Muscular System

Learning Targets:

I can describe parts of the muscular system and explain how they work together

I can name the three kinds of muscle tissue

I can list and explain some disorders that affect the muscular system

Muscles

• Muscle is one of our 4 tissue types and muscle tissue combines with nerves, blood vessels, and various connective tissues to perform movement.

• The human body has more than 600 muscles.

Muscle Functions

1.Movement– Movement of body parts– Movement of blood

through the heart– Movement of food– Movement of the air in

and out of the lungs

Muscle Functions

2.Body Temperature

– Generation of heat. Occurs by shivering – an involuntary contraction of skeletal muscle.

Muscle Functions

3. Stabilization of joints

• Muscles keep the tendons that cross the joint nice and tight.

How Muscles Work

Skeletal muscles work in pairs to move your bones.

•They contract, or shorten and they extend, or lengthen.

B. To straighten the arm again, the biceps brachii relax. The triceps brachii now contract, pulling the arm into a straight line.

A. To bend the arm, muscles in the top part of the arm—especially the biceps brachii—contract, or shorten, pulling the bone of the forearm upward. At the same time, the triceps brachii—on the opposite side of the arm—must relax and extend, or lengthen.

Biceps brachii

Triceps brachii

Triceps brachiiBiceps brachii

3 Types of Muscle Tissue

3 Types of Muscle Tissue

Muscle tissue responds to messages from the brain and contracts, or shortens, to cause movement.

Involuntary muscles move without your being aware of them. There are two types:

– Smooth muscles, which include the muscles of internal organs and blood vessels (ex. Diaphragm, stomach, arteries, throat, eyes)

– Cardiac muscles, found only in the heartBlink eyes and hold breath

Voluntary muscles are under your control.

- Skeletal muscles are voluntary or under your control.(ex. Face muscles, tendons, biceps, triceps)

Skeletal Muscle

• Attached to bones by the tendons

• Work with the bones of the skeleton to allow you to move.

Skeletal Muscle

• You control skeletal muscles.

• Skeletal muscles make up about 40 percent of your body weight.

Skeletal Muscle

Smooth Muscle

• Found in various organs in the body, such as the stomach and intestines.

• You do not control these muscles. For example, once you have swallowed your food, smooth muscles move it through the digestive system.

Smooth Muscle

Smooth Muscle can be found inmany body systems:• Integumentary system• Respiratory system• Urinary system• Digestive system• Reproductive system

Smooth Muscle

Cardiac Muscle

• Special type of muscle that is found only in the walls of the heart.

• Controlled by your brain, cardiac muscle constantly contracts and relaxes, causing your heart to pump blood

• Involuntary muscle