Klinical anatomy and phisiology of the nose, paranasal sinuses and pharynx

Theme 1

 

KLINICAL ANATOMY AND PHISIOLOGY OF THE NOSE, PARANASAL SINUSES AND PHARYNX.

Aim : To know the clinical anatomy and physiology of the the nose and paranasal sinuses and can use this knowledge in examination of patients with pathology of upper respiratory tract

 

Professional Motivation : Good Knowledges of anatomy and physiology of the nose and paranasal sinuses will allow right evaluation and management of  upper respiratory tract diseases.

Basic level : - To know general structure of the nose and paranasal sinuses.

 

Student’s Independent Study Program

Objectives for Student’s Independent Studies

You should prepare for the practical class using the existing textbooks and lectures. Special attention should be paid to the following:

 

1. Describe the basic structures of the external nose;
2. Describe the basic structures of the nasal cavity;
3. Describe the blood and nerve supply of the external and internal nose;
4. Describe the clinical physiology the nasal cavity
5. Describe the basic structures of the paranasal sinuses.
6. Describe the clinical physiology the paranasal sinuses

 

Key words and phrases : Meatus, turbinate, Paranasal Sinuses

The Nose

The nose is the air conditioner of the body, responsible for warming and saturating inspired air, removing bacteria and particulate debris, as well as conserving heat and moisture from expired air. Nasal breathing is important for optimal pulmonary function. It is also a prominent cosmetic feature of the face.

A. External Nose - the anterior, caudal portion of the nose is cartilaginous, while posteriorly and superiorly it is bony.

Framework

Cartilages: greater alar (lower lateral), septal, lateral nasal (upper lateral), lesser alar, sesamoid.

b. Bones: Nasal, maxillary, frontal  Musculature: Nasalis, depressor septi, procerus, dilator naris.

Blood supply  External carotid  External maxillary: lateral nasal, angular, alar, septal, external nasal.  Internal carotid: Ophthalmic, which gives rise to anterior ethmoid, posterior ethmoid, and dorsal nasal vessels.

Lymphatics: facial artery, submandibular, parotid nodal drainage.

Nerve supply

Sensory trigeminal 

Ophthalmic division: Nasociliary, external nasal, infratrochlear. 

Maxillary division: infraorbital 

Motor facial: Buccal, zygomatic branches

 

B. Internal Nose:

Floor - the floor of the nose is formed by the hard palate. The nasal cavity extends as far back as the soft palate, where the posterior choanae opens into the nasopharynx.

Roof - the roof of the nose is adjacent to the anterior cranial fossa. The cribriform plate contains numerous tiny perforations which transmit sensory fibers to the olfactory bulbs. The sensation of smell is limited in man to a very small area of mucosa in the superior recesses of the nose. Posteriorly, the roof slants downward as the anterior wall of the sphenoid sinus.

Lateral Walls - the turbinates, three or sometimes four bony shelves covered by erectile mucosa, project from the lateral wall of the nose. These processes serve to increase the interior surface area of the nose to facilitate heat and water exchange. They constantly engorge or shrink to accommodate changing physiologic requirements. They are also the chief structures involved in pathologic obstruction. A series of spaces are created by the overhanging edge of these turbinates.

Inferior Meatus - inferior to the inferior turbinate. Contains orifice of nasolacrimal duct.

Middle Meatus - inferior to the middle turbinate. Contains semilunar hiatus, with openings of the maxillary, frontal, and anterior ethmoidal sinuses.

Superior Meatus - drains posterior ethmoid cells.  Spheno-ethmoid recess - orifice of sphenoid sinus.

Comun Meatus - vertical slot between all nasal turbinates and septum.

 

Blood Supply 

Anterior ethmoid - to roof and anterior superior portion of septum and lateral wall.  Sphenopalatine - to lateral wall of nose

Nasopalatine - supplies roof, septum, and floor 

Lateral nasal - supplies lateral nasal wall anteriorly. 

Descending palatine - supplies the lateral nasal wall posteriorly. 

