Unit Three: Muscles of the Face and Neck Flashcards
Where is the origin for muscles of facial expressions? (2)
- Superficial fascia (hypodermis). Or 2. Skull bones.
Where is the insertion for muscles of facial expression?
Superficial fascia (hypodermis) of the skin.
What are most muscles of facial expressions innervated by?
Cranial nerve XII (the facial nerve).
What are the two bellies of the occipitofrontalis?
- Frontal. 2. Occipital.
What is the function of the frontal belly of the occipitofrontalis? (2)
- Elevate eyebrows. 2. Wrinkle scalp.
What is the function of the occipital belly of the occipitofrontalis?
Retracts scalp.
What does the epicranial aponeurosis (occipitofrontalis) do?
Connects the two muscle bellies of the occipitofrontalis.
What are the two muscles of the nose?
- Procerus. 2. Nasalis.
What is the function of the procerus? (2)
- Depresses medial eyebrows. 2. Wrinkles skin over nose.
What is the function of the nasalis? (3)
- Compresses the bridge. 2. Depresses the tip of the nose. 3. Elevates corners of the nostrils.
What is the function of the buccinator? (3)
- Compresses the cheek. 2. Draws the corners of the mouth laterally. 3. Hold food between teeth when chewing.
Does the buccinator open or close the jaw?
No.
What is the function of the depressor anguli oris?
Draws the corner of the mouth inferiorly and lateraly.
What is the function of the depressor labii inferioris?
Depresses lower lip.
What is the function of the levator anguli oris? (3)
- Widens oral fissure. 2. Elevates corners of the mouth. 3. Assists with smiling.
What is the function of the levator labii superioris? (2)
- Opens lips. 2. Elevates and furrows the upper lip.
What is the function of the levator labii superioris alaeque nasi? (2)
- Elevates upper lip. 2. Dilates nostrils.
What is the function of the zygomaticus major and minor? (2)
- Raises lateral corners of the mouth. 2. Smiling.
What is the function of the orbicularis oris? (3)
- Closes lips. 2. Purses and protrudes lips. 3. Kissing.
What is the function of the risorius? (2)
- Draws corner of the lip laterally and down. 2. Tenses lips.
What is the function of the mentalis? (2)
- Elevates and wrinkles skin of chin. 2. Protrudes lower lip.
What is the function of the platysma? (2)
- Tenses skin of inferior face and neck. 2. Depresses jaw.
Where is the origin of the sternocleidomastoid muscle? (2)
- Manubrium (sternum). 2. Clavicle.
Where is the insertion of the sternocleidomastoid muscle?
Mastoid process.
What is the bilateral action of the sternocleidomastoid muscle?
Flexes neck.
What are the unilateral actions of the sternocleidomastiod msucle? (2)
- Lateral flexion. 2. Rotation of head to the opposite side.
What nerve innervates the sternocleidomastoid muscle?
Accessory nerve (CN XI).
Where is the origin of the anterior, middle, and posterior scalene muscles?
Transverse process of cervical vertebrae.
Where is the insertion of the anterior, middle, and posterior scalene muscles?
1st and 2nd ribs.
What are the actions of the anterior, middle, and posterior scalene muscles? (2)
- Flexes the neck. 2. Elevates the 1st and 2nd ribs during forced inhalation.
What innervates the anterior, middle, and posterior scalene muscles?
Cervical spinal nerves.
How are muscles of the anterior neck divided?
Based on their location with respect to the hyoid bone.
Where do all suprahyoid muscles insert?
On the hyoid bone.
What is the function of the suprahyoid muscles? (2)
- Depresses mandible. 2. Elevates hyoid.
What are the two bellies of the suprahyoid muscle?
- Geniohyoid. 2. Mylohyoid.
What is the function of the geniohyoid?
Elevates hyoid.
What is the function of the mylohyoid? (2)
- Elevates hyoid. 2. Elevates floor of mouth.
What is the function of the stylohyoid?
Elevates hyoid.
Where is the origin of the stylohyoid?
Styloid process of the temporal bone.
Where is the origin of the sternohyoid?
Sternum (manubrium).
What is the function of the sternohyoid?
Depresses hyoid.
What is the function of the omohyoid?
Depresses hyoid.
Where is the origin of the thyrohyoid?
Thyroid cartilage.
What is the function of the thyrohyoid? (2)
- Depresses hyoid. 2. Elevates thyroid cartilage.
Where is the origin of the sternothyroid?
Posterior surface of the manubrium.
What is the function of the sternothyroid?
Depresses the thyroid cartilage.
Where is the insertion of the sternothyroid?
Thyroid cartilage.
What is the only infrahyoid muscle that doesn’t insert on the hyoid?
The sternothyroid.
What are the four infrahyoid muscles?
- Omohyoid. 2. Sternohyoid. 2. Thyrohyoid. 4. Sternothyroid.
What does the sternocleidomastoid muscle delineate?
Two clinically important regions: anterior triangle and posterior triangle.
What is contained within the submental triangle?
Lymph nodes.
What is contained within the submandibular triangle? (2)
- Submandibular gland. 2. Facial artery and vein.
What is contained within the carotid triangle? (5)
- Common carotid artery. 2. Jugular vein. 3. Vagus nerve. 4. Sympathetic trunk. 5. Hypoglossal nerve (VII).
What is contained within the muscular triangle? (2)
- Infrahyoid muscles. 2. Thyroid and parathyroid glands.
What is contained within the occipital triangle? (3)
- Accessory nerves. 2. Brachial plexus (trunks). 3. Lymph nodes.
What triangles are within the anterior triangle? (4)
- Submental. 2. Submandibular. 3. Carotid. 4. Muscular.
What triangles are within the posterior triangle? (2)
- Occipital. 2. Supraclavicular.