How did the small pimple on my neck come about?

1. Neck muscles The neck mainly has the following muscles: sternocleidomastoid muscle is located on the outside of the neck, one on each side. It has two starting points, starting from the surface of the manubrium of the sternum and the inner side of the clavicle, slanting upward, and ending at the surface of the mastoid process and the outer side of the supraoccipital nuchal line. It is mainly innervated by the accessory nerve. The sternocleidomastoid muscle is well developed and is an important muscular landmark during neck surgery. The carotid artery, internal jugular vein, and vagus nerve are located deep to it. The infrahyoid muscles include the sternohyoid muscle, thyrohyoid mechanism, thyrosternal mechanism, and omohyoid mechanism, with a total of 4 pairs on both sides. The upper end of the sternohyoid muscle is located at the lower edge of the hyoid bone, and the lower end is attached to the manubrium of the sternum. It is the shallowest of the infrahyoid muscles and the muscle is flat and band-shaped. The infrahyoid muscles are located in front of the larynx, trachea, and thyroid gland, and are closely related to operations such as laryngeal, thyroid, and tracheotomy. The neck also has muscles such as the digastric muscle and trapezius muscle. With the sternocleidomastoid muscle as the boundary, the neck is divided into two triangular areas, the anterior and posterior cervical areas; the former is further divided into the submental triangle, submandibular triangle, carotid triangle and muscular triangle, while the latter includes the occipital triangle and supraclavicular triangle.

2. Blood vessels and nerves in the neck

(1) Arteries: The common carotid artery is located deep in the cytocleidomastoid muscle and is divided into two branches, the external carotid artery and the internal carotid artery, at the level of the greater angle of the hyoid bone. The external carotid artery has branches such as the superior thyroid artery, lingual artery, facial artery, maxillary artery and superficial temporal artery, and is an important source of blood supply for the head and neck structures. The internal carotid artery enters the skull through the foramen rupture and has no branches in the neck. During neck surgery, the external carotid artery and the internal carotid artery must be distinguished.

(2) Vein: The external jugular vein is located on the surface of the sternocleidomastoid muscle. The internal jugular vein is a continuation of the intracranial sigmoid sinus, located deep to the omohyoid bone, and is the main route for venous return to the head and face.