Anterior Triangle of the Neck Flashcards
What divides the neck into anterior and posterior triangles?
The sternocleidomastoid muscle
The anterior triangle of the neck develops from what pharyngeal arch?
First pharangeal arch
What are the boundaries of the anterior triangle of the neck?
Superior = lower border of the mandible
Inferior = jugular notch
Anterior = midline of the neck
Posterior = anterior margin of the SCM
What are the features of the anterior triangle?
- suprahyoid muscles
- Infrahyoid (strap) muscles
- Blood vessels and nerves
- Thyroid cartilage (laryngeal prominence)
What suprahypid muscles are found in the anterior triangle?
- Mylohyoid
- Diagastric
- Geniohyoid
- Stylohyoid
What vessels and nerves are found in the anterior triangle of the neck?
- Common carotid (bifurcates into internal and external carotid)
- Internal jugular vein
- Cranial nerevs VII (facial), IX (glossopharyngeal), X (
What lymph nodes are found medial to the mandible?
Submandibular lymph nodes
What do the submadibular lymph nodes drain?
Area of the mouth, nasal cavity, maxillary sinus and lower parts of the face
If you found a painful enlargement of the submandibular lymph nodes, what might this suggest?
Infection of the lower mouth, lower face, nasal cavity or maxillary sinus
If someone had a painless enlargement of lymph nodes, what might this suggest?
Malignant change
What lymph nodes are found under the chin?
Submental lymph nodes
What do submental lymph nodes drain?
Drain the most anterior part of the lower mouth (lower lip, skin and chin, tip of the tongue, front of the floor of the mouth and submandibular salivary gland)
The submandibular salivary gland is found where?
Between the angle of the mandible and the hyoid bone
What is the muscle that is found under the skin which extends from just above the mandible into the face and sweeps down just below the neck on either side called?
Platysma
What does the platysma do?
Maintains the tone of tissues in the necl
Is a muscle of facial expression
What is labelled C in the diagram?
Anterior belly of digastric muscle
What connects the anterior belly of the digastric mucle to the posterior belly?
Central tendon ( which is held on by fascia to the hyoid bone)
Deep to the anterior belly of the diagstric muscle, there is another muscle that comes from the mandible and runs on upper surface of diagatric. What is it?
Mylohyoid muscle
What are the attachments of the sternocleidomastoid muscle?
- Mastoid process
- Sternum (manubrium)
- Calvicle
What are the 2 heads of the sternocleidomastoid muscle called?
- Sternal head
- Clavicular head
The external jugular vein comes from around the angle of the mandible and makes its way down the neck. Why might you be concerned if this vein stands out when standing or sitting?
Can be a sign of cardiac failure or obstruction
What strap-muscles are found in the anterior triangle of the neck?
- sternohyoid
- omohyoid
- sternothryoid
- Thyrohyoid
What does the omohyoid strap muscle regulate?
Movement of hyoid bone
What is Adam’s apple also termed?
The laryngeal prominence or thyroid cartilage
What cartilage is found below the laryngeal prominence about halfway between the manubrium and hyoid bone?
Cricoid cartilage
Note: there is a membrane between the cricoid and thyroid cartilage
Where is the first ring of the trachea found?
Just a bit down from the cricoid cartilage, above the thyroid gland
Where does the thyroid gland sit with reference to the tracheal rings and the sternothyroid muscle?
Sits just below the first traheal ring and part of it is behind the sternothyroid muscles
Describe the different parts of the thyroid gland.
The middle part is termed the isthmus and it has lobes
The isthmus sits in front of the 2nd, 3rd and 4th rings of the trachea
Where is the common carotid artery found?
Tucked behind a lobe of the thyroid gland and makes its way up the neck
At what level does the common carotid branch and into what?
At the level of the of the upper border if the thyroid cartilage
Branches into internal and external carotid artery
The external carotid artery gives off a branch at the start of it. What is it and what does it supply?
The superior thyroid artery and supplies the thyroid gland
Where does the internal jugular vein lie with regards to the common carotid?
Just lateral to it
What lymph nodes are found close to the internal jugular vein?
Deep cervical lymph nodes
Note: disease of the neck sometimes spread to these lymph nodes
What is the nerve supply to the diagastric muscle? (both anterior and posterior)
Anterior belly = nerve to mylohyoid
Posterior belly = facial nerve
What is the nerve supply ot the stylohyoid?
Facial nerve (then runs to posterior belly of diagastric)
What is the nerve supply to the the mylhyoid muscle?
Mylohyoid nerve
What is the nerve supply to the geniohyoid?
Hypoglossal nerve
What is the nerve supply to the omohyoid, sternohyoid and sternothyroid?
Ansa cervicalis
What is the nerve supply to the thyrohyoid muscle?
Hypoglossal nerve