Pharyngeal - supplies roof posteriorly 

Posterior ethmoid - supplies septum and lateral nasal wall superiorly 

Septal - supplies septum inferiorly and floor 

 

Nerve supply 

Medial internal nasal - to septum, anterosuperiorly 

Lateral internal nasal - to lateral wall, anterosuperiorly 

External nasal - to skin of back of nose 

Posterior superior nasal - supplies septum and lateral wall posteroinferiorly, to middle turbinate  Posterior inferior nasal - to floor and inferior turbinate 

Pharyngeal - to choana 

Anterior superior alveolar - to inferior meatus 

Infraorbital - to vestibule 

 

Lymphatics: drained by 

Facial venous drainage 

Retropharyngeal 

Superior deep cervical 

Submandibular

 

Paranasal Sinuses

These are air-filled, mucosal-lined cavities which develop in facial and cranial bones. The spaces communicate with the nasal airway. Their function is unknown but has been subject to a great deal of speculation. They could serve to decrease the weight of the skull or to function as resonators for the voice. In lower animals with a more acute sense of smell, the sinuses are largely lined by olfactory epithelium. Sinuses may have originally developed to increase the available surface area for the sense of smell. Therefore, in humans, with olfaction limited to a much smaller area, sinuses may be vestigial anachronisms.

Though their function is obscure, their medical significance is not. Sinuses frequently become infected due to obstruction of normal drainage, and negative pressure in a sinus can cause headache. Neoplasms which arise in the sinuses can be occult for quite a long time, so that they are usually very advanced at the time of diagnosis. There are four groups of sinuses:

A. Frontal - Paired, in frontal bone. Posterior wall is adjacent to anterior cranial fossa. Usually asymmetrical, occasionally absent.

B. Maxillary - Paired, in maxilla. Superior wall - floor of orbit. Medial wall - lateral wall of nose. Inferiorly related to tooth-bearing area of maxilla.

C. Ethmoid - Numerous cells in superior and lateral walls of nose, and in medial walls of orbits.

D. Sphenoid - Paired, in sphenoid bone. Sella turcica projects into this space.

 

The nose is a very narrow space, and it is impossible to completely examine the inner surface in the intact patient. Anterior rhinoscopy with a bivalve speculum usually discloses the anterior ends of the inferior turbinates and the septum. Topical vasoconstriction permits a somewhat more thorough examination. Nasal patency may be compromised by swollen turbinates, septal deviation, or intranasal masses, such as tumors, or nasal polyps. A perforation of the nasal septum can cause symptoms such as a whistling noise during breathing, epistaxis, and excessive crusting of the nose.

The sense of smell is rarely tested due to the difficulty in objectively quantifying responses, but by presenting common odors (lemon, coffee, vanilla) one can assess the patient's ability to detect an odor or identify it. Ammonia fumes will stimulate trigeminal endings, and thus produce a response in the absence of any olfaction; thus it is useful for distinguishing true anosmics from malingerers.

 

1. How many turbinates are in the nasal cavity?

a 1

b 2

c 3

d 4

 

2. How many meatuses are in the nasal cavity?

a 1

b 2

c 3

d 4

 

3. What orifice does open in the inferior meatus?

A - nasolacrimal duct;

B - semilunar hiatus;

C - sphenoid sinus;

D - posterior ethmoid cells.

 

4. What orifices do open in the middle meatus?

A - nasolacrimal duct;

B - semilunar hiatus;

C - sphenoid sinus;

D - posterior ethmoid cells.

 

5. What orifice does open in the superior meatus?

A - nasolacrimal duct;

B - semilunar hiatus;

C - sphenoid sinus;

D - frontal sinus.

 

Answers to the Self-Assessment

1. С; 2 - D; 3 - A; 4 - B; 5 - C.

 

Visual Aids and Material Tools :

Tables, cranium, healthy students.

 

Students’ Practical Activites :

anterior rhinoscopy;

posterior rhinoscopy;

palpation of external nose

palpation of paranasal sinuses

rentgenography

 

References :

 

Основна:

1. Заболотний Д.І., Мітін Ю.В., Драгомирецький В.Д. Оториноларингологія. Київ, “Здоров’я”, 1999.-С.84-95, 96-104.

Додаткова:

1. Зарицький Л. А. Хвороби вуха, носа, горла. Київ. «Вища школа», 1974, с 134—147, с. 189—194.
2. Исхаки Ю. Б., Кальштейн Л. Й. Детская оториноларингология. Душанбе. «Маориф», 1984, с. 9—31.
3. Лайко А.А. Дитяча оториноларингологія. Київ, “Здоров’я”, 1998.-С.199-200, 294-297.
4. Лайко А.А., Заболотний Д.І., Синяченко В.В. Обсяг і методика обстеження об’єктивного статусу дітей з ЛОР-патологією. Київ, ЛОГОС, 2000.-С.31-58.
5. Овчинников Ю.М. Оториноларингология. М., «Медицина», 1995.- С.8-37, 38-44.
6. Пальчун В. Т., Преображенский Н. А. Болезни уха, горла, носа. М., «Медицина», 1980,с. 11—29.
7. Солдатов И.Б. Лекции по оториноларингологии. М., «Медицина», 1990.- С.131-148.