A&P: Anatomy of the Neck

Visceral compartment

Contains glands, larynx, pharynx, and trachea

Vascular compartments (2)

Contains common carotid artery, internal jugular vein, and vagus nerve

Vertebral compartment

Contains cervical vertebrae and postural muscles

In green

Anterior triangle

In green

Posterior triangle

Mandibula

Mylohyoideus muscle

Digastricus muscle

Hyoideum bone

What triangle does hot pink show?

Submental triangle

What triangle does green show?

Submandibular triangle

Carotid triangle

What triangle does yellow show?

Muscular triangle

Omohyoideus muscle

Sternocleidomastoideus muscle

What triangle does dark red show?

Occipital triangle

What triangle does teal show? (Lower blue)

Subclavian triangle

M. Trapezius

Clavicula

CI, CII, CIII (Ansa cervicalis)

Internal jugular vein

Internal and external carotid arteries

CN X, XI, and XII

The larynx

Cartilaginous skeleton

Lets air pass from throat → trachea

Contains vocal chords

Prevents food from entering trachea

Paried vs. unpaired cartilages

Paired: Bilateral pairs of cartilage that are not connected

Unapaired: Symmetrical pairs of cartilage connected

Epiglottis

Unpaired, elastic cartilage

Cricoid cartilage

Hyaline, unpaired cartilage

Thyroid cartilage

Hyaline, unpaired cartilage

Arytenoid cartilages

Paired, elastic cartilage

Role in vocal processes

Corniculate cartilages

Paired, elastic cartilage

Cuneiform cartilages

Paired, elastic cartilage

Thyroid ligament (extrinsic)

Cricothyroid ligament (Intrinsic)

Cricotracheal ligament (Extrinsic)

What tissue type is the structure of the larynx

Cartilage

Function of larynx ligaments

Connect areas of cartilage

Attach larynx to nearby structures

What do muscles do for the larynx

Move larynx while swallowing

Help with breathing and produce vocal sounds

Mylohyoid muscle

Elevator

Anterior digastric muscle

Elevator

Posterior digastric muscle

Elevator

Superior belly of the omohyoid

Depressor

Inferior belly of the omohyoid muscle

Depressor

Geniohyoid

Elevator

Stylohyoid

Elevator

Sternothyroid

Depressor

Sternohyoid

Depressor

Cricoid cartilage

Transverse and oblique arytenoid muscle

Voca ladductor

Posterior cricoarytenoid muscle

Vocal abductor

Lateral cricoarytenoid muscle

Vocal adductor

Arytenoid cartilage

Thyroarytenoid muscle

Origin: Inner surface of thyroid cartilage

Insertion: Anterolateral surface ofarytenoid cartilage

Vocalis muscle

Sits parallel to the vocal ligament

Crucial part in controlling tonal quality of voice

Vocal ligament

Thyroid cartilage

Thyroid gland

Butterfly shaped, two connected lobes

Anterior to the trachea

20-60 grams

Larger in women, increases size during pregnancy

Parathyroid gland

Four of them, two on each side

6mm in length, 3-4 mm in width

T3 and T3 hormones

Made in follicular epithelial cells of thyroid

Iodine is main building block (Need to eat some)

Stimulates body tissues to produce proteins and increase amount of O₂

Calcitonin

Made by c-cells of thyroid gland

What % of hormones made by the thyroid are T4 and T3

80% T3 and 20% T4

Function of the thyroid

Regulates body’s metabolism

Parathyroid hormone (pTH)

Regulates level of calcium in blood

Released in response to decreased calcium levels

Negative inhibition in thyroid hormone production

Hypothalamus → TRH → Anterior pituitary gland → TSH → Thyroid gland → T3 + T4

T3 + T4 → Hypothalamus + Anterior pituitary gland to stop making TRH and TSH

Right Vagus nerve

Provides main sympathetic and parasympathetic fibers to the larynx

No role in hormones, mainly influences vasculature (Indirectly effects hormones)

Superior laryngeal nerve

Right recurrent laryngeal neve

Left recurrent laryngeal nerve

Internal jugular vein

Inferior thyroid vein

Superior thyroid artery

External carotid artery → Superior thyroid vein

Subclavian artery → Inferior thyroid artery

Middle thyroid vein

Path of blood from the superior and middle thyroid veins

Sup + Mid thyroid veins → Internal jugular vein → Braciocephalic vein

Characteristics of sailvary glands

Exocrine glands

Vary widely in size

Classified based on nature of the saliva they secrete

Function of salivary glands

Protect and lubricate oral mucosa

Release amylase that starts digestion of carbohydrates

Parotid gland

Largest salivary gland

20% of saliva production

Associated with CN IX, C2 and C3

Submandibular gland

70% of saliva production

Associated with CN VII

Sublingual gland

Smallest salivary gland

5% production of saliva

CN VII (Facial nerve)

Stensen’s duct

Parotid duct

Wharton’s duct

Submandibular duct

Bartholin’s ducts

Sublingual duct

Minor salivary glands

600-1000 of ‘em

>1% of saliva production

Located in oral cavity and muscles of the tongue

Ruch in mucin, antibacterial proteins, and secretory immunogloblin

Continuous, slow glands