41
Accessory muscles of laboured inhalation?
External and internal intercostal muscles
Diaphragm
Scalenes
Pectoralis minor
Sternocleidomastoid.
42
Accessory muscles of laboured exhalation?
Abdominal muscles + Internal intercostal muscles
43
Lung compliance info?
The effort needed for lung walls to stretch
Due to: scar tissue, pulmonary oedema, anything that impedes chest expansion, reduced surfactant
44
Ventilation info?
V/Q ratio (ventilation/perfusion ratio)
Volume of one normal breath = tidal volume.
30% of inhaled air remains in conducting zones.
Normal breathing moves ~ 500ml air.
45
Major organs of the respiratory system?
nose, pharynx, larynx, trachea, bronchi and bronchioles, lungs containing alveoli
46
Definition of tidal volume?
The volume of air inhaled or exhaled with a normal breath
47
Definition of inspiratory reserve volume?
The volume of air that can be forcibly inhaled above the tidal volume
48
Definition of expiratory reserve volume?
The volume of air that can be forcibly exhaled beyond tidal expiration
49
Definition of residual volume?
Air remaining in the lungs after exhalation that cannot be voluntarily exhaled
50
Why is residual volume air important?
- Allows gas exchange to go on continuously between breaths
- Helps to keep alveoli inflated.
51
Definition of vital capacity?
The total volume of air that can be expelled from the lungs by forcible expiration after the deepest inspiration, total exchangeable air.
52
Definition of dead space volume?
Volume of air that never reaches the alveoli and doesn’t participate in gas exchange. 150ml.
53
Definition of functional volume?
Volume of air that reaches alveoli and participates in gas exchange – 350ml.
54
How is respiratory capacity measured?
With a spirometer.
55
What are nonrespiratory air movements?
cough, sneeze, crying, laughing, hiccups, yawn.
56
Definition of rales?
abnormal bronchial sounds produced by presence of mucus or exudate in lung passages or by thickening of bronchial walls.
57
What is the palate?
The partition that separates the nasal cavity from the oral cavity.
58
What is hyperventilation?
An increase in the rate and depth of breathing that exceeds the body's need to remove carbon dioxide.
59
How can hyperventilation be solved.
By breathing into a paper bag. - Exhaled air contains more carbon dioxide than atmospheric air, it disrupts the normal diffusion gradient, so carbon dioxide begins to rise in the blood, ending alkalosis.
60
What are the inspiratory muscles?
diaphragm, external intercostal muscle.
61
Inhalation steps?
The drawing of air into the lungs (passive process)
Diaphragm contracts inferiorly
External intercostal muscles contract which lifts ribcage and thrusts sternum forwards.
Volume of thoracic cavity increases
This increases the anteroposterior and lateral dimensions of the thorax.
The lungs adhere to the thorax walls because of the surface tension of the fluid between the pleural membranes. – They are stretched.
The intrapulmonary volume increases, the gases within the lungs spread out. The decrease in gas pressure produces a partial vacuum causing air to flow into lungs. Air continues to flow in until the intrapulmonary pressure equals the atmospheric pressure.
62
Expiration steps?
The act of expelling air from the lungs (passive process)
Diaphragm relaxes superiorly
External intercostal muscles relax.
Both the thoracic and intrapulmonary volumes decrease.
Rib cage descends
Lungs recoil.
As the intrapulmonary volume decreases, the gases inside the lungs are forced more closely together and the intrapulmonary pressure rises to a point higher than atmospheric pressure. This causes gases to passively flow out to equalise the pressure with the outside.
If respiratory passageways are narrowed by asthma/chronic bronchitis/pneumonia, etc… expiration is an active process.
63
Forced expiration info?
Internal intercostal muscles are activated to help depress rib cage. Abdominal muscles contract and help to force air from the lung by squeezing abdominal organs upward against the diaphragm.
64
What is atelectasis?
(lung collapse), air in pleural space (via wound, etc…). which disrupts fluid bond between pleurae. – pneumothorax.
65
What is cleft palate?
