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Function of the respiratory system
- In order for cells to survive they must use oxygen and remove the metabolic waste
- The respiratory system allows the exchange of gasses
- Brings oxygen into thebody and removes carbon dioxide
- Helps control the tempature and water content of air
- Produces sounds
- Regulation of pH
- Sense of smell
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Nasal cavity
- Nasal conchae are bones that curl from the lateral walls of the nasal cavity
- The conchae support the mucous membrane and increase the surface area
- Mucous membrane contains pseudo stratified epithelium and goblet cells
- Traps dirt particles
- Responsible for heating and moisting incoming air
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Paranasal sinus
- Air filled spaces located within the frontal, sphenoid, ethmoid, and maxillary bones
- Mucous membrane that is continuous with the nasal cavity lines the sinuses
- Reduce the weight of the skull and act as resonant chambers for voice
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Pharynx
- Behind oral cavity, nasal cavity and larynx
- Named based on location:
- Nasopharynx, orapharynx, laryngopharynx
- Passageway of food and air
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Larynx
- conducts air in and out of the trachea
- prevents foreign objects from entering the trachea
- houses the vocal cords (muscle, connective, and epithealium tissue)
- contains the thyroid cartilage, cricoid cartilage, and epigloctic cartilage
- epiglottis is a flap like cartilagenous structure that routes the air and the food in the proper channels
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trachea (windpipe)
- flexible cylindrical tube anterior to the esophagus
- lined with a mucous membrane
- moves entrapped air particles to pharynx
- surrounded by C-shaped hyaline cartilage
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Bronchial tree
- consists of branched airways starting at the trachea and ending in the alveoli
- thrachea branches into right and left primary bronchi
- this leads to secondary bronchi, tertairy bronchi to bronchioles (terminal and respiratory)
- the branching ends wwith the alveolar ducts that leads to aveolar sacs and finally to alveoli which are the site of gas exchang in the blood
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structre of the Airways
- the primary bronchi are similar to the trachea and are surounded by cartilage
- secondary and tertiary bronchi have less cartilage
- bronchioles lack cartilage but have smooth muscle
- aveoli are made of simple squamous cells and have no cartilage or smooth muscle around them
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alveolus
- made of simple squamous epithelium to allow diffusion to occur
- the oxygen picked up from the aveoli goes through the pulmonary veins back to the left atrium of the heart
- surrounded by alot of capilaries for gas exchange
- contains macrophages to fight infection
- releases surfactant which is important in lung function
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breathing
- change in pressure within the luncgs is important for breathing to occur
- gas exchange occurs by process of diffusion
- the pressure gradient drives gas exchange
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inspiration
- during inspiration the thoracic cavity volume increases due to
- diaphragm pushing down
- external intercostals pushing out
- in forced inspiration, additional muscles such as pertoralis minor, sternocleidomastoid contract
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expiration
- passive porcess where muscles recoil
- forced expiration involves the use of internal intercostal, ext4ernal and internal obliques
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respiratory centeres
located in the pons and medulla oblongata
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