Muscular System Flashcards
What are the 3 types of muscles?
Skeletal muscle
Cardiac muscle
Smooth muscle
What is the skeletal muscles?
- it is voluntary
- connected to skeletal system via tendons
- responsible for movement, contracting and pulling bones
- help provide strength and power, posture and also helps generate heat
- can become fatigued during exercise
What is the cardiac muscle?
- only found in the wall of your heart
- works continuously
- involuntary
- does not fatigue
- helps circulate blood through and out of the heart
- contractions help to force blood through your blood vessels
What is smooth muscle?
- involuntary under the control of the nervous system
- located in walls of digestive system
- regulates digestion and blood flow
- control body functions such as movement of food
What’s the agonist?
The muscle that contracts - responsible for movement
What is the antagonist?
The muscle that relaxes
What are the antagonistic muscles for the trunk?
Abdominals and erector spina
What antagonistic muscle pair moves the shoulder?
Deltoid and latissimus dorsi
E.g. golf swing, breaststroke
What is a synergist?
It assists the agonist
What is a fixator?
Stabilises the origin
What is the role of the pectorals?
Helps with addiction of the shoulder and the horizontal flexion of the shoulder
What is a sporting example of isometric contraction?
Plank
Crucifix in gymnastics on the rings
What is a sporting example for concentric contraction?
Bicep curl
In the preparation phase, when rugby players prepare to kick the ball, hamstrings contract and shorten to flex the knee
What is a sporting example for eccentric contraction?
Lowering a dumbbell in a bicep curl
What is an isometric contraction?
Length of the muscle does not change, the joint angle does not alter
Muscle holds a static position
What is a concentric contraction?
Muscle will shorted and a movement occurs
What is an eccentric contraction?
When a muscle returns to its normal length after shortening against resistance
What is an isotonic contraction?
Where the muscle changes length as it contracts and causes movement of a body part.
What are the three muscle fibre types?
Type 1 (slow twitch)
Type 2 (IIa) (fast twitch)
Type 2x (IIX) (fast twitch fibres)
What is type 1?
- slow twitch
- contract slowly
- contract with less force
- most resistant to fatigue
- longer durations, aerobic activities
- rich blood supply
- contain many mitochondria
- high capacity for aerobic respiration
Type 2 (IIa)
- fast twitch
- produce a great force when contracting
- resistant to fatigue
- fatigue faster than type 1
- use oxygen
- suited to speed, power and strength activities
Type 2x (IIx)
- fast twitch fibres
- produce the greatest force when contracting
- contract rapidly
- anaerobic activities
- depend upon anaerobic respiration
- high intensity/ short duration activities
What is the all or none law?
In order for a muscle to contract, it must receive a nerve impulse.
This impulse must be sufficient to activate the motor unit.
Once activated, all the muscles fibres within the motor unit contract. If the impulse is not strong or sufficient to activate the motor unit, then none of the muscles contract.
This is the all or none law of muscle contractions.
What are the 2 responses of the muscular system?
Acute
Chronic