The Respiratory System
Respiratory System Functions Gas exchange: Oxygen enters blood and carbon dioxide leaves Regulation of blood pH: Altered by changing blood carbon dioxide levels Voice production: Movement of air past vocal folds makes sound and speech
Respiratory System Functions Olfaction: Smell occurs when airborne molecules drawn into nasal cavity Protection: Against microorganisms by preventing entry and removing them Temperature regulation: Panting in some animals
Parts of the Nose Nose Only externally visible part of the respiratory system Job is to begin warming, purifying, and humidifying air
Parts of the Nose External Nares (nostrils) Nasal Cavity Where air enters the nose The openings Nasal Cavity Interior of the nose Has thin-walled blood vessels to begin warming air
Parts of the Nose Nasal Septum Midline dividing nasal cavity into two
Parts of the Nose Sticky mucous Respiratory Mucosa Sticky mucous Moistens air and traps bacteria & debris Ciliated cells move mucous back toward throat
Parts of the Nose Mucosa-covered projections Conchae Mucosa-covered projections Increase surface area & air turbulence Provide more opportunity for warming & filtration
Parts of the Nose Anterior separation of nasal & oral cavity Hard Palate Anterior separation of nasal & oral cavity Supported by bone Soft Palate Posterior separation of nasal & oral cavity
Cleft Palate Palate does not fuse together Can also affect the lip
Parts of the Nose Paranasal Sinuses Openings in skull bones Lighten the skull Resonance chambers for speech Produce mucus
Parts of the Pharynx Pharynx Muscular passageway for food & air “Throat” About 5 inches long Broken into 3 parts
Parts of the Pharynx Opening between nasal cavity and pharynx Internal Nares Opening between nasal cavity and pharynx
Parts of the Pharynx Nasopharynx Oropharynx Laryngopharynx Three divisions of Pharynx Listed from superior to inferior After passing through, air enters larynx, food enters esophagus
Parts of the Pharynx Pharyngeal Tonsils: Palatine Tonsils AKA adenoids High in the nasopharynx Trap bacteria/pathogens Palatine Tonsils In oropharynx, end of soft palate When you get your tonsils out, this is what is removed Lingual Tonsils Base of the tongue
FYI: Tonsilitis Catch too much bacteria; palatine tonsils can’t keep up! EEW.
http://video.about.com/coldflu/Tonsillitis.htm
Larynx AKA Voice Box Routes air and food into proper channels Inferior to pharynx Formed by 8 rigid cartilages and a spoon-shaped flap of elastic cartilage (epiglottis) Thyroid cartilage = Adam’s apple
Epiglottis Cartilage flap of larynx; protector! When not swallowing: Epiglottis flapped up Does not block larynx When you are swallowing: Larynx rises Epiglottis falls Larynx closed off This means that food is directed into esophagus
FYI: If anything other than air tries to enter the larynx, a cough reflex is triggered to get it out and prevent it from going into the lungs!
Vocal Folds Formed from folds in larynx membrane Vibrate with expelled air Glottis Slit-like passageway between vocal folds
http://video.about.com/coldflu/Laryngitis.htm YouTube - Video Stroboscopy of the Vocal Cords YouTube - Mythbusters - Helium and Sulfur Hexafluoride
Trachea AKA windpipe Has cartilage rings around it to keep it open during pressure changes About 4 inches long Lined with ciliated mucosa to propel mucus (with dust particles & debris) away from the lungs to the throat
Primary Bronchi Two (right & left) Formed by division of trachea Enters the lung, and then breaks off into secondary bronchi
Mediastinum Most central area of the thoracic cavity Includes heart, great blood vessels, bronchi, esophagus, etc. (everything except lungs)
Lungs Left: 2 lobes Right: 3 lobes Site of gas exchange Soft & Spongy, only weigh about 2 ½ pounds Each lung divided into lobes Left: 2 lobes Right: 3 lobes
Parts of Lungs Apex Base Visceral Pleura Narrow superior portion By clavicle Base Wide inferior portion Rests on diaphragm Visceral Pleura Covers surface of lung Along with parietal pleura, provides attachment and eliminates friction
Bronchial Tree Bronchioles All of the branching of respiratory passageways in the lungs Divisions include Primary bronchi Secondary bronchi Tertiary bronchi Bronchioli Terminal bronchioli (end in alveoli)
This image is showing the carina – the point where the primary bronchi break off from each other.