Anatomy of the Neck Flashcards
What are in the Neck?
- Muscles
- Spinal cord
- Vertebra
- Common carotid artery
- Internal jugular vein
- Esophagus
- Thyroid gland
- Trachea
What are the Fascia of the Neck?
Deep cervical fascia
* Prevertebral layer
* Carotid sheath
* Pretracheal layer
* Investing layer
Superficial cervical fascia
What are the Bones of the Neck?
- Mastoid process
- Certival vertebrae (C1-C7)
- Clavicle
- Manubrium
- Trachea
- Cricoid cartilage
- Thyroid cartilage
- Hyoid
- Mandible
What are the parts of the hyoid?
- Body of hyoid
- Lesser horn (smaller)
- Greater horn (larger)
What is apart of the Cervical Vertebrae?
- Bifurcated spinous process
- Vertebral foramen - houses spinal cord
- Body
- Transverse foramen
- Atlas
- Dens
- Axis
What are the Atlanto-occipital & Atlanto-axial Joints?
Atlanto-occipital joint
* Nod head
Atlanto-axial joint
* Shake head
(diff. bones on slide 6)
What is the Prevertebral Layer of Deep Cervical Fascia?
- Encloses vertebrae and deep neck/back muscles
3 muscles:
- Anterior: longus colli and longus capitis
- Lateral: ANTERIOR, MIDDLE and POSTERIOR SCALENE MUSCLES
- Posterior: deep cervical muscles
What are the Scalene Muscles?
- Transverse processes of cervical vertebrae to 1st and 2nd ribs
Innervation:
* Anterior rami of
C4-C8
Action:
* Flexion of the neck
* Elevates ribs in forced inspiration
(anterior, middle & posterior scalene)
What is the Carotid Sheath of the Deep Cervical Fascia?
- Vagus Nerve
- Internal jugular vein
- Common carotid artery
What are the Carotid Arteries?
- External carotid artery
- Internal carotid artery
- Common carotid artery
Carotid sinus and carotid body are innervated by carotid sinus nerve (CN __)
IX (glossopharyngeal)
* Detect blood pressure and oxygen level
What is Internal Jugular Vein Puncture?
in carotid sheath
central line - where a lot of medication can go into & can check BP etc.
What is the Vagus Nerve?
Supplies parasympathetic innervation to most organs in the thorax and abdomen
What does the Vagus Nerve do IN THE NECK?
- General sensory from
pharynx and larynx - Somatic motor to pharynx and intrinsic laryngeal muscles
What is the Pretracheal Layer of Deep Cervical Fascia?
Includes:
- Infrahyoid muscles
- Respiratory organs
- Larynx
- Trachea
- Alimentary organs
- Pharynx
- Esophagus
- Endocrine organs
- Thyroid gland
- Parathyroid glands
What are the main parts of the Pharynx?
- Uvula
- Epiglottis
- Pharyngoesphageal junction
What is the Larynx?
- Connects the inferior pharynx to the trachea
- C3-6 vertebral levels
Functions:
* Protects airway
* Phonation (where air voice originates from)
* Directs food and air into esophagus and trachea, respectively
What is the Laryngeal Cartilages (paired & unpaired)?
Paired:
- Corniculate cartilage
- Arytenoid cartilage (hold onto vocal cords)
- Vocal cord
Unpaired:
- Epiglottis
- Thyrohyoid membrane
- Thyroid cartilage (means shield)
- Cricothyroid membrane (used if need to get air)
- Cricoid cartilage
What are the Laryngeal Folds?
VESTIBULAR FOLD (FALSE vocal cord)
* Does not contribute to sound production
* Protection of vocal fold
VOCAL FOLD (TRUE vocal cord)
* Contains vocal ligament and vocalis muscle
* Intrinsic laryngeal muscles change position and tension of vocal folds to produce sounds (phonation)
What is Phonation?
Abduction of vocal folds
Adduction of vocal folds
(intrinsic laryngeal: move vocal cords to make diff. sounds)
Describe the Innervation of the Larynx
Superior laryngeal nerve
* Arises from vagus nerve
* Motor to cricothyroid muscle
* Sensory from mucosa above vocal fold
Recurrent laryngeal nerve (disappeared in thorax & came back out)
* A branch of vagus nerve
* Motor to the other intrinsic muscles
* Sensory from mucosa below vocal fold
What is the Thyroid Gland?
- Largest endocrine gland
- Posterior to infrahyoid
muscles at C5-T1 levels
What are the functions of the Thyroid Gland?
