Respiratory System Lecture Notes PDF

 Respiratory system Upper respiratory system Nose The nasal cavity is divided by nasal septum. The posterior nasal openings connect the nasal cavity with the nasopharynx. Functions:...

 Respiratory system Upper respiratory system Nose The nasal cavity is divided by nasal septum. The posterior nasal openings connect the nasal cavity with the nasopharynx. Functions:  Warming, moistening of air  Filtration of air from dust  Organ of smell Para-nasal sinuses  Types:  Frontal air sinus  Ethmoidal air sinus  Maxillary air sinus  Sphenoidal air sinus  Function:  Resonance of voice  Lightening of skull weight Anatomist “respiratory system”  Pharynx Begin: the base of skull Termination: at level of 6th cervical vertebra. Subdivisions:  Naso-pharynx: lies behind the nose. It contains adenoid  Oro-pharynx: lies behind the mouth. It contains palatine tonsils  Laryngo-pharynx: lies behind the larynx. Function: Common pathway for food & air. Larynx Begin: C3 Termination: C6 Structure:  It consists of cartilages connected together by muscles & ligaments Functions:  Air passage.  Voice production Anatomist “respiratory system”  Lower respiratory system Trachea Length: 4 inches (10 cm) Site: in the neck & in the thorax. Begin: continuation of larynx at C6. Termination: it bifurcates at lower border of T4 giving right & left bronchi Structure: Formed of 15-20 C-shaped rings of hyaline cartilage Bronchi Right bronchus Left bronchus Shorter Longer Wider Narrower In line with trachea "vertical" Makes angle with trachea "oblique" Inhaled foreign bodies usually pass to it. Inhaled foreign bodies not usually pass to it. Anatomist “respiratory system”  Lungs Each lung is formed of: 1.Apex: directed upward to the neck 2.Bbase: directed downward on the diaphragm 3. three borders “anterior & posterior & inferior” 4. two surfaces: sternocostal "related to sternum and ribs" & mediastinal "has hilum and related to the heart" Right lung Left lung  Shorter  Longer  Wider  Narrower  Has Two fissures (oblique & transverse)  Has one fissure (oblique)  Has 3 lobes (Superior, middle &inferior)  Has 2 lobes (Superior &inferior) Pleura  Definition: is a closed serous sac which encloses the lung  Formation: it is formed of 2 layers  Visceral pleura: is the inner layer.  Parietal pleura: is the outer layer.  Pleural cavity between the two layers & contains a thin film of serous fluid to prevent friction between the 2 layers.