RESPIRATORY SYSTEM Introduction Outcomes By the end of this section you will understand: The principles of respiration The main structures of the nose, pharynx, larynx, trachea, bronchi and lungs The mechanisms and processes involved in breathing This section will enable you to link your knowledge of the respiratory system with your practical work as a beauty therapist. Principles of respiratory system The nose, pharynx and larynx The trachea and bronchi The lungs The mechanism of breathing The process of respiration

INTRODUCTION Introduction Respiration is one of the most basic functions of the body. The circulatory and respiratory systems share responsibility for supplying the body with oxygen and removing and excreting carbon dioxide and other unwanted gases. The lungs oversee this exchange of oxygen and carbon dioxide between the external air and the body. Principles of respiratory system The nose, pharynx and larynx The trachea and bronchi The lungs The mechanism of breathing The process of respiration

PRINCIPLES OF THE RESPIRATORY SYSTEM Introduction The respiratory system is made up of the nose, pharynx, larynx, trachea, bronchial tubes, lungs and diaphragm. Principles of respiratory system The nose, pharynx and larynx The trachea and bronchi Larynx Trachea Bronchial tube Lung The lungs The mechanism of breathing The process of respiration

THE NOSE, PHARYNX AND LARYNX Introduction The nose is lined with tiny hairs called cilia, which filter the incoming air, and mucous membrane, which secretes mucus which helps to prevent dust and bacteria from entering the lungs. Air is warmed as it flows through the nose, and pharynx on its way to the lungs. The pharynx or throat is a large muscular passageway for food and air. It cannot be used for both at the same time otherwise choking results. The larynx is a short, rigid tube that connects the pharynx to the trachea. It has a flap of elastic cartilage, the epiglottis, which protects the opening of the trachea and prevents food from entering the lower respiratory structures during swallowing. Principles of respiratory system The nose, pharynx and larynx The trachea and bronchi The lungs The mechanism of breathing The process of respiration Larynx

THE TRACHEA AND BRONCHI The trachea, or windpipe, is a fairly rigid tube with walls that are reinforced with cartilage. The trachea is lined with cilia that work to remove dirt and debris from the incoming air before it passes into the lungs. The trachea runs from the larynx, down through the thorax where it divides into two bronchi to enter the lungs. By the time the air enters the lungs it has been warmed and filtered. Introduction Principles of respiratory system trachea The nose, pharynx and larynx The trachea and bronchi The lungs The mechanism of breathing The process of respiration bronchi bronchi

THE LUNGS The lungs are spongy organs that are situated in the thoracic cavity, either side of the heart. Each lung is divided into lobes, the left lung has two lobes and the right lung has three. After the bronchi enter the lungs they divide into smaller and smaller passageways that eventually lead to minute air sacs called alveoli. There are millions of the clustered alveoli and they resemble bunches of grapes. The alveoli make up the bulk of the lungs with the result that the lungs are mostly air spaces. Introduction Principles of respiratory system The nose, pharynx and larynx The trachea and bronchi The lungs The mechanism of breathing The process of respiration

MECHANISM OF BREATHING There are two phases of breathing, inspiration when air is flowing into the lungs and expiration when the air is leaving the lungs. During inspiration the ribcage is raised by the intercostal muscles and the diaphragm contracts. This mechanical action increases the volume inside the lungs and air is drawn in through the nose or mouth. During expiration, the respiratory muscles relax, the rib cage falls and air is forced out of the lungs. Ordinarily expiration is passive, but during forced breathing, the internal intercostal muscles actively depress the ribcage. Introduction Principles of respiratory system The nose, pharynx and larynx The trachea and bronchi The lungs inspiration The mechanism of breathing The process of respiration expiration

THE PROCESS OF RESPIRATION Introduction External respiration refers to the gaseous exchange that takes place inside the lungs where oxygen is taken up by the blood and carbon dioxide is released. As air is breathed into the lungs it comes into contact with the blood in the capillary network surrounding the alveoli. Oxygen moves by diffusion through the capillary walls where it is taken up by the red blood cells and transported around the body. In exchange, carbon dioxide diffuses out of the blood and into the alveoli to be exhaled from the lungs through the nose and mouth. Principles of respiratory system The nose, pharynx and larynx The trachea and bronchi The lungs The mechanism of breathing The process of respiration