iscera and deep structures of the neck including vasculature Flashcards
What are the 3 parts the pharynx is divided into?
Nasopharynx – Posterior to nose and superior to the soft palate.
Oropharynx – Posterior to mouth
Laryngopharynx – Posterior to larynx
Where is the pharynx?
Extends from base of skull to inferior border of the cricoid cartilage anteriorly and the inferior border of C6 vertebra posteriorly
What is the pharynx?
Part of the digestive system
Widest (5cm) opposite the hyoid bone
Narrowest ( 1.5cm) at its inferior end, where it is continuous with the oesophagus
The flat posterior wall of pharynx lies against the prevertebral layer of deep cervical fascia.
What is the nasopharynx?
Respiratory function
Lies posterior to the nose and superior to the soft palate
Nose opens to nasopharynx through two chaonae
Lymphoid tissue – pharyngeal tonsil - adenoids
What is the oropharynx?
Digestive function
Lies inferior to soft palate and
superior to the base of the tongue and the superior border of the epiglottis
Palatine tonsils each side
What is the Laryngopharynx?
Lies posterior to the larynx, extending from the superior border of the epiglottis to the inferior border of the cricoid cartilage, where it narrows and becomes continuous with the oesophagus
Communicates with the larynx through the inlet of the larynx on its anterior wall
Posteriorly, it is related to the bodies of C4-C6 vertebrae
What are the pharyngeal muscles?
Longitudinal voluntary deep layer of muscles:
Palatopharyngeous - CN X pharyngeal branch and pharyngeal plexus
Stylopharyngeous - CN IX
Salpingopharyngeous - CN X pharyngeal branch and pharyngeal plexus
These muscles elevate the larynx and shorten the pharynx during swallowing and speaking.
Innervation:
Innervation: Pharangeal branch of vagus nerve CN X
CN X – All muscles of soft palate and pharynx, except stylopharyngeus (CN IX).
What is the oesophagus?
Digestive function
Muscular tube
Striated (voluntary muscle) in its upper third,
Smooth involuntary muscle in its lower third,
Mixture of striated and smooth muscle in-between
What are the course and relations for the oesophagus?
Course and Relations
Continuous with the laryngopharynx, posterior to cricoid cartilage
Inclines slightly towards the left
Through the superior mediastinum
Through the posterior mediastinum
Pierces the diaphragm
Enters stomach at the cardiac orifice
Anterior: Trachea
Posterior: Cervical vertebral column
Right: Cervical pleura in root of neck
Left: Thoracic duct lies between the pleura and the oesophagus
Left and Right: Recurrent laryngeal nerve lies in the tracheoesophageal groove
Lobes of the thyroid gland
Carotid sheaths and their contents
What is the larynx?
Guards the air passages, especially during swallowing, and maintains a patent airway
Lies in the anterior neck (level of the bodies of C3-C6)
Connects the laryngopharynx with the trachea
What are the intrinsic muscles of the larynx?
- Transverse and Oblique Arytenoid Muscles
- Posterior Cricoarytenoid Muscle
- Lateral Cricoarytenoid Muscle
- Cricothyroid Muscle
- Vocal Ligament
- Vocalis Muscle
- Thyroarytenoid Muscle
What is the innervation of the larynx?
Innervation – Vagus Nerve X - Recurrent laryngeal nerve with exception of Cricothyroid – Superior laryngeal nerve.
What is the trachea?
Fibrocartilaginous tube supported by incomplete cartilaginous tracheal rings
These rings, which keep the trachea patent, are deficient posteriorly where the trachea is adjacent to the oesophagus
What is the course and relations of the trachea?
Course and Relations
Extends from the inferior end of the larynx at the level of the 6th thoracic vertebra to the level of the sternal angle or the T4/T5 intervertebral disc, where it divides into the right and left main bronchi
Anterior: Sternothyroid and sternohyoid muscles, thyroid isthmus (2nd& 3rd rings)
Posterior: Oesophagus
Right: Brachiocephalic trunk in the root of the neck
Lateral: Common carotid arteries, Thyroid lobes
What is the thyroid gland?
Two lobes (left and right), united by an isthmus over the trachea usually anterior to the 2nd and 3rd tracheal rings
Surrounded by a thin fibrous capsule, which sends septa deeply into the gland
External to the capsule is a loose sheath formed by the visceral layer of the pretracheal deep cervical fascia
Dense connective tissue attaches the capsule of the thyroid gland to the cricoid cartilage and the superior tracheal rings
Extends from the level of C5 to T1 vertebrae
Deep to the sternothyroid and sternohyoid muscles
Anterolateral to the larynx and trachea
Hormonally regulated by the pituitary gland
What is the nerve supply to the thyroid gland via?
Nerve supply is via superior, middle and inferior cervical sympathetic ganglia
What are the parathyroid glands?
Most people have four parathyroid glands
Small ovoid glands
Lie external to the fibrous thyroid capsule on the medial half of the posterior surface of each lobe of the thyroid gland
Nerve supply is from cervical sympathetic ganglia