MUSCULAR SYSTEM
Structure of a striated muscle (skeletal muscle)
- Striped and is attached to bones
- It is controlled by the CNS and demonstrates (in)voluntary actions
- It contracts when it receives nerve impulses
- It has a lot of mitochondria to supply ATP (adenosine triphosphate) for energy
used in muscle contractions
Muscle structure
- Myofibrils are composed of actin (together with myosin) and myosin (together
with actin), which are fibrous proteins that forms the contractile filaments of
muscle cells and is involved in the motions of other types of cells
- Myofibrils join together forming muscle fibres (muscle cells)
- Muscle fibres form larger string-like bundles called fascicles
- Fascicles combines to form the muscle organ
Nerve actions movements
- Skeletal muscles can contract by the attachment of myosin to actin filaments
in muscles, which ratchets actin filaments towards the centre of cells
- Skeletal muscle has striations across its cells caused by arrangements of
contractile protein โ myosin and actin
Tendons (a fibrous connective tissue)
- Connects muscle to bone
- Inelastic soft tissue made up of strong collagen fibres that merge into bone
coverings
- Capable of resisting high tensile forces while transmitting contractile forces
from muscle to bone
- They do not contract or stretch โ they are inflexible
- However, when tendons are stressed, it can result in developing micro-tears โ
this can heal overtime but worsen if it does not rest
Fascia (Fai-shee-uh)
- Connects muscle to muscle
- It is a strong thick sheet of areolar tissue, where smaller muscles can be
attached e.g. muscles in the face are responsible for facial expressions
- It separates different muscles, protecting them while allowing them to move
alongside one another, e.g. facial muscles can move whereas the skull cannot.
- It wraps and connects the bones, muscles, nerve and blood vessels
