Head and Neck
The head and neck are made up of bones, muscles, joints, ligaments, and nerves. The bones provide support and protection for the brain and other organs. The muscles allow you to move your head and neck. The joints hold the bones together and allow them to move. The ligaments connect the bones to each other and provide stability. Finally, the nerves carry messages from the brain to the rest of the body.
The head and neck are divided into three regions: the skull, the face, and the neck. The skull comprises 22 bones that form a bony cage around the brain. The face includes the nose, mouth, cheeks, and jaws. Finally, the neck consists of the seven bones that connect the skull to the body.
Cervical Spine Anatomy (Neck)
The neck refers to the structure of a connection between the head and the back. This complex structure includes many skeletal bones, muscle cells, nerve cells, blood vessels, lymphatics and vascular systems.
Cervical vertebrae form the bony structure that makes up the neck. Its primary functions include supporting and moving the head (skull) and allowing movement.
This flexibility makes the scanning of the surrounding area easy. However, a significant portion of the sensory input is located within the head, so proper neck movements are crucial. It also connects the brain with the body and houses the spinal cord.
Roles of the Cervical Spine
The cervical spine is responsible for the following roles:
- Protecting the spinal cord
- Allowing a wide range of head and neck movement
- Supporting the head
Cervical Spine and supporting structures
The head rests on the Atlas (C1), which sits on the Axis (C2). These vertebrae allow a lot of movement between the head and neck.
In addition, between each vertebra is a small, round disc known as an intervertebral disc. These discs act as cushions between the bones.
Movement
- Flexion is the movement of bending the head and neck forward. This is often seen with those suffering from Text neck, which is associated with excessive periods on cellphones or other electronic devices.
- Extension is the movement of bending the head and neck backwards.
- Rotation is the movement of turning the head and neck left to right.
- Lateral Flexion (side bending) is the movement of bending the head and neck to one side – as if your ear is moving towards your shoulder.
Movement can be combined. For example, bending the head down (Flexion) while also looking to the left or right (rotation).
Neck Muscles
Neck muscles help to support the cervical spine and perform head, neck, upper back, and shoulder movements.
Neck muscles help to support the cervical spine and perform head, neck, upper back, and shoulder movements. These muscles can be categorized into three main groups:
- The extrinsic group includes the sternocleidomastoid muscle and trapezius muscles, which attach the neck to the chest and shoulder. These muscles are responsible for moving the head and neck.
- The intrinsic group includes the tiny muscles found within the neck. These muscles attach to the vertebrae and allow for rotation and side bending of the head.
- The third group is made up of the deep cervical flexor muscles. These muscles attach to the vertebrae in the back of the neck and are responsible for keeping the head upright.
Hyoid Bone
The hyoid bone is a small, U-shaped bone at the base of the skull that does not attach to any other bones. It functions as a point of attachment for many of the muscles of the neck and provides support for the tongue. It supports and houses:
- Larynx (Voice Box): The larynx, also known as the voice box, is a small, triangular-shaped organ located in the front of the neck. It houses the vocal cords and is responsible for producing sound.
- Thyroid Gland: The thyroid gland is a butterfly-shaped gland located in the lower front of the neck. It produces hormones that regulate metabolism.
- Parathyroid Glands: The parathyroid glands are four small, pea-sized glands located on the back of the thyroid gland. They produce a hormone that regulates calcium levels in the blood.
Primary Function of the Neck
The neck is responsible for a variety of functions, including:
- Supporting the head
- Allowing the head to move in a variety of directions
- Protecting the spinal cord
- Providing structural support for the throat and larynx
- Housing blood vessels and spinal nerves that travel to and from the brain
Nodding, side bending, and rotation of the head and neck are possible due to the shape and sizes of the vertebrae.
The Cervical Spine is between the head and the Rib Cage, with the head resting atop the first Cervical Vertebrae (the Atlas).
The neck offers the greatest variety and range of movement of all the spinal regions.
Diseases and Conditions of the Neck
Several diseases and conditions can affect the neck, including:
- Cervical spondylosis: This is a degenerative disease that affects the joints in the neck. It is caused by wear and tear on the bones and joints.
- Cervical herniated disc: This is a condition in which the cushion between the vertebrae in the neck ruptures.