- Regulates metabolic rate via thyroid hormones (T3 & T4)
- Regulates blood calcium via calcitonin
What is the Thyroid Vasculature?
- External carotid a.
- Superior thyroid a. (branch of external carotid a.)
- Common carotid a.
- Inferior thyroid a. (branch of thyrocervical trunk)
- Superior thyroid v. (drains into internal jugular v.)
- Internal Jugular v. (drain thyroid gland & others)
- Middle thyroid v. (drains into internal jugular v.)
- Inferior thyroid v. (drains into brachiocephalic v.)
- Brachiocephalic v.
What is a goiter caused by?
iodine deficiency
What are the Parathyroid Glands?
- On posterior aspect of thyroid gland
- Usually 4 glands
- Regulate calcium and phosphate via parathyroid hormone
What is the Retropharyngeal Space?
- Potential space (b/c most of the time it doesn’t exist) consists of loose connective tissue
- Between the prevertebral layer and the pretracheal layer
- Closed laterally by carotid sheath
- Permits movement of structures relative to each other
Why is the Retropharyngeal Space called the “Danger space”?
- Major pathway for infection to spread from neck to thorax
- Avascular therefore poor at healing
What are the Hyoid Muscles?
- Muscles attached to the hyoid bone
- SUPRAHYOID muscles: superior to hyoid
- INFRAHYOID muscles: inferior to hyoid
What are the Suprahyoid Muscles?
- Elevate hyoid bone during speech and swallowing
- Innervated by V3, VII and C1
(Stylohyoid, Digastric (posterior belly), Digastric (anterior belly), Mylohyoid, Geniohyoid)
What are the Infrahyoid Muscles?
- Depress hyoid bone
- Thyrohyoid elevates
larynx - Sternothyroid depresses larynx
- Innervated by ansa cervicalis (C1-C3)
(Omohyoid, Sternohyoid, Thyrohyoid, Sternothyroid)
What is the Investing Layer of Deep Cervical Fascia?
- Surrounds the entire neck
- Invests SCM and trapezius muscles
(supplied by CN XI - accessory nerve)
What is the Sternocleidomastoid (SCM) Muscle?
- Divides each side of the neck into anterior and lateral cervical regions
What is the Sternocleidomastoid (SCM) Muscle SUPERIOR attachment?
mastoid process of temporal bone
What is the Sternocleidomastoid (SCM) Muscle INTERIOR attachment?
- Sternal head: manubrium of sternum
- Clavicular head: medial third of clavicle
What is the Innervation of the Sternocleidomastoid (SCM) Muscle?
- Spinal accessory nerve (CNXI)
What are the actions of the Sternocleidomastoid (SCM) Muscle?
- Lateral flexion with rotation
- Extension at atlanto-occipital joint
- Flexion of cervical vertebrae
What is the Superficial Cervical Fascia & what does it contain?
- Subcutaneous tissue deep to the skin
Contains:
* Fat
* Superficial veins
* Cutaneous nerves
* PLATYSMA muscle (THIN & supplied by CN VII (facial nerve) therefore muscle in charge of facial expression!
What is the Platysma Muscle (within the Superficial Cervical Fascia)?
- Very thin muscle of facial expression
- Innervated by cervical branch of CN_VII_ (FACIAL NERVE)
- Action: tenses skin on the neck, depresses skin on chin
What are the Cervical Regions?
- Trapezius
- Posterior Cervical Triangle
- Sternocleidomastoid (SCM)
- Anterior Cervical Triangle
What is apart of the Anterior Cervical Triangle?
Hyoid muscles
* Suprahyoid muscles
– Floor of the mouth, base for tongue, elevate hyoid and larynx
* Infrahyoid muscles
– Anchor hyoid to sternum and clavicle, depress hyoid and larynx
Nerves
* Vagus nerve (CN X)
* Hypoglossal nerve (CN XII)
Vein
* Internal jugular vein
Arteries
* Common carotid artery
– Internal carotid artery
– External carotid artery
— Superior thyroid a.
— Facial a.
What is apart of the Posterior Cervical Triangle?
Muscles
* Anterior, middle, and posterior scalenes
Nerves
* Spinal accessory nerve(CNXI)
* Phrenicnerve (C3-5): diaphragm
* Roots of brachial plexus (C5-8,T1) between anterior and middle
scalene
Vein
* External jugular vein
Arteries
* Subclavianartery
– Vertebral artery
– Thyrocervical trunk
— Inferior thyroid artery
What are the Lymphatics in the Neck?
Superficial cervical lymph nodes
- travels with superficial vein
Deep cervical lymph nodes
- travel with deep vein
