ANATOMY 101

Anatomy: A Short Course to Anatomy

It is one of the greatest investments on your behalf to get acquainted to your own body, the bones and the muscles that move them. This short course on anatomy is going to get you up and running to a basic understanding of muscles interact with bones, joints, and other muscles. 

For ease of reading and to prevent boredom, I will split this articles in six parts namely, Neck, Upper Limbs, Trunk (Back), Trunk (Abdominal), Hips, Lower Limbs.
With the objective now being clear let's get to it and get familiar with the body.

Anatomy of Head & Neck : 

A description of major movable joints, and the muscles that move them in the head, and neck region.

The Human Skull 

Human Skull: Side View; Source: LadyofHats [Public domain]

The human skull is a complex bone which means that it is composed of many different, smaller bones. It supports the muscles of the face, and a lot of muscles in the neck also attach to various bony bumps (processes) on the skull. The skull also houses the brain, the eyes, and the nasal passage. 

Human Skull : Front View; Source : Dr. Johannes Sobotta [Public domain]

The joints in the human skull are known as sutures. Mandible, the bone of the lower jaw is the only bone in the skull which does not has a suture.

Muscles in the head, and neck. 

The muscles in the head, and neck are numerous. These muscles control everything from the movement of eyes, to chewing, swallowing, breathing. 

Muscles in the Head and Neck; Source : Henry Vandyke Carter [Public domain]

Out of these numerous muscles we'll restrict our discussion to the muscle that moves the major joints, and create big movements. In brief, these muscles move the lower jaw (masseter), Help to move the head up and down, side to side, bend sideways (scalene, sternocleido-mastoid, splenius, levetaor scapulae).

Muscles of Neck; Source : Henry Vandyke Carter [Public domain]

I will encourage the readers to click on the link above to see a bigger picture and familiarize themselves with the arrangement of muscles.

Let's learn about these muscles in a bit more detail.

Sternocleido-Mastoid : Sternocleiodo-mastoid (SCM) is one of the most superficial muscles of the neck. It runs from the bony bump of the collar bone (clavicle) and attaches to the skull under the earlobe and behind the ears (to the mastoid process in the mastoid bone, see the diagram of skull above). 

SCM; Source : Gray385.png modified by Uwe Gille [Public domain]

SCM is responsible for 

• flexing or bending the neck forward when SCM on both side work.
• Rotating the neck to the opposite side and tilting the head towards the same side one one side of the muscle works. 
• SCM also assists in breathing by elevating the rib-cage¹. 

Scalenes : Scalenes are three muscles, front, middle, and rear scalene respectively. Front scalene starts from the C3-C6 vertebrae, and the middle scalene starts at C2-C7 vertebrae. Both the muscles attach to the first rib. Rear scalene start at the C4-C6 vertebrae and attach to the second rib. Scalenes are responsible for the elevation of respective ribs to which they attach to.

Scalenes; Source : User:Mikael Häggström [Public domain]

Levator Scapulae : Levator scapulae is one of the powerful muscles in the body. Critical in posture, and performance. It starts at C1-C4 and inserts at the medial border (the side closest to the spine) of the scapula. The muscle lies deeper to both SCM and the trapezius.

Levator Scapulae, Posterior View; Source : modified by Uwe Gille [Public domain]

Due to it's connections levator scapulae perform these 3 functions

• Rotation of neck towards the same side
• Downward rotation of scapula
• Elevation of scapula which is its main function.