What is the plasma membrane of a skeletal muscle cell?
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What is the plasma membrane of a skeletal muscle cell?
the sarcolemma
Skeletal muscle cells or fibers are highly elongated cells with a very elastic and resistant plasma membrane, called the sarcolemma.
How are cell membrane affected in Duchenne muscular dystrophy?
This discovery led to the theory that the loss of dystrophin and associated proteins at the sarcolemma renders the membrane leaky and the muscle susceptible to contraction-induced injury.
What are inflammatory molecules called that activate the immune system to repair muscle injury?
Like mast cells, the resident neutrophils in skeletal muscles can be activated immediately after the muscle injury and release the proinflammatory cytokines including TNF-α (tumor necrosis factor alpha), IFN-γ (Interferon-γ), and IL-1β (interleukin-1β) [21], [22].
What is the membrane potential of skeletal muscle?
The resting membrane potential in skeletal muscle cells is similar to that in neurons, i.e. −70 to −90 mV.
Which of the following describes a plasma membrane of a muscle fiber?
The correct answer: The name of the plasma membrane of a muscle fiber is known as c) The sarcolemma.
What is the membrane called that surrounds a muscle?
Each muscle is surrounded by a connective tissue sheath called the epimysium. Fascia, connective tissue outside the epimysium, surrounds and separates the muscles.
What causes an increase in the muscle membrane permeability?
The most widely accepted theory to explain the increased membrane permeability is that the absence of dystrophin makes the membrane more fragile so that the stress of contraction causes membrane tears which provide the increase in membrane permeability.
How does inflammation affect skeletal muscle?
The presence of inflammatory cytokines can affect skeletal muscle through several direct mechanisms, relying on activation of the corresponding receptor expressed by muscle, and resulting in inhibition of muscle protein synthesis (MPS), elevation of catabolic activity through the ubiquitin-proteasomal system (UPS) and …
What is a skeletal muscle injury?
Muscular injuries are extremely common in athletes. Treatment of these injuries is based on a solid understanding of anatomy, physiology, and healing of skeletal muscle. Injuries discussed include contusions, hematomas, myositis ossificans, delayed onset soreness, strain, rhabdomyolysis, and lacerations.
What happens to the skeletal muscle cells when they are moved to a physiological solution without acetylcholine?
In some cases, insufficient amounts of ACh prevent normal muscle contraction and cause muscle weakness. Botulinum toxin prevents ACh from being released into the synaptic cleft. With no ACh binding to its receptors at the motor end-plate, no action potential is produced, and muscle contraction cannot occur.
How is skeletal muscle activated?
A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.
What will happen if plasma membrane will not function properly?
If the plasma membrane ruptures or breaks down, the cell will not be able to exchange material from its surroundings by diffusion or osmosis because it acts as a mechanical barrier. Thereafter, the protoplasmic material will be disappeared, and the cell will die. Was this answer helpful?
What is another name for the plasma membrane of a skeletal muscle fiber?
A skeletal muscle fiber is surrounded by a plasma membrane called the sarcolemma, which contains sarcoplasm, the cytoplasm of muscle cells. A muscle fiber is composed of many fibrils, which give the cell its striated appearance.
Which chemical is responsible for skeletal muscle fatigue?
Intracellular acidosis due mainly to lactic acid accumulation has been regarded as the most important cause of skeletal muscle fatigue.
What would happen to skeletal muscle if the epimysium were destroyed?
What would happen to skeletal muscle if the epimysium were destroyed? Muscles would lose their integrity during powerful movements, resulting in muscle damage.
What causes depolarization of the muscle membrane?
Activation of the nAChR leads to an influx of cations (sodium and calcium) that causes depolarization of the muscle cell membrane. This depolarization in turn activates a high density of voltage-gated sodium channels on the muscle membrane, eliciting an action potential.
What causes depolarization of skeletal muscle?
Skeletal Muscles The excitation of skeletal muscle by motor neurons causes the opening of voltage-gated sodium channels. The opening of sodium channels causes depolarization of the skeletal muscle.
What is the role of dystrophin in skeletal muscle function?
In skeletal and cardiac muscles, dystrophin is part of a group of proteins (a protein complex) that work together to strengthen muscle fibers and protect them from injury as muscles contract and relax.
What is the function of dystrophin in muscles How does a mutation affect the function of dystrophin?
Individuals with BMD genetic mutations make dystrophin that is partially functional, which protects their muscles from degenerating as badly or as quickly as in DMD. The dystrophin protein transfers the force of muscle contraction from the inside of the muscle cell outward to the cell membrane.
