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Amy Arteaga Period 7: Muscular System - Coggle Diagram
Amy Arteaga Period 7: Muscular System
Major functions of the muscular system
Generate force to cause different movements. Skeletal muscles allow for movement of bones and maintain posture. Smooth muscles allow for movement of viscera, peristalsis, digestion, urination. Cardiac muscles pump the heart allowing circulation of blood/oxygen.
3 types of muscles & their functions
Smooth
: Movement of viscera, peristalsis, vasoconstriction
Cardiac
: Pumping action of the heart
Skeletal
: Movement of bones at joints, maintenance of posture
Names of skeletal muscles
Sternocleidomastoid
: sides of neck, rotates head and flexes neck forward
Trapezius
: upper back, elevates shoulders
Pectoralis major
: located in chest, rotates & adducts shoulder
External oblique
: sides of abdomen, flexes and rotates vertebral column
Serratus anterior
: along ribs, raises ribcage
Deltoid
: shoulder, abduct/flex/extend arm
:
Rectus abdominis
: middle of abdomen,
Gluteus medius
: hips; abducts/rotates thigh
Gluteus maximus:
buttocks; extends thigh/back at waist
Latissimus dorsi
: majority of lower back
Biceps Brachii
: front of upper arm; flexes forearm
Triceps brachii:
back of upper arm; extends forearm at elbow
Brachioradialis:
sides of elbow; flexes forearm at the elbow
Gracilis
: inside thigh; adducts/flexe leg
Quadriceps
: front of thigh, extyend to top of knee
Tibialis anterior:
shinbone; dorsiflexion/inversion of foot
Soleus
: back of leg (deep); flexes ankle
Gastrocnemius
: more calf, back of leg (superficial); flexes ankle
Hamstring
: back of thigh; flexes leg at knee/ extends thigh
Sartorious muscle
: diagnal along front thigh
Buccinator
: checcl, suction
Brachialis
: front of arm, flexes arm
Rectus femoris:
middle front thigh; part of hamstrings
Vastus lateralis:
lateral thigh; part of hamstrings
Vastus medialis
: medial thigh, part of hanstring
Vastus medialis
: back of thigh; part of quadriceps
Semitendinosus
: medial back of thigh, part hanstring
Semimembranosu
s: middle back of thigh
Fibularis longus
: lower leg, lateral
Facial muscles:
Frontalis
: forehead; raises eyebrows
Orbicularis oculi
: eyes; closes the eyes
Temporalis
: temples; closes jaw
Masseter
: jaw; closes jaw
Orbicularis Oris
: mouth; closes lips
Zygomaticus
: cheeckbone and mouth; raises corner of mouth
Platysma
: tenses neck
Sarcomere
Myosin
: thick filament of myofibril. Protein myofilament that pulls actin towards center of sarcomere. +found in A band.
Sarcolemma
; cell membrane of muscle cell or fiber +functional unit of muscle cell.
sarcoplasm
: cytoplasm of muscle cell or fiber
actin
: thin filament of myofibril
Troponin
: components of actin
Tropomyosin
: protein wrapped around actin that prevents it from contacting myosin, component of actin
Striations
: bands created by thick and think filaments
Sarcomere
: many units/sections of myofibrils
Z line
: end of sarcomere
I bands
: light bands made of actin filaments
A bands
: dark bands made up of overlapping thick/thin filaments
H Zone
: center of A band, made ONLY of myosin filaments
Sarcoplasmic reticulum
: stores calcium in muscle cell. network of membrane channels; endoplasmic reticulum of muscle cell. stores Ca2
Calcium
: triggers binding of myosin to actin
Transverse (T) tubules
: folded areas of sarcolema
Cisternae
: area between T tubules
Neuromuscular junction
Potassium(
K
+) and Sodium(
Na
+) needed for muscle contraction
Motor neuron
: nerve found in skeletal muscle
Where motor neuron comes into close contact w nuscle cell
Synapse
: connection between nerve and muscle or another nerve
Neurotrasmitter:
chemical messenger in neuromuscular junction
Synaptic vesicles
: stores neurotransmitters at the end of an axon (circle w dots inside)
Motor end plate
: specialized region of muscle fiber membrane
Synaptic cleft
: gap between membrane of neuron and muscle fiber
Cross bridge
: attachment of the myosin head to binding site of actin filament
Acetycholine
: neurotransmitter for skeletal muscle contraction. +neurotransmitter initiatws an action potential in sarcolemma
Acetylcholinesterase
: enzyme that causes breakdown of acetylcholine; causes muscles to relax. +breaks down muscle cell neurotransmitter and ends impulse
ATP
: energy needed for muscle fiber contraction. +required to break crossbridge between actin and myosin filaments.
Troponin and tropomyosin
: regulary proteins bount to actin.
Fast twitch muscle fibers
: contract rapidly w great force but fatigue fast. Use creatine phosphate pathway.
Threshold stimulus
: minimal amount of stimulus neededto cause a muscle to contract
Sliding filament theory of muscle contraction
Step 5
: ATP energy is used to create a power between filaments. The actin filament slides inward and shortens/contracts the whole muscle.
Step 3
: Calcium binds to actin causing it to change shape.
Step 2
: impulse travels into the transverse tubules releasing calcium from sarcoplasmic reticulum.
Step 4
: The change in shape then allows for myosin heads to form cross-bridges between actin and myosin.
Step 1
: muscle contraction starts in the brain. Within neuro neuron, vesicles contain neurotransmitter (acetycholine). Acetylcholine reach receptors on sarcolemma which cause an impulse.
Action potential in a muscle fiber
Insertion
: more movable end of a skeletal muscle
Extension
: increase angle between bones at a joint. EX straightening arm
Origin
: less movable end of a skeletal muscle
Flexion
: decrease in angle between bones at a joint. EX bending arm
Agonist
: muscle that causes an action and does majority of work. (prime mover)
Synergist
: assists prime mover
Antagonists
: muscles that oppose an action
Action potential in a muscle fiber
Insertion
: more movable end of a skeletal muscle
Extension
: increase angle between bones at a joint. EX straightening arm
Origin
: less movable end of a skeletal muscle
Flexion
: decrease in angle between bones at a joint. EX bending arm
r
Synergist
: assists prime mover
Antagonists
: muscles that oppose an action
Hypertrphy
: +Increase in muscle mass. enlargement of muscle due to repeated exercise
Atrophy
: decrease in muscle size and strength due to disuse
Isometric
contraction
: when muscle stays the same size . isolated
Muscle coverings
Tendons
: extends beyond the ends of muscle, gives rise to tendons that are fused to periosteum of bones
Aponeuroses
: broad sheets of connective tissue
Fascia
: Layers of dense connective tissue, surround and separate each muscle
Epimysium
: blends w fascia, layer of connective tissue around each skeletal muscle
Perimysium
: surrounds bundles of skeletal muscle,extends inward from the epimysium
Fascicles
: bundles of skeletal muscle fibers
Endomysium
: covers each muscle cell fiber