Chapter 2 - Surface anatomy

Surface anatomy overview

• Must thoroughly examine anatomy of head and neck

• Surface anatomy - study of structural relationships of external features of the body to internal organs and parts

Why need to know

• Know normal/ abnormal structures to record/ chart accurately

Regions of the head

Region	Description
Frontal	Forehead and area superior to the eyes. Deeper skull bone Glabella to hairline.
Parietal and occipital	Covered by scalp and deeper skull bones.
Temporal and auricular	Side of the head. External ear is most prominent feature.
Orbital	Eyeball and supporting structures in orbit (bony socket).
Nasal	Main feature is the external nose.
Infraorbital	Each side of the head on the facial aspect. Inferior to orbital region, lateral to nasal region.
Zygomatic	Each side of the head on the facial aspect. Overlies cheekbone (zygomatic arch), anterior to TMJ (temporomandibular joint). Extends from lateral margin of the eye to the middle part of the ear.
Buccal	Each side of the head on the facial aspect composed of the soft tissue of cheek.

Regions of the head (detailed)

Frontal region of head landmarks

• Supraorbital ridge

• Glabella (flat between eyebrow)

Extraoral exams

• Bilateral palpate

Parietal and occipital regions

• Regions at the back of the head and base of the skull (covered by hair and scalp)

Extraoral exams

• Visually inspect and move hair/ especially around hairline

• Start from 1 ear → other ear

• Hairline = not stable landmark (receding, bald etc)

Temporal and auricular regions

• External ear only

• Temporal = temple/ lateral to frontal region

• External ear has 2 parts

  • Auricle (oval flap of ear)

    • Collects sound waves

  • External acoustic meatus (EAM)

    • Tube where soundwaves are directed to the middle ear

    • How to see -— pull posterior, superior, lateral

• Posterior and superior free margin of auricle

  • Helix

  • Lobule (piercings on)

• Tragus

  • Small flap tissue covering auricle anterior / EAM

  • Antitragus (flexible)

  • Intertragic notch

Extraoral exams

• Palpate this to feel masseter region

• Inspect auricle, move gentle, palpate external ear and pull back gently

• Inspect ear canal for deformity, redness, and inspect scalp around ear

Orbital region

Part	Description
Sclera	White area of eye.
Iris	Colored central area of eye.
Pupil	Center of iris (black), dilates in response to changing light conditions.
Eyelid	Covers and protects eyeball. Two movable parts, upper and lower.
Lacrimal gland	Produces lacrimal fluid or tears.
Conjunctiva	Thin membrane lining inside of the eyelid and front of eyeball.
Canthus	Where upper and lower eyelids meet. Lateral and medial canthus.

Parietal and occipital regions

Orbital regions

• Close to eyes

• Supporting structures are bony socket (orbit)

• Eyeball

  • Sclera

  • Iris - colored

    • Jaundice - yellow discoloration caused by hyperbilirubinemia (increase bilirubin in blood)

  • Pupil (black)

    • Changes according to light conditions (dark dilate)

    • Healthy diameter = 3-4 mm

    • Bright light = 1.5 mm

    • dim light = 8 mm

    • Narrow = more focal range

  • — Alcohol can cause pupil constriction

  • — Drugs/ psychedelics can cause pupil dilation

  • Eyelid - protect eyeballs

    • Control amount of light entering eyes

    • Prevent threat

    • Remove irritants, improve secretions (moisture)

    • Voluntary reflect = winking (moving 1 eye)

    • Blink rate = higher means nervous or pain

  • lacrimal glands = above (tears)

  • Conjunctiva = delicate and thin membrane lining eyeball/lid

    • Conjunctivitis = pink eye (inflammation of conjunctiva) = inflammation or allergies

  • Lateral canthus

    • Outer corner upper and lower eyelids meet

    • Medial canthus = inner angles of the eye

  • Lens

    • Make image sharp/ detailed

    • Change shape to focus on object (accomodation)

  • Cataract (clouding on lens of the eye)

    • Age related

Extraoral exam = eyes respond to light

• Abnormal = redness, tears, discoloration, clouding, pinpoint pupil, yellow (infection)

Auricular region

Part	Description
External ear/Auricle	Oval flap of ear that collects sound waves.
Helix	Top of ear.
Lobule	Bottom of ear.
External acoustic meatus	Tube that transmits sound waves to middle ear.
Tragus	Flap of tissue found at opening of external acoustic meatus.

Nasal region

Part	Description
Root of nose	Between the eyes.
Bridge of nose	Inferior to the root of the nose.
Nasal septum	Separates the nares.
Naris/nares	Nostril (an opening).
Ala	Side of the nares.
Apex of the nose	Tip/end of the nose.

Nasal region

Extraoral exam

• Root of nose = between eyes

• Nasion = bridge of nose

• Apex of nose (tip)

• Naris = side

• Nasal septum

Lip region

Part	Description
Philtrum	Vertical groove on skin which is superior to the midline of the upper lip.
Tubercle	Thicker area at the midline of the upper lip.
Labial commissure	Corner of lip, where upper and lower lip meet.
Vermilion zone	Darker appearance than the surrounding skin. External covering of lip.
Vermilion border	Fine line of paler skin border. “Cupid’s bow” on the upper vermilion border.
Mucocutaneous junction	Where the skin of the lip meets the skin of the face.
Nasolabial sulcus/groove	Groove between labial commissure and each ala of the nose.
Nasolabial fold	Each side of the nasolabial sulcus. Accentuates with age.
Labiomental groove	Separates the lower lip from the chin.

