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Muscular System Linh Le Period 1 - Coggle Diagram
Muscular System Linh Le Period 1
Functions
Produce movement
Maintain posture & body position
Stabilize joints
Generate heat
Skeletal Muscles
Frontalis: movement to eyebrows & forehead
Temporalis: jaw/mandible
Masseter: prime mover; jaw/mandible
Orbicularis oculi: eyelids
Zygomaticus: corners of mouth (smile)
Orbicularis oris: lips
Platysma: neck
Infraspinatus: below scapula
rhomboid major: connects scapula to spine
teres major: laterally borders scapula
triceps brachii: back of upper arm
latissimus dorsi: back
extensor carpi radialis: back of forearm- lateral
extensor carpi ulnaris: back of forearm- medial
gluteus maximus: butt
semitendinosus: medial muscle in back of thigh
semimembranous: more medial muscle in back of thigh
biceps femoris: back of thigh- lateral
rectus abdominus: abdomen
serratus anterior: lateral chest
pectoralis major: breast area
sternocleidomastoid: neck
trapezius: shoulder
deltoid: upper arm
biceps brachii: anterior upper arm
brachioradialis: lateral forearm
flexor carpi radialis: forearm
palmaris longus: medial forearm
internal oblique: lateral abdomen
illiopsoas: inner hip
sartorius: muscle from hip to knee
adductor longus: medial thigh
vastus lateralis: lateral thigh
gastrocnemius: achilles tendon
tibialis anterior: inverts the foot
gracilis: medial thigh
rectus femoris: middle thigh
vastus medialis: bottom of thigh
fibularis longus: below gastrocnemius
soleus: calf
extensor digitorum longus: lateral front leg
Sliding Filament Theory
Step 1) A neural impulse from the brain/spinal cord travels through motor neuron to neuromuscular junction which releases acetylcholine from the synapse to the sarcolemma
Step 2) The impulse goes through the sarcolemma and T tubules that surround myofibril, causing calcium ions to be released from the sarcoplasmic reticulum
Step 3) When the impulse stops, Ca2+ is released from troponin and tropomysoin prevents contraction from happening by covering binding sites
Step 4) Myosin and actin bind together creating a crossbridge
Step 5) ADP and potassium ions are released from the myosin which creates a powerstroke
Step 6) ATP binds to myosin which removes it from the actin and converts to ADP and potassium ions to prepare for the next powerstroke
Step 7) Ca2+ binds to troponin and tropomyosin moves to allow myosin into the binding site
Neuromuscular Junction
Calcium channels open, sends calcium to motor neutron
ACh releases into synaptic cleft
Ach diffuses and into enters ACh receptors
NA+ enters gates causing end plate potential
Acetylocholinesterase breaks down Ach
Sarcomere
I band: only contains actin (thin filaments)
A band: only contains myosin (thick filaments)
H zone: where thin and thick filaments meet
Muscle Types & Functions
1) Cardiac: Pumps blood in the heart (involuntary)
2) Smooth: push food along the GI tract (involuntary)
3) Skeletal: allows for movement of the body (voluntary)
Muscle Coverings
Epimysium: Surrounds entire muscle; dense irreg ct
Perimysium: Surrounds fasicles; fibrous ct
Endomysium: Surrounds muscle fiber; arreolar ct
Disorders
Duchenne Muscular Dystrophy: degeneration of muscle; weakens and loses mass