- Cervical osteoarthritis: This is a degenerative disease that affects the joints in the neck. It is caused by the breakdown of cartilage in the joints.
- Whiplash: This condition occurs when the neck is suddenly and forcefully jerked backwards and forwards. It can cause pain, stiffness, and tenderness in the neck.
- Torticollis: This is when the neck muscles become so tight that the head is forced to tilt to one side. It can be caused by muscle spasms, injury, or birth defects.
Posture Considerations regarding the neck
The position of the head in relation to the rest of the body cannot be overstated.
The head’s only attachment to the rest of the body is between the base of the skull and the topmost vertebrae of the neck. As a result, the head is heavily influenced by changes and limitations occurring below it, especially from its near neighbors, the neck, shoulders, and rib cage.
For example, when the head sits too far forward out of alignment (as found in forward head posture), undue strain and weight are placed upon the neck. The more the head sits forward from the preferred posture alignment, the greater the need for the muscles and ligaments of the head and neck to work to keep balance possible.
This is becoming a more significant issue as we spend more time on mobile devices. Leading to such matters as Text Neck.
Therefore by improving the alignment of the head on the neck, it is possible to ease a range of concerns that may lead to head, neck, and shoulder discomfort. This can lead to Forward Head Posture and the possibility of neck pain.
Head Anatomy - Cranium and Face
Cranium (Skull)
The cranium is the section of the skull that encloses the brain. It comprises eight bones: two frontal bones, two parietal bones, two temporal bones, and two occipital bones. The bones are connected by ligaments and muscles. The cranium is covered by a layer of skin and hair.
The cranium protects the brain from injury and provides a surface for the attachment of muscles that move the head.
Frontal Bone
The frontal bone is located at the front of the skull. It forms the forehead and the upper part of the eye sockets. The frontal bone is connected to the parietal bones by two joints: the sagittal suture and the coronal suture.
Parietal Bones
The parietal bones are located at the sides of the skull. They form the upper part of the skull and the sides of the head. The parietal bones are connected to the frontal bone by the sagittal suture and to the temporal bones by the squamous suture.
Temporal Bones
The temporal bones are located at the sides of the skull, behind the ear. They form the lower part of the skull and the sides of the head. The temporal bones are connected to the parietal bones by the squamous suture, and they are connected to the occipital bone by the lambdoid suture.
Occipital Bone
The occipital bone is located at the back of the skull. It forms the base of the skull and the back of the head. The occipital bone is connected to the temporal bones by the lambdoid suture.
Foramen Magnum
The foramen magnum is a large hole in the occipital bone. It is located at the base of the skull, and it allows the spinal cord to pass through to the brain.
Face
The face is made up of many different muscles and bones. The muscles allow us to move our facial features, and the bones give our face its shape. Some of the most important bones in the face are the cheekbones, the forehead, and the nose.
14 bones make up the face, collectively known as the craniofacial bones. These include the upper jawbone (maxilla), the lower jawbone (mandible), and the cheekbones (zygomatic bones).
Temporomandibular Joint
Jaw and mouth movements are created through the temporomandibular joints (TMJ). The TMJ are the two joints that connect the jawbone to the skull. These joints are unique because they are bilateral (on both sides of the head) and work together as one unit.
The TMJ is connected to the mandible, so the right and left joints must always work together. TMJ allows you to move your jaw up and down and side to side, so you can talk, chew, and yawn.
Finally
The spine is a complex structure that can be challenging to understand. It consists of the upper neck and lower trunk, which are bones, joints, ligaments, muscles and nerves. In addition, the cervical spine has 7 vertebrae (C1-C7) in it. Each one is responsible for providing support for the weight of your head.
The bones (vertebra) are connected by ligaments and muscles. The nerves in the spine send signals from the brain to the body and vice versa.
The cervical spine is a vital part of the spinal cord as it connects the brain to the rest of the body. It is responsible for many functions such as head movement, balance, and posture. Because of its importance, it is essential to keep the cervical spine healthy and free from injury.
Neck pain is a common problem caused by many things, such as poor posture, muscle strain, or a herniated disc. If you are experiencing neck pain, it is essential to see a doctor or other recognized health care professional to rule out any serious problems.
Thank you for reading! I hope this article has helped you to better understand the anatomy of the cervical spine.