Wk 8 Ch 10 + 11 Flashcards
What are the three types of muscle tissue?
skeletal, smooth, cardiac
5 universal characteristics of all muscle tissue
Excitability, conductivity, contractility, extensibility, elasticity
Excitability
ability of a muscle cell (or nerve cell) to respond to a stimulus by generating an electrical signal called an action potential
Conductivity
ability of muscle tissue to transmit an electrical impulse or stimulus along its entire length, enabling coordinated muscle response
Contractility
ability of muscle tissue to shorten and generate force when stimulated, transforming chemical energy into mechanical work
Extensibility
ability of muscle tissue to be stretched or elongated beyond its resting length without damage, then return to its original shape
Elasticity
ability of muscle tissue to return to its original length and shape after being stretched or deformed, without permanent change
Functions of skeletal muscle
movement, stability, heat production, hormone secretion, glycemic control
3 Muscle cells
Skeletal muscle: muscle fiber
Cardiac muscle: cardiomyocyte
Smooth muscle: smooth muscle cell
How do muscle fibers develop?
myogenesis
What are the types of fascicular arrangements/orientations?
Fusiform muscles, parallel muscles, triangular muscles, pennate muscles, circular muscles
Aponeurosis
A broad, flat sheet of connective tissue that connects muscle to bones; tendon
Prime mover (agonist)
muscle that produces most of the force during a particular joint action or movement
Synergist
muscle that aids the prime mover by supporting the primary movement and helping to coordinate the action of a joint
Antagonist
muscle that opposes the action of the prime mover, working on the opposite side of a joint to slow, stop, or limit movement
Fixators
muscle that prevents a bone from moving, holding it steady to allow another muscle to pull on something else
How are muscles named?
location, size, shape, direction of muscle fibers, number of origins, action, attachments
Sarcolemma definition and function
- specialized plasma membrane of a muscle fiber cell
- surrounds and protects the muscle fiber, support muscle fiber excitation and contraction
Sarcoplasm definition and function
- cytoplasm of a muscle fiber
- contains cellular organelles, houses myofibrils, supports muscle fiber metabolism and contraction. stores glycogen, myoglobin, mitochondria
Myofibrils definition and function
- long protein cords that fill most of a muscle cells cytoplasm
- responsible for muscle contraction, contain myofilaments. generate muscle movement, transmit contractile force, enable muscle fiber shortening
Myofilaments definition and function
- protein strands within muscle fibers that enable muscle contraction
- generate muscle movement, transmit tactile force, create muscle tension
Transverse tubules definition and function
- tubular infoldings of the sarcolemma that penetrate through the muscle fiber
- conduct electrical signals deep into muscle fiber, trigger calcium release from sarcoplasmic reticulum, enable rapid signal transmission within muscle cell, coordinate muscle fiber excitation and contractiom
Sarcoplasmic reticulum definition and function
- specialized smooth endoplasmic reticulum in muscle cells that stores and releases calcium ions
- stores calcium ions, release calcium during muscle contractions, regulate calcium levels in muscle fiber, trigger muscle for fiber activation
Terminal cisternae definition and function
- dilated end sacs of the sarcoplasmic reticulum that cross the muscle fiber
- store calcium ions, release calcium during muscle contraction
