Anatomy and Physiology of Respiratory System

Conchae – these are three mucosa-covered projections or lobes that greatly increase the surface area of the mucosa exposed to the air.  Aside from that, conchae increase the air turbulence in the nasal cavity.

Palate – a partition that separates the nasal cavity from the oral cavity.  Anteriorly, the palate that is supported by a bone called the hard palate and the one which is unsupported is the soft palate.

Paranasal Sinuses – these are structures surrounding the casal cavity and are located in the frontal, sphenoid, ethmoid and maxillary bones.


The pharynx is a 13 cm long muscular tube that is commonly called the throat. This muscular passageway serves as a common food and air pathway. This structure is continuous with the nasal cavity anteriorly via the internal nares.

Parts of pharynx:

  1. Nasopharynx – the superior portion of the pharynx. The pharyngotympanic tubes that drain the middle ear open in this area. This is the main reason why children who have otitis media may follow a sore throat or other tyoes of pharyngeal infections since the two mucosae of these regions are continuous.
  2. Oropharynx – middle part
  3. Laryngopharynx – part of pharynx that enters the larynx.

When food enters the oral cavity, it travels to the oropharynx and laryngopharynx. However, instead of entering the larynx, the food is directed into the esophagus and not to the larynx.

Tonsils – clusters of lymphatic tissues found in the pharynx.

Types of Tonsils:

  1. Palatine tonsils – tonsils found at the end of the soft palate.
  2. Pharyngeal tonsils – lymphatic tissues located high in the nasopharynx. This is also called adenoid.
  3. Lingual tonsils – located at the base of the tongue.


The larynx is the one that routes the air and food into their proper channels. Also termed as the voice box, it plays an important role in speech. This structure is located inferior to the pharynx and is formed by:

  1. Eight rigid hyaline cartilages
  2. Spoon-shaped flap of elastic cartilage, which is called the epiglottis.

Thyroid cartilage – this is the largest hyaline cartilage that protrudes anteriorly in males and is referred to as the Adam’s apple.

Daisy Jane Antipuesto RN MN

Currently a Nursing Local Board Examination Reviewer. Subjects handled are Pediatric, Obstetric and Psychiatric Nursing. Previous work experiences include: Clinical instructor/lecturer, clinical coordinator (Level II), caregiver instructor/lecturer, NC2 examination reviewer and staff/clinic nurse. Areas of specialization: Emergency room, Orthopedic Ward and Delivery Room. Also an IELTS passer.

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