Muscle Tissue

Elasticity

The ability of muscle tissue to return to is original length + shape after contraction or extension

Four special properties that enable muscle tissue to function + contribute to homeostasis

Electrical excitability, contractility, extensibility, elasticity

Skeletal muscle tissue

Function to move bones of the skeleton, tissues are striated, alternating dark + light bands, works in a voluntary manner: can be consciously controlled by neurons of the somatic (voluntary) division of the nervous system, most skeletal muscles are controlled subconsciously to some extent, muscles of the diaphragm work while we sleep and the stabilizer muscles that help maintain our posture stabilize body positions

Extensibility

ability of muscle to stretch without being damaged, allows a muscle to contract forcefully even if it is already stretched, smooth muscle is subject to the greatest amount of stretching, cardiac muscle stretches each time it beats, stretch on skeletal muscles remains almost constant

Smooth muscle tissue

Located in the walls of hollow internal structures such as blood vessels, airways, + most organs in the abdominopelvic cavity, in the skin attached to hair follicles, lacks striations thus the term "smooth", action is usually involuntary, some tissues have autorhythmically, is part of the autonomic (involuntary) division of the nervous system, also controlled by hormones released by the endocrine glands

Main differences between the three muscle tissues

Microscopic anatomy, location, control by the nervous and endocrine system

Producing body movements

Movements of all types regardless of how big or small rely on the integrated functioning of bones, joints, + skeletal muscles

generating heat

Muscle contractions produce heat by a process known as thermogenesis, used to maintain normal body temperature, involuntary contractions of skeletal muscle called shivering can increase the rate of heat production

Cardiac muscle tissue

Only the heart has cardiac muscle tissue, forms the heart wall, they are striated but the action is involuntary, the alternating contraction and relaxation of the heart is not consciously controlled, heart has a pacemaker that initiates every contraction with a chemical and electrical impulse, this intrinsic rhythm is termed autorhythmicity, hormones and neurotransmitters adjust the heart rate

Storing + moving substances within the body

Ring like bands of smooth muscle fibers called sphincters control the outflow of the contents of a hollow organ, urinary, intestinal, + reproductive tracts, smooth muscles in the blood vessels control the flow of blood, skeletal muscle contractions promote the flow of lymph + aid in the return of blood to the heart

Three types of muscle tissue

skeletal, cardiac, smooth

Stabilizing body positions

Skeletal muscles contraction stabilize joints + help maintain body positions, postural muscles contact continuously when we are awake

electrical excitability

the ability to respond to certain stimuli by producing electrical signals such as action potentials, in simple terms, muscles respond to electrical signals created by such things as a pacemaker in the heart, chemical stimuli such as neurotransmitters released by neurons, or hormones in the blood

Contractility

Ability of muscle tissue to contract forcefully when stimulated to do so, muscle contraction generates tension while pulling on its attachment points. isometric contraction- muscle develops tension but does not shorten. Isotonic contraction- tension great enough to overcome the resistance of the object, muscle shorten + movement occurs, tension remains almost constant

The four major functions of muscle tissue

Producing body movements, stabilizing body positions, storing + moving substances within the body, generating heat