Exam 1 study guide flash cards
Which structure defines the borders of the sarcomere?
Z disk
Primary contractile unit of skeletal muscle
sarcomere
Also known as connectin, provides stucture and elasticity to sarcomere
titin
Intermediate filament protein that connects adjacent myofibrils
Desmin
Region of the sarcomere that becomes shorter during muscle contraction and longer during relaxation
I band
Giant protein that spans half the lenght of the sarcomere
Titin
Binds myosin to Z disk
titin
Binds calcium ions, initates muscle contraction by triggering a conformationan change
troponin
Covers the myosin binding sites on actin in relaxed muscle
tropomyosin
Region within the A band where only mysin filaments are present
H zone
Protein responsible for pulling actin filaments during muscle contraction
Myosin
Central region of the sarcomere where myosin is anchored
M line
Structural protein that cross-links actin filaments @ the Z disk
Alpha-Actinin
During which developmental stage are the body’s major organs and system developed?
Embryonic Development
Supports and binds muscle fibers, plas a role in force transmission and repair.
Basement Membrane
Which cells have the potential to fuse with damaged muscle fibers aiding in repair and regeneration?
Satellite cells
Which membrane system is responsible for releasing and storing calcium in the muscle cell?
Sarcoplasmic Reticulum
Thick filament protein
Myosin
Myocyte appearance
Long cylindrical cells with nuclei pushed to the periphery
Structure made up of sarcomeres respnsible for muscular contraction
myofibril
Process of muscle fibers increasing size after birth
Hypertrophy
Extracellular signals that play a role in muscle differentiation
-Growth Factors
-Hormones
-Neuronal Signals
What is the final product of differentiated myoblasts during muscle development?
Mature muscle fibers or myotubes
Embryonic signaling pathway that plays a vital role in the segmentation of somites
Notch signaling
Structure that stabilizes and cuncentrates AChR @ the NMJ
Basement Membrane
Where are ACh receptors densely located in a muscle cell?
NMJWh
A group of transciption factors which play a crucial role in muscle cell differentiation and development
mrfs Myogenic Regulatory Factors
This helps to maintain resing membrane potential by moving 3Na in and 2k out of the cell
Sodium Potassium Pump
Which structures in early embryonic development eventually give rise to structures like vertebrae, dermis and skeletal muscle?
Somites
Structur in a muscle cell responsible for propagating an actionpotential deep into the muscle fiber?
T tubule
Myogenesis
Phase of muscle development where myoblasts become mature muscle fibers
Differentiation
Phase where myoblasts exit the cell and begin turning into myocytes
Segmentally aligned blocks of mesoderm adjacent to neural tube
Somites
Role of Calcium Pump
Return Ca to SR after muscle contraction
Primary function of satellite cells
Muscle growth and repair
Proliferation
Phase of muscle development where myoblasts rapidly multiply
Mesoderm
Embryonic layer which muscle tissue originates from
Somite
Structure derived from mesoderm which gives rise to muscle, vertebrae, and dermis
MyoD
Myogenic regulatory factor essential for muscle development
ACh
Acetylcholine - neurotransmitter released at NMJ which stimulates muscle contraction
Na+ /K+ pump
Responsible for returning the membrane to resting potential by moving 3 na out and 2 k in against their respective concentration gradients
SR
Sarcoplasmic Reticulum Stores Ca+ ions in musle
Perimysium
Sheath of connective tissue that covers fascicles
WnT and SHH
WnT and Sonic Hedgehog: signaling pathways that play a role in muscle differentiation
AChE
Acetylcholinesterase - enzyme responsible for breaking down ACh at the NMJ
Na+
Calcium, released from SR initiats muscle contraction
Epimysium
Connective tissue sheath which covers the entire muscle organ
during muscle development what do myocytes fuse to form
Multinucleated myotubes
Plasmalemma
Sarcolemma, plasma membrane of a muscle cell
Na+ Channel
Voltage gated ion channel which allows Na+ ions to flow into the cell
K+ Channel
Potassium channel- repolarizes a cell followinig an action potential by letting potassium out of the cell
Which structures are formed from fused myocytes during muscular development?
Multinuclated Muscle Fibers
Where are Ca+ channels notably found in muscle cells that paly a role in contraction?
T tubules and SR
Channels which allow the passage of negatively charged ions across the membrane
Anion Channels
NMJ
Neuromuscular Junction - motor end plate, rich in ACh receptors, site of motor stimulatio of a muslce
