Respiratory System Part 1 Flashcards
Physiology
What type of mechanism are the lungs?
Defence mechanism
What are the respiratory organs?
Lungs, epiglottis, trachea, bronchi, mouth, nose, larynx, pharynx
What are some of the main functions of the respiratory system?
Moves oxygen from the outside environment into the body
Removes carbon dioxide and water from the body
Main site for gas exchange
Site for immune system reaction and functions- provides protection
What do lung capacities and lung volumes refer to?
The volume of air in the lungs at different phases of the respiratory cycle
What is the average total lung capacity for males and females?
Males= 6 litres
Females= 4-5 litres
What is tidal breathing?
Breathing at rest
What is tidal volume?
The volume of air that is inhaled or exhaled in only a single breath
What is the average adult respiratory rate?
12-20 breaths per minute
What is the average respiratory rate at birth?
3-60 breaths per minute
What is the inspiratory reserve?
3100 ml
The amount of air a person can inhale forcefully after normal tidal volume inspiration
What is the tidal volume?
500 ml
What is the expiratory reserve volume?
1200 ml
The volume below the tidal end-expiratory level that can be forcefully expired from the lungs
What is the residual volume?
1200 ml
The air that remains in the lungs after maximum forceful expiration
What is the inspiratory capacity?
3600 ml
The maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration
It is the sum of the TIDAL VOLUME and the INSPIRATORY RESERVE VOLUME
What is the functional residual capacity?
2400 ml
The volume of air present in the lungs at the end of passive expiration
What is the vital capacity?
4800 ml
The maximum amount of air that a person can exhale from their lungs after taking a deep breath
It is typically measured using a spirometer or vitalograph, and a normal, healthy adult has a vital capacity between 3 and 5 liters
What is the total lung capacity?
6000 ml
What happens during a spirometry test?
Measure of forceful expulsion of air
It is used to identify respiratory conditions such as asthma, pulmonary fibrosis, cystic fibrosis, and COPD by analyzing breathing patterns
What happens when you breathe in?
Rib muscles relax
Diaphragm contracts
Air leaves the alveoli
Air moves between the chest wall and the lung
What occurs during inspiration?
During inspiration (inhalation), the diaphragm and intercostal muscles contract
What occurs during exhalation?
During exhalation, the intercostal muscles relax and the diaphragm domes upwards
How does air move into and out of the respiratory system?
Pressure gradient
What occurs during the mechanics of breathing?
Prior to breathing in: the diaphragm and intercostal muscles are relaxed
During inhalation (active): diaphragm contracts and flattens, intercostal muscles contract and rise, pressure in the lungs decreases so air rushes in
During exhalation (passive): diaphragm relaxes, intercostal muscles relax and fall, increasing pressure in the lungs so air is pushed out
What does circulatory refer to?
The link between the heart and the lungs
How are the respiratory and cardiovascular system linked?
Gas exchange at the lungs and in the body cells moves oxygen into cells (via blood stream) and carbon dioxide out
Which structure is responsible for gas exchange in the lungs?
Alveoli, which are moist thin-walled pockets that are the site of gas exchange
Why do the alveoli walls not collapse on themselves or stick together?
There is a slightly oily surfactant present
What are the additional benefits of the alveoli?
Provide a larger surface area
Thin walls= shorter diffusion pathway= increased rate of gas exchange
Slightly oily so therefore will prevent friction and inflammation
What is the respiratory surface made up of?
Alveoli and capillary walls
What is significant about the respiratory surfaces’ alveoli and capillary walls?
They share the same membrane
How are the capillaries and alveoli adapted to improve efficiency?
The epithelium of the alveoli are 1 cell thick and so contain blood capillaries
The blood capillaries have a small diameter and so only allow one red blood cell through at a time
Where does blood enter the alveoli from?
The pulmonary artery and leaves via the pulmonary vein
How do erythrocytes carry oxygen?
The oxygen associates with haemoglobin
What happens to carbon dioxide in the blood?
Diffuses out and is then exhaled
What is significant about the air entering the lungs?
