Lecture 7 Flashcards
Where is smooth muscle found and is it under voluntary control?
Found in hollow organs (e.g., gut, blood vessels) and is not under voluntary control.
Where is cardiac muscle located and is it under voluntary control?
Located only in the heart and is not under voluntary control.
What is the primary function of skeletal muscle?
To apply force to bones to control posture and body movements, mostly under voluntary control.
What are muscle fibres and how are they organized in skeletal muscles?
Individual muscle cells that gather into bundles called fascicles, which bundle into muscles.
What do muscle fibres, fascicles, and muscles contain?
Many blood vessels and nerves, sheathed in connective tissue.
What is the role of tendons in skeletal muscles?
Connect muscles to bones.
What are myofibrils and what are they made of?
Bundles within muscle fibres made of repeating units called sarcomeres.
What are sarcomeres and what do they contain?
Repeating units in myofibrils made of contractile proteins: actin (thin filaments) and myosin (thick filaments).
What is the sarcolemma?
The cell membrane of a muscle fibre.
What are transverse tubules (T-tubules) and their function?
Tube-like extensions of the sarcolemma that conduct electrical signals deep into the muscle fibre.
What is the sarcoplasmic reticulum (SR) and its function?
A membrane network that stores and releases calcium (Ca2+) during muscle contraction.
