Head and Neck - Lecture 3 Flashcards
What are the boundaries of the neck?
Superiorly - external occipital protuberance, tip of mastoid process, inferior border of mandible
inferiorly - suprasternal notch, clavicle, acromion,, spinous process of C7 vertebra
what nerve innervates the platys?
facial nerve
3 deep cervical fascia
- investing
- pretracheal
- prevertebral
What muscle divides the neck into anterior and posterior compartments?
sternocleidomastoid muscle
Name the supra hyoid muscles
- digastric (ant and post belly)
- stylohyoid
- geniohyoid
- mylohyoid
- all depress the mandible and generally elevate the hyoid bone during speaking and swallowing
Also,
mylo –> brings hyoid forward
stylohyoid –> retracts hyoid
Name the infra hyoid muscles
- sternohyoid
- sternothyroid
- omohyoid
- thyrohyoid
Nerves of Erb’s point
- Lesser occipital nerve
- Greater auricular nerve
- Transverse cervical nerve
- Supraclavicular nerves
What are 3 important structures that reside in the lateral triangle of the neck?
- Brachial Plexus
- Vagus Nerve
- Sympathetic trunk
Which two roots merge to form the median nerve?
Lateral cord and the medial cord
The ulner nerve is a terminal branch of what cord?
Medial cord of the brachial plexus
The radial nerve is a terminal branch of what cord?
Posterior cord of the brachial plexus
What muscle group function is the radial nerve responsible for?
Innervates extender muscles
What muscle group function is the ulner and median nerve responsible for?
innervation of flexors
What nerves make up the brachial plexus?
C5-T1
Describe the Brachial Plexus starting from the roots
Roots (C5-T1) –> trunks (Superior C5&C6, middle C7, inferior C8) –> Divisions (anterior and posterior) –> cords (lateral, medial, posterior)
In the brachial plexus, the anterior divisions of the trunks (superior, middle and inferior) supply what compartments of the upper limb?
Anterior (flexor) compartments of the upper limb
In the brachial plexus, the posterior divisions of the trunks (superior, middle and inferior) supply what compartments of the upper limb?
posterior (extensor) compartments of the upper limb
What happens when the ulnar nerve is damaged?
weakness in flexing the wrist, little and ring finger with hyperextended metacaarpophalangeal joints
What happens when the median nerve is damaged?
weakness in flexing the wrist, weakened flexion of the thumb, index, and middle finger
What happens when the radial nerve is damaged?
weakened ability to extend elbow, wrist and fingers
Innervation areas of the vagus nerve
- pharynx
- Larynx
- lung
- heart
- spleen
- stomach
- liver
- kidney
- colon
- small intestine
The cervical sympathetic trunk
One of three major nerves found in the root of the neck
- located on top of the anterior scalene muscle
- provides sympathetic innervation for head, neck and heart
The stellate ganglion
- a.k.a cervicothoracic ganglion
- sympathetic
- located at the level of C7
- provides sympathetic efferents to the upper extremities, head, neck and heart
What sections are is the pharynx divided into?
- nasopharynx
- oropharynx
- laryngopharynx
All the muscles of the larynx close the gap except for one. Which muscle is this?
posterior crico-arytenoid
What produces sound in our larynx?
movement of the cartilages. The vibrations create sound
What are the main arterial branches of the thyrocervical trunk?
- inferior thyroid artery
- Transverse cervical artery
- suprascapular artery
What is the action of the stylohyoid?
Elevation and retraction of the hyoid bone; assists in lowering the mandible (opening the mouth)
What is the action of the mylohyoid?
Elevates and draws the hyoid bone forward; elevates the tongue, depresses the mandible during swallowing and speaking
What is the action of the digastric ?
depresses mandible; raises hyoid bone and steadies it during swallowing and speaking
What is the action of the geniohyoid?
depresses the mandible and elevates the hyoid bone
What is the action of the sternohyoid?
depresses the HYOID bone after swallowing
What is the action of the omohyoid?
depresses, retracts and fixes (stabilizes) hyoid bone during phonation and swallowing
What is the action of the sternothyroid?
Depresses LARYNX after swallowing
What is the action of the thyrohyoid?
depresses hyoid bone and elevates larynx when the hyoid bone is fixed
