Chapter 6 Part 1 (Muscular System) Flashcards
What are the 3 types of muscle tissue and their location?
- Skeletal, attached to bones
- Cardiac, walls of the heart
- Smooth, walls of hollow organs
Define muscular system.
The system in the body composed of muscle cells and tissues that brings about movement of an organ or body part.
What is the endomysium?
Connective tissue that sheath each muscle cell
What is the function of perimysium?
To envelope bundles of muscle fibers
What is the epimysium?
Tougher “overcoat” of connective tissue surrounding a muscle
What is the role of tendon?
Connect muscles to bones, allowing us to move
What is the aponeurosis?
A fibrous or membranous sheet connecting a muscle and the part it moves
What is the role of actin and myosin filaments in muscles?
In muscle cells, actin filaments are aligned and myosin proteins generate forces on the filaments to support muscle contraction.
What is actin?
Principle contractile proteins found in muscle
What is the sarcolemma?
The plasma membrane of the muscle fiber.
Explain the steps of an action potential.
- Calcium channels open, and calcium enter the terminal
- Calcium entry causes release of acetylcholine (ACh).
- ACh diffuses across the synaptic cleft and attaches to membrane receptors.
- Sodium ions enter the cell and potassium ions leave the cell. More sodium ions enter the cell than potassium ions leaving the cell causing a positive cell interior. (This is called depolarization.)
- This movement of ions crat an electrical current called an action potential.
- To prevent continuous contractions muscle fibers relax until stimulated by ACh again.
What is graded response?
A response that varies directly with the strength of the stimulus.
What is a unfused tetanus?
Muscle contraction in which the muscle does not completely relax between stimulation events.
What is a isometric contraction
Muscle contraction without motion
What is muscle tone?
Sustained partial contraction of a muscle in response to stretch receptor inputs
