Functions of Muscular Tissue
Movement, thermogenesis, Storing and moving substances in body, posture
Properties of Muscular tissue
Electrical excitability, contractility, extensibility, elasticity
ability to respond to stimuli by producing action potentials.
ability to contract with force when stimulated
Ability to stretch without being damaged.
ability to return to it's original length and shape after contraction or extension.
Dense regular connective tissue
flat sheets of tendon
muscles get larger due to enlargement of fibers
Dense irregular connective tissue that protects muscles.
Holds fascicles together
generate force in myofibrils
Turn contraction on and off
keep filaments aligned, provide elasticity and extensibility
1 neuron + all cells it stimulates
Synapse between motor neuron and muscle fiber.
Sliding Filament theory
explains how muscle contraction occurs
1 molecule of ATP is used every time a cross-bridge breaks and reforms.
tension in muscle due to weak, involuntary contractions
Muscle wasting due to lack of use. Myofibrils are lost
muscle shortens in length. Produces body movements, moves objects
Muscle generates tension but does not shorten. Maintains posture, support.
how ATP is made
chemical found in sarcoplasm. Bonds to O2. Uses aerobic respiration to make ATP
Chemical found in sarcoplasm. made of chains of glucose molecules that can be released to make ATP.
Types of Fibers
Slow Oxidative fibers, Fast oxidative-glycolytic fibers, fast glycolytic fibers
Slow Oxidative Fibers (SO)
Smallest in diameter, least powerful, high myoglobin composition. Dark Red. Makes ATP aerobically. Slow contraction speed.
Fast Oxidative-Glycolytic Fibers (FOG)
Medium sized. Dark Red. Makes ATP aerobically and anaerobically. Fast contraction speed.
Fast Glycolytic Fibers (FG)
Largest in diameter. White. Makes ATP anaerobically. Fast and strong contraction speed. Fatigue easily.
Fast Glycolytic muscles
Muscles used for lifting, throwing
Slow Oxidative muscles
Muscles used for posture
Fast Oxidative-glycolytic muscles
Muscles used for walking, running.
accounts for differences in physical performance.
Increases size, strength, Glycogen, content of FG fibers.
transform FG fibers into FOG fibers.
Elongates connective tissue structures to add to elasticity of muscle tissue.
Muscle mass is slowly lost, replaced by fibrous connective and adipose tissue.
Cardiac Muscle Location
Smooth muscle fibers
elongated cells. 2 types. visceral multiunit
Visceral Smooth Muscle
Sheets of fibers in close contact found in walls of hollow organs. Fibers contract rhythmically
Multiunit Smooth Muscle
Separate fibers found in blood vessel walls. Contracts in response to motor nerve impulse or hormonal stimulation.