Gross Anatomy
SESSION 10
Dr. Firas M. Ghazi
Nose and paranasal sinuses
Curricular Objectives
By the end of this session students are expected to:
Practical
1. Review the parts of the external nose
2. Label the dermatomes of the external nose
3. Feel the cartilaginous and bony parts of the nose
4. Locate the nasal cavity and define its extents and main divisions
5. Mark the boundaries of the nasal cavity
6. Identify prominent features of lateral wall of nasal cavity
7. Name and locate the different types of epithelial tissue lining the nasal cavity
8. Recognize Little’s area and acknowledge its clinical importance
9. Trace the sphenopalatine artery and recall its origin and importance
10. Name & Locate the paranasal sinuses & their openings into lateral wall of nasal cavity
11. Mark the site of frontal and maxillary sinuses on the face (surface anatomy)
12. Label the paranasal air sinuses in skull X-ray
13. Palpate the frontal and maxillary air sinuses
14. Distinguish the nerves supplying the frontal and maxillary air sinuses
15. Follow the olfactory nerves to the bulb
Theory
1. Recall the main functions of nose and acknowledge its importance in clinical practice
2. Review the prominent features and dermatomes of the external nose
3. Outline the extent, divisions, and boundaries of the nasal cavity
4. List and describe the main features of the lateral wall of the nasal cavity
5. Summarize the function of the different epithelia lining the nasal cavity
6. Discuss the blood supply of the nasal cavity
7. Define Kiesselbach’s plexus and list the arteries forming it
8. Acknowledge the importance of the submucosal venous plexus
9. Underline the types of innervations of the nasal cavity
10. Review the course of the nerve supplying the olfactory mucosa
11. List the spaces communicating with the nasal cavity and their opening sites
12. Describe function, drainage, and nerve supply of paranasal sinuses.
13. Relate the sensory nerve supply of paranasal sinuses to possible sites of pain
14. Uncover the relation between frontal and maxillary sinuses regarding their drainage
15. Appraise the fact that drainage orifice of the maxillary sinus lie near its roof
Selected references and suggested resources
 Clinical Anatomy by Regions, Richard S. Snell, 9th edition
 Grant's Atlas of Anatomy, 13th Edition
 McMinn's Clinical Atlas of Human Anatomy, 7th Edition
 Anatomy for Babylon medical students (facebook page)
 Human Anatomy Education (facebook page)
 Human anatomy education (you tube channel)
Further assistance on:
University website: http://staff.uobabylon.edu.iq/site.aspx?id=93
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Gross Anatomy
SESSION 10
Dr. Firas M. Ghazi
Lab check list
 Clinical importance
Diseases like rhinitis, sinusitis, nasal septal deviation and epistaxis are very common. It is
essential for junior doctors to have a detailed knowledge of the anatomy of the region
 Functions:
1. ……………………………….
2. ……………………………….
 External Nose
 Nostrils
 Nasal septum
 Ala nasi
 Skeleton: hyaline cartilage plus the following bones …………………………..
 Note: Fractures of nasal bones are common facial fractures from direct trauma to nose
 Nasal Cavity
 Extent:
 Communicates with the exterior through………………… and with the nasopharynx
posteriorly through……………………
 Divisions:
 The inside of the nose is divided by a nasal septum into …………..and ………nasal cavities
 Each nasal cavity is divided into vestibule (area just inside the nostril) and nasal
cavity proper
 Nasal septum
 Upper part is formed by…………………. And ………………………...
 Lower (anterior) part is formed by …………………….
 Walls
1. Floor
 Separates the nose from …………………… cavity
 Made up of …………………….. and …………………. bones
2. Roof
 Separates the nose from ………………….. cavity
 The middle third is formed by the cribriform plate of the ethmoid.
3. Medial wall, what forms it ?
4. Lateral Wall
 Three bony projections ………………, …………………, and…………….. conchae (choncha)
 Three spaces below each concha ………………., ……………….., and meati (meatus)
 Sphenoethmoidal Recess is a small area located above the …………….
 Task: Using a Sagittal section of the nasal cavity, try to identify and describe the
vestibule, nasal cavity proper, roof, floor, nasal septum and its components, and the
structures seen on the lateral wall.
 Linings of the cavity
 Task: The nasal cavity is lined by three types of epithelium, list and locate them
 Blood supply of the nasal cavity
Further assistance on:
University website: http://staff.uobabylon.edu.iq/site.aspx?id=93
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Gross Anatomy
SESSION 10
Dr. Firas M. Ghazi

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By branches of Maxillary, Ophthalmic, and Facial arteries
Little’s area:
 Location:
 Branches of the three main arteries anastomosis with each other forming a vascular
plexus called Kiesselbach’s plexus
 Common site of epistaxis (nose bleeding)
 Submucous venous plexus
 A plexus of veins in the respiratory region.
 Contain warm blood to warm up the inspired air
Nerve Supply of the Nasal Cavity
 Smell is provided by ………………… nerves, they ascend from a specialized mucosa located at
………………….. up through the ………………. of the ethmoid bone to reach the olfactory bulbs
 The rest of the nasal cavity is supplied by somatic sensation from branches of the
trigeminal nerve (V1,V2)
Openings into the nasal cavity and their related spaces
 Task: Complete the following statements(Use a Sagittal section of nasal cavity to help you)
1. Sphenoid air sinus opens into …………………..
2. Posterior ethmoid sinuses open into …………………..
3. Middle ethmoidal air sinuses open into ……………… on the upper border of……..…….
4. Frontal & anterior ethmoidal sinuses drain through a channel called ..….…... into …..……..
5. Maxillary sinus opens into ………………..
6. The nasolacrimal duct transmit …………………….. from ………… to open into …………………… its
opening is guarded by a fold of mucous membrane.
The Paranasal Sinuses
 Task: Four paranasal sinuses are found within four skull bones. Identify the bones and
distinguish the sinuses within.
 Task: Using a skull specimen, name and locate the cavities related to maxillary sinus
 Task: Palpate the frontal and maxillary sinuses for tenderness
Nerve supply
 The ……………………. Nerve supply the frontal sinus.
 The ……………………. Nerve supply the maxillary sinus
Review questions:
1. List two places in the head where the external and internal carotid arteries anastomose.
2. The dorsum & the tip of the nose are supplied by …………………….division of CNV
3. What are the mechanisms responsible for draining the mucous of the paranasal sinuses?
4. Infection of the ethmoid sinus can easily spread to the orbit. Explain why?
5. Pain in patients with frontal sinusitis may be referred to ………………….. area
6. Pain in patients with maxillary sinusitis may be referred to …………………. Area and ……………..
Homework
 The statement (The nasal septum usually lies in the midline) is INCORRECT.
Further assistance on:
University website: http://staff.uobabylon.edu.iq/site.aspx?id=93
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Gross Anatomy
SESSION 10
Dr. Firas M. Ghazi
1. Correct it
2. In your opinion, what can be the consequences if the septum is severely deviated?
 A 12-year-old boy admitted to casualty suffering a unilateral nose bleed. Examination revealed
bleeding spot on the nasal septum.
A. Which area is the most likely source of bleeding?
B. What are the arteries supplying this location?
C. Which one of the arteries is most likely to be responsible?
 What happens when an opening of a paranasal sinus into the nose is closed? Think of common
illnesses that may close these openings
 The location of the opening of the maxillary sinus exposes the sinus to infection and pus
collection. Discuss
Further assistance on:
University website: http://staff.uobabylon.edu.iq/site.aspx?id=93
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