Muscles

There are 3 types of muscles:

• Smooth-cover organs such as digestive system. A wavelike motion in the digestive system which allows food to move is called Peristalsis.

• Cardiac-these are found in the heart and are specialized to keep going and going…

• Skeletal-skeletal muscle fiber is a single cell that contracts in response to stimulation, then they release. They are a thin, elongated cylinder and contain myofibrils for contractions.

Skeletal Muscle, continued…

Skeletal muscle contains 2 types of protein filamentsthick ones=protein Myosin

Thin ones+ protein Actin(alternations create dark and light bands in

muscle)Part of myofibril that extends is called the

sarcomere: http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/animation__sarcomere_contraction.html

Skeletal muscle, cont.

– Each skeletal muscle connects by a nerve cell called a Motor Neuron

– At the end of each motor neuron there are tiny vesicles that store chemicals called neurotransmitters that stimulate the muscle to contract

– A muscle fiber usually has a single motor and plate that is densely branched. This allows them to connect to many muscle fibers

– Together, the motor neuron and muscle fibers it controls is called a motor unit

Motor Unit

• Esophagus - food passageway (heartburn is caused by the effects of gastric juice on the esophagus)

• Stomach - secretes gastric juices (pepsin, hydrochloric acid) which digest proteins and creates a paste of food called chyme.

• Pancreas - secretes pancreatic juice which helps digest carbs, fats, and nucleic acids and proteins.

The Muscular System

Muscles continued:

Muscles continued:

Muscles, continued.

Muscles cont.

Muscles cont.

Muscles

Muscle Diagram

Muscles

Muscle medical terms

Muscle medical terms cont.

Muscle medical terms cont.

Muscle terms continued