Respiratory Physiology Flashcards
List the constituents of the URT and its zone
Nose, nasal cavity, mouth, pharynx, larynx.
Conduction zone
List the constituents of the LRT and its zone
Trachea, Lungs, Bronchi, Bronchioles, alveolar ducts, alveolar sacs, alveolus.
Respiratory zone
Where is the carina of the trachea located? What is the conformation of the bronchi?
Carina of trachea located at bifurcation of bronchi. Left bronchus more lateral and right bronchus more vertical
Describe the two types of cells in alveoli.
Type 1 cells - Thin and flat epithelial lining cells
Type 2 cells - Secrete surfactant
Where is the pons located? Name the two regions of interest.
Pons is located in the respiratory control centre of the brain.
Apneustic region and pneumotaxic region.
Name the two groups of importance in the medulla.
Ventral group and dorsal group
List the nerves involved in respiratory physiology.
Spinal: -Phrenic nerve (C3-C5 root) -Intercostal nerve (T1-T11 root) Cranial: -Vagus nerve (X) -Glossopharyngeal nerve (IX)
List the receptors involved in respiratory physiology.
Chemo -Central Peripheral (Carotid and sortic bodies) Mechano Irritant Peripheral proprioceptors
List the muscles involved in respiratory physiology.
Accessory (Sternocleidomastoids, scalenes)
Diaphragm (75% of work of breathing)
Intercostals
Abdominals
What is Boyle’s Law?
Pressure of a gas in a closed container is inversely proportional to the volume of the container at a constant temperature.
Describe the process of Inhalation.
- Diaphragm flattens, external intercostals up and out
- Elevation of ribs
- Increase volume, decrease pressure in lungs
- Air moves in
Describe the nature of exhalation at rest
-Passive at rest (Elastic recoil)
Compare asthmatics and controls.
Asthmatics have:
- Higher oxygen cost for given work rate
- Higher frequency of breathing for given work rate
- Tidal volume and minute ventilation volume lower for given work rate
What are the functions of the regions in the Pons?
Apneustic - Prolong and slow rate of breathing
Pneumotaxic - Inhibitory impulse, speeds breathing
Which part of the respiratory control centre regulates rythmicity? Which neurons are associated with which regions of this area?
Medulla.
Dorsal group - Inspiratory neurons
Ventral group - Inspiratory and expiratory neurons
Which receptors respond to changes in Oxygen in the blood?
Outline the response to a reduction in Oxygen in the blood.
What do central chemoreceptors primarily respond to?
Peripheral chemoreceptors -Potassium channels blocked -Build up of potassium within the cell -Calcium channels open, calcium influx -Exocytosis of vesicles containing dopamine Changes in blood carbon dioxide levels
Define tidal volume.
The volume of air moved into and out of the lungs during each ventilation cycle.
500mL or 7mL/kg body mass
Define inspiratory capacity.
The volume of air that can be inspired following a normal, quiet expiration. Equal to tidal volume + inspiratory reserve.
Define residual volume.
The amount of air that remains in the lungs following forced expiration.
Define vital capacity
The maximum amount of air that can be expelled from the lungs after a maximum inhalation.
Define inspiratory reserve volume.
The additional amount of air that can be inhaled after a normal inspiration.
Define functional residual capacity
The volume of air present in the lungs after passive expiration.
Define expiratory reserve volume
The amount of extra air above a normal breath exhaled during forceful expiration.
Define total lung capacity.
The maximum volume of air that the lungs can accomodate.
What is the equation for minute ventilation?
Minute ventilation = Breathing rate x Tidal Volume
What is alveolar ventilation? What is a typical value in a healthy adult?
The portion of minute ventilation that mixes with air in alveoli.
150-200ml.
What is physiological dead space?
Non-functioning alveoli.
What is the equation for alveolar ventilation?
Alveolar ventilation = Minute ventilation - Dead space
What is the ventilatory threshold?
What is respiratory compensation point?
The point at which pulmonary ventilation increases disproportionately with oxygen consumption during graded exercise.
A secondary rise after VT.
What is the result of the respiratory muscle metaboreflex?
- Increased sympathetic efferent discharge
- Increased limb vasoconstriction
- Decreased Oxygen transport
- Increased locomotor muscle fatigue
- Increased effort perceptions
