Week 3 Muscles and Movements Flashcards
what are the characteristics of muscles ?
- highly cellular
- highly vascular: good blood supply
- Contractile: ability to contract and cause movement
Name and explain each type muscle
SMOOTH
Involuntary muscle that can be found in visceral organs in the body such as arteries and airways. These muscles can only contract very slowly
CARDIAC
These are the muscular walls of the heart that involve a forceful contraction. Involuntary movement
SKELETAL
Muscles that are attached to bone to create movement. these muscles are voluntary. eg biceps branchii
What are the function of muscles
- movement
- maintain posture
- stabilise joints
- generate heat
- provide organ protection eg abdominals
describe the structure of skeletal muscles
- the muscle cell are called muscle fibres which are bundled together to form a fasicle
- A number of these fasicles form the muscle belly
- tendons attach and transfer the force produced by muscles to the bone
what is the Epimysium, Endomysium and perimysium
Epimysium: A type of loose connective tissue that surrounds the muscle belly
Perimysium: The connective tissue that surrounds the fasicle
Endomysium: The connective tissue that surrounds the muscle fibre.
What is the difference between the origin and insertion?
the origin is where the muscle begins while the insertion is where the muscle stops.
Name all of the types muscle fibre orientation and give an example
Circular: arranged in concentric circles which surround openings in our body, eg mouth
Convergent: All the muscle fibres originate in a broad area and converge into a single insertion. eg pectoralis major
Parallel: fibres run parallel from origin to insertion. eg sartorius
Fusiform: similar to parallel but with expanded midsection. eg biceps branchii
Unipennate: feather like structure as fibres run on an oblique angle into tendous thickening. eg extensor digtorum longus (extensor of toes)
Bipennate: central tendon rather than being on one side.
eg. rectus femoris
Multipennate- multiple tendons that attach to multiple muscle fibres which all attach to one central tendon. eg deltiods
what is the difference between muscle contraction, tension and tone?
Muscle contraction: the active process of generating force and movement
Muscle tension: two types; active tension is produced by muscle contraction and passive tension caused by stretching and lengthening of connective tissues
Muscle Tone: A reflex activity that maintains a level of muscle contraction at all times
what is a motor unit?
A motor unit is made up of multiple muscle fibres that is activated by a single motor neuron.
Explain the all or nothing principle
This is the principle that means if there is an excitory impulse sent to a motor neuron, all of those motor neurons in that motor unit will be activated
what are the 4 main factors involving strength
- number of muscle fibres activated
- muscle fibre size
- frequency of stimulation
- amount of stretch
Describe the muscle contraction types
Dynamic/isotonic: The length of the muscle changes.
concentric: the length of muscle shortens
eccentric: the length of the muscle increases
Isometric/static: the muscle length does not change when contracting
eg rugby scrum
what is the:
prime mover
antagonist
fixator
prime mover: muscle producing movement
antagonist: muscle opposing a movement
fixator: muscle stabilising a body part
describe the difference between open and closed chained movement
open-chained: this is where the muscle contracts and the insertion moves. (proximal moves)
eg free movement of the hand
closed chained: where the muscle contracts and the origin moves (distal fixed)
eg doing a push up hand fixed
doing a squat feet fixed
