Muscular system Flashcards
What are the functions of the muscular system? (3)
- works together with skeletal system to create movement.
- maintains posture.
- maintains bodily functions: heart pumps blood, digests food, breathing.
What are the types of muscles? (3)
- skeletal muscle
- smooth muscle
- cardiac muscle
What is a smooth muscle? (2)
- Found in digestive system and walls of vital organs.
- called involuntary muscles because we don’t control them.
What are skeletal muscles? (4)
- they have a striped appearance, also called striated.
- responsible for voluntary movements.
- we can exercise and train them.
- responsible for good posture.
- they pull on skeletal muscles in order to create movement.
What is a cardiac muscle? (4)
- has a striped appearance.
- only found in the heart.
- it can become stronger through exercise.
- its actions are involuntary.
What is reciprocal inhibition?
When two muscle are working together to create opposite movement. One muscle is contracting while the other is relaxing. They never work in isolation.
What is the antagonist muscle?
The muscle that is relaxing.
What is the agonist muscle?
The muscle that is contracting.
What is a stabiliser muscle?
Muscles in the body that act to stabilise on joint so a desired movement can be performed in another joint?
What is the origin?
The site where the muscle is attached to a stable bone, which the muscle can pull against. Usually flat bone.
What is the insertion?
The insertion occurs where the muscle attaches to the bone and is pulled by the action of the muscle. During contraction the muscle pulls on the bone to create movement.
What is a fast twitch fibre? (3)
White muscle fibre, used for:
- power
- speed
- strength
- short distance
- contracts quickly
- aerobic and anaerobic
What is a slow twitch fibre? (3)
Red muscle fibre, used for:
- longer duration
- low effort, low force
- endurance
- contracts slowly
- aerobic
How are muscles attached to bones?
Tendons which are situated at the end of a muscle called a muscle belly.
What is an isoinertial movement?
When a muscle is applying force and there is an increase/ decrease in in muscle length. Either concentric or eccentric.
What is an isometric movement?
Muscle creates force but there’s no change in muscle length.
What is an isokinetic movement?
Isokinetic exercise is a type of strength training in which specialized machines, maintain a constant speed of movement.
A machine will continually create max contraction.
What is hypertrophy?
The growth and increase of the size of muscle cells.
What is a motor unit?
Consists of one motor neuron and all the muscle fibres it stimulates.
What is the all or nothing principle?
States that when the electrical impulses reaches a certain threshold, all of the fibres of that motor unit will contract at the same time and as forcefully as possible.
How does the intensity of a muscular contraction vary?
- varying the number of motor units stimulated.
- varying the frequency at which the impulses arrive at the motor unit.
Why is an electrical threshold relevant in muscle contractions?
Threshold is considered to be the level of stimulation required to trigger the smallest measurable contraction.
What is myosin?
A thick protein filament that is found in myofibril.
What is actin?
A thin protein filament found in myofibril.
What is muscle atrophy?
A decrease in the mass of the muscle, due to not using the muscle for an extended period of time.
