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Muscular System Alissa Tagle Period 3 - Coggle Diagram
Muscular System
Alissa Tagle
Period 3
3 types of muscles & their functions
Cardiac Muscle
-involuntary
-in walls of heart
-pumps heart
-has striations
-single nuclei
-transverse tubule system
-interclated discs
-network of cells contracts as unit; self exciting, rhythmic
Smooth Muscle
-involuntary
-in walls of hollow viscera & blood vessels
-movement of viscera, vasoconstriction
-no striations
-single nuclei
-spindle shaped
-no transverse tubule
-contract and relax slow; single unit type; self exciting, rhythmic
Skeletal Muscle
-voluntary
-in skeletal muscles
-maintains posture
-allows movement of bones
-has striations
-many nuclei
-transverse tubule system
-contract and relax fast; stimulated by motor neuron
Sarcomere
striations consist of alternating patters of light and dark bands
A Bands (light)- made of over lapping myosin and actin
smallest unit of contraction
I Bands (dark)- made up of actin, anchored to z line
Z line separates sarcomeres
Center of A band (myosin) = H zone
Line in middle of H zone is M line (consists of proteins that hold myosin in place)
More space= Relaxed
Less space= Contracted
Sliding filament theory of muscle contraction
4) Head pulls on actin, and moves toward the center of the sarcomere
3) binding causes head of myosin to bend,
5) Head releases and attaches to next binding site
2) Binding forms a cross brindge
6) Repetition of binding and releasing causes filaments to increase overlap and
1) Myosin head attatches to binding site of actin filament
7) The sarcomere shortens
ATPase
: enzyme that converts ATP to ADP; causes head to return to "cocked" position
1) Acetylcholine produced at motor neuron and stored in synaptic vesicles
2) Acetycholine released into synaptic cleft after an impulse
3)SR releases stored calcium
4)Calcium exposes myosin binding sites in actin
Muscle coverings (connective tissue coverings)
3) Fassicle- a bundle of skeletal muscle fibers
4) Endomysium (covering)- covers a single muscle cell fiber
2) Perimysium (covering)- extends from epimysium and surrounds bundles of muscle fibers
5) Muscle Fiber- One singular fiber
1) Empimysium (covering)- bleds with fascia and sourands each skeletal muscle
Biggest-smallest
Disorders associated with the Muscular system
Myasthenia Gravis
Neromuscular disorder that blocks neurotransmitters
Cerebral Palsy
spastic paralisis causing muscle nerve weakness
Fibromyalgia
Muscle pain
Myositis
Inflammation of the muscle
Muscular Dystrophy
muscle weakness and atrphy
Names of all the skeletal muscles
Anterior/Superior View
Bicep brachii
Brachialis
Brachioradialis
Deltoid
External obliques
Flexor carpi radialis
Flexor carpi ulnaris
Frontalis (Epicranius frontal belly)
Iliopsoas
Masseter
Orbicularis oris
Orbicularis oculi
Palmaris longus
Pectinus
Pectoralis major
Pronator teres
Rectus abdominis
Serratus anterior
Sternocleidomastoid
Sternohyoid
Temporalis
Tensor fasciae latae
Trapezius
Tricep brachii
Zygomaticus
Anterior/Inferior View
Adductor longus
Fibularis longus
Extensor digitorum longus
Gastrocnemius
Gracilis
Iliotibial tract
Rectus femoris
Sartorius
Soleus
Tibialis anterior
Vastus lateralis
Vastus medialis
Posterior/Superior View
Brachioradialis
Deltoid
Extensor carpi radialis
Extensor carpi ulnaris
Flexor carpi ulnaris
Gluteus maximus
Gluteus medius
Infraspinatus
Latissimus dorsi
Occipitalis (Epicranius occipital belly)
Rhomboid major
Sternocleidomastoid
Teres major
Trapezius
Tricep brachii
Posterior/Inferior View
Bicep femoris
Adductor magnus
Gastrocnemius
Gracilis
Soleus
Fibularis longus
Semitendinosus
Semimembranosus
Calcaneal (Achilles) tendon (not a muscle)
Action potential in a muscle fiber
Neuron communicates with muscle fiber with chemicals (neurotransmitters)
Skeletal muscle fiber not
actually
connected to axon in neuron; connected functionally (creates synapse)
Skeletal muscle fibers contract only by stimulation of motor neurons
Major functions of the muscular system
Movement of viscera, peristalisis, vasoconstriction
Pumping of heart
Maintnence in posture
Heat production( through cellular respiration)
Movement of bones
Joint stability
Neuromuscular junction
Synapse
: connection between nerve and muscle or another nerve
Neurotransmitter
: chemical messenger in neuromuscular junction
Neuromuscular junction
: synapse between motor neuron and muscle fiber it controls
Synaptic vesicles
: stores neurotransmitters at the end of an axon
Motor End Plate
: specialized region of muscle fiber membrane; sarcolemma tightly folded
Synaptic
cleft
: gap between membrane of neuron and muscle fiber
Acetycholine
: neurotransmitter for skeletal muscle contraction
Acetylcholinesterase
: enzyme that causes breakdown of acetylcholine; causes muscles to relax
ATP
: energy needed for muscle fiber contraction; created in cellular respiration
1) Electrical impulses reach ends of axon of motor neuron
2) Synaptic vesicles release neurotransmitters into synaptic cleft
3) Neurotransmitters diffuse across cleft
4) Neurotransmitters bind to motor end plate
5) Stimulate muscle fiber