Myofibril Banding Patterns

Involvement of muscles in neurological disease has been extensively studied over the past century. By 1830, Charles Bell had identified muscular dystrophy as a cause of progressive weakness among boys (McConville & Vincent, 2002). After extensive research, it was established that the disorder was of neurological origin. Together with other diseases such as Myasthenia gravis, Parkinson disease among others, it has been determined that muscular involvement in these diseases arises from the neuromuscular connection. More importantly, many neural transmissions occur at the muscle junctions through the actions of neurotransmitters. Any changes in the amount or structural defects of the synapse cause muscular weakness and gradually loss of function. In other severe cases, loss of nerves at the junctions causes permanent disability since nerves cannot be regenerated. This focus will examine existing literature to provide an association of muscles properties and neurological involvement.

Myoneural junction. This is where the nerve and muscle join. A synapse forms between the motor neuron and the muscle fiber. This is where the motor neuron is able to send a signal to the muscle fiber, which makes the muscle contract. The brain then sends a signal to the muscle fiber to contract. The signal moves down the neuron and gets to the chemical junction between the neuron and the muscle. The signal goes over the synapse and comes to the the muscle which in turn causes the muscle to

A synapse is the space located between the motor neuron and the skeletal muscle which is also referred to as a neuromuscular junction. The motor neurons that originate from the spinal cord, help activate the skeletal muscle fibers. The innervation happens by the processes of the axon. The synapses are present along with these processes and are also known as motor endplate. The neuromuscular junction synapse has three characteristics. It consists of two membranes called the pre and post synaptic membranes and the space between the two membranes is known as the synaptic cleft. A high density of small spherical vesicles are present and they contain neurotransmitter substances. A thickened post synaptic membranes is present and it contains a high

Skeletal muscle cells (single cell with many nuclei) are cells that are often under voluntary control. Skeletal muscle cells are attached to bones of the body and assist in bone movement. Attached to the bone via tendons (strong bands of connective tissue) is the belly of the muscle which alternates in thickness. Connective tissue also creates a sheath, binding together groups of muscle cells. Every skeletal muscle cell is arranged length ways adjacent to one another comprised of a multitude of myofibrils. Surrounding each skeletal muscle cell is the sarcolemma with contains sarcoplasm. A sarcomere has two recognisably different bands, one light, one dark. The I band is light in colour and represents where

Muscle proteins are often classified into three groups referred to as myofibrillar proteins (MP), sarcoplasmic proteins, and connective tissue or stromal proteins. The MP fraction is the structural proteins that make up the myofibrils, constitute about 55 to 60% of the total muscle protein, or 10% of fresh skeletal muscle; composed mainly of myosin, C-protein, M-protein, actin, tropomyosin, troponin complex and α-actinin among others. Sarcoplasmic and stromal proteins constitute approximately 30‒35% and 3‒10% of the total muscle proteins (Nip and others 2008).

Without the neuromuscular junction, and the action performed by exocytosis, the body simply cannot move. The neuromuscular junction (NMJ) is a specialized synapse that is responsible for commuting between the motor neuron and the muscle fiber by transmitting signals. The process of exocytosis is important as it involves the use of vesicles fusing with the plasma membrane and secreting its contents into the extracellular space. The NMJ has been extensively studied to understand its process of synaptic transmission, one of which is the muscle relaxant called Botox.

In health and science, the neuromuscular junction, is an integral part of an impressive biological amplification system, which converts nerve action potentials into muscle contraction in a quick amount of time. The mature neuromuscular junction is dividing into three parts: synpatic, post-synpatic phase and pre-synpatic phase. Synpatic transmission is the process by which signaling molecules called neurotransmitters are released by a neuron. The neuron being the pre-synpatic. The medical definition of pre-synpatic is a neuron from the axon terminal of which an electrical impulse is transmitted across a synaptic cleft to the cell body or one or more dendrites of a postsynaptic neuron by the release of a chemical neurotransmitter. Post-Synaptic

Skeletal muscle is what is attached to our skeleton, by tendons. It’s the most common out of the three types of muscle in the body. It is considered a voluntary muscle because we have direct control of moving them because of nervous impulses sent from our brain. There are different types of fibers within skeletal muscle, and not all of them contract the same. It varies depending on the type of activity and they vary in color depending on the Myoglobin content. The skeletal muscle has a very distinctive appearance. It’s long and thin, with fine red and white lines. The fibers are bound together by

The somatic nervous system comprises of nerve cells that run down the spinal cord and in between vertebrae, excluding the ones found around the face, head and neck. These nerves do not form synapses, instead they run directly into the respective muscle cells and when activated release he neurotransmitter, acetylcholine. The nerve terminals meet the muscle cells at a structure called the neuromuscular junction (Frayn, 2010, p. 222). Below is an image of a neuromuscular junction:

Each myofiber is in turn composed of hundreds of contractile organelles called myofibrils that run through the length of the myofiber. These are rod-like structures made up of protein, and are comprised of parallel protein myofilaments (Fig. 1.1). There are two types of myofilaments – thin and thick – whose major components are the proteins actin and myosin, respectively. For each thick myofilament, there are 6 thin myofilaments surrounding? Hexagonal lattice? Striated muscles are called so because of an alternating pattern of light and dark bands (or striations) that can be seen under a … microscope, and this feature was first observed in 1682 by Antonie van

The myotubes are placed in a ring and begin to put on bulk, growing into a small strand of muscle tissue.

Muscular tissue is made up of cells that have sliding protein (actin, a globular protein, and myosin) filaments. As these filaments slide over each other, they cause the cell to contract. Cells are arranged in cables within cables, twined around each other, so that when a muscle contracts, it is actually millions of cells contracting synchronously. There are three types of muscle tissue; cardiac muscle that operates in the heart; skeletal muscle which is used for locomotion (among other functions) and is found all over the body; and smooth muscle which is found in a variety of organs (such as the stomach and bladder) and in blood vessels. Smooth muscle also causes our hair to stand on end.

The axon transmits a chemical signal through a neurotransmitter, then the synapse which is located between the nerve and muscle cell called a neuromuscular junction. When released it connects with a receptor protein called the motor end plate which allows the muscles to move.

Unlike many other cells, muscle cells only appear strung together in fibers. The nucleus or nuclei of a fiber is pushed up against the edge of the membrane to make room for myofibrils within the cell. Myofibrils within the cell are part of the cytoskeleton and contain filaments of actin and myosin that work to move the muscle. These myofibrils have repeating patterns that appear as bands on muscle fibers. Each of these repeating sections is known as a sarcomere. These fibers cause the overall shape of the myocyte to be long and tubular. (Liner, 2017)

* The terminal end of the axon nears the surface of a muscle fiber at its motor end plate region (remain separated by synaptic cleft gap)