Intro To Respiration W1 Flashcards
Neural control of respiration involves 3 components. What are they?
- Generation of alternating inspiration/expiration rhythm
- Regulation of the magnitude of ventilation
- Modified respiratory movements (voluntary and involuntary)
What is Regulation of the magnitude of ventilation?
How much we breath in and out
ie hold breath or slow down breathing. If not getting enough oxygen the brain will take back control and wont be voluntary
What does breathing depend on?
Cyclical respiratory muscle contraction
What is the pre-botzinger complex?
In the brain and sets respiratory rhythm
What is inspiration indicated by ?
Burst of action potentials in spinal motor nerves :
- phrenic nerve innervates the diaphragm
- intercostal nerves innervate the external intercostal
When these motor neurons are activated, what do they stimulate?
They stimulate muscle contraction leading to inspiration and when action potentials in these neurons cease the muscles relax leading to expiration
What determines how deep and quickly we breathe
This is determined by the oxygen and carbon dioxide in our system. More carbon dioxide needs more deeper breathing and more rapidly.
Our respiratory rate and tidal volume isn’t ……
Fixed
The Mac sheet of ventilation is adjusted in response to …..
Three chemical factors:
- PO2
- PCO2
- H+`
What do the three chemical factors respond to?
Changes in blood pH and gas content
Changes in blood pH and gas content detected by?
Peripheral chemo receptors in carotid and aortic bodies
Central chemo receptors stimulated by increased hydrogen in brain extra cell cellular fluid
Which part of the spiritually anatomy of medicines used to treat asthma/COPD?
The bronchi
What does bronchial smooth muscle depend on?
The balance between the parasympathetic input, circulating adrenaline/non-noradrenergic and non-cholinergic nerves
Cartilage and smooth muscle as you move from bronchi to bronchioles
There is less cartilage and more smooth muscle
Is bronchodilation agonist or antagonist?
Agonist
Relaxation/sympathetic
Is bronchoconstriction agonist or antagonist?
Antagonist
Contraction
Which types of muscarinic receptors and adrenergic receptors are most prominent in airway smooth muscles?
Muscarinic subtype = m1 and m3 (antagonist)
Adrenergic subtype = a1, a1 and b2 (agonists)
Both are GPCR’s
Where do we use agonists?
At adrenergic to encourage broncho dilation
Where do we use antagonists?
At muscarinic to encourage bronchoconstriction
What do bronchodilators do and what are the different types?
They open up the airways
Type one = beta adrenergic agonist
- SABA - salbutamol
- LABA - serovent
Type two = muscarinic antagonist
- SAMA - atrovent
- LAMA - incruse
Type three = xanthines
What do anti-inflammatories do and what are the different types?
They target the causes of bronchi dilation
One = corticosteroids
Two = leukotriene modifiers (LTRA) - motelukast
Three = anti IgE antibody
Four = biologics
What is asthma?
An inflammatory disease of the airway categorised by recurrent attacks of breathlessness and wheezing, which vary in severity and frequency from person to person. The airway obstruction is mostly reversible with treatment or spontaneously.
Classification of asthma
Extrinsic
- atopic
- Indoor triggers and outdoor triggers
Intrinsic
- non-atopic
- Obesity, stress, food additives, exercise, infections, occupation, exposure, cold air, drugs
Asthma aetiology
Environmental
- allergens
- pollutants
- Tobacco smoke
- infections
- Diet
- Drugs
- Object
Host
- Genetic predisposition
- Age
- atrophy
- Airway hypersensitivity
- Biological sex
- ethnicity