2 - Head & Neck - General Flashcards
How would you test for cranial nerve XI during an examination?
Innervates Sternocleidomastoid and Trapezius:
- Lateral rotation of head against resistance
- Shrug shoulders against resistance
Which number cranial nerve is the facial nerve?
CN VII
Name the muscle which surrounds the eye socket, and the nerve which innervates it:
Orbicularis oculi Facial nerve (CN VII)
What is the function of Orbicularis oculi?
Inner palpebral part = gently closes eyelid
Outer orbital part = closes eyelid more forcefully
Name the muscle which opens the eyelid, and the nerve which innervates it:
Levator palpebrae superioris Oculomotor nerve (CN III)
Name the muscle which raises the eyebrows, and the nerve which innervates it:
Occipitofrontalis Facial nerve (CN VII)
What is the function of Occipitofrontalis?
Raises eyebrows
Name the muscle which surrounds the mouth, and the nerve which innervates it:
Orbicularis Oris Facial nerve (CN VII)
What is the function of Orbicularis Oris?
Purses lips
Name the muscle which sucks in your cheeks, and the nerve which innervates it:
Buccinator Facial nerve (CN VII)
What is the function of the buccinator muscle?
Sucks in cheeks
Is the buccinator a muscle of facial expression, or of mastication? Therefore which nerve innervates it?
Facial expression Facial nerve (CN VII)
Name the muscle which depresses the mandible, and the nerve which innervates it:
Platysma Facial nerve (CN VII)
What is the function of Platysma?
- Depresses mandible
- Depresses angle of mouth
Which nerve innervates the dilator muscles of the lips?
Facial nerve (CN VII)
Name the main muscles of mastication, and the nerve which innervates them:
1) Masseter
2) Temporalis
3) Medial Pterygoids
4) Lateral Pterygoids
Mandibular branch of Trigeminal nerve (CN V)
Name the main muscle which opens the mouth, and the nerve which innervates it:
Lateral Pterygoids
Mandibular branch of Trigeminal nerve (CN V)
Name the most powerful muscle of mastication, and its main function:
Masseter
Elevates mandible
Name the 2 muscles which can elevate the mandible, and the nerve which innervates them:
1) Masseter
2) Temporalis
3) Medial Pteygoids
Mandibular branch of Trigeminal nerve (CN V)
Which muscles are innervated by the Accessory nerve? What number cranial nerve is it?
1) Sternocleidomastoid
2) Trapezius
CN XI
What is the function of Sternocleidomastoid, and what nerve is it innervated by?
- Lateral flexion of head
- Flexion of neck
- Extension of neck
Accessory nerve (CN XI)
What is the function of Trapezius, and what nerve is it innervated by?
- Upper = elevates scapula (shrugs shoulders)
- Middle = retracts scapula
- Lower = depresses scapula
Accessory nerve (CN XI)
Name the 5 layers of the scalp:
1) Skin
2) Dense Connective tissue
3) Epicranial Aponeurosis
4) Loose areolar connective tissue
5) Periosteum
Use SCALP to remember
Which layer of the scalp connects the Occipitalis to the Frontalis?
Epicranial Aponeurosis
Which layer of the scalp is the ‘danger area’, and why?
Loose areolar connective tissue
- Pus and blood spread easily within it, and can pass into the cranial cavity via the Emissary veins, leading to Meningitis
Give 3 factors which increase bleeding from scalp lacerations:
1) Pull of Occipitofrontalis muscle prevents closure of wound
2) Blood vessels are adhered to dense connective tissue, preventing vasoconstriction
3) Many anastomoses between blood vessels
Which artery can be palpated at the inferior margin of the mandible?
Facial artery (branch of external carotid artery)
Name the 3 main branches of the External Carotid Artery which supply the scalp:
1) Superficial Temporal artery
2) Occipital artery
3) Posterior Auricular artery
The arteries supplying the scalp are branches of which main artery?
External Carotid artery
Name the vessels which connect the loose areolar connective tissue of the scalp to the intracranial venous sinuses:
Emissary veins
Which artery supplies most of the skull?
Middle meningeal artery
Injury to the scalp can cause heavy bleeding. Why can this blood surround the orbit (presenting as periorbital eccymosis) but not enter the neck?
The frontalis muscle inserts into skin and subcutaneous tissue, so blood can move below this from the scalp to the orbit.
The occipitalis muscle inserts to the zygomatic and occipital bones, preventing blood passing into the neck.
Name the 2 main dural venous sinuses:
1) Superior sagittal sinus
2) Inferior sagittal sinus
Most of the dural venous sinues drain into which vein?
Internal jugular vein
via which hole does the internal jugular vein leave the skull?
Jugular foramina
