Respiratory I Flashcards
Respiration is the exchange of gases between the atmosphere, blood, and cells. It takes place in several basic steps: pulmonary ventilation (breathing), pulmonary respiration, transport of gases, tissue respiration, and cellular respiration. Be able to list these and know what is happening in terms of gas exchange and structures involved
- Pulmonary ventilation: gases inhaled from atm. go to lungs and back to atm. on exhale
- Pulmonary respiration: gas exchange where O2 loads into blood and unloads @ tissue cells & CO2 loads into blood and unloads @ alveoli for exhalation
- Transport respiratory gases: CV system delivers O2 and CO2 to lungs and tissues
- Tissue respiration: gas exchange where CO2 leaves the cell and loads into blood and unloads @ alveoli of lungs and CO2 leaves blood and enters cells
- Cellular respiration: production of cellular energy 6O2 + C6H12O6 -> 6CO2 + 6H2O + ATP
Know the relationship between the respiratory and cardiovascular systems. What happens if this relationship fails?
Respiratory delivers oxygen to the blood the cardiovascular system delivers oxygen to the body. If one fails catastrophy happens
Know the two types of lung circulation. Be able to write the pulmonary circuit and the lung circuit
Pulmonary circulation: deoxygenated blood- right ventricle, pulmonary trunk, p. arteries, p. capillaries, oxygenated blood- p. veins, left atria, left ventricle
Lung circulation: aorta, bronchial arteries, oxygenated blood, lung tissue, bronchial veins
Know the components of the respiratory system. This includes the structures of the upper and lower respiratory systems. Define the conducting and respiratory portion of the respiratory system.
Upper: anything above vocal cords
Lower: anything below vocal cords
Conducting zone: modifies and carries air
Respiratory zone: gas exchange of O2 & CO2
Know the difference between upper and lower respiratory infections
Upper: above vocal cords
Lower: below vocal cords
Describe the mechanisms that removes dust and other debris from the respiratory system
Filtration: sticky mucous w/ cilia in nose, trachea, and bronchi moves irritants to throat to be swallowed where stomach acid will hopefully destroy the pathogen
Describe how we make sounds for speech
Vocal folds do vocalization, assisted by sinuses and nose for resonance and tongue/lips for sound shaping
Air coming up from lungs on exhale goes through glottis and vocal folds vibrate to produce sound, pitch controlled by tension of vocal folds
Describe the structure and function of the lungs and be able to name the pleural membranes. Why do the two lungs differ in shape and size? Which bronchi do most inhaled objects lodge in?
Enclosed and protected by pleural membrane
Differ in shape due to the heart
Right bronchi is where mose inhaled objects end up
Know the types of alveolar cells and their function
Type I: simple squamous cells that allow for diffusion of blood gasses
Type II: secrete fluid containing surfactant
Describe the respiratory membrane. Be able to describe ventilation-perfusion coupling
Where gas is exchanged between alveoli and capillaries through the process of simple diffusion, composed of a layer of Type I and Type II alveolar cells and associated alveolar macrophages that constitutes alveolar wall, epithelial basement membrane underlying alveolar wall, capillary basement membrane that is often fused to epithelial basement membrane
Ventilation-perfusion coupling: Smooth muscle of capillaries contract and dilate for control of blood flow for this
Describe alveolar surface tension. Explain why is this significant in respiratory distress syndrome in premature infants
Layer of fluid containing water coats inside lining of alveoli which creates surface tension based on cohesive properties of water and pulls alveoli to itself
Sufactant is produced to lower surface tension
Sufactant it insufficient in premature infants therefore the alveoli collapse at the end of each exhalation and without something to break the surface tension inhaled air is not able to get into them
ESSAY QUESTION: Be able to explain the three basic steps in pulmonary ventilation
- At rest, when diaphragm is relaxed, alveolar pressure is equal to atm. pressure, no air flow
- During inhalation, diaphragm contracts and intercoastal contract, chest cavity expands, alveolar pressure drops below atm pressure, air flows into lungs in response to pressure gradient and lung volume expands
- During exhalation, diaphragm relaxes and external intercostals relax, chest and lungs recoil, chest cavity contracts, alveolar pressure increases above atm. pressure, air flow out of lungs, lung volume decreases
Know the role Boyle’s Law plays in the respiratory function. How does that relate to the diaphragm? What role does the diaphragm play in breathing?
Pressure changes that drive inhalation and exhalation are governed by Boyle’s Law
Volume varies inversely with pressure
Diaphragm helps change the volume and pressure in the lungs, draws air in and out
Know the muscles of inhalation and exhalation. Know the structures involved in deep forceful inhalation vs forceful exhalation.
Inhalation:
* Sternocleidomastoid
* Scalene
* External Intercostals
* Diaphragm
* Pectoralis Minor
Exhalation:
* Internal Intercostals
* External Obliques
* Internal Obliques
* Transversus Abdominis
* Rectus Abdominis
Explain the role the pleural membrane plays in breathing
Allows for lungs to expand and retract without friction, provide protection, expands lungs
Know the forces acting on the lungs in inhalation and exhalation. Define lung compliance and what creates it
Atm. pressure-760mmHg
Surface tension on pleural cavity opens lungs for inhalation while surface tension from water in alveoli collapse lungs on exhale
Lung compliance: ease with which the lungs and thoracic wall can be expanded, created through the muscles acting on it
ESSAY QUESTION: Be able to summarize breathing in terms of inspiration and expiration. Know what is happening with the diaphragm, ext. and Int. intercostals, volume, lungs, pressure, and other accessory muscles
Inspiration (active):
1. contract diaphragm down and ext intercostals up (raises rib cage)
2. increases volume of thoracic cavity & increases volume in lungs, elastic tissue in lungs make this possible
3. decreases pulmonary pressure in alveoli to -2 mmHg, creating vacuum in alveoli
4. air moves in until alveolar pressure equals atm pressure
Expiration (passive):
5. diaphragm relaxes and raises up & ext intercostals lower ribs down, decreasing lung volume
6. decreased volume in thoracic cavity decreases volume of lungs
7. increases pulmonary pressure to +2 mmHg in alveoli which allows air to move out of the lungs until alveolar pressure equals atm pressure
Know other factors that affect the rate of air flow and pulmonary ventilation and how they affect the flow: surface tension, 2) lung compliance because of elastic recoil, and airway resistance.
Surface tension: inwardly directed force in alveolli which must be overcome to expand lungs during inspiration
Elastic recoil: decreases size of alveoli during expiration
Compliance: ease with which lungs & thoracic wall can be expanded
Airway resistance: depends upon airway size, size of chest, constriction of dilation of smooth muscles in airway/lungs
Define anatomical and alveolar dead space.
Anatomical dead space: air that always remains in conducting zone ~150 mL
Alveolar dead space: zero
Name normal and abnormal breathing patterns
Eupnea: normal breathing rate & depth @ 12 breaths/min w/ volume of ~5L
Apnea: cessation of breathing
