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Yaretzi Torres Per.5 Muscular system - Coggle Diagram
Yaretzi Torres Per.5 Muscular system
Disorders associated with the muscular system
Myasthenia Gravis: Neuromuscular disorder that blocks neurotransmitter
Causes and risk factors: Autoimmune, possible tumor of thymus, age.
Cerebral Palsy: Spastic paralysis causing muscle weakness
Causes and risk factors: Brain injury or abnormality. Hypoxia during premature birth.
Fibromyalgia: Muscle pain
Causes and risk factors: Physical trauma, abnormal pain response, sleep disturbances.
Myositis: Inflammation of the muscle
Causes and risk factors: Autoimmune, infection, medication induced.
Muscles Dystrophy: Muscle weakness and atrophy
Causes and risk factors: Genetic, Different types depending on mutation, ex: Duchenne.
Names of all the skeletal muscles(including the fascial muscles)
Frontalis
Masseter
Orbicularis Oris
Sternocleidomastoid
Orbicularis Oculi
Sternohyoid
Temporalis
Zygomaticus
Trapezius
Deltoid
Serratus anterior
Brachialis
Biceps brachii
Brachioradialis
Pronator teres
Flexor Carpi radialis
Palmaris Longus
Flexor carpi ulnaris
external oblique
illiopsas
Rectus abdominis
Pectinius
Adductor Longus
Vastus lateralis
Vastus medialis
Rectus femoris
Sartorius
Gracilis
Tenor fascia lata
Fibularis Longus
Tibialis anterior
Extensor digitorium Longus
soleus
pectoralis major
Posterior
Extensor digitorium
Extensor carpi radialis Longus
Triceps brachii
Teres major
Teres minor
Infraspinatus
Extensor Carpi ulnaris
Rhomboid
Latissimus dorsi
Gluteus medius
Semitendinosus
Biceps femoris
Semimembranous
Adductor magnus
Gastrocnemius
Action potential in a muscle fiber
EPP (end plate potential) causes a wave of depolarization that spreads to adjacent sarcolemma.
Depolarization, generates and propagates an action potential (AP).
The AP then depolarizes the muscle membrane/sarcoplasmic reticulum to release Ca+ ions.
Producing attractive forces between myosin and actin to cause them to slide against each other(contraction.
Major functions of the muscular system
Maintain posture and body position.
Stabilize joints.
Produce Movement: responsible for all locomotion and manipulation. Ex: walking, digesting, pumping blood.
Generate heat as they contract.
3 types of muscles and their functions
Cardiac: Walls of heart.
Smooth: Unitary muscle in walls of hollow visceral organs. Multi unit eye muscles, large arteries, airways, etc...
Skeletal: Attached to bones or (some fascial muscles) to the skin.
Sarcomere
Smallest contractile of unit (functional unit) of muscle fiber. Contains A band half an I band at each end. Consists of an area between Z discs. Individual sarcomeres align end to end along myofibril.
Neuromuscular Junction
The ligand gated ion channels open. Sodium ions, enter the muscle fiber. While potassium ions exit the muscle fiber. Both sodium and potassium ion channels permit for Na and K to pass through one another.
Membrane potential reaches threshold value, an action potential is released along the sarcolemma below
Acetylcholine, also known as Ach, diffuses across the synaptic cleft and binds to Ach receptors which hold ligand gated channels.
Voltage-gated calcium channels open and calcium diffuses into the axon terminal.
The brain sends an impulse to the muscle down the axon (motor neuron) and to the axon terminal. This travels down to the site of a neuromuscular junction, which is also known as the motor end plate, where the motor neuron triggers the skeletal muscle fiber.
Calcium entry causes the synaptic vesicles to release acetylcholine.
Ach is removed from the synaptic cleft. Neural transmission to a muscle fiber has ended. Ach is broken down by the enzyme acetylcholinesterase and becomes acetic acid and choline. Both are transported back into the axon terminal for the resynthesis of acetylcholine.
Muscle coverings (connective tissue coverings)
Endomysium: Fine areolar connective tissue surrounding each muscle fibers.
Perimysium:Fibrous connective tissue surrounding fascicles(groups of muscle fibers)
Epimysium: dense irregular connective tissue surrounding entire muscle; may blend with fascia.
Sliding filament theory of muscle contraction
Filaments slide past thick filaments, causing myosin and actin to overlap. When the nervous system stimulates muscle fiber, myosin heads are allowed to bind to actin, forming cross bridges, which cause sliding(contraction) processes to begin.