Muscular System Joshua Ojeda P.2
Major functions of the muscular system
Abdominal and lower back muscles protect vital organs in the body.
The primary function of the muscular system is to produce voluntary, gross and fine movements. Large movements consist of walking and running and small consists of writing and talking.
Cardiac muscle is involuntary and is primarily controlled by the heart's electrical system. Cardiac muscle helps provide blood circulation throughout the whole body.
The smooth muscles lined within the stomach and intestines help process the food we ingest daily. These involuntary contractions aid in the digestion and moving the food along the digestive tract, which will lead indigestible substances to the rectum.
Muscle types
Skeletal muscle
Cardiac muscle
Smooth muscle
lined within the gut and other internal organs. Not under voluntary control and contractile fibrils are not highly ordered.
connects to the skeleton and forms part of the mechanical system that helps move our body
Muscular tissue of the heart
Muscular disorders
Muscular Dystrophy
May appear in infancy, childhood or once someone has reached middle age. Different types may vary depending on the person, muscles, and symptoms. All forms start to worsen as the persons muscles becomes weaker.
Soft Tissue Sarcoma
Cancer of the soft tissue and has a variety depending on the soft tissue that is infected. May cause lumps or swelling in the soft tissue and can spread. Causes pain and difficulty breathing due to the pressing of nerves and organs.
Myositis
Inflammation of the muscles that we use to move our body. Injuries, infection or an autoimmune disease can be a cause of it. Two specific kinds are Polymyositis and Dermatomyositis
Neuromuscular disorders
Many of these are genetic and are caused by varying factors. Some neuromuscular disorders are autoimmune diseases and the cause is unknown.
Muscular Dystrophy
Amyotrophic Lateral Sclerosis
Spinal Muscular Atrophy
Structure and levels of skeletal muscles
Transverse Tubules
Long tubes are continuous with the plasma membrane
Thick and Thin filaments
Attached to one end of a Z disk and extended toward the center of the sarcomere. The thick filaments lie in the center sarcomere and overlap the thin filaments.
Fascicle
Group of muscle cells that are bundled together by collagen
Muscle Fiber
Elongated and Cylindrical
Myofibrils
Cylindrical strands of contractile proteins
Sliding filament
Thin and thick filaments slide next to one another. Using ATP as a source of energy , the Z disks are pulled closer together as a result of the sliding
Sarcoplasmic Reticulum
Membranous bags
Myosin
Thick filaments that are comprised of an elongated protein
Actin
The main protein of the thin filament
Body movement terminology
Rotation
Circumduction
Supination and pronation
Abduction and adduction
Lateral Flexion
Flexion and extension
Dorsiflexion and Plantar flexion
movements of the ankle joint
movements of the forearm
The twisting movement of the neck or body produced by the summation of the small rotational movements available between the adjacent vertebrae
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 as a circle
occurs within the coronal plane and involves mid-lateral motions of the limbs, fingers, toes and thumbs
The bending of the neck or the body towards the right or left side
Movements take place within the sagittal plane and involve anterior and posterior movements of the body or limbs
Pronation
The motion that moves the forearm from the anatomical position to the pronated position
Physiology of muscle contraction
Sliding filament theory
Explanation on how muscles contract to produce force. Actin and Myosin filaments within the sarcomeres of muscle fibers bind to create cross bridges and slide past one another, which in turn will create a contraction
The Reaction
Created from the arrival of an impulse stimulates the " heads " of the myosin filaments to reach forward, attach to the actin filaments and pull it towards the center of the sarcomere.