Nasal cavity: area divided by nasoseptal cartilage. Made up of the vomer and perpendicular plate. Has nasal conchae extending from the walls. Lined with olfactory mucosa and olfactory epithelium
Pharynx: muscular tube connecting the nasal cavity to the larynx
Nasopharynx: part of pharynx located posterior to nasal cavity. Pharyngeal tonsil (adenoids) can be found here.
Oropharynx:part of pharynx located posterior to mouth and uvula, epiglottis is its inferior boundary. Lingual and palatine tonsils found here.
Laryngopharynx: area surrounding larynx. The continuation of the laryngopharynx becomes the esophagus
What is the larynx?
A valve that serves for protection and vocalization. It contains the vestibular ligaments and the vocal ligaments. The vestibular ligaments are for protection and the vocal ligaments are for vocalization.
What are the types of cartilage that support the larynx?
Epiglottis: closes the larynx when swallowing to prevent food from entering the windpipe
Cricoid cartilage: inferior boundary of the larynx, makes one complete circle around the larynx
Thyroid cartilage: protective cartilage known as “adam’s apple”…medial to thyroid gland
What is the functions of the laryngeal muscles?
To close the glottis for protection and open it for air flow and also to control the tension of vocal ligaments to allow different pitch in voice
**The continuation of the larynx is the trachea and this will be lined with Pseudostratified ciliated columnar epithelium.**
Provide a brief description of the structure(s) of the trachea (include 3 types of tissues one may find in the trachea).
Trachea contains c-shaped cartilage rings for support from collapse and a band of smooth muscle on its posterior surface called trachealis muscle. The trachea has a luminal surface made up of pseudostratified ciliated columnar epithelium. The cartilage around the trachea is called hyaline cartilage
After the trachea splits at the carina, it becomes the bronchi and then the bronchioles. Compare or contrast the structure of bronchi and bronchioles
Bronchi are large, have cartilage, and goblet cells
What are the different types of bronchioles? What type of tissue can you find in each?
Muscular bronchioles: have smooth muscle, ciliated simple columnar tissue in lumen and are continuous with terminal bronchioles
Respiratory bronchioles: no smooth muscle. This allows for some gas exchange to happen here. Lined with simple cuboidal tissue
Alveolar ducts are continuous with respiratory bronchioles, describe the structure and function of alveoli.
Alveolar lobules are clusters of alveoli which are sacs formed by simple squamous tissue. This is where most if not all gas exchange occurs. Walls of the alveoli are fused to the walls of blood vessels. This allows for a smoother transition and exchange of gases.
Type 1 alveolar cell helps with gas exchange and type II alveolar cell is also called clara or club cell and it is important in the release of surfactant which helps reduce surface tension. Without this, alveolar sacs will collapse
Provide a “flow” of air from trachea to an alveoli sac/lobule
**Alveoli are composed of one layer of squamous cells therefore red blood cells can only squeeze through the walls of the alveoli ONE BY ONE.**
What are the membranes that surround the lungs and the thoracic cavity?
Epithelial membranes called pleura. The visceral pleura surrounds the lungs and the parietal pleura surrounds the thoracic cavity. In between these there may be a potential space that can be created by the accumulation of air or fluid. This however would cause a collapsed lung (pneumothorax) because the presence of air or fluid in between the pleura would not allow the lung to fully expand.
What are some differences between the right and left lungs?
L lung has 2 lobes, slightly smaller because it has to compensate for the heart’s slight left deviation
Describe how the blood becomes saturated with oxygen and how CO2 leaves the body
As blood arrives to the alveoli, oxygen that came from the outside will diffuse into the red blood cell and the waste or CO2 that the cell carried will diffuse out of the cell into the alveoli and travel back up through the bronchioles, bronchi, trachea, and eventually out of the body.
What muscle of the body is responsible for the greatest increase in volume of the thoracic cavity?