Muscular System Flashcards
Movement
Contraction pulls on insertions where a tendon attaches to a bone or other tissue
Posture
By producing muscle tone with continuous contractions to stabalize joints.
Thermogenesis
Metabolism can be regulated to produce heat and warm the body temperature
Excitability
Muscles respond to stimuli. In the case of skeletal muscles, we will see that the stimulus comes from a motor neauron
Contractility
Muscles can shorten when stimulated
Cardiomyocyte
have a central round nucleaus and for cell junctons called intercalated discs
Intewrcalated discs
Disks that contain desmosomes and gap junctions
Striations
Alternating light and dark bands (stripes)
Contraction is:
Voluntary
Functional properties of smooth muscles are:
Involuntary
Fibers
Long, striated cells that contain multiple nuclei
Fascicle
A bundle of skeletal muscle fibers
Origin
Location where a tendon attaches to a bone that remains stationary during the action produced by contraction of that skeletal muscle
Insertion
Attachment that moves during the action produced by contraction
Epimyysium
Superficial covering of fibrous CT that encloses the skeletal muscle organ and connects to the tendons
Perimysium
Fibroud CT covering bundles of muscle fibers called fascicles
Endomysium
Areolar CT covering individual fibers within a fascicle
Sarcolemma
Plasma membrane of a muscle fiber
Myofibril
Non-membranous organelles withinmuscle fibers made of repeating structural and functional units called sarcomeres
Sarcoplasmic Reticulum
Membranous organelles similar to smooth endoplasmic reticulum surrounding myofibrils
Myofilaments
Fibrous proteins within myofibrils that produce contraction
Myosin ATPase
Motor Proteins
Actin
Cytoskeletal protein supports shape of the cell and contains binding sites for myosin
Troponin
Calcium sensor protein
Tropomyosin
Fibrous Protein covers myosin binding sites of actin
Z-Lines
End of sarcomere contain proteins that anchor thin filaments in place
A-Band
Entire length of the thick filaments
I-Band
Only thin filaments with no overlap of thick filaments
H-Band
Central region of thick filoaments with no overlap of thin filaments
M-Line
Center of H-Band
Axon terminal
End of motor neauron that releases neaurotransmitters to excite msucle fiber
Motor end plate
Sarcolemmal surface adjacent to axon terminal that has receptors that detect neurotransmitters
Synaptic Cleft
Small space between the axon terminal and motor end plate
Motor Unit
A motor neauron and all the muscle fibers it excites
Parallel (non-fusiform)
Fibers run straight from origin to insertion
Parallel Fusiform
Spindle shaped large belly tapers at ends
Convergent
Spread out broadly at the origin but come together to a narrow tendon for the insertion
Circular
Fascicles form concentric rings that surround an opening
Pennate
Fibers arranged at an oblique angle to a tendon
Unipennate
All muscle fibers on same side of the tendon
Bipennate
Fibers on both sides of the tendon
Multipennate
Tendon branches within the muscle
Prime Mover
Main muscle responsible for the action
Antagonist
Muscle that stretches and stabilizes in support of the action of the antagonist
Synergist
Muscles assist by adding additional force for movement or stability.
