muscular system

Question 1

what is the function of the skeletal muscles?

Answer 1

Skeletal muscles move the body by responding to signals from the nervous system

Question 2

what is the function of the smooth muscles?

Answer 2

Smooth muscles, in many organs throughout the body, respond to hormones and involuntary signals from the nervous system. They contract and relax to contain substances and move substances through the body.

Question 3

what is the function of the cardiac muscles?

Answer 3

Cardiac muscle responds to involuntary signals from its own conduction system. Heartbeats are the heart muscle contractions that pump blood

Question 4

what are the three types of muscle in the body?

Answer 4

skeletal, smooth, and cardiac muscle.

Question 5

is skeletal muscle striated?

Answer 5

yes, Skeletal muscle is striated and responds to voluntary commands from the nervous system.

Question 6

is cardiac muscle striated?

Answer 6

Cardiac muscle, a special type of striated muscle found only in the myocardium of the heart, has branching fibres connected by intercalated discs that allow for synchronized involuntary contraction to maintain a constant heart rate.

Question 7

is smooth muscle striated?

Answer 7

no, smooth muscle is non-striated and contracts involuntarily in peristaltic waves that move substances through the body’s digestive, raspatory, urinary and reproductive tracts.

Question 8

what do skeletal bones attach to?

Answer 8

Skeletal muscles attach to bones of the skeleton and contract voluntarily to produce movement.

Question 9

what does smooth muscle line?

Answer 9

Smooth muscle lines the gastrointestinal tract, raspatory tract, blood vessels of the circulatory system, urinary tract, and reproductive organs.

Question 10

where is cardiac muscle found?

Answer 10

Cardiac muscle, found only in the myocardium of the heart, contracts in response to signals from the cardiac conduction systems to make the heartbeat.

Question 11

what are the body’s main muscle regions?

Answer 11

The body’s main muscle regions are the head, neck, shoulder girdle, back, thorax, abdomen, pelvis, hip, and upper and lower limbs.

Question 12

state

Answer 12

skeletal muscles are supplied with blood vessels and nerves. The pectoralis major, for example, is innervated by the brachial plexus and supplied with blood by the thoracoacromial artery.

Question 13

movement occurs through a series of steps:

Answer 13

• impulses from the nervous system reach the neuromuscular junction.
• the neuron releases a neurotransmitter called acetylcholine.
• it binds to receptors on the muscle and begins a chemical reaction within the fibres.
• the muscle filaments slide across each other and the muscle shortens, or contracts.
• this muscle produces movement.

Question 14

what is epimysium?

Answer 14

A layer of connective tissue called the epimysium protects each skeletal muscle.

Question 15

what are fascicles?

Answer 15

muscle fibres that are grouped into bundles are called fascicles

Question 15

what are myofibrils?

Answer 15

The proteins within a muscle cell are organized into units called myofibrils.

Question 16

what are sarcomeres?

Answer 16

Each myofibril is formed by long paired chains of thick filaments and made thin filaments organized into repeating segments called sarcomeres.

Question 17

what does the ability of skeletal muscle to contract relies on?

Answer 17

The ability of skeletal muscle to contract relies on the structure of these muscle fibres and the surrounding nerves.

Question 18

state

Answer 18

When a nerve impulse reaches a motor neuron, a chemical message passes into the muscle fibre, and the thick and thin filaments of a sarcomere slide across each other to shorten the muscle, creating the contraction.

Question 19

what are skeletal muscle fibres?

Answer 19

Skeletal muscle fibres are long, cylindrical, striated, and multinucleate cells, called myocytes, that are composed of sarcoplasm and numerous rodlike myofibrils and enclosed in sarcolemma