TEAS Muscular System

What parts of the body does the muscular system affect?

Every part of the human body (like the nervous system)

Muscular system

An integrated system in the body that is vital for controlling involuntary and voluntary movement.

Tissue

A group of cells with similar structure that function together as a unit, but at a lower level than organs.

What are the three (3) types of muscle?

Skeletal, cardiac, and smooth

What does skeletal muscle often attached to?

Bone (involved in the movement of bones)

How is skeletal muscle in composition?

Striated and very strong

Which is the only voluntary muscle tissue in the body?

Skeletal muscle

Where can cardiac muscle be found?

In the heart (it’s also striated)

How is cardiac muscle in terms of control?

Cardiac muscle tissue cannot be controlled consciously, making it involuntary.

Where can smooth muscle be found?

• In the walls of hollow organs, such as the stomach and intestines and intestines

• In the walls of passageways, such as blood vessels

• Elsewhere throughout the body, such as the eyes, the tracts of the reproductive system, and the skin

Which is the weakest of all muscle tissues?

Smooth muscle

How is smooth muscle in terms of control?

It is considered an involuntary muscle because it is controlled by the unconscious part of the brain.

Bone

Hard, calcified material that makes up the skeleton

Skin

The thin layer of tissue that covers the body

How many named muscles are there?

700

• make up approximately half of a person’s body weight (40-50%)

What are most skeletal muscles attached to?

To bones by a tendon

What are tendons?

Tough bands of connective tissue that have strong collagen fibers.

• Collagen is NOT elastic

What do collagen fibers do?

Firmly attach the muscle to the bone

How do muscles move?

By contracting and shortening their length, which pulls on the tendons, moving one bone closer to another bone that is stationary.

Based on what factors are skeletal muscles named?

Location, shape, and size.

How do skeletal muscles work?

Rarely work alone, but rather often work in groups to produce movements.

What do muscles contain?

Long myofibrils made of sarcomere units

What do sarcomere units consist of?

Long strands of proteins called “actin” (thin filaments) and “myosin” (thick filaments).

What is each muscle fiber connected to?

A nerve fiber

What does it take for the entire muscle to move?

A concerted effort by many nerves and fibers and the use of ATP to power the contraction and relaxation.

What happens when a muscle is relaxed?

Myosin and actin filaments are NOT attached.

What happens when a muscle contracts?

The filaments bind and are pulled together.

What happens when the brain wants to send a message to a particular part of the body?

The nervous system sends a signal to a muscle

How is a contraction or a relaxation of the muscle created?

When actin and myosin proteins in the muscle slide past each other

Which two basic motions are responsible for all muscle movement?

Contraction and relaxation

Skeletal muscles

Muscles that attach to bones and are connected to and communicate with the central nervous system

Tendons

Tough connective tissue that attaches muscle to bone

Collagen

The primary structural protein of connective tissue

What do receptors and muscles allow them to do?

Receive a signal and respond with the appropriate magnitude and movement.

What can the signal and response be disrupted by?

Disorders ranging from muscle strain to muscular dystrophy.

Sarcomere

Contracting unit of a muscle

Contraction

The process leading to shortening and/or development of tension in a muscle.