Respiratory System

Main Function Gas Exchange –To work closely with the cardiovascular system to supply the body with oxygen and to dispose of carbon dioxide

Organs Include 1. Nose 2. Pharynx 3. Larynx 4. Trachea 5. Bronchi –And their smaller branches 6. Lungs –Containing alveoli (terminal sacs)

The Nose Externally visible –Nostrils – External Nares –Internally – Nasal Cavity –Divided by nasal septum –Olfactory receptors in the superior cavity in the mucosa

Function of Nose Mucosa lining rests on thin walled veins that warm the air Mucous produced by the mucosa, moistens the air and traps bacteria and other particulates

Bone Structures Conchae- Increase surface area of mucosa and create turbulance Palate- Separates from oral cavity –Hard palate (bone ) is anterior –Soft palate(tissue) is posterior

Cleft Palate Genetic Defect Bones do not fuse medially Causes Problems: –Breathing –Chewing –Speaking

Paranasal Sinuses Surround the nasal cavity Located in Bones: –Frontal –Sphenoid –Ethmoid –Maxillary

Function of Sinuses Lighten the skull Resonance for speech Produce mucous Nasolacrimal ducts –Drain tears from eyes

Rhinitis, Sinusitis, Sinus Headache Inflammation of the nasal mucosa –Virus –Allergens Mucosa is continuous so that these infections often spread

Pharynx 13cm muscular passageway (Throat) Food and air Nasopharynx- Superior Oropharynx- central Laryngopharynx- Inferior

Pharynx Tonsils are located in the pharynx –Pharangeal or Adenoids (superior) –Palatine (oropharynx) –Lingual (base of tongue)

Larynx AKA Voice box, routes air, role in speech Inferior to pharynx Eight rigid hyaline cartilage –Largest is Thyroid cartilage (Adam’s Apple) –Protrusion angel 90˚ in males and 120˚ in females Cartilage flap – Epiglottis protects opening

Larynx Mucous Membrane forms Vocal folds (vocal cords) –allow us to speak Glottis - Slit-like passageway between the vocal folds

Trachea Windpipe Goes to the 5 th Thoracic Vertebrae Reinforced with C- shaped cartilage rings to keep it open anteriorly and allow flexibility for food to pass through the esophagus posteriorly

Airway Obstruction Heimlich Maneuver –Physical Procedure where someone assists in dislodging a blockage Tracheostomy –Surgical Procedure cuts a new opening

Main Bronchi Division of the trachea Runs obliquely Ends at the hilus (medial depression of the lung) –The right is wider and shorter and more often the site of inhaled objects

Lungs Occupy entire thoracic cavity (except mediastinum where the heart is) Narrow superior portion (apex) is deep to clavicle Broad base rests on the diaphragm Left lung = 2 lobes Right lung = 3 lobes

Lungs Surface covering is visceral serosa called Pulmonary Pleura Walls of the cavity are covered with parietal pleura Pleural fluid reduces friction during breathing movements

Pleurisy Inflammation of the pleura due to decreased secretion of pleural fluid Pain with each breath Excess fluid may hinder breathing

Bronchioles Primary bronchi subdivide into smaller branches Bronchial Tree –Secondary Bronchi –Tertiary Bronchi –Then Bronchioles

Alveoli Small cavity or air sac –Millions of clustered alveoli look like bunches of grapes Site of gas exchange Make up a bulk of the lungs –Also stroma which is elastic

Respiratory Membrane Thin squamous epithelial cells Alveolar pores connect sacs External surfaces have a “cobweb” of capillaries Respiratory Membrane is the Air / Blood barrier