Dr. Martin's notes

Thursday September 15, 2016

Myology - Day 1

Muscles comprise 40-50% of your body weight. They effect movement of the body as a whole, help to move blood through the circulatory system, food through the digestive tract and other bodily functions. They do this through two actions, contraction and movement.

There are three types of muscle:

Striated: AKA skeletal muscle are long and slender and contract upon stimulus. They are subject to the All or Nothing principle.
Muscle spasm is the involuntary contraction of a muscle or a group of muscles by repetative overstimulation. (Tetany/tetanus). Muscles receive their energy to contract from the hydrolysis ATP breaking down into ADP+phosphate+energy (Krebs cycle)

Smooth Muscle: Found in the digestive tract and other hollow structures such as bladder, blood vessels and gall bladder. It is under the control of the ANS and cannot be influenced at will.

Cardiac muscle: Is involuntary muscle with a special design to allow it rhythmic motion. (Found in the heart only).

Disorders of Muscles:
Contracture: disease or injury which shortens muscle length
Myalgia: Muscle Pain
Myositis: Inflammation of muscle
Fibrositis: Inflammation of the connective tissue within a muscle
Muscular dystrophy: a slow progressive degeneration of the muscle tissue, causing it to not function.
Atrophy: shrinkage from disease or lack of use

Muscles are named by: Action, Shape, Origin-insertion, number of Divisions, Location, and Direction of Fibers

Major Cranial/cervical muscles:
Masseter - Chewing Muscle
Sternocleidomastoid - Front of neck
Trapezius- Upper back and back of neck
Rectus and Obliques of the eye
Major arm/shoulder muscles:
Pectoralis Major-Chest
Latissimus Dorsi - Side into shoulder
Biceps & Triceps - upper arm
Brachioradialis - Thumb side, lower arm
Supraspinatous & infraspinatous - Scapular