Anatomy And Physiology Of Nose 1v1u3e

Anatomy and Physiology of Nose Prepared by : Nurul Syazwani Binti Ramli

Anatomy of Nose Nose

External

Bony Part

Cartilaginous Part

Internal (nasal cavities)

Skin-lined portion (Vestibule)

Mucosa-lined portion (Nasal cavity proper)

External Nose • Pyramidal in shape (root up & base downward) • Consists of osteocartilaginous framework covered by muscles and skin.

External Nose

Osteocartilaginous framework

Bony

-Upper one-third

Part

-2 nasal bone

Cartilaginous Part

-lower two-thirds -it consists of : a) Upper lateral cartilages b) Lower lateral cartilages (alar cartilages) c) Lesser Alar (sesamoid) cartilages d) Septal cartilage

Nasal Musculature

-F(x) : movement of nasal tip, ala and the overlying skin -eg: procerus, nasalis (transverse and alar parts), levator labii superioris laeque nasi, ant. and post. dilator nares and depressor septi.

Nasal Skin

-over nasal bone and upper lateral cartilages is thin and freely mobile -cover alar cartilges is thick and adherent and contain many sebaceous gland

External Nose

Internal Nose • Divided into right and left nasal cavities • Communicates with: – Exterior: through naris (nostril – Nasopharynx: through post. nasal aperture (choana) Vestibule

-lined by skin and contains sebaceous glands, hair follicles and hair (vibrissae)

Internal Nose Nasal Cavity Proper

Has a lateral wall, a medial wall, a roof and a floor

Internal Nose Turbinates (conchae)

-superior -middle -inferior

Meatus

-superior -middle -inferior

Lateral nasal wall

Medial wall Nasal Cavity Proper Roof

Floor

Internal Nose Lateral nasal wall

Nasal Cavity Proper

Medial wall (nasal septum) Roof Floor

1) Columellar septum 2) Membranousseptum 3) Septum proper

Internal Nose Lateral nasal wall Medial wall

Anterior Sloping Part :- nasal bones

Roof

Posterior Sloping Part :- body of sphenoid bone

Floor

Middle Horizontal Part :cribriform plate of ethmoid

Nasal Cavity Proper

Internal Nose Lateral nasal wall Medial wall Nasal Cavity Proper Roof Anterior three-fourths :- palatine process of the maxilla Floor Posterior one-fourth :- horizontal part of the palatine bone

Lining Membrane of Internal Nose Vestibule • Lined by skin containing hair, hair follicles and sebaceous glands Olfactory region • Mucous membrane is paler in colour Respiratory region • Lined by pseudostratified ciliated columnar epithelium which contains plenty of goblet cells

Mucose membrane

Paranasal Sinuses

Lymphatic Drainage

Blood Supply of Nose Nasal septum : – Internal carotid :

• Anterior ethmoid • Posterior ethmoid – External carotid :

• Sphenopalatine • Greater palatine • Superior labial

Blood Supply of Nose Lateral wall : – Internal carotid : • Anterior ethmoid • Posterior ethmoid – External carotid : • Sphenopalatine • Greater palatine • Anterior superior dental (infraorbital ) • Facial artery

Little’s Area (Plexus Kiesselbach) – Anterior inferior nasal septum – Anastomoses from : • • • •

Anterior ethmoid Superior labial Sphenopalatine Greater palatine

Plexus Kiesselbach

Nerve Supply of Nose •

•

Olfactory nerve : – Carry sense of smell and supply olfactory region of nose – Arranged into 10-12 nerves which through the cribriform plate and end in the olfactory bulb Nerves of common sensation : – Anterior ethmoidal nerve – Sphenopalatine ganglion – Infraorbital nerve – Greater palatine nerve

•

Autonomic : – Parasympathetic  greater superficial petrosal  vidian sphenopalatine ganglion – Sympathetic  upper 2 thoracic superior cervical gangglion  deep petrosal nerve  parasympathetic to form vidian

Physiology of Nose Functions of the nose: 1) Respiration 2) Air conditioning of the inspired air 3) Protection of Lower Airway 4) Vocal resonance 5) Nasal reflex functions 6) Olfaction

RESPIRATION •

Nose = natural pathway for breathing INSPIRATION: air  thru middle part of nose btwn turbinates and nasal septum. Very little air es thru inferior meatus or olfactory region. EXPIRATION : same but entire air current is not expelled directly thru nares friction at limen nasi converts it into eddies under cover of inferior and middle turbinates  and this ventilates the sinuses thru the ostia

AIR CONDITIONING OF INSPIRED AIR • ‘air-conditioner’ for lungs:

a)

Filtration and Purification :  nasal vibrissae filters larger particles (3µm)  Finer particles adhere to the mucus over surface of mucous membrane (0.5-3.0µm)  Smaller than 0.5µm can thru nose into lower airways without difficulty b) Temperature control : mucous membrane (region of middle and inferior turbinatesand adjacent parts of the septum) is highly vascular with cavernous venous spaces or sinusoids which control the blood flow)this increase and decrease the size of turbinates  efficient ‘radiator’ mechanism to warm up the cold air (near body T0 = 370C) c) Humidification : adjust relative humidity of inspired air to 75% or more that is essential for integrity and function of ciliary epithelium.

PROTECTION OF LOWER AIRWAY a)

Mucociliary mechanism:  Rich in goblet cells, secretory glands both mucous and serous)  Form a cont. sheet called mucous blanket which consist of superficial mucus layer and deeper serous layer that floating on top of cilia which constantly beating to carry it towards nasopharynx = ‘conveyer belt’

b) Enzymes and Immunoglobulins: (in nasal secretion)  Muramidase (lysozyme) :- kills bacteria and viruses.  IgA and IgE and Interferon :- provide immunity against URTI c) Sneezing : protective reflex. Foreign particles which irritate nasal mucosa are expelled by sneezing.

VOCAL RESONANCE • Resonating chamber for certain consonant in speech. • In phonating nasal consonants ( M/ N/ NG ), sound es

thru nasopharyngeal isthmus and is emitted thru the nose. • When blocked, speech becomes denasal. Eg:- M/ N/ NG are uttered as B/ D/ G respectively

NASAL REFLEXES •

Nasal Mucosa reflex receptors closely related to gastrointestinal and

pulmonary functions.

•

Examples:

- irritation of nasal mucosa cause sneezing - smell of palatable food reflex secretion of saliva and gastric juice.

OLFACTION • Sense of smell: – Animal :- give warning of environmental danger – Man :- for pleasure and eng the taste of food • Olfactory region : – upper one-third of lateral Wall – corresponding part of nasal septum – roof of nasal cavity • Disorder of smell: – Anosmia – Hyposmia – Parosmia

Thank You