RESPIRATORY SYSTEM Flashcards
how long can a human survive without breathing?
3 minutes
the respiratory system can be divided into the?
conducting zone: part of the respiratory system that includes organs that provide passageways for air and are not directly involved in gas exchange.
respiratory zone: includes structures of the respiratory system that are directly involved in gas exchange.
major function of the conducting zone?
provide route for incoming and outgoing air, remove debris and pathogens from the air, humidify the air, sensing odours.
the major entrance and exit for the respiratory system is through the?
nose and some air also enters through the oral cavity.
large particles such as dirt is removed from the air by?
the hairs as it enters the external nares(nostrils) of the nose and flows into the nasal cavity.
what do the conchae of the nasal cavity do?
increase surface area for air filtration and humidification and warm and moisten air.
what is the nasal cavity lined with?
ciliated columnar epithelium and goblet cells that produce mucus to trap debris. cilia of the epithelium clear mucus.
where does air exit the nasal cavity from?
internal nares and moves into the pharynx.
what is the pharynx and what is it divided into and what is it formed by?
the pharynx is a tube formed by skeletal muscle. it is divided into 3 major regions: nasopharynx, oropharynx, and the laryngopharynx.
what is the nasopharynx function?
serves only as an airway.
what do the oropharynx and laryngopharynx do?
passageway for both air and food. at the bottom end of the laryngopharynx, the digestive and respiratory systems diverge.
what does the anterior side and posterior side of the laryngopharynx open into?
anterior side: larynx
posterior side: esophagus
what is the larynx?
cartilaginous structure inferior to the laryngopharynx. it connects the pharynx to the trachea.
- regulates the volume of air that enters and leaves the lungs.
what are the 3 cartilage pieces the larynx is made of?
thyroid cartilage: adams apple
epiglottis: covers opening of the trachea to make sure food and drink dont enter.
cricoid cartilage
what is a trachea?
the trachea is the windpipe that extends from the larynx to the lungs. it is formed by 16-20 stacked c shaped pieces of hyaline cartilage.
what does the trachea branch into?
the trachea branches into right and left primary bronchi.
- primary bronchi enter the lungs and then each primary bronchus branches into a secondary bronchus and then into a tertiary bronchus.
- primary, secondary, and tertiary bronchi are referred to as the brochial tree,
what is the function of bronchi?
provide a passageway for air to move into and out of each lung.
what branches off of the tertiary bronchi?
bronchioles are 1mm in diameter, branch from the tertiary bronchi. bronchioles branch into terminal bronchioles which lead to the structures of gas exchange.
how many terminal bronchioles are in each lung?
over 1000 terminal bronchioles in each lung.
the respiratory zone begins when?
the respiratory zone begins when the terminal bronchioles join the respiratory bronchiole which then leads to an alveolar duct which then leads to alveolar sac which then leads to alveoli.
what is an alveoli/alveolus?
one of the many sacs in the alvoelar sac responsible for gas exchange.
- they have elastic walls that allow the alveolus to stretch which increases the surface area.
- they are connected to other alveoli with alveolar pores.
what tissues make up the alveolar wall?
simple squamous epithelial cells.
- attached to basement membrane.
- attached to capillary membrane.
- respiratory membrane allows gases to cross via simple diffusion.
what is the anatomy of the lungs?
- connect to the trachea by right and left bronchi.
- under the lungs is the diaphragm.
- the lungs are enclosed by the pleura.
- the right lung is shorter and wider than the left lung and the left lung occupies less volume to make space for the heart.
- each lung is composed of smaller units called lobes.
RIGHT LUNG: superior, middle, inferior
LEFT LUNG: superior, inferior
what is the pleura of the lungs?
each lung is surrounded by the pleura.
the pleura has 2 layers: visceral pleura(connects to lungs) and parietal pleura(connects to diaphragm and thoracic wall).
- between the visceral and parietal layers is the pleural cavity.
what are the two major functions of the pleura?
- produce pleural fluid and to create cavities that separate the major organs.
what is the function of pleural fluid?
- lubricates surfaces to reduce friction.
- causes the lungs to enlarge to be able to fill with air.
what is the major mechanisms that drive pulmonary ventilation?
atmospheric pressure: Patm
air pressure within alveoli called intra-alveolar pressure: Palv
pressure within pleural cavity: intrapleural pressure: Pip
What is atmospheric pressure?
the pressure exerted by the air around our bodies.
- 760 mmHG
- negative pressure is lower than atmospheric pressure.
- positive pressure is greater than atmospheric pressure.
- pressure equal to atmospheric pressure is 0.
what is intra-alveolar pressure?
pressure of the air within the alveoli and it changes during different phases of breathing.
- since the alveoli are connected to the atmosphere via tubing of airways, the intra-alveolar pressure always equalizes with the atmospheric pressure.
