Slide set 5 Flashcards
Muscle cell is
Muscle fiber
Cell membrane in muscle is
Sarcolemma
Cytoplasm in muscle is
Sarcoplasm
Modified ER in muscle is
Sarcoplasmic reticulum
Skeletal muscles are usually attached to
Bones and tendons
What are flexor and extensor
Flexor muscles- brings bones together
Extensor- moves bones away
Antagonistic pair: flexor-extensor pair
Properties of skeletal muscles and their function
Responsible for moving the framework of the body
•Can contract rapidly but tires easily
•Remarkably adaptable
•Function: Maintain posture and body position
•Movement of the body as a whole or of its parts
•Stablilizejoints
•Heat production
•Contract only in response to a signal from a motor neuron
Skeletal muscles are surrounded by ___, muscles divide into ___, where you can find individual muscle fibers
Connective tissue
Muscle fascicle
What are epi,peri and endomysium
Epimysium—coarse sheath covering the muscle as a whole
–Perimysium—tough connective tissue binding together fascicles
–Endomysium—connective tissue membrane that covers skeletal muscle fibers
–These three fibrous components are continuous with eachother and with the tendon
Characteristic of muscle fibers to movement
Excitability—ability to be stimulated
Contractility—ability to contract, or shorten, and produce body movement
Extensibility—ability to extend, or stretch, allowing muscles to return to their resting length
What is the role of SR in muscle
Plays a role in Ca+regulation during contraction
What are T tubules
extend across the cell. They are formed from inward extension of the sarcolemma.
–T-tubules chief function is to allow electrical signals traveling along the sarcolemma to move deeper into the cell
–Requirement for contraction
What is the triad
formed from a triplet of tubules made of the sacroplasmic reticulum which surrounds the T-tubule
–This arrangement allows a signal traveling along the T-tubule to stimulate adjacent membranes on the SR
Muscle fibers contain many ____
Mitochondira and multiple nuclei
What is sacromere
Segment of myofibril between two successive Z lines
•Each myofibril consists of many sarcomeres
•Contractile unit of muscle fibers
Sacromerers are a part of
Myofibril
Z lines function
an anchor for the myofibrils
Muscle fibers are made up of smaller units ___, which are made up from _____ that can be thick and thin. Thick is made up from ____ and the thin from ____
Myofibrils, myofilaments, myacin, actin
The bands of sacromere that are made only of thin microfilaments are ___ and thick microfilaments are ___
I band
H zone
What is A band
Where there is an overlap of thick filaments and thin filaments + H zone
Sacroplasm contains
SR
Myofibrils
Mitochodnria
Glycogen granules (energy)
Thin filaments in addition to actin are made up from
troponin
tropomyosin
What microfilamants play regulational role on muscle contraction
Titin
Nebulin
Thick myosin filaments do not attach to ___
Z lines