A&P Muscular System

Muscular system

Body system responsible for movement, posture, and heat production

What is the main function of the muscular system?

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

Muscle tissue

Tissue specialized for contraction and movement

What are the three types of muscle tissue?

Skeletal, cardiac, and smooth

Skeletal muscle

Striated, voluntary muscle attached to bones

What is the function of skeletal muscle?

To move bones and control voluntary movements

Cardiac muscle

Striated, involuntary muscle found in the heart

What is the function of cardiac muscle?

To pump blood through the body

Smooth muscle

Non-striated, involuntary muscle found in organs and vessels

Where is smooth muscle found?

In walls of organs like 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

Tough connective tissue that attaches muscle to bone

What is the function of tendons?

To connect muscles to bones and transmit force

Collagen

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 of 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 factors like 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 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?

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

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?

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?

They attach to bones and allow for voluntary movement