Related Experiment Video
Updated: Jul 18, 2026
19:53
Single-stage Dynamic Reanimation of the Smile in Irreversible Facial Paralysis by Free Functional Muscle Transfer
Published on: March 1, 2015
Anatomical study of accessory nerve innervation relating to functional neck dissection
Kazunari Shiozaki1, Shinichi Abe, Hiroko Agematsu
1Department of Anatomy, Tokyo Dental College, Chiba, Japan. shiozaki@tdc.ac.jp
Summary
Understanding accessory nerve branching patterns in the neck is crucial for preventing dysfunction after neck dissection. Attention to nerve branches and the superficial cervical vein as a landmark can improve surgical outcomes.
Area of Science:
- Anatomy
- Surgical Anatomy
- Neuroanatomy
Background:
- Functional neck dissection carries a risk of postoperative dysfunction.
- Accessory nerve (CN XI) injury can lead to sternocleidomastoid and trapezius muscle deficits.
- Detailed anatomical knowledge is essential for minimizing surgical complications.
Purpose of the Study:
- To investigate the anatomical variations of accessory nerve innervation in the neck.
- To correlate accessory nerve branching patterns with the sternocleidomastoid and trapezius muscles.
- To identify potential landmarks for preserving nerve function during neck dissection.
Main Methods:
- Macroscopic observation of 35 human cadavers.
- Detailed examination of the accessory nerve in the posterior triangle of the neck.
- Identification of accessory nerve branching patterns and muscle innervation.
Main Results:
- Three distinct types of accessory nerve innervation were observed in the sternocleidomastoid muscle (Types A, B, and C).
- Five types of accessory nerve innervation were identified in the trapezius muscle, with 0 to 4 branches.
- The superficial cervical vein was noted near the accessory nerve's innervation area on the trapezius muscle.
Conclusions:
- Awareness of accessory nerve main trunk and branch variations is key to preventing postoperative dysfunction.
- The superficial cervical vein can serve as a valuable surgical landmark for accessory nerve identification.
- Optimizing surgical technique based on detailed anatomical understanding can improve functional outcomes after neck dissection.
Related Concept Videos
01:22Cranial Nerves: Types Part II
Cranial nerves are responsible for transmitting motor and sensory information between the brain and various parts of the body. There are twelve pairs of cranial nerves. While the first six innervate the head and neck, the latter six nerves innervate the head and neck, as well as organs and tissues in the thoracic and abdominal cavities. They facilitate communication, expression, and autonomic control within the human body.
Facial Nerve (Cranial Nerve VII)
Cranial nerve VII, or the facial nerve,...
Facial Nerve (Cranial Nerve VII)
Cranial nerve VII, or the facial nerve,...
01:19Cranial Nerves: Overview and Anatomy
The cranial nerves are an important part of the complex network of nerves in the human body. These nerves emerge directly from the brain and are responsible for transmitting essential information between the brain and various parts of the head and neck. There are 12 pairs of cranial nerves, systematically numbered using Roman numerals from I to XII, beginning from the anterior and moving to the posterior of the brain. Each cranial nerve is uniquely identified by names that reflect its function...
01:22Spinal Nerves: Plexus I
Nerve plexuses are networks of interlacing nerves that serve as communication hubs to distribute and organize nerve action across various body regions. The nerve plexuses are organized into the cervical plexus located in the neck region, brachial plexus in the shoulder area, lumbar plexus found in the lower back, sacral plexus situated in the pelvis, and coccygeal plexus located in the coccygeal region.
The Cervical Plexus
The cervical plexus, formed by the anterior rami of the first four...
The Cervical Plexus
The cervical plexus, formed by the anterior rami of the first four...
01:19Muscles that Move the Head
The muscles that move the head are a dynamic and complex group of structures that work together to facilitate a wide range of head movements, including rotation, flexion, extension, and lateral bending.
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
01:26Muscles of the Anterior Neck
The anterior neck muscles are the group of muscles covering the front part of the neck. These muscles are classified into three subgroups. The first one is the superficial muscles, the most visible muscles in the front of the neck. It includes the platysma and sternocleidomastoid. The second group is the suprahyoid muscles, located above the hyoid bone. This group comprises the digastric, mylohyoid, geniohyoid, and stylohyoid. Lastly, the infrahyoid muscles are found below the hyoid bone and...
01:26Arteries of the Head and Neck
The human body's intricate network of arteries ensures that every organ system receives the necessary oxygen and nutrients for optimal function. The arterial network in the head and neck region is particularly complex, providing vital blood flow to the brain, eyes, and other critical structures. Prominent arteries in this region include the internal carotid arteries and the vertebral arteries.
The internal carotid arteries supply blood to the anterior portion of the cerebrum. They enter the...
The internal carotid arteries supply blood to the anterior portion of the cerebrum. They enter the...