Module 7 - Respiratory Flashcards
What are the structures of the upper respiratory system?
Nose
Mouth
Sinuses
Pharynx
Larynx
What are the structures of the lower respiratory system?
Trachea
Bronchi
Bronchioles
Alveoli
What is the primary drive of breathing?
Elevated CO2 levels in blood make it more acidic –> medulla oblongata respiratory sensors feel this and control rate and depth of breathing to remove CO2 from blood
What is the secondary drive for breathing?
When O2 is low in blood, chemoreceptors in the carotid sinuses and aortic arch sense hypoxic conditions and send signals to medulla oblongata that more O2 is needed
Define ventilation
The amount of air in the alveoli - NOT the amount in the lungs!
Aka - the air that is available to perform gas exchange
Define perfusion
The amount of blood in the pulmonary capillaries of the lungs
Aka - how much blood is available to perform gas exchange
What are some factors that affect ventilation?
- Resistance to airflow
- Lung compliance (elasticity)
- Lung volume and capacity (atelectasis)
TLC
Total Lung Capacity
FEV1
Forced Expiratory Volume (in 1 second)
(The total amount of air that can be expelled in 1 second)
FVC
Forced Vital Capacity (the total amount of air that can be exhaled by a person)
PEF
Peak Expiratory Flow
Maximum speed of exhalation
Define hypoxemia
reduction in the partial pressure of O2 in the blood to below 60mmHg - causes cyanosis
What are signs/symptoms of hypoxia?
Agitation, confusion, euphoria, impaired judgement, convulsions, delirium, stupor, coma, combative behavior
Hypotension and bradycardia
What are compensatory mechanisms when a person becomes hypoxemic?
Increase in vasoconstriction and BP in an effort to conserve O2 while still perfusing tissues
^Sympathetic NS is activated by low PO2 and causes that vasoconstriction
Define hypercapnia
Increase in arterial PCO2 to above 50mmHg
Compensations for hypercapnia
- Increased rate/depth of breathing to expel CO2
- Vasodilation to increase perfusion of alveoli
- HA, warm and flushed skin
- Disorientation, somnolence, coma
What are antitussives?
Drugs that decrease the sensitivity of cough receptors by acting on the medullary cough center of brain
CNS depressants so CI w/ head injury or when a productive cough is desired