Neck II Lecture Flashcards
What is the posterior triangle?
Trianngel formed between the sternocleidomastoid muscle, clavical, and trapezius muscle.
What are the two triangles withing the posterior triangle?
- Occipital triangle (sup)
- Omnoclvicular triangle
What are the two posterior triangles divided by?
They are divided by the omohyloid muslces (inferior bell)
What is the occipital triangle surrounded by?
- Sternocleidomastoid (medially)
- Trapezius (laterally)
- Inferior bellly of the omhyoid.
What is the subclavian omnoclavicular triangle surrounded by?
- Sternocleidomastoid (medially)
- Clavicle inferiorly
- Inferior belly of omohyoid muscle
What are the nerves in the posterior triangle ?
- Acessory N. (CN11)
- Cutaneuous branches of Cervical Plexus
- Brachial Plexus.
Explain the path of the acessory nerve (CN 11) in the posterior triangle.
What does it innervate?
- Passes out from the skull
- Goes uner the sternocleidomastoid m. 2/3 way the
- Heads toward the **trapezius **
What are the 4 cutaneous branches of the cervical plexus?
Sensory!
- Lesser occispital n
- Great Auricular n
- Transverse Cervical n
- Supraclavicular n
Superficial Sensory!
Alll come out of one point an then spread out
What Cutaneous Branch
nerves goes back up to the head
lesser occipital n.
What Cutaneous Branch
Nerve goes behind the ear
Great Auricular n.
What Cutaneous Branch
Nerve comes across the neck and toward the anterior part of neck
Transverse Cervical n.
What Cutaneous Branch
Comes out with many branches above the clavical and back shoulder.
Supraclavicular N.
What cervical nerves contribute ot the cervical plexus?
C1,C2,C3,C4
** Explain which cervical nerve each come off of:**
Lesser occipital n.
Great auricular n.
Transverse cervical n.
Supraclavicular n.
- Lesser occipital n. = C2
- Great auricular n.= C2/C3
- Transverse cervical n.= C2/C3
- Supraclavicular n.= C3/C4
What prominant nerve comes off the cervical plexus?
Phrenic Nerves
C3,C4, C5
Loops that comes off C1, C2 contributes, and C3.
In the cervical Plexus.
Ansa Cervicalis
Superior and Inferor root
Post. Triangle
Explan the sternocleidomastoid muscles.
Innervation?
Function?
- Has a clavicular head and a sternal head
- Innervated by Acessory nerve CN 11 & anterior rami of C2-C3
Function:
Unilaterally: tilt head to shoulder (same side) turn face (opposite)
Bilaterally: draw head forward
Post. Triangle
Explain the Omohyoid muscles.
Innervation?
Function?
- Laterally on superior boarder of the scapula
- Superiorly attached on the inferior boarder of the hyoid bone
- Has a mid way tendenous structure forming inferior & superior belly
Innervated: Ansa Cervicalis (C1-C3)
Function:
Contract-> depress hyoid bone
Post. Triangle
Explain the Anterior Scalene muscles.
Innervation?
Function?
- Attaches to the transverse process of vertebrae C3-6
- Rib 1 upper surface
Innervated: Anterior rami nerves C4-C7
Function:
Contract-> Elevate rib 1
Floor of triangle.(more posterior)
Post. Triangle
Explain the Middle Scalene muscles.
Innervation?
Function?
- Attaches to the transverse process of vertebrae C2-C7
- Rib 1 upper surface
Innervated: Anterior rami nerves C3-C7
Function:
Contract-> Elevate rib 1
Post. Triangle
Explain the Posterior Scalene muscles.
Innervation?
Function?
- Attaches to the transverse process of vertebrae C4-C6
- Rib 2 upper surface
Innervated: Anterior rami nerves C5-C7
Function:
Contract-> Elevate rib 2
Explain the relationship of the subclavian artery and scalene muscles
The subclavian artery passes between the anterior and middle scalene muscles on rib 1.
