Muscular system Flashcards
Skeletal muscle
- Voluntary
- Controlled by somatic nervous system
- Striations
- Rapid and forceful contraction
- Multiple nucleus
- Responsible for movement, heat production and maintain posture
Smooth muscle
- Involuntary
- Controlled by somatic nervous system
- No striations
- Peristalsis
- Digestive system, blood vessels, urinary system, reproductive organs
- Facilitates movements in these organs
Cardiac muscle
- Involuntary
- Autorhythmic contractions (no neural input due to pacemaker)
- Striations with unique structure
- Wave like contractions to pump blood around body
- Functional syncytium (intercalated disks with gap junctions to allow coordinated contractions)
Epimysium
Wraps the muscle bundle as it’s the most external layer
Perimysium
Wraps the fascicle (connective tissue within epimysium shell) and is the middle layer
Endomysium
Deepest layer and wraps individual muscle fibres
Epi, peri and endomysium
Epimysium - Most external
Perimysium - Middle layer
Endomysium - Deepest layer
Sarcolemma
Muscle cell membrane
Sarcoplasmic reticulum
Organelle where calcium is stored and released and provides structure to the cell
Myofibril
Contractile elements in skeletal muscle
- Made up of numerous sarcomeres joined end to end at the z-disks
Actin
Thin protein filament
Myosin
Thick protein filament with globular heads
2 protein strands twisted together
Where does calcium bind to
Troponin C which allows for muscle contraction
Different names for muscle cell
Muscle fibre, cell or myocyte
Fascicle
Bundle of muscle fibre
