RESPIRATORY SYSTEM Breathing n Breathing in is called

RESPIRATORY SYSTEM

Breathing n Breathing in is called Inspiration. n Breathing out is called expiration.

PARTS OF THE RESPIRATORY SYSTEM n Nasal Cavity n Epiglottis n Pharynx n Larynx n Trachea n Lungs n Diaphragm

NASAL CAVITY n The nostrils or nares openings of the nose. and moisten the air particles. are usually located in the Mucus Membranes warm while cilia trap inhaled

PHARYNX n The human pharynx is the part of the throat situated immediately behind the mouth and the nasal cavity. The pharynx is where the nasal cavities, oral cavities converge. Both food and air are passed into the pharynx.

EPIGLOTTIS n The epiglottis is a cartilaginous valve that covers the entry of the larynx preventing food from entering it and the trachea. n When inhaling the epiglottis remains opened. n The epiglottis closes when food gets swallowed. This prevents food from obstructing the larynx.

TRACHEA n The trachea (or windpipe) is the bony tube that connects the nose and mouth to the lungs. When an individual breathes, air that is caught flows into the lungs through the trachea.

LARYNX n The larynx, commonly called the voice box, is located at the top of the trachea. n The larynx houses the vocal cords which are an essential component of phonation (making sound). n The vocal cords are folds of membrane stretched across the larynx. They vibrate when air passes by causing a sound.

Bronchi Once air progresses through the trachea, it branches into two tubes called the bronchi which lead to a lung. Once in a lung the bronchi keep branching into smaller and smaller tubes known at bronchioles.

Chest x rays Normal female Lateral (male) 10

Alveoli n The bronchioles have air sacs at the end. n Each air sac is called an alveolus (pularal aveoli)

Cilia n Along the Bronchi and down into the lungs are little hairs called cilia (microtubules). n These act as a filter catching chemicals and substances that are not supposed to get into your body.

Lungs Each Alveolus is encapsulated by capillaries Which allows oxygen to diffuse into the blood And carbon dioxide to diffuse out of the blood.

n The “air-blood barrier” (the respiratory membrane) is where gas exchange occurs – Oxygen diffuses from air in alveolus (singular of alveoli) to blood in capillary – Carbon dioxide diffuses from the blood in the capillary into the air in the alveolus 14

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DIAPHRAGM It is a dome-shaped muscle that separates the chest cavity and the abdominal cavity. n When the diaphragm contracts it pushes down on the abdomen and other chest muscles push the ribs out making more room for the lung. n Then the chest muscles and diaphragm relax and the diaphragm moves up. n

Diaphragm n Hiccups are caused by the diaphragm spamming. n The vocal cords snap shut to stop the sudden inward flow of air making the hiccup sound.

INHALATION n Normal respirations are 10 to 18 breaths per minute, with each lasting around 2 seconds. n During vigorous inhalation (at rates exceeding 35 breaths per minute), or when approaching respiratory failure, accessory muscles of respiration are recruited for support.

Smoking n When you smoke the chemicals in the cigarrett kill off all the cilia. n The tar and harmful chemicals are now stuck in your lungs and able to diffuse into your blood.

n There are many diseases of the respiratory system, including asthma, cystic fibrosis, COPD (chronic obstructive pulmonary disease – with chronic bronchitis and/or emphysema) and epiglottitis example: normal emphysema 20