Respiratory System Bullets 001

• Respiration is the process of gaseous exchange between the individual and the environment.
• The three process of respiration are: Ventilation, Diffusion and Perfusion.
• Ventilation refers to the movement of gases in and out of the lungs.
• Diffusion – the exchange of gases from an area of higher pressure to an area of lower pressure.

• Perfusion – the availability and movement of blood for transport of gases, nutrients and metabolic waste products.
• The respiratory system is composed of airways, pleura, lungs, respiratory centers and thorax.
• Upper airways composed of nasal cavity or nares, pharynx and larynx or voice box.
• Lower airways (Tracheobronchial Tree) is composed of trachea, right and left mainstem bronchi, segmental bronchi, subsegmental bronchi and terminal bronchi.
• Functions of the upper airways are to transport gases to the lower airways, protection of the lower airways from foreign matter and warming, filtration and humidification of inspired air.
• Functions of lower airways are clearance mechanism, immunologic response and pulmonary protection in injury.
• The opening of the nose on the face area are called nostrils or nares. 
• Each nostril leads to a cavity called vestibule. 
• The hair that lines the vestibule are called vibrissae.
• The vibrissae filter foreign objectsThe paranasal sinuses are open areas with the skull, lined with mucous membrane. They help in phonation. The different sinuses are as follows: frontal, maxillary, ethmoid and sphenoid.
• The pharynx is a funnel shaped tube that extends from the nose to the larynx. It is a common opening between the digestive and respiratory system.
• The three sections of the pharynx are as follows; nasopharynx, oropharynx and laryngopharynx.
• From the middle ear, the Eustachian tubes open into the nasopharynx.
• The larynx is the voice box.
• The epiglottis covers the larynx, when eating, the epiglottis closes, when speaking it opens.
• The trachea (windpipe) is 12 cm long. The point at which it divides is called carina.
• The trachea and bronchi are lined with cilia and goblet cells.
• The cilia sweep out debris and excessive mucous from the lungs.
• The goblet cells secrete 120 ml of mucous per day. The mucous secretions entrap debris in the respiratory tract.
• The right mainstem bronchus is shorter, broader and more vertical that the left.