The Respiratory System Respiratory System Upper nasal cavity

The Respiratory System

Respiratory System Upper nasal cavity Sinuses Pharynx Epiglottis Larynx Lower Trachea Bronchi bronchioles Alveoli Lungs Pleura.

Structure of Respiratory System Nasal Cavity NASAL SEPTUM = divides nasal cavities into R and L sides

Structure Respiratory System Nasal Cavity Turbinates bones that protrude into the nasal cavity they increase surface area for filtering dust and dirt particles by the mucous membrane

Structure of Respiratory System Nasal Cavity CILIA – the hairs in your nose, trap larger dirt particles

Structure of Respiratory System Sinuses 1) 2) 3) 4) Cavities in the skull filled with air and lined with mucus to moisten air Ducts connect them to the nasal cavity, . Give resonance to the voice. Frontal Maxillary Ethmoid Sphenoid

Structure of Respiratory System Pharynx The throat Common passageway for air and/or food Tonsils are located in the pharynx

Nasopharynx – upper part (air only) Oropharynx – middle region (air, food and liquid) Laryngopharynxlower region (air food and liquid) 3 sections of Pharynx

Nasopharynx Oropharynx Laryngopharynx

Structure of Respiratory System Epiglottis Lies at the base of the tongue and the larynx “gatekeeper” Controls the destination of ingested food and liquid and inspired air Covers the opening to larynx when we swallow so food doesn’t go to trachea Cough to expel if food gets passed Air freely moves to lower resp. tract

Structure of Respiratory System Larynx Voice box Triangular chamber below pharynx Routes air and food to the proper passageways Within the larynx are vocal cords Glottis – space between vocal cords. Air causes vibration – produces sound Adam’s Apple (thyroid cartilage)

Respiratory System Upper nasal cavity Sinuses Pharynx Epiglottis Larynx Lower Trachea Bronchi bronchioles Alveoli Lungs Pleura.

Structure of Respiratory System TRACHEA Windpipe 4 ½ in. long Walls are alternate bands of membrane and C-shaped rings of hyaline cartilage – to keep trachea open Lined with ciliated mucous membrane Coughing and expectoration gets rid of dust-laden mucous

Bronchus, Bronchial tubes & Bronchioles Lower end of trachea divides into R and L bronchus As they enter lungs, subdivide into bronchial tubes and bronchioles Bronchi – similar to trachea with ciliated mucous membrane and hyaline cartilage Bronchial tubes – cartilaginous plates (instead of C-shaped rings) Bronchioles – thinner walls of smooth muscle, lined with ciliated epithelium At the end, alveolar duct and cluster of alveoli

Bronchial tubes

Structure of Respiratory System Alveoli Composed of a single layer of epithelial tissue Inner surfaces covered with SURFACTANT – to keep alveoli from collapsing Each alveolus surrounded by capillaries O 2 and CO 2 exchange takes place between the alveoli and capillaries

Structure of Respiratory System Lungs Fill thoracic cavity Upper part = apex Lower part = base Base fits snugly over diaphragm Lung tissue porous and spongy – it floats R lung = larger and shorter (displaced by the liver) and has 3 lobes L lung smaller (displaced by the heart) and has 2 lobes Filled mostly with air

Apex 1 Base 3 2 1 2

Structure of Respiratory System Mediastinum Center of thoracic cavity between lungs Contains heart, great vessels, trachea, esophagus, thoracic duct, thymus gland

Structure of Respiratory System Pleura Thin, moist slippery membrane that covers lungs Double-walled sac parietal-lines cavity Visceral-covers lung Space is pleural cavity – filled with pleural fluid to prevent friction