Muscular System Pt. 1 Flashcards
How can muscles make energy from the food we eat?
Converting it from chemical energy to mechanical energy
Allows exertion of force
What are the different types of muscle tissue?
Smooth, Cardiac and Muscle
Only muscle is attached to bone, and voluntary
When muscle contracts what happens to it in terms of length?
It shortens
What does muscle fibre mean?
A muscle cell (skeletal or smooth)
fibres because they are elongated
Why isn’t cardiac muscle associated with muscle fibre?
Fibre means that it’s elongated but cardiac muscle cells are not elongated.
What are the functions of muscle?
- Producing movement
- Maintain posture and body position
- Protecting organs, regulate passage of substances, constriction/dilation
- Generating heat
- Stabilizing joints
Describe the structure of skeletal muscle
Consciously controlled, Rich blood supply, each fibre is supplied with a nerve ending, and the cells have multiple nuclei
Require motor units in most skeletal muscle
What is a motor unit?
A single nerve (neuron) and all the muscle fibres it innervates (supplies)
What is a sarcomere and what does it contain?
A sarcomere is a repeating contractile units that make up musce fibres
Contain: myosin (thick myofilament), actin (thin myofilament), z disc (separates sarcomeres from one another)
Skeletal muscle have striations (stripes that form when sarcomeres are all lined up)
Describe the structure of smooth muscle
Elongated and look like spindles; smaller than skeletal muscle fibres and not striated because they are organized diagonally
Single neuron reaches more muscle fibres
Some have no nerve at all
Found on walls of body organs and blood vessels
Describe the structure of cardiac muscle
Have thick/thin filaments like the skeletal muscle (striated), No nerves (only rely on chemical/electrical contractions), Interconnected (contract as one)
