Musculoskeletal System Flashcards
The muscle responsible for voluntary movement & is therefore innervated by the somatic NS is the ?
Skeletal muscle
- Red fibers (slow-twitch): high myoglobin content & primarily derive energy aerobically
- White fibers (fast-twitch): less myoglobin; contract rapidly but fatigue quickly
What type of muscle is responsible for involuntary actions & is controlled by the autonomic nervous system ?
Smooth muscle
-Myogenic activity; can contract w/ NS input
What is the basic contractile unit of skeletal muscle ?
Sarcomere (composed of actin & myosin)
What are the different lines, zones, & bands of sarcomeres ?
Z-line: boundaries of each sarcomere M-line: center of sarcomere I-band: only thin filaments H-zone: only thick filaments A-band: thick filaments in their entirety (contains overalp w/ thin filaments)
Sarcomeres are attached to form ?
Myofibrils
- Surrounded by sarcoplasmic reticulum: modified ER w/ high Ca2+
- Sarcoplasm & sarcolemma: cytoplasm & cell membrane
The configurational change caused by Ca2+ binding to troponin results in what being exposed ?
Myosin-binding sites
What is the difference between the axial & appendicular skeleton ?
Axial provides the basic central framework of the body, while appendicular consists of the bones of limbs.
The classification of strength in terms of bone is derived from ?
Compact bone
*Other type is spongy (cancellous) bone: consist of trabeculae
What is the difference between red & yellow bone marrow ?
Red is filled w/ hematopoietic stem cells (responsible for generating all cells of the body), & yellow is composed primarily of fat & is relatively inactive
What surrounds the long bone to protect it & also serves as a site for muscle attachment ?
Periosteum
What are the functions of tendons & ligaments respectively ?
T attach muscle to bone & ligaments hold bones together @ joints