Cleft palate – failure of bones forming the palate to fuse medially. – results in breathing difficulty as well as problems with oral cavity functions, like nursing and speaking.
66
Sinusitis info?
When the passageways connecting the sinuses to the nasal cavity are blocked with mucus, the air in the sinus cavities is absorbed – partial vacuum and sinus headache over inflamed area.
67
Rhinitis info?
inflammation of the nasal mucosa.
68
Tonsils and tonsilitis info?
Tonsils are clusters of lymphatic tissue in the pharynx. If the pharyngeal tonsil becomes inflamed and swollen, it obstructs the nasopharynx and forces the person to breathe through mouth, where air isn’t warmed or filtered. – tonsilitis.
69
Haemoglobin info?
Oxygen carrier. 4 O2 molecules per haemoglobin – fully saturated. Oxyhaemoglobin.
70
Things that cause oxygen to dissociate from haemoglobin?
Decreased pH, increased COs, increased temp.
Binding affinity is reduced.
71
Bohr effect?
Haemoglobin's oxygen binding affinity is inversely related both to the acidity and to the concentration on carbon dioxide.
72
Carbon monoxide info?
Competitive, irreversible binding to haemoglobin.
Carboxyhaemoglobin.
73
Carbon monoxide poisoning info?
probe will be inaccurate as it will detect high CO as high O2. Pulse oximetry reading – 100% O2.
High flow oxygen administration needed to treat.
74
If patient has increased levels of CO2 in blood, what happens?
Blood pH will fall/ become acidotic.
When acidotic – initially breathe faster – fast respiratory rate to expire more carbon dioxide rapidly. , then deeper and slower to expel larger volumes of carbon dioxide – Kussmauls respirations. Nausea vomiting, coma, decrease in consciousness, lethargy, confusion. Can lead to coma.
75
Basic concept: what happens to CO2 if all is well.
Carbon dioxide produced in cells
Diffuses into the bloodstream as lower level in bloodstream
Carried as carbonic acid around body
Reaches lungs
Converted back to carbon dioxide
Diffuses into alveoli as lower level in alveoli
Carbon dioxide respired out
76
- Raised carbon dioxide effects?
Leads to an increase in hydrogen ions (H+)
- And so, pH decreases
- Patient becomes acidotic (and confused)
- So a respiratory issue can cause not only hypoxia but acidiaemia (pH lower in blood)
77
If breathing too fast and too slow, what happens in terms of CO2.
Too fast – losing CO2.
Not fast enough – Build up of CO2 from body.
All about H+ ions, and the effect they have on the body.
78
Activity of respiratory muscles regulated by what?
Regulated by nerve impulses transmitted from brain by phrenic nerves and intercostal nerves.
79
Medulla respiratory centre info?
Medulla contains 2 respiratory centres: ventral respiratory group (VRG) –contains inspiraoty and expiratory neurones that send impulses to control rhythm of breathing. Dorsal respiratory group: Helps modify breathing rhythms.
80
Bronchioles and alveoli receptors info?
Bronchioles and alveoli have stretch receptors (baroreceptors) that respond to extreme overinflation.
81
Respiration stimulation info?
Respiration process is a negative feedback mechanism.
Respiration is driven by the level of Carbon dioxide in the blood
The main stimulus for increasing the breathing rate and depth of the lungs involves an increase in the level of carbon dioxide in the blood.
82
Respiration stimulation with COPD?
For those with COPD – the drive to respire comes from the detected low level of oxygen instead. This is called the hypoxic drive.
When administering oxygen to COPD patient, if If diminished respiratory drive already and high oxygen is administered, respiratory drive will be diminished further, slower respiration and can progress into ventilatory failure.
83
If not breathing on purpose for long time, what happens?
Involuntary control takes over if too far.
84
What do chemoreceptors do?
Detect chemical changes in Co2, hydrogen ions, O2 levels.
They detect an increase in carbon dioxide, a decreased pH or hypoxia (an increased rate and depth of respiration)
85
Hering -Breuer reflex info?
protect against excessive lung inflammation
Paramedic Science
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