Oral cavity

Part	Description
Oral mucosa	Lining of the oral cavity (buccal mucosa and labial mucosa).
Buccal mucosa	Lining for the inside of the cheek.
Buccal fat pad	Dense pad of inner fatty tissue (under buccal mucosa).
Labial mucosa	Lining for the inside of the lips.
Parotid papilla	Elevation of tissue found on the buccal mucosa opposite the 1st or 2nd maxillary molar.
Alveolar mucosa	Red, thin, and movable, not attached to bone.
Vestibule / mucobuccal fold	Trough-like space between the cheeks or lips. Maxillary vestibule and mandibular vestibule.

Oral Cavity: Orientational terms

Term	Description
Facial	Closest to the facial surface.
Labial	Closer to the lips.
Buccal	Closest to the inner cheek.
Lingual	Closest to the tongue.
Palatal	Lingual structures (maxilla) closest to the palate.

Teeth and Jaw

Part	Description
Maxilla	Upper jaw.
Mandible	Lower jaw.
Anterior teeth	Incisors, canines.
Posterior teeth	Premolars, molars.
Gingiva	Gums.
Attached gingiva	Tightly adheres to the bone around the roots of the teeth.
Mucogingival junction	Line of demarcation between the attached gingiva and alveolar mucosa.
Marginal/Free gingiva	Gingival margin of each tooth, nonattached.
Gingival sulcus	Inner surface of the marginal gingiva.

Roof of the mouth

Part	Description
Palate	Forms the roof of the mouth (hard and soft palate). 15% of the palate (soft palate) is not attached to bone.
Hard palate	Firmer, whiter, hard because attached to underlying bone.
Soft palate	Posterior to hard palate, not attached to bone.
Incisive papilla	Small elevation behind the maxillary central incisors. Bulge of tissue (incisive foramen is underneath it).
Palatine rugae	Firm, irregular ridges of tissue on the anterior part of the palate.
Median palatine raphe	Midline ridge of tissue on hard palate.
Palatine tori	Bony growth causing raised area at the midline of palate.

Tongue

Part	Description
Dorsal surface	Top part of the tongue.
Lateral surface	Side of the tongue.
Ventral surface	Under part of the tongue.
Apex	Tip of the tongue.
Body of the tongue	Anterior 2/3 of the tongue.
Base of the tongue	Posterior 1/3 of the tongue.
Lingual tonsils	Irregular mass of lymphatic tissue at the base and side of the tongue.
Midline lingual sulcus	Midline depression on dorsal surface of tongue.
Sulcus terminalis	V-shaped groove that separates base of tongue from body of tongue on dorsal surface.
Foramen cecum	Small pit-like depression where sulcus terminalis points back.
Circumvallate lingual papillae	10–14 taste buds anterior to sulcus terminalis.
Foliate lingual papillae	Vertical ridges on the side of the tongue. Contain taste buds.
Filiform papillae	Slender, thread-like projections on dorsal surface of tongue. Velvety texture.
Fungiform lingual papillae	Red mushroom-like dots on dorsal surface of tongue. Lesser in number than filiform, contain taste buds.
Lingual veins	Large blue blood vessels on the ventral surface of tongue.
Plicae fimbriatae	Fringe-like projections on the ventral surface of tongue.
Lingual frenum	Midline fold of tissue between ventral surface of tongue and floor of the mouth.
Sublingual fold	Ridge of tissue on the floor of the mouth.
Sublingual caruncle	Small papilla at the base of lingual frenum which is the opening for Wharton’s duct.

Salivary glands

Gland Name	Gland Location	% Saliva	Duct Name	Duct Location
Parotid gland	Cheek area. Largest salivary gland.	25%	Stensen’s duct	Parotid papilla. Usually opposite 1st or 2nd maxillary molar.
Submandibular gland	Posteriorly in the jaw.	60–65%	Wharton’s duct	Ends at sublingual caruncle.
Sublingual gland	Under front part of chin.	10%	Sublingual or Bartholin’s duct	Ends at sublingual caruncle.

Oropharynx

Part	Description
Hard palate	Firmer, whiter, hard because attached to underlying bone.
Soft palate	Posterior to hard palate, not attached to bone.
Uvula	Midline muscular structure.
Dorsal surface of the tongue	Top surface of the tongue.
Fauces	Opening from the oral region into the oropharynx.
Maxillary tuberosity	Pad of tissue posterior to the most distal maxillary molar.
Pterygomandibular fold	Fold of tissue that extends from the junction of the hard and soft palates on each side down to the mandible, just posterior to the most distal mandibular molar, and stretches when the patient opens the mouth wider.
Posterior pillar	Pillar or wall of tissue behind the palatine tonsils.
Palatine tonsil	Pair of soft tissue masses located at the rear of the throat (pharynx). Lymph tissue covered by mucosa. Crypts – pits in the mucosa of each tonsil.
Anterior pillar	Pillar or wall of tissue in front of the palatine tonsils.
Retromolar pad / retromandibular pad	Pad of tissue posterior to the most distal mandibular molar.

Pharynx

Part	Description
Pharynx	Entrance to the throat.
Nasopharynx	Above the soft palate.
Oropharynx	Soft palate and opening of larynx.
Laryngopharynx	Not visible from mouth.
Esophagus	Tube for food going to stomach.
Oral cavity	Base of tongue and in front of the oropharynx.
Epiglottis	Located at the base of the tongue and in front of oropharynx. Controls food going down.
Larynx	Voice box.
Trachea	Tube for air going to lungs.

Neck Region

Part	Description
Sternocleidomastoid (SCM)	Divides each side of the neck diagonally into anterior and posterior cervical triangles. Has superficial and deep cervical lymph nodes.
Anterior cervical	Anterior cervical region of the neck.
Posterior cervical	Posterior cervical region of the neck.
Hyoid bone	Controls position of base of tongue.
Thyroid cartilage	Adam’s apple.