The anterior and middle scalene muscles can therefore act as a consrictor point of the subclavian artery if they have too much tension. Pinch it off!
What are the 4 triangular divisions of the Anterior triangle?
- Submental : below chin
- Submandibular : Jaw
- Muscular : ant. portion of neck
- Carotid: posterior lateral
Ant. Triangle
Explpaint the boundry, floor, and contens of the submental triangle
Boundaries:
Anterior belly of digastric
Hyoid bone (inferiory)
Floor:
Mylohyoid muscle
Contents:
Submental nodes
Beginning of anterior jugular vein
Submental Triangle
AExplain the Anterior belly Digastric muscles.
Innervation?
Function?
- Attaches to the mandible
- Inferiorly attaches to the hyoid bone via a tendon
Innervated: Mylohyoid n. (from inferior alveolar branch of mandibular nerve V3 from CN5.
Function:
* Fix hyoid bone, open mandible
* Raise hyoid bone, close mandible
Explain the Mylohyoid muscles.
Innervation?
Function?
Behind Digastric
* Attaches to the mandible at the mylohyoid line
* Attaches to at the hyoid bone and muscle fibers opposite (posterior) to the hyoid.
Innervated: Mylohyoid n. (from inferior alveolar branch of mandibular nerve V3 from CN5 trigeminal nerve)
Function:
* Support and elevation of the oral cavity
*Contact, elevate hyoid and elevate floor of oral cavity
Explain the Geniohyoid muscles.
Innervation?
Function?
not part of submental triangle
Behind Mylohyoid m.
* Attaches to the inferior mental spine of the mandible
* Attaches to at the hyoid bone (ant surface) .
Innervated: Branch from anterior ramus of C1 (Carried along Hypoglossal n. CN12)
Function:
* Fix mandible, hyoid bone forwards
* Fix hyoid, pulls mandible downward and inwards
Explain the boundary, floor, and contents of the Submandibular triangle
Boundaries:
Mandible
Posterior & anterior digastric m
Floor:
Mylohyoid m.
Hyoglossus m.
Superior Constrictors of the pharynx
Contents:
Submandibular salivary glands
Submandibular nodes
Facial artery and vein
Hypoglossus and Stylohyoid mm.
Carotid sheet (Internal carotid, Internal jugular, Vagus n.)
Explain the Digastric post. belly muscles.
Innervation?
Function?
- Attaches to the mastoid process (next and below ext. auditory meatus)
- Tendon attachment to hyoid (loop)
Innervated: Facial N (CN7)
Function:
* Pull hyoid upward and back
Explain the Stylohyoid muscles.
Innervation?
Function?
- Attaches to the styloid process
- Attached to hyoid bone laterally
Innervated: Facial N (CN7)
Function:
* Pulls hyoid bone upward in a posterosuperior direction
Explain the boundary, floor, and contents of the Muscular Triangle
Boundaries:
Omohyoid
Sternocleidomastoid
midline of neck
Floor:
Sternohyoid
Sternothyroid
Thyrohyoid mm.
Contents:
Thyroid gland
Larynx
Trachea
Esophagus
Explain the Sternohyoid muscles.
Innervation?
Function?
- Attaches to the manubrium + sternoclavicular joint
- Attaches to hyoid bone (inferior border)
Innervated: Ansa Cervicalis; Anterior Rami C1-C3
Function:
* Depresses hyoid bone after swallowing when it contracts.
Explain the Sternothyroid muscles.
Innervation?
Function?
- Attaches to the manubrium (post surface )
- Attached to thyroid cartilage (superiorly)
Innervated: Ansa Cerivcals (ant. Rami C1-C3)
Function:
* Draw Larynx (thyroid cartilage) downward
What the two muscles that sit directly beneath the sternohyoid muscle and omohyloid in the neck?
- Sternothyroid
- Thyrohyoid