PE muscualr system (copy)

What are the names of the 11 muscles?

What are the names of the 11 muscles?

Pectorals, deltiods, trapezius, latissimus dorsi, biceps, triceps, abdominals, hamstrings, gluteals , quadriceps, gastrocnemius,

what are the 3 functions of the muscles?

- Movement - Allows us to move by surrounding joints and attaching to bones
- Support - Allows us to maintain an upright posture
- Produce heat - When energy is produced from foods and other fuel allowing muscle contractions to occur

What are the terms used to describe muscle attatchment?

Origin and Insertion

define origin

Origin – The site where a muscle is attached to a stable bone

define insertion

Insertion - The site where the muscle attaches in order to pull the bone towards the origin

define agonist

Agonist: The muscle primarily responsible for producing movement

define antagonist

Antagonist: The muscle that relaxes as the agonist contracts to allow ease of movement and minimise the risk of injury

define stabilisers

Muscles that stabilise one part of the body while another part is moving

Define reciprocal inhibition

Reciprocal Inhibition: One muscle contracts and its opposite muscle relaxes

Muscles working in pairs to efficiently create movement

what are the three types of muscles

smooth, cardiac, skeletal

define cardiac muscles

a type of striated, involuntary muscle that forms the wall of the heart

define smooth muscles

involuntary, Spindle cells are Blood vessels, bladder & intestines

define skeletal muscles

Voluntary - direct control, Striped/striated cells, External muscles that attach to bones

What are the 5 muslce fibre arrangement?

- Circular
- Convergent
- Parallel
- Pennate (Uni, Bi, Multi)
- Fusiform

circular

Surround external body openings. Close when contracted

convergent

Fan-shaped

parallel processing

Fascicles run parallel to tendon

Pennate

Fascicles run obliquely to tendon
Most common type of skeletal muscle (75%)
Uni -Fascicles insert into one side of the tendon
Bi - Fascicles insert into both sides of the tendon
Multi - Multiple fascicles insert into both sides of the tendon

fusiform

Fascicles run parallel to tendon (similar to parallel) they are more spindle-shaped

sensory neurons

Sensory Neurons: Conduct impulses FROM muscles, organs and cells TO the brain

motor neurons

Motor Neurons: Carry impulses from the brain to the muscles in order for movement to occur

all or nothing principle

• The strength of a response of a muscle fibre is not dependent on the strength of the stimulus

• If a stimulus reaches a certain threshold, a muscle fibre will fire

muscle fibre type

• Slow twitch

• Fast twitch A

• Fast twitch B

Slow twitch fibres

Best suited to AEROBIC work, meaning endurance or long lasting work efforts such as marathon running or completing a triathlon

Fast twitch fibres

Best suited to short duration, high intensity ANAEROBIC work such as sprints and throwing events

muscle actions

• Isometric actions

• Isokinetic actions

• Isoinertial actions

Isometric actions

During contraction there is little or no movement in muscle length. e.g. pushing against an immovable object

Isokinetic actions

Speed or velocity of movement is held constant regardless of the amount of force that is applied. e.g. use of specialised resistance machines such as the Cybex, Biodex, Lido and Kin-Com

Isoinertial actions

When the muscle shortens (concentric contraction) or when the muscle lengthens (eccentric contraction) while force is applied

Sliding filament theory

Impulses triggers muscle fibers to contract by causing myosin cross-bridges to pull actin filaments inward, shortening sarcomeres. Contraction occurs throughout the muscle fibre, leading to the shortening of myofibrils, muscle fibres, and fascicles, without any change in the length of actin or myosin.