Muscular system notes

How many muscles do we have?

Over 600

What muscles give you goosebumps?

Arrector pili

How many muscles does it take to smile?

17 muscles

How many muscles does it take to frown?

42 muscles

What is the hardest working muscle in the body?

The heart

What is the largest muscle in the human body?

Gluteus maximus

What are the smallest muscles in the human body?

Tensor tympani and stapedius in the inner ear

What percentage of body weight is made up of muscles?

40% of body weight

What are the five functions of the muscular system?

Movement, generates heat, supports posture, protects internal organs, and moves blood, food, and waste.

What is excitability in muscle traits?

The ability to respond to stimuli, such as a nerve or hormone.

What does extensibility refer to in muscles?

The ability to be stretched and lengthen.

What is muscle tone?

The state of being contracted at all times and readiness to act.

What unique feature does each muscle have?

Its own nerve, vein, and artery.

What type of muscle forms the walls of the heart?

Cardiac muscle.

What are the three types of muscles?

Cardiac, smooth (visceral), and skeletal muscles.

What is the origin of a muscle?

The end connected to the bone that does not move.

What is the insertion of a muscle?

The end connected to the bone that moves when the muscle contracts.

What are the four shapes of muscle?

Triangular, spindle, flat, circular.

Give an example of a triangular muscle.

Shoulder.

What does flexion involve?

Bending a body part, which decreases the angle of the joint.

What is the main function of the diaphragm?

Respiration (inspiration).

What is the sliding filament theory?

The mechanism of muscle contraction where actin and myosin filaments slide over each other.

What happens in isotonic exercise?

Muscles contract and movement occurs.

What happens in isometric exercise?

Tension in muscles increases, but no movement occurs.

What is a tendon?

A band of fibrous tissue that attaches muscle to bone.

What is a ligament?

A band of tissue that connects bone to bone.

What condition is characterized by a reduction in muscle size and strength?

Atrophy.

What is muscular dystrophy?

An inherited disease where muscles gradually deteriorate.

What are symptoms of fibromyalgia?

Chronic pain in specific muscle sites, fatigue, headache, and feelings of numbness.

What can muscle strains lead to?

Torn or stretched muscles or tendons.