Question

The basically stages of respiration,types, frequency and rhythms of respiration?

Answer 1

The organs of the respiratory system are:

nose (external nares and nasal chamber)Internal nares and pharynxlarynxtracheatwo bronchi (one bronchus to each lung)bronchioles and smaller air passagestwo lungs and their coverings, the pleuramuscles of breathing – the intercostal muscles and the diaphragm.1. Nose (external nare and nasal chamber)Structurally the nose can be divided into the external portion which is in fact termed as the nose and the internal portions being the nasal cavities.The nose is the only visible part of the respiratory system, protruding from the face, and lying in between the forehead and the upper lip.Opening is known as nostril. The two nostrils are separated by nasal septum. The two nostril openings leading to two nasal chambers or cavities.The nasal cavity is the main route of air entry, and consists of a large irregular cavity divided into two equal passages by a septum.The posterior bony part of the septum is formed by the perpendicular plate of the ethmoid bone and the vomer. Anteriorly, it consists of hyaline cartilage.The nasal cavity is lined with very vascular ciliated columnar epithelium which contains mucus-secreting goblet cells.

The functions of nasal passage are:

Prevent entry of dust particle into lungsWarm the incoming air entering the nasal cavityMoisten the dry airOlfactory receptor present in the roof of nasal cavity detect the smellHold and sweep the microorgnisms entering the nasal chamber2. Internal nares and pharynxThe internal nares are the openings from the nasal cavity into the pharynx.The pharynx (throat) is a passageway that  extends from the posterior nares, and runs behind the mouth and the larynx to the level of the 6th thoracic vertebra, where it becomes the oesophagus.Structurally the pharynx can be divided into three anatomical parts ie. nasopharynx (posterior to the nasal chambers), the oropharynx (posterior to the mouth), and the laryngopharynx (posterior to the pharynx).3. LarynxThe larynx or ‘voice box’ links the laryngopharynx and the trachea. It lies in front of the laryngopharynx and the 3rd, 4th, 5th and 6th cervical vertebrae.Until puberty there is little difference in the size of the larynx between the sexes. Thereafter, it grows larger in the male, which explains the prominence of the ‘Adam’s apple’ and the generally deeper voice.The larynx is composed of several irregularly shaped cartilages attached to each other by ligaments and membranes.The main cartilages are:1 thyroid cartilage, 1 cricoid cartilage, 2 arytenoid cartilages and 1 epiglottisThe vocal cords are two pale folds of mucous membrane with cord-like free edges, stretched across the laryngeal opening. They extend from the inner wall of the thyroid prominence anteriorly to the arytenoid cartilages posteriorly.

 

Sound production:

When the muscles controlling the vocal cords are relaxed, the vocal cords open and the passageway for air coming up through the larynx is clear; the vocal cords are said to be abducted.Vibrating the vocal cords in this position produces low-pitched sounds.When the muscles controlling the vocal cords contract, the vocal cords are stretched out tightly across the larynx, and are said to be adducted (closed).When the vocal cords are stretched to this extent, and are vibrated by air passing through from the lungs, the sound produced is high pitched.The pitch of the voice is therefore determined by the tension applied to the vocal cords by the appropriate sets of muscles.When not in use, the vocal cords are adducted. The space between the vocal cords is called the glottis.4. TracheaThe trachea or windpipe is a continuation of the larynx and extends downwards to about the level of the 5th thoracic vertebra where it divides at the carinainto the right and left primary bronchi, one bronchus going to each lung.It is approximately 10–11 cm long and lies mainly in the median plane in front of the oesophagus.The tracheal wall is composed of three layers of tissue, and is held open by between 16 and 20 incomplete (C-shaped) rings of hyaline cartilage lying one above the other.The rings are incomplete posteriorly where the trachea lies against the oesophagus.The tracheal mucosa consists of pseudo stratified, ciliated columnar epithelium, while its submucosa contains cartilage, smooth muscle, and seromucous glands.5. Bronchus
The trachea divides into the two main bronchi (primary bronchi) ie. the right bronchus wider, shorter and more vertical than the left bronchus.The right bronchus: This is wider, shorter and more vertical than the left bronchus and is therefore more likely to become obstructed by an inhaled foreign body. It is approximately 2.5 cm long. After entering the right lung at the hilum it divides into three branches, one to each lobe. Each branch then subdivides into numerous smaller branches.The left bronchus.