Dentistry

Paranasal sinuses Paranasal air sinuses Air-containing bony-pockets located around the nasal cavity all lined by mucous membrane (normally respiratory epithelium) All of them are paired: (i) Frontal air sinus, (ii) Ethmoidal air sinuses, (iii) Sphenoidal air sinus (iv) Maxillary air sinus. Functions (i)Air-conditioning of the inhaled air by adding moisture and temperature regulation. (ii) Resonating boxes for sound production. (iii) Making the facial bones lighter. (iv) Establishing adult contour of face - Teeth and sinus development are responsible for the enlargement of the cranium Contd.. All the sinuses are rudimentary at birth   maxillary sinus is the first paranasal sinus to develop   have two spurts of growth - once at 7-8 years of age (during eruption of permanent teeth)   and again at 14-16 years of age (post-pubertal) Hence a baby's face changes towards adultface during these two phases of growth of the air sinuses. Frontal sinus lie b

Lung Volumes and Capacities Recording Changes in Pulmonary Volume—Spirometry Spirometer is an instrument which records the volume movement of air into and out of the lungs. Lung volumes Tidal volume Inspiratory reserve volume Expiratory reserve volume Residual volume Lung capacities Inspiratory capacity Functional residual capacity Vital capacity Total lung capacity Lung volumes

NOSE INTRODUCTION The part of the respiratory tract superior to the hard palate and contains the peripheral organ of smell. FUNCTIONS Olfaction (smelling) Respiration Filtration of dust Humidification of inspired air Reception and elimination of secretions from the paranasal sinuses and nasolacrimal ducts. Nose consists of the external nose and nasal cavity. External nose the visible portion that projects from the face Covered with skin It is a pyramidal projection Presents : tip or apex, root, dorsum, Inferior surface presents a pair of apertures known as nostrils or nares. SKELETON OF EXTERNAL NOSE Bony part: Nasal bones Frontal process of maxilla Nasal part of frontal bone and its nasal spine Cartilagenous part Two lateral cartilages Two alar cartilages One septal catilage NASAL CAVITIES Refers either to entire cavity or to right and left half Entered anteriorly through nostrils Opens posteriorly into nasopharynx through c