Black Belt
DEVELOPMENT CLASSES
THE RESPIRATORY SYSTEM
Hand-Out
2009
DEVELOPMENT CLASS
RESPIRATORY SYSTEM
ANATOMY
The respiratory system consists of: -
· The Nasal Passages
· The Pharynx
· The Larynx
· The Trachea
· The Bronchi
· The Bronchioles
· The Alveoli
· The Lungs and Pleura
THE NASAL PASSAGES
THE NOSE
Vestibule - - - - - - - - Entrance to the nose
Nasal septum - - - - - -Separates the two nasal passages
Ciliated Mucous Membrane - - - - Lines the air passages, whose surface area
Is greatly increased by the Conchae
THE RESPIRATORY SYSTEM
Air passing through the nose is: -
WARMED - - - - - - - - - - to body temperature
MOISTENED - - - - - - - -By contact with warm, damp mucous membrane
FILTERED - - - - - - - - - Partly by the hairs around the nostrils, partly by the
mucous produced by glands in the Mucosa.
CILLA are microscopic filaments (hairs) move mucous to the pharynx where it is swallowed.
THE OLFACTORY NERVE ENDINGS detect smell; they are found in the mucosa at the upper part of the nasal cavity.
THE PHARYNX
The pharynx is a muscular tube (12 – 14cm) at the end of the nasal passages and is shared with the Digestive system. It is behind the nose, the mouth and larynx and in front of the cervical vertebrae. The pharynx becomes active during swallowing. When the pharynx is immobile the air passage stays open.
The pharynx is divided into three parts: -
1. THE NASOPHARYNX - - - - - - - - - - - - Behind the Nose
2. THE ORO-PHARYNX - - - - - - - - - - - --Behind the Mouth
3. THE LARYNGOPHARYNX - - - - - - - --Behind the Larynx
The pharyngeal muscles are controlled by the ninth cranial nerve.
THE ADENOIDS - - - are masses of lymphoid tissue, situated partly in the pharynx and partly in the nasal cavity. The adenoids tend to shrink with age.
THE TONSILS - - - - - Two other masses of lymphoid tissue situated on either side of the oro-pharyngeal junction.
THE LARYNX
The larynx lies in the neck (opposite the 3rd to 6th cervical vertebrae). It is larger in men than in women because it grows during puberty under the influence of the hormone Testosterone. Male vocal cords are longer and their voices deeper.
The larynx is composed of pieces of cartilage held together by fibrous tissue.
THE RESPIRATORY SYSTEM
The Respiratory Tract
THE EPIGLOTTIS
This is a leaf-shaped piece of cartilage attached to the base of the tongue. During swallowing, the rest of the larynx is pulled up tight to it so that communication between the larynx and pharynx is sealed off.
THE RESPIRATORY SYSTEM
THE VOCAL CORDS
The larynx is lined by ciliated mucous membrane, which extends on both sides to form two pleats (the vocal cords). The edges of the vocal cords are thickened with fibrous tissue and have no ciliated cells. So when air is forced between them they vibrate and produce sound. The sounds are refined by the pharynx, tongue and lips to produce speech.
THE TRACHEA
The trachea or windpipe (10cm) continues below the larynx. It lies in front of the oesophagus (gullet), and is composed of between 16-20 C-shaped pieces of cartilage with the open part of the “C” facing to the rear). It is lined with ciliated membrane.
THE BRONCHI
The trachea divides into two, the left and right bronchi at the CARINA. At the level of the 5th thoracic vertebrae, one to each lung. The bronchi enter the lung at the HILIUM, eventually dividing off to very fine bronchioles.
THE RIGHT BRONCHUS (2.5cm)
Is shorter and descends more steeply than the left and more in line with the trachea. Therefore there is a greater risk of any inhaled foreign material entering the right bronchus than the left.
THE LEFT BRONCHUS (5cm)
Passes under the arch of the aorta and crosses over the front of the oesophagus before entering the left lung.
THE RESPIRATORY SYSTEM
THE LOBES OF THE LUNGS
Shortly after entering the lungs, the bronchus divides into three branches that are distributed into the lobes of the lungs. There are two lobes in the left lung but the upper lobe is large and receives two branches of the bronchus.