The air entering the lungs has more oxygen and less carbon dioxide than the blood that flows in the pulmonary capillaries
How does air enter the blood stream from the pulmonary capillaries?
Haemoglobin has a greater affinity for oxygen than the carbon dioxide and so will associate with the oxygen and allow oxygen to enter the blood stream
Hb binds to the oxygen that diffuses into the bloodstream
What are some of the benefits of haemoglobin being used to distribute oxygen in the body?
Controlled way of distributing oxygen in the body
Prevents too much oxygen being taken up by cells and tissues which could then damage them
Many haemoglobin molecules in a red blood cell, and each molecule has 4 binding sites for oxygen, therefore meaning that a large quantity of oxygen can be distributed
What can carbon dioxide do in the body, but more specifically the cells?
Can dissolve in plasma, and approximately 70% forms bicarbonate ions
What is dangerous about carbon dioxide?
Some carbon dioxide can bind to haemoglobin for transport
How is carbon dioxide able to bind to haemoglobin?
Quicker/increased use of oxygen for cellular respiration
Causes a shift in the diffusion concentration gradient
Leads to an increase in carbon dioxide concentration
Hb has a higher affinity for carbon dioxide than oxygen
What does the Bohr’s affect describe?
The oxygen binding affinity of haemoglobin
What does a graph of the Bohr’s effect normally show?
Oxygen transport
Bound to Hb
Myoglobin
Different Hb forms
How do cilia cells and mucus act as defence mechanisms for the respiratory system?
Cilia cells are finger like projections that help to waft things away
Mucus helps to trap pathogens
What are the components of the respiratory tract that act as the first line of defence?
Nasal hairs
Mucus secretions
Irregular chambers
Cilia cells
Cough reflex
Specific immune cells
How does the line of defence help the respiratory system?
Traps pathogens and triggers the immune response
How do irregular chambers help defend the respiratory system?
Trap things/particles so as to prevent them from reaching the lungs
How do cilia cells help to defend the respiratory system?
Cilia cells waft the mucus so that it can be coughed up and the trapped pathogens in the mucus are also expelled
Why is a decreased cough reflex dangerous?
The person becomes more prone to respiratory conditions as the pathogens are not expelled
What are the structures of small airways and alveoli?
Epithelial cells
Alveolar macrophages
Lymphocytes
Immune factors
What are the structures of the nasopharynx?
Squamous epithelial
Nasal hairs
Turbinates and mucosal lymphoid tissue
Ciliated epithelium
Mucus layer
Immune factors
What are the structures of the larynx?
Cords
Epiglottis
Cough reflex
What are the structures of the trachea and bronchi?
Ciliated epithelium
Mucociliary escalator
Cough reflex
What are the physical and physiological mechanisms regarding the respiratory system?
Humidification
Particle removal
Particle expulsion
Respiratory tract excretions
What is the benefit of humidification?
Prevents dehydration of the epithelium
What is significant about particle removal?
90% of particles over 10um are removed in the nostril or nasopharynx – includes pollen, 5-10um become impacted in carina, smaller than 1um remain airborne. Thus particles between 1-5um capable of reaching lung
What effects particle expulsion?
Coughing, sneezing or gagging
Why is it important to remove respiratory tract excretions?
Mucus of resp tract is gelatinous substance mainly acid and neutral polysaccahrides, impermeable to water
Floats on liquid ‘sol layer’ present around the epithelial cells/cillia
Gel layer is secreted by goblet cells and mucous glands. Under normal conditions cillia in contact with gel blanket and movement helps to move mucous
What properties of the particle that could determine the particle interaction?
Surface
Volume
Shape
Density
Aerodynamic diameter
(Speed)
What would happen if a particle is smoother?
The particle could get trapped further down
What is an example of a therapeutic use of particles?
Asthma inhalers: theory of understanding as to inhaler techniques
Why are carbon particulates hazardous to health?
The carbon particulates can bind to lungs and decrease lung volume
What is one way that the number of harmful particles could be decreased?
By improving the air quality of external environments
