"A neuromuscular junction (or myoneural junction) is a chemical synapse between a motor neuron and a muscle fiber. It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction."
The study of the nervous system and how it controls and coordinates muscular activity, including the structure and function of neurons, muscle fibers, and motor units.
Neuromuscular junction: The site where the motor nerve meets the muscle fiber and communication takes place.
Motor unit: The basic functional unit of muscle, consisting of a motor neuron and all the muscle fibers it stimulates.
Muscle contraction: The process by which muscle fibers generate tension and force.
Types of muscle fibers: Slow-twitch and fast-twitch muscle fibers, which differ in their contractile properties.
Muscle fiber recruitment: The process by which motor units are activated to produce varying levels of tension.
Energy sources for muscle contraction: ATP and various metabolic pathways that produce energy necessary for muscle contraction.
Muscle fatigue: The decline in muscle performance due to prolonged or intense exercise.
Muscle hypertrophy: The increase in muscle size and strength due to resistance exercise or high-intensity training.
Muscle atrophy: The decrease in muscle size and strength due to inactivity, aging, or injury.
Neural adaptation to exercise: The changes in the nervous system that occur in response to exercise training.
Stretch reflex: The automatic contraction of a muscle in response to stretching.
Golgi tendon organ reflex: The protective mechanism that prevents overloading and injury to the muscle-tendon unit during contraction.
Muscle spindle reflex: The sensory feedback system that monitors muscle length and velocity of movement.
Proprioception: The sense of the relative positions of body parts and the strength and direction of movement.
Electromyography (EMG): The measurement of electrical activity in muscles during contraction.
Neuromuscular adaptations to aging: The changes in muscle function, structure, and metabolism that occur with age.
Central fatigue: The decline in motor output due to changes in the central nervous system.
Neuromuscular adaptations to injury or disease: The changes in muscle function and structure that occur in response to injury or disease.
Strength Training: This type of exercise physiology focuses on building muscle and gaining strength through exercises such as weightlifting, bodyweight exercises, and resistance training.
Endurance Training: Endurance training is aimed at improving the body's ability to deliver and utilize oxygen, which is key to enhancing endurance performance. This type of exercise physiology involves activities such as running, swimming, and cycling.
Speed and power training: Speed and power training are important for improving athletic performance. This type of exercise physiology involves exercises that help to increase muscle speed and power, such as sprinting and explosive jumps.
Flexibility and mobility training: This is aimed at improving joint range of motion and helps to alleviate stiffness and soreness. Exercises that fall into this category include stretching and yoga.
Neuromuscular training: This type of exercise physiology aims to improve coordination and neuromuscular control. Neuromuscular training can be useful for injury prevention and improving sports performance.
Cardiovascular training: Cardiovascular training focuses on developing the heart and cardiovascular system. This type of exercise physiology includes activities such as running, cycling, and swimming.
Cross-training: Cross-training involves engaging in a variety of exercises to improve overall health and fitness. This can include a combination of strength training, endurance training, and flexibility training, among others.
Rehabilitation: Rehabilitation exercise physiology involves exercises designed to help individuals recover from injuries, illnesses, or surgeries. Exercises are often focused on improving strength, mobility, and coordination.
"Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy."
"In the neuromuscular system, nerves from the central nervous system and the peripheral nervous system are linked and work together with muscles."
"Synaptic transmission at the neuromuscular junction begins when an action potential reaches the presynaptic terminal of a motor neuron."
"Calcium ions bind to sensor proteins (synaptotagmins) on synaptic vesicles, triggering vesicle fusion with the cell membrane and subsequent neurotransmitter release from the motor neuron into the synaptic cleft."
"In vertebrates, motor neurons release acetylcholine (ACh), a small molecule neurotransmitter."
"Acetylcholine diffuses across the synaptic cleft and binds to nicotinic acetylcholine receptors (nAChRs) on the cell membrane of the muscle fiber."
"nAChRs are ionotropic receptors, meaning they serve as ligand-gated ion channels."
"The binding of ACh to the receptor can depolarize the muscle fiber, causing a cascade that eventually results in muscle contraction."
"Neuromuscular junction diseases can be of genetic and autoimmune origin."
"Genetic disorders, such as Congenital myasthenic syndrome, can arise from mutated structural proteins that comprise the neuromuscular junction."
"Autoimmune diseases, such as myasthenia gravis, occur when antibodies are produced against nicotinic acetylcholine receptors on the sarcolemma."
"An action potential reaches the presynaptic terminal of a motor neuron, which activates voltage-gated calcium channels to allow calcium ions to enter the neuron."
"Calcium ions bind to sensor proteins (synaptotagmins) on synaptic vesicles, triggering vesicle fusion with the cell membrane and subsequent neurotransmitter release from the motor neuron into the synaptic cleft."
"Acetylcholine (ACh) is responsible for transmitting signals from the motor neuron to the muscle fiber."
"Nicotinic acetylcholine receptors (nAChRs) on the sarcolemma bind to acetylcholine and initiate a cascade that leads to muscle contraction."
"When antibodies are produced against nicotinic acetylcholine receptors, as in myasthenia gravis, it can affect the functionality of the neuromuscular junction."
"Motor neurons transmit signals to muscle fibers through the neuromuscular junction, leading to muscle contraction and coordinated movement."
"The release of neurotransmitter, such as acetylcholine, at the neuromuscular junction initiates a series of events that eventually result in muscle contraction."
"Muscles require ongoing innervation and maintenance of muscle tone to avoid muscle atrophy and ensure proper functionality."