THE RESPIRATORY SYSTEM
BRONCHIOLES
Once inside the lobes the bronchus gets smaller and the amount of cartilage decreases and the amount of involuntary (smooth) muscle increases. Spasms of this muscle can cause severe breathing difficulties and wheezing in such conditions as asthma. In the bronchioles there is no cartilage present. Instead, there are circular fibres of involuntary (smooth) muscle and bundles of elastic tissue. Eventually the bronchioles divide down and get smaller and become one of 50 million anatomical units in the lungs called LOBULES.
THE ALVEOLI
These are minute air-sacs at the ends of the bronchioles. This is oxygen enters the blood and carbon dioxide diffuses out. There are approximately 750 million alveoli in the lungs.
THE RESPIRATORY SYSTEM
LUNGS AND PLEURA
THE LUNGS
The lungs occupy most of the space in the thorax. They are spongy organs and are separated by the mediastium. The right lung is slightly bigger and thicker than the left because the left lung has a notch in the lower right quadrant to make room for the heart.
THE PLEURA
The lungs are covered by a double layer of serous membrane called the pleura.
VISCERAL PLEURA
Lines the lungs and follows the fissures between the lobes. Filled with Serous Fluid.
PARIETAL PLEURA
Attached to the chest wall and upper surface of the diaphragm.
THE RESPIRATORY SYSTEM
CAPILLARIES
These minute blood vessels (only one cell thick), are so fine that red cells have to pass through them in single file. The red cell has only about one second to give up its carbon dioxide and take on a supply of oxygen before it is out of the capillary network and on its way back to the heart.
If the body is at rest, all the blood passes through the lungs about once every minute. If there is strenuous muscular activity then it may pass through the the lungs as often as once every six seconds.
EXTERNAL & INTERNAL RESPIRATION
EXTERNAL RESPIRATION is the normal process of breathing where oxygen from inhaled air is absorbed into the blood via the capillaries of the lung. Carbon dioxide is released from the blood into the lungs and is exhaled.
INTERNAL RESPIRATION – Blood in the circulatory system carries oxygen to the body cells. Oxygen is given off for use by the cells and carbon dioxide is absorbed by the blood which is carried to the lungs.
PRINCIPAL MUSCLES OF RESPIRATION
INTERCOSTAL MUSCLES - Between the ribs
DIAPHRAGM - Sheet of muscle that separates the thorax from the abdomen.
SECONDARY MUSCLES OF RESPIRATION
These are used if the principal muscles are not working due to injury or disease,
SHOULDER MUSCLES
CHEST WALL MUSCLES
ABDOMINAL MUSCLES
COMPOSITION OF AIR
INSPIRED AIR EXPIRED AIR
Nitrogen -----------------79% Nitrogen ------------------- 79%
Oxygen ------------------ 20% Oxygen --------------------- 16%
Carbon dioxide ---------0.04% Carbon dioxide ----------- 4%
Inert gasses -------------- 1% Inert gasses ---------------- 1%
Water vapour -----------variable Water vapour ------- saturated
THE RESPIRATORY SYSTEM
MECHANISM OF RESPIRATION
Inspiration (2 secs.)
Expiration (3 secs.)
Pause
RESPIRATION RATES
AVERAGE ADULT ---------------------------------- 15 - 20 Times per min.
5 – 12 CHILD ----------------------------------------- 20 – 25 Times per min.
1 – 5 CHILD ------------------------------------------- 25 – 30 Times per min.
<1 Year ------------------------------------------------ 30 – 40 Times per min.
FACTORS NEEDED FOR ADAQUATE VENTILATION
Good ventilation of the lungs
Good diffusion at the lungs and tissues
Good perfusion of both lungs and tissues
RESPIRATORY CONDITIONS
BRONCHITIS - A blockage of the bronchi by mucous secretions by
Repeated infection or irritation by smoking.
EMPHYSEMA - A chronic disease in which the alveoli in the lungs
become distended which reduces the surface area
for exchange of gasses. Caused by smoking, air
pollution, age progression of chronic bronchitis.
THE RESPIRATORY SYSTEM
ASTHMA - This is a narrowing of the bronchioles due to spasm
of the smooth muscle. This causes difficulty on
expiration, wheezing is often heard.
Causes – allergic reaction, hereditary.
ATELACTESIS - A collapsed part of the lung – collapsed alveoli due to
External pressure i.e pneumothorax, flail chest.
Internal pressure i.e secretions plugging airways.
RESPIRATORY ARREST - Cessation of breathing caused by head injury, CVA,
Electric shock.
RESPIRATORY OBSTRUCTION – Tongue, blood, vomit or foreign body in upper
respiratory tract.
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