Osteology of Skull & Mandible + Scalp & Face

Flashcards for reviewing the osteology of the skull and mandible, as well as the scalp and face.

What is the definition of the scalp?

Soft tissues covering the vault of the skull.

Name the five layers of the scalp.

Skin, Connective Tissue (Dense), Aponeurosis, Loose areolar tissue, Pericranium.

Which layers of the scalp unite and move as a single unit?

First 3 layers unite to each other, forming a single unit that can move over the pericranium.

Anteriorly, what is the extension of the scalp?

Eyebrows.

Posteriorly, what is the extension of the scalp?

Superior nuchal lines.

Laterally, what is the extension of the scalp?

Superior temporal lines.

Describe the key characteristics of the skin layer of the scalp.

Thick, hair-bearing, and contains numerous sebaceous glands.

Describe the dense connective tissue layer of the scalp.

Fibro-fatty layer that tightly connects skin to underlying aponeurosis contains numerous arteries, veins & nerves.

What leads to sebaceous cysts in the scalp?

Block of the ducts.

What is the epicranial aponeurosis (galea aponeurotica)?

Thin sheet tendon that unites the two bellies of Occipito-frontalis muscle (Epicranius).

What is the action of the Occipito-frontalis muscle?

Raise eyebrows & wrinkles forehead.

What is the loose areolar tissue layer of the scalp?

Potential space that occupies subaponeurotic space.

Why is the loose areolar tissue layer considered the dangerous layer of scalp?

Allows spread of blood & pus under the aponeurosis.

What causes a black eye due to Subgaleal (Subaponeurotic) Hemorrhage?

Blood entering the eyelid.

What is scalp swelling of newborn after delivery using vacuum extraction called?

Caput succedaneum.

What does hemorrhage under the pericranium layer lead to?

Subperiosteal collection of blood (hematoma) that takes the shape of the underlying skull bone.

What is the medical term for subperiosteal collection of blood (hematoma)?

Cephalhematoma.

What is the pericranium?

Periosteum covering the outer surface of the skull.

How many nerves supply the scalp in front of the auricle?

5 nerves (1 motor, 4 sensory).

How many nerves supply the scalp behind the auricle?

5 nerves (1 motor, 4 sensory).

Which motor nerve innervates the scalp in front of the auricle?

Temporal branch of facial nerve.

Which motor nerve innervates the scalp behind the auricle?

Posterior auricular branch of facial nerve.

Name the sensory nerves that innervate the scalp in front of the auricle.

Supratrochlear n., Supraorbital n., Zygomatico-temporal n., Auriculo-temporal n.

Name the sensory nerves that innervate the scalp behind the auricle.

Great auricular n., Lesser occipital n., Greater occipital n., Third (3rd) occipital n.

How many arteries supply the scalp, and where are they located?

3 infront of ear & 2 behind the ear (from both Internal carotid artery (ICA) & External carotid artery (ECA)).

Which artery supplies the forehead & ant. ½ of scalp?

Ophthalmic a.

Which vessel supplies the scalp?

2. External carotid a.

What are the two branches of the External Carotid Artery that supply the scalp?

Occipital a., Posterior auricular a.

How are veins of the scalp related to arteries?

Veins accompany arteries and have similar names.

Which veins drain the scalp in front of the auricle?

Supratrochlear v., Supraorbital v., Superficial temporal vein.

Which veins drain the scalp behind the auricle?

Posterior auricular vein, Occipital vein.

What do the Supratrochlear and Supraorbital veins form?

Angular vein continues as facial vein.

Where does the anterior part of the scalp drain lymphatically?

Submandibular lymph nodes.

Where does the lateral part of the scalp drain lymphatically (in front of auricle)?

Preauricular (parotid) lymph nodes.

Where does the lateral part of the scalp drain lymphatically (behind the auricle)?

Retro-auricular (postauricular, mastoid) lymph nodes.

Where does the posterior part of the scalp drain lymphatically?

Occipital lymph nodes.

Besides occipital lymph nodes, where does the posterior part of the scalp drain lymphatically?

