Module One, Lecture Eight Flashcards
Skeletal Muscle Structure and Function (15 cards)
What are the types of Muscle in the Human Body? ( 3 )
- Smooth
- Cardiac
- Skeletal
Describe the structure and function of Smooth Muscle… ( 5 )
- Spindle-shaped with a central elongated nucleus
- Involuntary movements in the body
- Controlling organ size, wall movement and stiffness
- Regulating blood vessel diameter, allowing food to move through the digestive system
- Enables bladder control
Describe the structure and function of Cardiac Muscle… ( 3 )
- Branched shape, intercalated discs which form a network that facilitates rapid coordinated contraction ( heartbeat )
- To contract rhythmically and involuntary
- Generates the force needed to pump blood through the entire body
Describe the structure and function of Skeletal Muscle…
- Complex structures composed of various layers of connective tissue, muscle fibres, and cellular components
- Production of voluntary movements
- Maintaining Posture
- Stabilizing Joints
Detailed Structure of Skeletal Muscles… ( 4 )
- Individual muscle cells are called muscle fibres that are gathered into bundles called fascicles
- Fibres, fascicles, and muscles are sheathed in connective tissue
- Connective tissue is gathered to form tendons, which connect muscles to bones
What is a Muscle Fibre comprised of?
Myofibrils which are made of repeating units called sacromeres
What are Sacromeres made of? ( 2 )
- Actin ( thin filaments )
- Myosin ( thick filaments
What is the Cell Membrane that lines the Muscle Fibre?
The Sarcolemma
What are Transverse Tubules?
Tube-like extensions of the sarcolemma
What is the function of T-Tubules? ( 3 )
- Excitation-Concentration Coupling
- Signal Transmission
- Calcium Release
Define Excitation-Contraction Coupling…
The process by which an electrical signal ( action potential ) triggers a muscle fibre to contract
Define Signal Transmission…
The facilitation of the AP into the cell’s interior, ensuring that the entire muscle fibre is activated simultaneously
Define Calcium Releasing…
The arrival of the AP at the T-Tubules triggers the release of calcium from the sarcoplasmic reticulum ( SR )
What is the function of the Sarcoplasmic Reticulum?
Take up and store calcium while the muscle is relaxed, then to release calcium into the cytoplasm when the muscle contracts