ch.10 muscle tissue Flashcards
What are the three muscle types?
- Skeletal
- Cardiac
- Smooth
Is Skeletal muscle involuntary or voluntary?
Voluntary
Is cardiac muscle voluntary or involuntary?
Involuntary
Is smooth muscle involuntary or voluntary?
Involuntary
What is auto rhythmic?
Automatic. Able to generate an action potential without external stimulation by nerve cells.
What muscle type(s) are auto rhythmic?
- Smooth
- Skeletal
- Cardiac
Smooth and Cardiac muscles
Muscle cells specialize in what?
Contractions
What does each organ or muscle consist of?
Skeletal muscle tissue, nerves, blood vessels, and connective tissue
What are the functions of a skeletal muscle?
Movement posture Guard entrances and exits of the urinary and digestive systems Protect and support produces heat store nutrients
What is in a muscle organ?
Muscle fiber and muscle fascicle
Where are muscle fibers found?
Inside the muscle fascicle
Where are muscle fascicles found?
Muscle fascicles are found in the skeletal muscle
What is a muscle fascicle?
A bundle of cells
What are the three layers of connective tissue in a skeletal muscle?
Epimysium
Perimysium
Endomysium
What is the perimysium?
Surrounds the muscle fascicles and contains blood vessels and nerves
What is the Endomysium?
Surrounds individual muscle cells (fibers) within the fascicle
What is epimysium?
Surrounds the entire skeletal muscle and it contains a dense layer of collagen fibers.
What is the plasma membrane of a muscle cell?
Sarcolemma
What is sarcoplasm?
Cytoplasm of the muscle cell
What are myofibrils?
Bundles of protein filament
What do myofibrils contain?
thick and thin filaments
What are thick filaments composed of?
Myosin
What are thin filaments composed of?
Actin
What do myofibrils do?
Responsible for muscle contractions and movement
What does sarcolemma develop?
Develops a membrane potential due to active transport of ions
What is a membrane potential charge?
-70mV
What does -70mV mean?
Muscle is at rest
What are t-tubules?
Narrow tubes that are continuous with the sarcolemma
What is sarcoplasmic reticulum?
A membrane complex related to the endoplasmic reticulum.
It forms a tubular network around each myofibril
Muscle contraction occurs when calcium in the sarcoplasmic reticulum is released into the sarcoplasm.
What happens to calcium in the sarcoplasmimc reticulum when muscles contract and relax?
Calcium is released for contraction and returns when relaxed
What is a sarcomere?
A functional repeating unit in the myofibril
What causes the dark and light color difference in sarcomeres?
Protein density
What does the a band consist of?
The thick filaments in the center of the sarcomere
What is the m line?
The central portion of the thick filaments (the middle)
What is the h-zone?
The light region of the sarcomere structure
Contains only thick filaments
What is the zone of overlap?
The overlap of thick and thin filaments
What does the I band contain?
Thin but not thick filaments
What does the z line mark?
The boundary of the sarcomere
What proteins does the thin filaments contain?
Actin, tropomyosin, troponin
What proteins does the thick filaments contain?
Myosin
What do myosin heads do?
what causes contractions by pulling actin (found in the z line) inward.
When the muscle fiber contracts, the I bands get what?
Smaller
When the muscle fibers contract the zones of overlap get what?
larger
When the muscle fiber contracts the z line gets what?
Closer together
When the muscle fiber contracts the width of A band gets what?
Remains constant
What signals muscles to contract?
Action Potential (electrical impulses)
