GEP (Life support) Week 1 Flashcards
What are the subparts of the pharynx?
-Nasopharynx
-Oropharynx
-Laryngopharynx
Where is the larynx located and what is its role?
The larynx is below the vocal cord and above the trachea.
It Mediates the crossover of digestive and respiratory passageways
Voice production
How many ribs do we have and how are they catogarised?
-We have 12 pair of ribs
-1-7 are true ribs that articulate to the sternum directly
-8-10 are flase ribs that articulate to the sternum by joining with other ribs coastal cartilage.
-11-12 are floating ribs, and they do not attach to the sternum.
What is the Pleura and how is it divided?
The pleura is a double memebrane covering the lungs and thorax that is divided into visceral and parietal.
Viscerel: This covers the surface of the lungs ( this is innervated by the pulmonary plexus and is only has a strech sensation).
Parietal: Covers the inside of the thorax (this is innervated by phrenic and intercostal nerve and can sense pain).
The space inbetween is also know as the intrapleural space (pleural cavity), this is a thin film of serous fluid.
How many lobes does the lung have?
Right lobe: 3 lobes and 2 fissures
Left lobe: 2 lobes and 1 fissure
Describe the histology of the lungs?
The lungs have:
Ciliated pseudostratified columnar cells (lines the epithelium of the lungs)
Mucous secreting goblet cells
Basal cells (Basal cells are the stem cells or progenitors of the airway epithelium )
Describe the lung vasculature?
Pulmonary circulation (for gas exchange):
-For each lobe there is 1 pulmonary artery which carries deoxygenated blood and 2 pulmonary vein which carries oxygenated blood (2A and 4V in total for both lungs).
Systematic Circulation (supplying the tissue):
-Bronchial arteries: supplies bronchi, lung roots, visceral pleura, supporting lung tissue
Bronchial Veins: Right bronchial vein –> Azygous vein
Left bronchial vein –> Hemiazygous vein
Describe the innervation of the lungs?
Parasympathetic (derived from the vagus nerve):
-This stimulates the seceretion from bronchial glands.
-This stimulates the contraction of bronchial smooth muslce
-Vasodilation of pulmonary vessels
Sympathetic (derived from the sympathetic trunk):
-Stimulates the relaxation of the bronchial smooth muscle
-Vasoconstriction of pulmonary vessels
Visceral afferent:
-Pain impulses to sensory ganglion of vagus nerve
Identify Hila anatomical regions
Outline the key landmarks in the throax vertebre
Describe the anatomy of breathing
Inspiration
External intercostals contract, raising the ribcage upwards and outwards
Diaphragm contracts and flattens, displacing digestive organs below
Increases intrapulmonary volume and decreases the intrapulmonary pressure below atmospheric pressure
Air is then drawn into the lungs down its pressure gradient from higher atmospheric pressure to lower intrapulmonary pressure
**Expiration **
External intercostal relax, which lowers the ribcage
Diaphragm relaxes and moves upwards
This decreases intrapulmonary pressure above atmospheric pressure
Air is drawn out of the lungs down its pressure gradient, from higher intrapulmonary pressure to low atmospheric pressure
What is a GPCRs and its mechanism?
GPCRs is also known as G protien coupled receptors
-The structure is where 1 protien is embedded in the membrane. There is 7 transmembrane region, N-terminal extracellular binding domain, C-terminal G-protein binding domain.
Mechanism
-Ligand binds to the N-terminal
-Induces a conformational chain in the GPCR
-Exposes the alpha subunit protein
Once exposed, the alpha subunit will swap its bound GDP for GTP
-Binding of the GTP to the alpha subunit causes it to detach from the GPCR
The beta and the gamma units remain bound
-Detached alpha subunit will then activate enzymes that produce secondary messengers inside the cell
-When not in use, the alpha subunit converts GTP back to GDP
This is it utilising its intrinsic GTPase activity
-Alpha GDP complex reforms with beta and gamma subunits again
Describe the different subunits of GPCRs?
Describe Ligand gated ion channels?
**Ligand gated ion channel **
Binding of a ligand to an extracellular site induces a conformational change in the protein subunits
Channels open and allow ions to move in/out of the cell
Response time = milliseconds
Example = Nicotinic ACh receptors
Describe a Receptor Tyrosine Kinase ?
Receptor Tyrosine Kinase
Ligand binds to extracellular binding domain
Activates the intracellular G protein
Intracellular RTK monomers then phosphorylate tyrosine residues on eachother
Phosphorylated monomers then induce an intracellular enzyme/proteins
Response time = hours
Example = Cytokine and insulin receptors
Describe a Nuclear Receptor?
Nuclear Receptors (Corticosteroids)
Lipophilic ligand passes through the plasma membrane and binds to a cytosolic receptor
HR complex translocates to the nuclease, where it binds to a Hormone Response Element (HRE) on the DNA
Receptor complex acts as a transcription factor and induces a desired response
Response time is longer
Example = steroid hormones
Define Asthma and the triggers for an asthma attack?
Asthma is a type 1 hypersensitivity reaction of the airway leading to inflammation and reversible bronchoconstriction.
What are the differential diagnosis of asthma?
Describe the pathophysiology of asthma (sensitisation)
What is the pathophysiology of asthma on re-exposure
How does the inflammatory mediators work and causes signs and symptoms?
What are the investigations for Asthma and daignosing asthma?
-Peak Flow - highest of 3 readings. Results decrease in an asthma attack
-Respiratory exam
-Bloods - ABG, FBC, U&E’s, Serum IgE
-Chest X ray
Special Tests:
Sputum culture
Spirometry
Fractional exhaled nitric oxide (FENO)
Bronchodilator reversibility test (BDR)
Direct bronchial challenge test
Describe the different sounds on auscultation of respiratory conditions
What is the management of Asthma?
What is the management of asthma continued
**Conservative: **Avoid triggers like pets, smoke etc
Medical:
Salbutamol reliever
SABA
>3 times a week = poorly controlled & needs further medication
Low dose ICS - usually beclomethasone
LABA - usually salmeterol
If still poorly controlled:
Stop LABA (if no response)
Increasing ICS to medium dose
Adding leukotriene receptor antagonist (LRTA)
If STILL poorly controlled:
High dose ICS
LRTA (Leukotriene Receptor Antagonists, like montelukast)
LAMA (long acting muscurenic antagonist)
