Pharmacy

What Are the Main Parts of the Respiratory System?

Published by Ravindra Barala on 16/01/2024

Human body is made of different cell. Each cell requires energy for their different biochemical reaction. The energy is provided by the help of oxidation of food. Oxidation of food occur by oxygen. Carbon dioxide is liberate after oxidation of food. Oxygen is inhaled and carbon dioxide exhaled by the help of respiratory system.

Respiratory System

Classifications of Respiratory system consists –

Respiratory airway
Lungs

Respiratory airway :- Respiratory airway is made up of different structures.

How work of respiratory system –

Nose
Pharynx
Larynx
Trachea
Bronchus
Bronchioles
Alveolar ducts
Alveoli’s

1.) Nose :- It is first part of respiratory airway. It is main route of air entry, and consists of a large irregular cavity divided in to two equal parts by a septum.

Posterior part
Anterior part

Wall of nose :-

In wall of nose different bone are present.

Lateral wall :-

Lateral wall of nose is made up of maxilla and Palatine bone.

Anterior wall :-

It is formed by to nasal bone.

Inferior wall :-

Hard palate forms inferior wall of nasal cavity. Inferiorly nasal cavity lined up by mucus membrane. hair follicles and mucus secreting giblet cells are present in mucus membrane.

Nasal cavity is divided in two compartments by a cartilage.

(Right and left nasal cavity)

Their are three grooves which present in nasal mucosa known as meatus

Superior meatus
Middle meatus
Inferior meatus

Opening in nasal cavity :-

Nasolacrimal duct opens in to nasal cavity.

Nasal sinuses :-

Maxillary sinuses in the lateral walls.
Fontal and spheroidal sinuses in the roof.
Ethmoidal sinuses in the upper part of the lateral wall.

Function of nose :-

Warming :- This is due to the highly vascularity of the mucosa. This explains the large blood loss when a nosebleed (epistaxis) occurs.

Filtering and cleaning :-

This occur as hairs at the anterior nares trap larger particles.

Humidification :-

As air travels over the moist mucosa, it becomes saturated with water vapor.

Transportation :-

Nose transfer air, environment to pharynx.

2.) Pharynx :-
(It is second part of respiratory system. The pharynx is divided into three parts.)

Pharynx

Nasopharynx
Oropharynx
Laryngopharynx

Nasopharynx is important in respiration. Oro pharynx and laryngopharynx are common to both the respiratory and the digestive system.

The wall of pharynx consists three layers.

Mucosa
Middle layer
Outer layer

Mucosa :- It is lined up by stratified squamous epithelial cells.

Middle layer :- The middle Layer consists of connective tissue which becomes thinner towards the lower end and contains blood vessels, lymph vessels and nerves.

Outer layer :- The outer layer is consists of a number of involuntary muscles. Which is involved in swallowing.

Blood supply
Arterial supply
Branch of facial artery’s
Venous supply
Facial vein and inter juggler vein
Nerve supply
Automatic nerve system

3.) Larynx :-
It is also known as voice box. Larynx is a structure of respiratory airway. Which is related to voice production.

Structure of larynx :-

Different cartilage are present in wall of larynx.

The cartilage are:

Epiglottis
Thyroid cartilage
Cricoid cartilage
Arytenoid cartilage

A.) Epiglottis :-
It is unpaired cartilage of larynx. It is leaf shape structure.

Anteriorly the steam of epiglottis attached with superior border of thyroid cartilage.

During swallowing epiglottis closes the opening of larynx or it act as a slight for Larynx.

Function of larynx :-

It prevent from expiration of food and water during swallowing.

B.) Thyroid cartilage :-

It is a unpaired Cartilage of larynx. It having two lamina.

Anterior two lamina articulate with each other and form a laryngeal prominence.

Immediately above the laryngeal prominence the laminae are separated, forming a V-shaped notch known as the thyroid notch.

Posterior each lamina elongated superior and inferiorly called the superior and inferior corny.

C.) Cricoid cartilage :-

It is unpaired cartilage of larynx. It having signet ring shape structure. Cricoid cartilage is broad in posterior region then anteriorly.

D.) Arytenoid Cartilage :-

It is paired cartilage of larynx. Arytenoid cartilage present in posterior wall of larynx. Arytenoid cartilage are pyramid in shaped.

Based of arytenoid cartilage articulate with cricoid cartilage.

Functions of larynx :-

Sound has the properties of pitch, volume and resonance depends upon larynx.

Passageway for air :-

This is between the pharynx and trachea.

4.) Trachea :-

It is a wind pipe ,which is situated in mid axis of anterior part of neck. It length is about 10-12 cm long and weight about 2cm.

Relations :-

Anteriorly :- Thyroid gland ,lower part the arch of the aorta and the sternum.
Superiorly :- The larynx.
Inferiorly :- Right and left bronchi.
Laterally :- Lungs and lobes of the thyroid gland.

Lungs :-
It is a vital sponge organ. Which is situated in thoracic cavity. Each lung is cone shaped organ. Weight and length 25cm. The Apex is directed upward while base is directed downward diaphragm.

Structure of lungs :-

3 surface and 2 border are present in each lung.

Surface

Costal surface
Medial surface
Diaphragmatic surface

Borders

Anterior border
Posterior border

Blood supply :-

Arterial supply :- Bronchial artery branch of thoracic aorta.

Pulmonary artery :-

Venus supply:- Pulmonary vein and bronchial vein.

Nerve supply:- Automatic nerve system.

Pleura:- It is a serous membrane which enveloped lung in thoracic cavity.

Respiration :-

It is a mechanism in which exchange of gases occur through

semipermeable membrane at alveolar level and tissue level.

Respiration is classified in two type.

External respiration
Internal respiration

External respiration :-

It is a type of respiration in which exchange of gases occur at alveolar level through respiratory membrane. Exchange of gases occur by diffusion mode.

Internal respiration :-

It is type of respiration in which exchange of gases occur at tissue level. Exchange of gases by diffusion mode.