Nose
- Introduction
• The nose is the primary organ of smell (olfaction) and an important part of the respiratory system.
• It warms, filters, and moistens inhaled air before it reaches the lungs.
• The nose also contributes to voice resonance and taste perception. - External Nose Structure
• The external nose is a pyramidal-shaped structure located centrally on the face.
• Composed of:
• Root: superior part connecting to forehead.
• Dorsum: bridge of the nose.
• Apex (Tip): rounded end with nostrils.
• Nares (nostrils): two external openings for air entry, separated by the nasal septum.
• Supported by a bony framework (nasal, maxillae, frontal bones) and cartilage (alar, lateral, septal cartilages) giving shape and flexibility. - Internal Nasal Cavity
• The nasal cavity is divided into two chambers by the nasal septum, made of bone and cartilage.
• Lined with mucous membrane that warms, moistens, and filters air.
• The lateral walls have three curved nasal conchae (turbinates): superior, middle, and inferior, that increase surface area and create air turbulence for better filtration.
• Contains three corresponding passages (nasal meatuses) below each concha for air flow and drainage. - Paranasal Sinuses
• Air-filled cavities located within bones around the nose: frontal, maxillary, ethmoid, and sphenoid sinuses.
• Lined by mucosa and connected to nasal cavity through small openings.
• Functions: lighten the skull, produce mucus, and provide resonance to the voice. - Olfactory Region
• Located at the roof of the nasal cavity.
• Contains olfactory receptors responsible for detecting odors.
• Signals are transmitted to the brain via the olfactory nerve (cranial nerve I). - Blood Supply and Nerve Innervation
• Blood supply mainly from branches of the external carotid artery and internal carotid artery.
• Sensory innervation by the trigeminal nerve (cranial nerve V).
• Olfactory nerves handle smell sensation.
• Parasympathetic fibers stimulate mucus gland secretion. - Functions of the Nose
• Air passage: conducts air to lungs.
• Filtration and humidification: traps dust and microbes; moistens air.
• Olfaction: detects odors for smell sensation.
• Voice resonance: nasal cavities affect sound quality during speech. - Common Disorders
• Rhinitis: inflammation causing congestion and runny nose.
• Sinusitis: infection/inflammation of sinuses.
• Nasal polyps: benign growths causing obstruction.
• Deviated nasal septum: crooked septum affecting airflow.
• Epistaxis: nosebleeds from fragile vessels. - Nursing Care
• Assess nasal patency and breathing.
• Encourage humidification and hydration for congestion relief.
• Educate on proper nasal hygiene and avoiding irritants.
• Assist in management of nasal bleeding and infections.
• Support post-operative care for nasal surgeries. - Summary for Quick Review
The nose serves as the entrance for air, where it is filtered, warmed, and humidified before reaching the lungs. It consists of an external pyramidal framework and internal cavities lined with mucosa and turbinates to enhance function. Olfactory receptors enable the sense of smell. The paranasal sinuses lighten the skull and contribute to voice resonance. Nursing care includes airway assessment, infection prevention, and patient education.