Respiratory System Flashcards
What are the three steps involved in respiration and their main functions?
- Pulmonary Ventilation (breathing) - flow of air into and out of the lungs
- External Respiration - exchange of gases in the lungs
- Internal Respiration - exchange of gases in the tissues
What are the structural components of the upper respiratory system?
- nose
- nasal cavity
- pharynx
What are the structural components of the lower respiratory system?
- larynx
- trachea
- bronchi
- lungs
What are the functional components of the respiratory system? Including the 2 zones.
Conduction Zone (series of tubes and cavities that conduct air into and out of the lungs):
- nose
- nasal cavity
- pharynx
- larynx
- trachea
- bronchi
- bronchioles
- terminal bronchioles
Respiratory Zone (tissues within the lungs where gas exchange occurs):
- respiratory bronchioles
- alveolar ducts
- alveolar sacs and alveoli
What are the organs included in the respiratory system?
- nose
- pharynx
- larynx
- trachea
- bronchi
- lungs
What are the key functions of the respiratory organs?
- provide for gas exchange
- intake of oxygen
- removal of carbon dioxide
What are some additional functions of the respiratory system?
- regulate blood pH
- sense of smell
- filters, warms & moistens inspired air
- produces sounds
- rids the body of some water and heat in exhaled air
What are the respiratory organs in the head & neck and their functions?
- nose (warming, moistening & filtering air; olfaction; resonating chamber)
- pharynx (passageway (air&food); resonating chamber; house tonsils):
-> naso pharynx
-> oropharynx
-> laryngopharynx
What does the larynx contain and its functions?
contains:
- thyroid cartilage
- epiglottis
- cricoid cartilage
- aryntenoid cartilages
- vocal cords
functions:
- air passage
- prevents inhalation of food / liquids
- sound production
Branching of airways: trachea to segments of lungs
lungs -> lobes -> segments -> lobules
branching of bronchial tree:
trachea
|
main bronchi
|
lobar bronchi
|
segmental bronchi
|
bronchioles
|
terminal bronchioles
How does inhalation occur?
Pressure inside the lungs is less than the atmospheric air pressure therefore air flow into the lungs.
What skeletal muscle contractions/relaxations occur in forced and normal inhalation?
Forced inhalation:
- contraction and relaxation of sternocleidomastoids, scalenes and pectoralis minors alter volume inside lungs
Normal inhalation:
- passive process - no skeletal muscle contraction
How doe exhalation occur?
Pressure inside the lungs is more than the atmospheric air pressure threrefore air is forced out of the lungs.
What skeletal muscle contractions/relaxations occur in forced and normal exhalation?
Forced:
- internal intercostals
- external oblique
- internal oblique
- transverse abdominis
- rectus abdominis
Normal:
- diaphragm & external intercostal muscles
Pressure changes during breathing.
- at rest, diaphragm is relaxed, alveolar pressure = atmospheric pressure, no airflow
- during inhalation, diaphragm contracts, external intercostal muscles contract, chest cavity expands, alveolar pressure drops below atmospheric pressure, air flows into lungs and lung volume expands. during deep inhalation, the scalene and sternocleidomastoid muscles expand the chest further, thereby creating a greater drop in alveolar pressure.
- during exhalation, diaphragm + external intercostals relax. chest and lungs recoil, chest cavity contracts, alveolar pressure increases above atmospheric pressure. air flows out, lungs volume decreases. during forced exhalations, internal intercostals and abdominal muscles contract, reducing chest cavity, further creating a greater increase in alveolar pressure.
