Respiratory system Flashcards
State the functions of respiratory system
- 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
State components of upper respiratory system
Nasal cavity, nostril, oral cavity, pharynx, larynx
State components of lower respiratory system
Trachea, primary bronchi, lungs (right and left), pleura, bronchus (left and right primary), diaphragm, carina of trachea(split airflow into bronchus)
Whats between the upper and lower respiratory system?
Base of larynx or the cricoid cartilage (circle of cartilage stopping people vomiting when being intubated)
What are the sections of the pharynx?
Throat
1. Nasopharynx (nasal cavity)
2. Oropharynx (mouth)
3. Laryngopharynx (larynx/ voise box)
What are lungs asymmetrical?
Due to mediastinum and heart positions accommodated for
Whats the trachea?
- 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
Whats the carina of trachea?
- particularly concentrated nerve endings and chemo sensory and mechanical sensory nerve endings
- helping with cough and gag reflex
What are trachealis muscles?
- 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
What is adventitia?
- simple endelthium surrounding outsides of trachea to partition off from other organs and body parts
Whats mucosa?
- 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
Whats submucosa?
- containing seromucous gland in submucosa
- pump mucus up to lubricate the trachea
Whats cilia?
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
Whats the hilum?
- 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
What are the divisons of the lungs lobes by fissures?
Right lung:
1. horizontal fissure
2. oblique fissure
left lung:
1. cardiac notch (allowing space for heart so no horizontal fissure)
2. oblique fissure
Whats the costal surface of lungs?
Surface nearest to the ribcage
Whats the thorasic surface of the lungs?
Orientated towards the heart on inside of the lungs
Further from the ribcage
Whats lobar?
(secondary) bronchi – supply’s one of the lobes
3 right and 2 on left
What are segmental bronchus?
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
What are bronchioles?
- cartilage rings disappear
- smooth muscle increases
- cilia and goblet cells decrease
Whats the passage from bronchioles to alveoli?
- bronchiole
- pulmonary arteriole - deoxygenated
- terminal bronchiole
- respiratory bronchiole
- alveoli
- capillary network – gasous exchange
- pulmonary venule – oxygenated to heart
Whats the respiratory zone?
respiratory bronchioles
alveolar ducts
alveoli
Explain the microscopic structure of alveoli
- 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
Whats parenchyma?
lung tissue
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
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
What are alveolar pores?
Allow air to equalise in pressure between the alveoli
Acting as an alternative air route
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
What effects gas trasnfer at the respiratory membrane?
- partial pressure
- thickness of respiratory surface
- area of respiratory surface
- ventilation/perfusion coupling
- temperature of fluids/tissue – solubility (and gases)
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
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
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.
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
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
Whats alveolar ventilation?
Volume of air which takes part in gas exchange
Whats perfusion?
The blood that reachs the alveoli via the capillaries
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
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
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
Whats haemoglobins struction?
Deoxyghaemoglobin
- 4- haem groups
- 4 – iron atoms
Oxyhaemoglobin
- 4 – hame groups
- 4 – iron atoms
- 4 – O2 molecules
Binding oxygen producing hygrogen
Whats cooperatuve bings loading?
As more oxygen Is binded to haemoglobin its easier to bidn the next oxygen molecule
Whats cooperative unbinding or unloading?
Takes hydrogen and releases oxygen easier to unload as each oxygen is released.
What affectes loading and unloading?
- Molecular conformation
- pH – availibility of H+ ions
- P02 – availiability of oxygen
- PCO2 – availibility of CO2
- Temperature
Whats the oxyhaemoglobin dissociation curve?
Diagram to explain how its easier to load oxygen two and three over 1.
Whats venous O2 reserve?
Access of extra oxyegn in emergency – done due to BPG
Whats BPG?
A byproduct of areobic respiration
Promoting the unloading of oxygen from haemoglobin within cells – due to conformational change
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
How is gas exchange adjust to metabolic needs?
- PCO2 – Bohr effect
- BPG
- PO2
- Temperature