Flashcards in Chapter 10 - Muslce Tissue Deck (208)
How does muscle tissue contribute to homeostasis?
By producing body movements, moving substances through the body and producing heat to maintain normal body temperature
What are the four key functions of muscular tissue?
1. Produce body movement
2. Stabilize body position
3. Storing and moving substances within the body
4. Generate heat
What is myology?
The study of muscles
What are the three different kinds of muscle tissue?
What is skeletal muscle tissue?
Moves the bones of the skeleton
Work in a voluntary manner
However, some are unconscious ... Muscles to maintain posture or stabilize body position, diaphragm for breathing
What is cardiac muscle tissue?
Contained only in the heart
What is autorhythmicity?
Built-in rhythm of the heart
Several hormones and neurotransmitters can adjust heart rate by speeding or slowing the automatic pacemaker of the heart
What is smooth muscle tissue?
Located in the walls of hollow internal structures (blood vessels, airways), in the skin
Non striated muscle - hence ... Smooth muscle
Some smooth muscles have autorhythmicity (gastrointestinal tract)
Part of autonomic nervous system
What is a sphincter?
Ring-like band of smooth muscle that prevents the outflow of the contents of a hollow organ
What is thermogenesis?
The heat produced from muscle tissue
What is shivering?
Involuntary contractions of the skeletal muscles can increase the rate of heat production
What are the four special properties of muscle tissue?
1. Electrical excitability
What is electrical excitability?
Ability to respond to certain stimuli by producing electrical signals called action potentials
For muscle cells, what two main types of stimuli trigger action potentials?
1. Electrical signals - autorhythmic, arising from the muscle tissue itself (heart's pacemaker)
2. Chemical stimuli - neurotransmitters released by neurons, hormones distributed by the blood or even local changes in pH
What is contractility?
The ability of muscular tissue to contract forcefully when stimulated by action potentials
What is extensibility?
The ability of muscular tissue to stretch, within limits, without being damaged
What kind of tissue allows muscle tissue to stretch?
Connective tissue - limits the range of extensibility and keeps it within the contractile range of the muscle cells
What kind of muscle tissue is subject to the greatest amount of stretching?
Smooth muscle tissue (example - stomach)
What is elasticity?
The ability of muscular tissue to return to its original length and shape after contraction of extension
What separates muscle from the skin?
Subcutaneous layer or hypodermis
Composed of areolar connective tissue and adipose tissue
Provides a pathway for nerves, blood vessels, lymphatic vessels
What is fascia?
A dense sheet of broad band of irregular connective tissue that lines the body wall and limbs and supports and surrounds muscles and other organs of the body
What are the functions of fascia?
Holds muscles with similar functions together
Allows free movement of muscles
Carries nerves, blood vessels, lymphatic vessels
Fills space between the muscle
What is the epimysium?
The outermost layer of dense, irregular connective tissue, encircles the entire muscle
What is the perimysium?
A layer of dense irregular connective tissue, surrounds groups of 10-100 muscle fibres, separating them into bundles called fascicles
What is a fascicle?
A bundle of structures, such as nerve or muscle fibres
What is the endomysium?
Penetrates the interior of each fascicle and separates each individual muscle fibres from each other
Mostly reticular fibres
What is a tendon?
Connective tissue that attaches muscle to bone
What happens if the three connective tissue layers of muscle extend beyond the muscle fibres?
Forms a ropelike tendon
Attaches a muscle to the periosteum of a bone
What is the calcaneal (achilles) tendon?
Attaches the gastrocnemius (calf) muscle to the calcaneus (heel bone)