Muscular, Nervous, And Skeletal Systems Flashcards
A types of muscle
Smooth, cardiac, skeletal
Muscle generate force when they are activated. This is referred to as
Muscle contraction or muscle action
Connective tissue that surrounds the muscle
Epimysium
Bundles of muscle fibers
Fasciculus or fascicle
Connective tissue covering fascicle or fasciculus
Perimysium
Each muscle fiber is surrounded by
Endomysium
Which connective tissues help transmit forces
Epimysium Perimysium Endomysium & Tendon
A muscle fiber is a
Cell that is specialized to contract and generate force (tension)
What is a muscle fiber surrounded by?
A plasma membrane called sarcolemma
Function is sarcolemma
Encloses the muscle fiber contents
Regulated the passage of materials such as glucose
Receives and conducts stimuli in the form of electrical impulses or action potentials
Nuclei in muscle cells
Multinucleated as a result of embryonic fusion.
Contain DNA of the cell.
Largely responsible for adaptation to exercise (hypertrophy), adaptation to resistance training and aerobic endurance.
Within the sarcolemma is the cytoplasm called
Sarcoplasm
What energy sources are contained in the sarcoplasm?
ATP (the only direct source)
Phosphocreatine
Glycogen
Fat droplets
What organelles are in the sarcoplasm
Mitochondria (site of aerobic ATP production) Sarcoplasmic reticulum (stores calcium and regulates muscle action by altering intercellular concentration)
Specific function is sarcoplasmic reticulum.
Releases calcium into the sarcoplasm when an action potential passes to the interior of the cell via the transverse tubules.
Transverse tubules are
Channels that form from openings in the sarcolemma.
Myofibril
Columnar protein structures that run parallel to the length of the muscle fiber and contain myofilaments.
Myofilaments consist of
Myosin and actin that are arranged in a regular pattern.
Myosin filaments are
Thick
Formed from an aggregation of myosin molecules
Each molecule consists of a head, neck, and tail.
Are kept in position by the protein titin.
Actin filaments are
Thin
Formed from globular or g-actin proteins with binding sites for myosin heads.
G-actins form strands of filaments or F-actin
Contain two regulatory protein structures- tropomyosin and troponin.
Troponin
Binds to calcium and causes movement of tropomyosin away from the binding sites on actin.
Protein nebulin
Ensures the correct length of the actin filaments
Sarcomere
The contractile unit of muscle.
Extends from z line to z line.
Z-line
At the end of a sarcomere.
Anchors for actin filaments within and the connecting sarcomeres.
Actin’s extend inward from z lines.
A band
The width of a myosin filament
The dark striation of skeletal muscle.
H zone
The area of the A band that contains the myosin without the overlapping actin..