Upper respiratory track composed of nose, pharynx, larynx. These Structure allow to breathe and speak.
Nose
Nose is first respiratory organ.
Air normally enters the respiratory track through nose.
External nose is supported at the nose bridge by nasal bone.
Nasal septum is bone and cartilage in the nose that separates nasal cavity into two nostrils (External nose).
Nasal cavity fills space between base of skull and roof of mouth.
Posterior bony part of septum formed by the perpendicular plate ethmoid bone and vomer.
Roof of Nose
Roof of nose is formed by - cribriform plate of ethmoid bone and inferior surface of body of the Sphenoid bone, nasal part of frontal bone, nasal bone and nasal cartilage.
Floor of Nose
Floor of nose about 5cm long, 1.5 cm wide, formed by roof of mouth consist of palate -
1. Hard palate in front
2. Soft palate behind
1. Hard palate
Hard palate composed of - palatine process of axillary bone and horizontal palates of the palatine bones.
2. Soft palate (back part of palate)
Flexible
Movable muscular fold
Separate oropharynx from nasal cavity
It prevents food from entering nasal pharynx
Continuous with posterior border of hard and consist of several skeletal muscles covered by mucus membrane.
When elevated for swallowing and sucking, it completely blocks and separates nasal cavity and nasal portion of pharynx from mouth and oral part of pharynx.
Middle Wall of Nose
Formed by septum is osseocartilaginous partition between two halves of nasal cavity.
Bony part of septum is formed by -
Vomer
Prependicular palate of the ethmoid bone
Cartilaginous part formed by -
Septal cartilage
Inferior nasal cartilages (septal processess)
Blood Flow of Septum
Sphino palatine, anterior or posterior ethmoid arteriey, Superior labial artery (anteriorly).
Lateral Wall of Nose
Partly bony
Partly cartilaginous
Partly made up of soft tissue
Bony part formed by-
Nasal bone
Maxilla
Lacrimal bone
Ethmoid bone with superior and middle conchae
Prependicular palate of palatine bone
Middle pterygoid palate
Posterior Wall of Nose
Formed by posterior wall of pharynx.
Opening into the Nasal Cavity
Anterior nares/ External nares/ nostrils - External openings to the nasal cavity (hair present in this area )
Posterior (internal) nare, posteriorly nose communicate with pharynx throught two opening called choanae.
Paranasal sinuses
Nasolacrimal duct
Paranasal Sinuses
Paranasal sinus are group of four paired air- filled cavities( sac) that surrounds nasal cavity.
1. Frontal sinuses - above the eyes
2. Ethmoidal sinuses - between the eyes
3. Sphenoidal sinuses - behind the eyes
4. Maxillary sinuses - located under eyes
Sinuses are lined with mucus membrane.
Give voice a full, rich tone and make skull lighter.
Nasolacrimal Duct (Tear Duct)
The nasolacrimal duct begins in the eye socket between maxillary and lacrimal bones.
Carries tears from the lacrimal sac (connected nose to the conjuctival sac of eye) of eye into nasal cavity.
Lacrimal Apparatus
Lacrimal gland (paired) , endocrine gland
Containing orbital structure for tear production and drainage.
Secrete of tear and secretory duct, convey fluid to surface of human eye.
Drain to nasolaryngeal duct.
Lining of Nose
Vascular ciliated columnar epithelium which contains mucus secreting goblet cells.
Conchae
Nasal conchae are curved bony projections directed down ward and medially.
1. Superior conchae - projection from ethmoid bone
2. Middle conchae - projection from ethmoid bone
3. Inferior conchae - there are independent bone.
Nasal conchae responsible for regulating the air flow through nasal passage. They increases surface area of these cavity thus, providing rapid warming and humidification of air as it passes to lungs. Large surface area maximize warming, humdification and filtering.
Meatuses (Passage) of Nasal Cavity
Meatuses are air passage way, communicate freely with nasal cavity proper.
Blood Vessels in meatuses are called venous sinuses.
Function of Nose
1. Respiratory function
2. Passage way of air
3. Olfactory function (sense of smell)
4. Protection, nasal hair in nostrils trap large particle preventing entry into lungs
5. Warming cold air to body temperature
6. Humidification and prevent drying
7. Filtering and cleaning air, trap large particles, filtration of dust
8. Modify speech vibration
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