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Karlie Casillas P.5 Muscular - Coggle Diagram
Karlie Casillas P.5 Muscular
Major functions of the muscular system
Produce Movement
Posture & Body Position
Stabilize Joints
Generates heat as they contract
3 types of muscles & their functions
Skeletal
are voluntary muscles and allow movement (attatched to bones or skin)
Smooth
involuntary muscles, happen without our conscious awareness (unitary muscle in walls of hollow visceral organs)
Cardiac
heart contracts and relaxes without our conscious awareness (walls of heart)
Skeletal muscles
Upper Body
: Pectoralis Major, Trapezius, Serratus Anterior, Deltoid, Biceps Brachii, Brachialis, Brachioradalis,
Abdomen
: Rectus Abdomen, External Oblique,
Lower Body
: Sartorius, Rectus femoris, Adductor Longis, Vastus Medialis, Fibularis Longus, Tibialis anterior, Gastrocnemius, Soleus, Biceps femoris, Semitendinousus, Semimembranous, Vastus lateralis, Gluteus maximus
Sarcomere
smallest contraction unit if muscle fiber
Contains A band with half of an I band at each end
A myofibril feature
Neuromuscular junction
Motor End Plate
Region where a motor neuron comes into close contact with a skeletal muscle cell
Events at the Neuromusculae Junction
1)AP arrvies at axon terminal
2)Voltage gated calcium channels open, calcium enters motor neruon
3)Calcium entry causes release of ACh neurotransmitter into synpatic cleft
4)ACh diffuses across to ACh receptors on sarcolemma
5)ACH binding to receptors , opens gates, allowing Na+ to enter resulting in end plate potential
6)Acetylcholinesterase degrades ACh
Sliding filament theory
During Contraction
Thin filaments slide past thick filaments
Causing acting and myosin to
overlap more causing using bridges
When nervous system stimulates muscle fiber, myosin heads are allowed to bind to actin, forming cross bridges, which cause sliding (contraction) process to begin
Action potential in a muscle fiber
An action potential travels along a motor nerve to its endings on uncle fibers.
Then at the nerve ending, the nerve secrets ACh.
ACh acts on the muscle fiber membrane to open ACh-gated cation channels.
Muscle coverings (connective tissue coverings)
Epimysium
(dense irregular connective tissue surrounding entire muscle)
Perimysium
(fibrous connective tissue that surrounds fascicles)
Endomysium
(fine areolar tissue surrounding each muscle fiber)
Disorders associated with the Muscular system
Muscular Dystroph
y : Muscle weakness & atrophy
Fibromyalgia
: Muscle pain
Myasthenia Gravis
: Neuromuscular disorder that blocks neurotransmitters
Cerebral Palsy
: Spatic paralysis causing muscle weakness
Myositis
: inflammation of the muscle