Neck (Anterior Triangle) Flashcards
What are the boundaries of the Anterior Triangle of the Neck?
- Median line of neck (Midline “strap muscles”)
- Anterior border of SCM
- Inferior border of mandible
- Contains:
a. Submandibular Triangle
b. Carotid Triangle
c. Muscular Triangle
d. Submental Triange
What is the Muscular Triangle?
- Boundaries:
- Omohyoid (Superior belly)
- SCM (anterior border)
- Median plane (Midline)
- Roof:
* Superifical and Investing Fascia - Contains:
- Infrahyoid muscles
- Larynx
- Trachea
- Thyroid (and parathryoid glands)
- Suprasternal space contains: (anterior jugular veins and jugular venous arch)
- Pretracheal space contains: (Inferior thyroid veins and Thyroid ima artery)
*Thyroid ima artery is not present in everybody. Some people have it and other don’t
- Clinical Case:
a. Emergency Tracheostomy: Allergic reaction that causes aliphatic shock, which vocal chords become swallon. Prevents air from passing and choking occurs.
- Conducted at the gap between the Right and Left infrahyoid muscles
- Below the 3rd level of the tracheal ring
- Common of accidently cutting the Thyroid ima artery because it is not present in everyone
What is a Hyoid Bone?
- Between the floor of the mouth and thyroid cartilage
- Does not articulate with any other bone
- Muscles that keep it in place:
a. Suprahyoid
b. Infrahyoid
*Find adam’s apple and move superiorly to the next hard structure
What is the Suprahyoid Muscle?
- Connects the hyoid bone to the skull
- Contains: “My Gravy Spoon Darling”
- Mylohyoid (Floor of the mouth); raphe mylohyoid attaches to the body of the hyoid bone
- Geniohyoid
- Stylohyoid
- Digastric (Anterior and Posterior belly)
What is the Infrahyoid Muscles?
- Anchor the hyoid, sternum, clavicle, and scapula and depress the hyoid and larynx during swallowing and speaking
- Contains: “TOSS”
- Sternohyoid
- Omohyoid
- Sternothyroid
- Thyrohyoid
What is the muscular action of the Suprahyoid Muscules?
- Elevate hyoid bone and larynx
- Stylohyoid retracts hyoid bone
- Digastric depress the manible
What is the muscular action of the Infrahyoid Muscles?
- Depress hyoid bone and larynx
- Thyrohyoid elevates larynx
What is the Nerve supply for the Suprahyoid Muscles?
- CN VII (facial nerve)
* Supplies Stylohyoid and Digastric (posterior belly) - Mylohyoid nerve (V3)
* Supplies Mylohyoid and Digastric (anterior belly) - C1 via XII (Hypoglossal nerve)
* Geniohyoid
What is the Nerve supply of the Infrahyoid Muscles?
- Supply by the Ansa cervicalis
* Except: Thyrohyoid (C1 via XII; hypoglossal nerve)
What is the Carotid Triangle?
- Boundaries:
- Omohyoid (Superior belly)
- SCM (anterior border)
- Digastric (posterior belly)
- Roof:
- Superficial and Investing fascia
- Cervical branch of VII (facial nerve)
What are the Contents of the Carotid Triangle?
- Contains:
- Deep cervical lymph nodes
- Hypoglossal nerve
- Ansa cervicalis
- Carotid sheath and its contents
- External carotid artery and branches except its terminal branches
- Internal and External laryngeal nerve (superior laryngeal nerve)
- Tonsilar branches of IX (Glossopharyngeal nerve)
- Pharyngeal branches of IX and X
What is the Submental Triangle?
- Boundaries:
- Digastric (anterior belly)
- Hyoid Bone
- Roof:
* Superficial and Investing Fascia - Floor:
* Mylohyoid muscles
What is the Submandibular Triangle?
- Boundaries:
* Digastric (anterior / posterior belly)
* Mandible (inferior border) - Roof:
* Superficial / investing fasciae - Floor:
* Mylohyoid muscles
What are the Contents of the Submental Triangle?
- Small veins unite to form Anterior Jugular veins
- Submental lymph nodes
What are the Contents of the Submandibular Triangle?
- Submandibular gland (superficial part)
- Superficial to gland
- Submandibular gland
- Lymph nodes
- Facial vein
- Deep to gland
* Facial artery
* Hypoglossal nerve
What are the Zones of the Neck Trauma?
Serve as guides to determine the severity of the trauma
- Zone 1:
- From: Clavicles and manubrium sterni
- To: Inferior border of cricoid cartilage
- Zone 2:
- From: Cricoid cartilage
- To: Angles of the mandible
- Zone 3:
* From Angles of the mandible and above
*Injury to Zone 1 and 3:
- Obstruct airway
- May cause severe bleeding
- Greater risk of morbidity and mortality
*Injury to Zone 2:
- Most common
- Bleeding is more easily controlled, which lowers morbidity and mortality
What are the Structures at Risk in ZONE 1?
- Cervical pleura and apex of lungs
- Thyroid and parathyroid glands
- Trachea (obstruct respiratory)
- Esophagus (Compromise breathing)
- Common carotid arteries
- Jugular veins
- Cervical part of vertebral column
What are the Stuctures at Risk in ZONE 2?
- Superior pole of thyroid gland
- Thyroid and cricoid cartilages
- Larynx
- Esophagus
- Carotid arteries
- Jugular veins
- Cervical part of the vertebral column
What are the Structures at Risk for Zone 3?
- Salivary Glands
- Oral and Nasal Cavities
- Oropharynx and Nasopharynx
