Muscles Lesson

4.2 Muscles

Types of Muscles

​Histology:

​Fibers:

What do we use our muscles for?

Some text here about the topic of discussion

Muscles also generate body heat

Smooth muscle helps facilitate movement of substances within the body (e.g. peristalsis)

Skeletal muscles contract, exerting forces on the tendons.

Tendons then pull on the bones causing joint movement.

Postural muscles stabilize and maintain body positions.

Ability to shorten.

Excitability

Ability to receive and respond to stimuli via generation of an electrical pulse which causes contraction of the muscle cells.

​Contractility

Write the definition for the words below in your lab notebook:

Ability of a muscle fiber to recoil and resume its resting length.

Elasticity

Ability to be stretched or extended.

​Extensibility

Write the definition for the words below in your lab notebook:

Origin and Insertion

When a muscle contracts, only one bone moves leaving the other stationary. The points at which the tendons are attached to the bone are known as the origin and the insertion.

The origin is where the tendon of the muscle joins the stationary bone(s).

The insertion is where the tendon of the muscle joins the moving bone(s).

Antagonistic Muscles

Skeletal muscles work across a joint and are attached to the bones by strong cords known as tendons.

They work in pairs, each contracting or relaxing in turn to create movement.

Ex. The biceps brachii and the triceps brachii are known as antagonistic muscles; as one muscle shortens, the other lengthens.

Subject | Subject

Some text here about the topic of discussion

​Add color to your worksheet to the following muscles:

Abdominal Muscles

(muscles of the trunk)