A&P Muscular System

Muscular system define: (3)

Body system responsible for movement, posture, and heat production

What is the main function of the muscular system? (2)

To produce movement and work with the nervous system to control body actions

Muscle tissue define (2)

Tissue specialized for contraction and movement

What are the three types of muscle tissue?

Skeletal, cardiac, and smooth

Skeletal muscle (3)

Striated, voluntary muscle attached to bones

What is the function of skeletal muscle? (2)

To move bones and control voluntary movements

Cardiac muscle (3)

Striated, involuntary muscle found in the heart

What is the function of cardiac muscle?

To pump blood through the body

Smooth muscle (3)

Non-striated, involuntary muscle found in organs and vessels

Where is smooth muscle found? ^{where? and provide 3 examples}

In walls of organs; stomach, intestines, and blood vessels

Which muscle tissue is the strongest?

Skeletal muscle

Which muscle tissue is the weakest?

Smooth muscle

What is the difference between voluntary and involuntary muscle?

Voluntary is consciously controlled, involuntary is automatic

Which muscle type is voluntary?

Skeletal muscle

Which muscle types are involuntary?

Cardiac and smooth muscle

Tendon (type of tissue; attatchment)

Tough connective tissue that attaches muscle to bone

What is the function of tendons? (2)

To connect muscles to bones and transmit force

Collagen (include where they are found too)

Strong protein fibers found in tendons

How many muscles are in the human body?

About 700 (named muscles)

What percentage of body weight do muscles make up?

(Approximately) half a person's total body weight

How do muscles cause movement?

By contracting and pulling on bones

What happens when a muscle contracts?

It shortens and pulls on a bone

What happens when a muscle contracts (bone movement)?

It pulls one bone closer to another bone that remains stationary

How are skeletal muscles named?

Based on location, shape, and size

Why do muscles work in groups?

To create coordinated movements

Myofibril

Long structure in muscle cells made of repeating units

Sarcomere

Functional unit of muscle contraction

Actin

Thin filament in muscle fibers

Myosin

Thick filament in muscle fibers

Which filament is thick?

Myosin

Which filament is thin?

Actin

Sliding filament theory

Actin and myosin slide past each other to cause contraction

What happens during muscle contraction? (actin & myosin terms)

Actin and myosin bind and slide, shortening the muscle

What happens during muscle relaxation?

Actin and myosin detach and the muscle lengthens

ATP (adenosine triphosphate)

Energy source used for muscle contraction

Why is ATP needed for muscle contraction?

It provides energy for actin and myosin movement

How does the nervous system control muscles?

By sending signals through neurons to muscle fibers

What happens when a nerve signal reaches a muscle?

It triggers contraction

Muscle fiber

Individual muscle cell connected to a nerve

What is required for full muscle movement? (2)

Many muscle fibers and nerve signals working together

Receptors (muscle)

Structures that detect signals and allow proper muscle response

What happens if nerve signals are disrupted?

Muscle movement is impaired

Muscle strain (2)

Injury caused by overstretching or tearing muscle

Muscular dystrophy

Disease causing progressive muscle weakness

How do muscles and the nervous system work together?

Nervous system sends signals and muscles respond by contracting

What happens when you touch a hot stove? (2 step)

Sensory neurons send signal to spinal cord, motor neurons trigger muscle to pull away

Why is the response to a hot stove fast?

It is a reflex controlled by the spinal cord

What is the role of reflexes in muscle movement?

To provide quick, automatic responses to stimuli

Which muscle is located at the shoulder?

Deltoid

Why are skeletal muscles important for movement? ^{(what do they attatch to & what do they allow)}

They attach to bones and allow for voluntary movement