Muscular System Crystal Ramirez P.1 (Body movement Terminology (Flexion…
Muscular System Crystal Ramirez P.1
Skeletal muscles help keep the body in the correct position when someone is sitting or standing. This is known as posture.
Good posture relies on strong, flexible muscles. Stiff, weak, or tight muscles contribute to poor posture and misalignment of the body.
Long-term, bad posture leads to joint and muscle pain in the shoulders, back, neck, and elsewhere.
Breathing involves the use of the diaphragm muscle.
The diaphragm is a dome-shaped muscle located below the lungs. When the diaphragm contracts, it pushes downward, causing the chest cavity to get bigger. The lungs then fill with air. When the diaphragm muscle relaxes, it pushes air out of the lungs.
When someone wants to breath more deeply, it requires help from other muscles, including those in the abdomen, back, and neck.
Smooth muscles in the gastrointestinal or GI tract control digestion. The GI tract stretches from the mouth to the anus.
Food moves through the digestive system with a wave-like motion called peristalsis. Muscles in the walls of the hollow organs contract and relax to cause this movement, which pushes food through the esophagus into the stomach.
The upper muscle in the stomach relaxes to allow food to enter, while the lower muscles mix food particles with stomach acid and enzymes.
Abductor Longus-The adductor longus is located on the inner thigh. The adductor longus muscles on the inner thighs allow the thigh bone to move inward and to the side.
Pectoralis major- the pecsThe pectoralis major is a large, fan-shaped muscle. It covers much of the front upper chest, beginning at the sternum including the second to the sixth ribs.
The pectoralis major attaches to the clavicle and converges on the humerus, just below the shoulder. This muscle moves the arm across the body.
deltoid-The deltoids are the triangular muscles of the shoulder. The strongest point is the central section, which raises the arm sideways. The front and back parts of the muscle twist the arm.
Muscle Tissue and Major function
smooth muscle tissue- allows for contraction and relaxation with great elasticity.
Skeletal muscle tissue-is used to effect skeletal movement such as locomotion and to maintain posture.
Cardiac muscle is specialized tissue that is found only in the heart. It has characteristics similar to both smooth and skeletal muscle tissue, as well as specialized properties, that allow it to function with fast but sustained contractions, rapid conduction and coordinated movement.
Body movement Terminology
Flexion and extension are movements that take place within the sagittal plane and involve anterior or posterior movements of the body or limbs
Abduction and adduction motions occur within the coronal plane and involve medial-lateral motions of the limbs, fingers, toes, or thumb.
Circumduction- is the movement of a body region in a circular manner, in which one end of the body region being moved stays relatively stationary while the other end describes a circle.
Rotation- can occur within the vertebral column, at a pivot joint, or at a ball-and-socket joint. Rotation of the neck or body is the twisting movement produced by the summation of the small rotational movements available between adjacent vertebrae.
Supination and pronation are movements of the forearm
Dorsiflexion and plantar flexion are movements at the ankle joint, which is a hinge joint
Inversion and eversion are complex movements that involve the multiple plane joints among the tarsal bones of the posterior foot and thus are not motions that take place at the ankle joint
Protraction and retraction are anterior-posterior movements of the scapula or mandible
Depression and elevation are downward and upward movements of the scapula or mandible
Excursion is the side to side movement of the mandible.
structure and organizational levels of the skeletal muscle
The endomysium is the connective tissue surrounding individual muscle fibers, and they're packed within a fascicle. Myofibrils are organelles within the muscle cell that contain thick and thin myofilaments. The myofilaments are organized into sarcomeres, and they serve as the functional units of skeletal muscle.
physiology of muscle contraction
The sliding filament theory is the explanation for how muscles contract to produce force. the actin and myosin filaments within the sarcomeres of muscle fibres bind to create cross-bridges and slide past one another, creating a contraction. The sliding filament theory explains how these cross-bridges are formed and the subsequent contraction of muscle.
For a contraction to occur there must first be a stimulation of the muscle in the form of an impulse from a motor neuron.The motor end plate is the junction of the motor neurons axon and the muscle fibres it stimulates.When an impulse reaches the muscle fibres of a motor unit, it stimulates a reaction in each sarcomere between the actin and myosin filaments. This reaction results in the start of a contraction and the sliding filament theory.
muscular dystrophy(muscle weakening diseases)
tendinosis (degenerative tendon disease)
fibromyalgia (chronic pain)
mitochondrial myopathy (mitochondria ATP disorder)
myasthenia gravis (immune system problem)
etanus (paralyzing bacterial infection).