Human Anatomy - Muscle tissue Flashcards
Muscle is the primary tissue in the ______, _____ of ______ _____ and attached to the ________.
Indicate which type of muscle corresponds to each case.
Muscle is the primary tissue in the heart (cardiac), lining the walls of hollow organs (smooth) and attached to the skeleton (skeletal).
Muscle tissue makes up nearly ____ the body mass, around ___%.
Half, 40
What are the function of muscle tissue. Indicate which type of muscle provides the function.
Producing body movements - skeletal
Stabilizing body positions/posture/joints - skeletal (tone)
Movement of substances within the body - smooth for digestive; cardiac for heart
Opening and closing passageways (sphincters - skeletal or smooth)
Producing heat - (shivering) skeletal
What is muscle tone?
Involuntary contraction of a small number of muscle fibres.
Keeps the muscles firm even though they are relaxed.
Does not produce movement.
Tone is essential for what?
Posture, stabilizing synovial joints, maintaining blood pressure.
What are the properties of muscle tissue?
Contractibility
Excitability
Extensibility
Elasticity
Describe contractiblity.
Muscle cells can contract to generate force.
Describe excitability.
Muscle cells are innervated by nervous impulses.
Describe extensibility.
Muscles can be stretched, especially when opposing muscles contract.
Describe elasticity.
Once stretches, muscles can recoil back to their original length
How is muscle tissue characterized?
1 - Presence or absence of striations.
2 - If the tissue is under voluntary or involuntary control
Describe skeletal muscle. How is it characterized? What does it attach to.
Long, multinucleated cells.
Striated, light and dark bands visible under microscope.
Under voluntary control.
Attaches to bone, skin, fascia.
Describe cardiac muscle.
How is it characterized?
Where is it found?
Shorter in length compared to skeletal muscle, branched and attached by intercalated discs. Uninucleate.
Under involuntary control and striated.
Principle tissue of the heart wall.
Intercalated discs are composed of what tissue type?
Connective tissue
Describe smooth muscle.
How is it characterized?
Where is it located?
Spindle shaped muscle cells with central nuclei.
Non-striated under involuntary control
Walls of hollow organs of the urinary tract, in the respiratory tubes, GI tract, blood vessels and as the erector pili muscle.
Describe the similarities in muscle tissue.
In both skeletal and smooth muscle, muscle cells are know as fibres.
The myofilaments, actin and myosin, are similar in all three muscle tissues.
The plasma membrane is called the sarcolemma.
The cytoplasm is called the sarcoplasm.
The ER is called the SR.
Each muscle is considered an ______.
Other than muscle tissue, it contains what?
Organ
Connective tissue
Blood vessels (endothelium and muscle)
Nerves (Nervous tissue)