Cells in the body require oxygen to survive. Vital functions of the body are carried out as the body is continuously supplied with oxygen. Without the respiratory system exchange of gases in the alveoli will not be made possible and systemic distribution of oxygen will not be made possible. Thetransportation of oxygen in the different parts of the body is accomplished by the blood of the cardiovascular system. However, it is the respiratory system that carries in oxygen to the body and transports oxygen from the tissue cells to the blood. Thus, cardiovascular system and respiratory system works hand in hand with each other. A problem in the cardiovascular system would affect the other and vice versa. Functional Anatomy of the Respiratory System
The nose is the only external part of the respiratory system and is the part where the air passes through. During inhalation and exhalation, air enters the nose by passing through the external nares or nostrils. Nasal cavity is found inside the nose and is divided by a nasal septum. The receptors for the sense of smell, olfactory receptors are found in the mucosa of the slit-like superior part of the nasal cavity which is located beneath the ethmoid bone. Respiratory mucosa lines the rest of the nasal cavity and rests on a rich network of thin-walled veins that warms the air passing by. Important information about nose is the presence of the sticky mucus that is produced by the mucosa’s gland. This important characteristic moistens the air and traps the incoming bacteria and other foreign debris passing through the nasal cavity. Cells of the nasal mucosa are ciliated and it creates a gentle current that moves the contaminated mucus posteriorly towards the throat, where it is swallowed and digested by stomach juices. In cases where the temperature of the environment is cold, the cilia become sluggish. Thus, more mucus are allowed to accumulate in the nasal cavity and to dribble outward through the nostrils. This is the main reason why a “runny nose” is noted during a cold day. 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. Pharynx
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 thenasal 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. Larynx
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...