Superficial cervical L.N

What common skin condition affects the face?

Acne – infected sebaceous glands.

What are the extensions of the face?

Vertically from hair line above to chin; Horizontally between right and left Tragus of ears.

What sensory nerve innervates the skin of the face, and what is its cranial nerve number?

Rich in sensory nerves supplied by trigeminal nerve (cranial nerve V).

What nerve supplies the muscles of facial expression, and what is its cranial nerve number?

Facial nerve (cranial nerve VII).

What are the three divisions of the trigeminal nerve that provide sensory supply to the face?

Ophthalmic (V1) ,Maxillary (V2), Mandibular (V3).

What are the main symptoms of trigeminal neuralgia?

Patient experiences severe pain in the distribution of the mandibular or maxillary division.

What is Herpes Zoster, and which nerve(s) may it affect in the face?

Viral infection with vesicles along the distribution of any sensory nerve; may affect branches of trigeminal ganglion.

What are two characteristics of the muscles of the face?

Arise from bones of skull, inserted into the skin.

What are the two main functions of facial muscles?

They are either sphincters or dilators; Modify the expression of the face.

Into what groups are facial muscles divided?

Scalp, Eye, Nose, Mouth, Ear, Neck

Name the three muscles responsible for eye movement.

Orbicularis occuli ,Corrugator supercilii ,Levator palpebrae superioris.

Name the four muscles associated with the nose.

Procerus, Compressor naris, Dilator naris, Depressor septi.

Which muscle belongs to the 'Neck' group?

Platysma.

What are the three parts of the Orbicularis Oculi muscle?

Orbital part, Palpebral part, Lacrimal part.

What is the action of the Orbicularis Oculi muscle?

Sphincter of the eyelids.

What is the action of the Orbicularis Oris muscle?

Closes lips/mouth, compresses lips against teeth and protrudes lips (kissing).

What is the action of the Buccinator muscle?

Compresses & Flattens cheeks, blows air, Whistling, suckling.

Which nerve supplies all muscles of the face, and what is its cranial nerve number? What is the exception?

All muscles of face, EXCEPT levator palpebrae superioris, are supplied by facial nerve (cranial nerve VII).

What are the five terminal branches of the facial nerve?

Temporal, Zygomatic, Buccal, Mandibular, Cervical.

What produces facial muscles paralysis?

Facial nerve [VII] palsy (Bell’s palsy).

What is one clinical manifestation of facial nerve palsy on the affected side?

Inability to close the eyes & drooping of the lower eyelid (Orbicularis oculi lesion).

What is another clinical manifestation of facial nerve palsy on the affected side?

Inability to close the mouth (Orbicularis oris lesion).

What is a symptom of facial nerve palsy related to location?

Deviation and drop/sagging of the angle of mouth (Orbicularis oris lesion).

From the external carotid artery, what vessels comprise arterial supply of the face?

Facial Artery, Superficial temporal artery , Transverse facial a (branch of superficial temporal a), Mental , buccal & infraorbital branches of maxillary a.

From the internal carotid artery, what vessels comprise arterial supply of the face?

Supratrochlear a., Supraorbital a.

What is the main course of blood supply to face?

Facial Artery.

Where is the pulsation felt in the face.

It enters the face by winding round lower border of mandible at anteroinferior border of masseter muscle (where its pulsation can be easily felt).

Where can the pulse of the facial artery be felt?

Against the body of mandible.

Where can the pulse of the Superficial Temporal Artery be felt?

Its pulsation is felt as it crosses the zygomatic arch in front of ear, at tragus.

How is the facial vein formed?

At medial angle of eye by union of supraorbital & supratrochlear veins → Angular vein → Facial vein.

With which structures does the facial vein communicate?

with pterygoid venous plexus by deep facial vein; With cavernous sinus by ophthalmic vein.

The submandibular lymph nodes drain which part of the face?

anterior part of face.

The Parotid lymph nodes drain which part of the face?

Lateral part of face.

The Submental lymph nodes drain which parts of the face?

philtrum, central part of lower lip, and chin.