The Muscular System

Flashcards covering the key concepts of the muscular system, including muscle types, functions, anatomy, contraction mechanisms, and age-related changes.

What are the primary responsibilities of muscles in the body?

Muscles are responsible for movement, maintaining posture, communicating with facial expressions, and various involuntary functions.

What attaches muscles to bones?

Tendons attach muscles to bones.

How many skeletal muscles do humans generally have?

Humans have somewhere between 650 and 700 skeletal muscles.

Name the three types of muscle tissue.

Cardiac muscle, Skeletal muscle, Smooth muscle.

What is the primary function of cardiac muscle?

To pump blood throughout the body.

What is the muscular organ that pumps blood?

The heart.

What is the function of skeletal muscles?

Skeletal muscles are responsible for voluntary movements of the body.

How do muscles contract to produce movement?

Muscles contract or shorten, pulling on tendons which pull on bones at joints.

What do we call the muscle that produces a particular movement?

The prime mover or agonist.

What is the role of antagonist muscles?

Antagonist muscles produce the opposite effect to the prime mover.

Describe the sliding filament theory.

The sliding filament theory states that the sarcomere shortens as thin and thick myofilaments slide past each other.

What is a motor unit?

A motor unit consists of one motor neuron and all the skeletal muscle cells it stimulates.

What is the neuromuscular junction?

The synapse where the neuron and muscle cell meet.

What neurotransmitter is responsible for muscle contraction?

Acetylcholine (ACh).

What occurs to muscle cells when a single nerve impulse is produced?

It causes a single muscle contraction.

How do graded responses in muscles occur?

Graded responses can occur by changing the frequency of stimulation or the number of muscle cells being stimulated.

What is muscle atrophy?

Muscle atrophy refers to the loss of tone and muscle mass due to inactivity.

What type of exercise increases muscle size and strength?

Resistance training increases muscle size and strength.

What are isotonic and isometric contractions?

Isotonic contractions occur when muscles shorten with movement, while isometric contractions occur when muscles do not shorten and there is no movement.

What happens to muscles as we age?

Muscles become more stringy and decrease in mass and strength due to an increase in connective tissue.

What is Duchenne muscular dystrophy?

A genetic disease that causes progressive muscle weakness and is inherited as an x-linked recessive disorder.