Neck Anatomy Lecture Powerpoint Flashcards
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Regions of the pharynx
Nasopharynx ending at the soft palate
Oropharynx ending at the epiglottis
Laryngopharynx below that
Extrinsic muscles of the neck function
Position larynx in neck and manipulation during swallowing and valsalva
Intrinsic muscles of the neck function
Responsible for movement of the vocal folds within the larynx as well as subtle tension adjustments related to phonation
Epiglottis
Flap of tissue in throat at base of tongue projecting out of the thyroid cartilage over the larynx above the glottis that is moved into a closed position upon elevation of the hyoid bone during swallowing to cap over the larynx and prevent aspiration ofmaterial
Glottis
Opening between the vocal folds within the larynx
Thyroid cartilage
Most prominent cartilage forming the anterior wall of the superior portion of the larynx below the hyoid bone connected via the thyrohyoid membrane, forms the adams apple
Thyrohyoid membrane
Connection between the thyroid cartilage and hyoid bone
Larynx lining (same as nasal cavity)
Respiratory epithelium - pseudostratified ciliated columnar epithelium
True vocal folds
Bands of tissue that extend from the arytenoid cartilage to the thyroid cartilage posterior wall, the tighter they are stretched through the relaxation or stress of the arytenoid cartilage by the thyroarytenoid muscle the higher the pitch of sound
Thyroarytenoid muscle
Function: relax the arytenoid cartilage and therefore the true vocal folds resulting in lower pitch
Insertion: Thyroid cartilage to arytenoid cartilage of larynx
Innervation: Recurrent laryngeal branch of vagus nerve
False vocal folds
Sit above the true vocal folds and are associated with forceful closure such as valsalva and reflex laryngeal closure due to choking or noxious stimuli
The vocal folds form an arrow, always oriented…
…anteriorally
Recurrent laryngeal branch of vagus nerve pathway
From the vagus nerve’s descent, the left travels under the aortic arch and back upward to supply intrinsic muscles of the larynx, right travels under the right subclavian artery back upward to supply the same
Superior laryngeal branch of vagus nerve pathway
Branches off the vagus and travels deep to the internal carotid artery to then supply cricothyroid muscle and sensation to the vocal folds
If superior laryngeal nerve is lost, this complication could occur
Aspiration of a foreign body without coughing it back up because no sensation
Vagus nerve pathway
Provides sensory function at the external auditory canal and the hypopharynx as well as motor function of the pharynx before giving rise to the superior laryngeal branch and the recurrant laryngeal branches
Resonance of sound produced at the vocal folds is achieved by the….
…nose and pharynx
Trachealis muscle
Smooth muscle at the posterior border of the trachea conjoining the ends of the c shaped rings, adjusts airflow by expanding or contracting
Aspirated objects are far more likely to end up in the…
Right lung
At what level does the esophagus start
The lower border of the cricoid cartilage, the 6th cervical vertebra
At what level does the esophagus end
11th cervical vertibra, cardiac oriface of the stomach
3 constrictions in the esophageal course
1) cricopharyngeal sphincter which relaxes to let food down at the 6th cervical vertebrae
2) At the chrossing of the aortic arch and left main bronchus
3) The lower esophageal spincter, where it pierces the diaphragm
Swallowing is controlled by…
…medulla and lower pons in brainstem, motor impulses carried primarily via vagus nerve
5 phases of swallowing
1) buccal phase - begins in mouth and is voluntary contraction of tongue to force bolus into oropharynx
2) Uvula and larynx rise, tongue blocks off mouth, upper esophagus sphincter relaxes
3) Constrictor muscles of the pharynx contract forcing food into esophagus, upper esophageal sphincter contracts after entry
4) Food moves through esophagus to stomach by peristalsis
5) gastroesophagesal sphincter allows food to enter stomach
Stylohyoid muscle
Function: initiate swallowing by pulling the hyoid posteriorally and superiorally
Insertion: Hyoid bone to styloid process of temporal bone
Innervation: facial nerve
Digastric muscle
Function: depress mandible (open mouth) and elevate hyoid bone
Insertion: anterior inferior aspect of mandible to hyoid bone to mastoid process of temporal bone
Innervation: Anterior trigeminal nerve manidbular branch, posterior facial nerve
Mylohyoid muscle
Function:Elevate hyoid bone and form floor of mouth
Insertion: Mylohyoid line of mandible to hyoid bone
Innervation: trigeminal nerve
Geniohyoid muscle
Funciton: depress mandible and elevate hyoid bone
Insertion: medial surface of mandible to hyoid bone
Innervation: hypoglossal nerve
Suprahyoid muscle group
- stylohyoid
- digastric
- mylohyoid
- geniohyoid
Infrahyoid muscle group
- omahyoid
- sternohyoid
- sternothryoid
- thyrohyoid
Omohyoid muscle
Function:depress hhyoid bone and larynx
Insertion: scapula and clavicle to hyoid bone
Innervation: C1-3
Sternohyoid muscle
Function: depress hyoid bone and larynx
Insertion: sternum and sternoclavicular joint to hyoid bone
Innervation: C1-3
Sternothyroid muscle
Function:depress thyroid cartilage
Insertion: Manubrium of sternum to thyroid cartilage
Innervation:c1-3
Thyrohyoid muscle
Function: depress hyoid
Insertion: thyroid cartilage to hyoid bone
Innervation: C1
Pharyngeal constrictors
Constrict to propel food bolus into esophagus, can be manually stimulated by physical manpulaiton
Sternoclydomastoid muscle
Function: flex neck, bend head to shoulder, rotate neck
Insertion: clavicle and manubrium to mastoid process
Innervation: accessory nerve
Isthmus
Conjoins 2 lobes of the thyroid
Thyroid gland location
Anterior neck between 2nd and 3rd tracheal ring
Thyroid arterial supply
Superior and inferior thyroid artery (derived from the external carotid and thyrocervical trunk of subclavian artery, respectively)
Thyroid venous drainage
Superior, middle, and inferior thyroid veins
Thyroid nerve supply
Sympathetic from superior, middle, and inferior cervical gangila, parasympathetic from vagus nerve
T4 is converted to ____ at the target tissue
T3
Calcitonin function
Decrease blood Ca2+ levels
Hypothalamic pituitary thyroid axis
- TRH from hypothalamus stimulates TSH from anteiror pit
- TSH stimulates thyroglobulin conversion via iodine presence to T3/T4 in the thyroid
- Increased thyroid hormone causes decreased TRH and TSH
Hyperthyroidism
High levels of thyroid hormone in the blood, low TSH
Hypothyroidism
Low levels of thyroid hormone in blood, high TSH
Parathyroid gland location
Posterior aspect of thyroid gland in 2 pairs
Chief cells
Parathyroid gland cells that release PTH
PTH function
Increase blood Ca2+ levels by enhancing reabsorption in the kidney, stimulating calcitrol secretion, mobilizes Ca2+ by inhibiting osteoblasts and increasing number of osteoclasts
Vagus nerve supplies…
Motor/sensory function of the lower pharynx, sensory function of the external auditory canal
Sensory, motor, or both?
Some say money matters, some say brains. My brother says big boobs matter most.
Borders of the anterior triangle of the neck
Mandible, midline of anterior neck, sternocleidomastaoid
Borders of the posterior triangle of the neck
Sternocleidomastoid, clavicle, trapezius
