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Delia Ocampo Muscular System Period:2 - Coggle Diagram
Delia Ocampo Muscular System Period:2
Major Functions of the Muscular System
Movement-skeletal muscles pull on the bones causing movements at the joints.
Support-muscles of the body wall support the internal organs.
Protection-skeletal muscles protect the body internal organs from force applied to the exterior of the body.
Heat generation-the heat is carried by the blood to the other tissues and helps maintain body temperature.
Blood circulation-cardiac muscles aid pumping action of the heart by aiding blood circulation.
3 Types of Muscles&their Function
Smooth- Movement of viscera,peristalsis,vasoconstriction
Cardiac- Pumping action of the heart
Skeletal-Movement of bones at joints,maintenance of posture
Skeletal Muscles & Facial Muscles
Pectoralis major:named for size and location ;large size,located in chest
Deltoid:named for shape;shaped like a triangle
Extensor digitorum:named for action; extends digits(fingers,toes)
Biceps brachial:named for number of attachments and location; has 2 origins/heads, and is found in the arm
Frontalis-raises the eyebrows
Orbicularis Oculi-closes the eyes
Masseter-jaw closure
Platysma-skin of neck
Orbicularis oris-closes lip
Buccinator- compresses the cheek
Zygomaticus-raises corners of mouth
Temporalis-closes jaw
Sarcomere
The sarcomere is the basic unit of muscle fiber and each of them is composed of 2 main protein filaments which are actin and myosin which are responsible for muscular contraction. It is also composed of mitochondria,transverse tubules,sarcolemma,sarcoplasmic reticulum and different type of bands and zones.
Neuromuscular junction
1:The impulses travels down the motor neuron to the end of the axon
2: Calcium channels open in order to be able to go into the axon terminal
3: Calcium entry causes vesicles to release acetylcholine
4:Acetylcholine moves across the cleft and binds together to the receptors.
5:The ligand-gated cation channels begin to open
6:Sodium ions enter the muscle fiber
7:Action potential spreads along sarcolemma
It is a synapse between a motor neuron nerve terminal and its muscle fiber which are responsible for converting electrical impulses by the motor neuron into electrical activity in the muscle fiber.There is 7 steps to this.
Sliding filament theory
1:A muscle contraction starts and signals are sent along the motor neurons. And in that includes the vesicles and the Acetylcholine.
2:The impulse travels down the membrane and into the transverse tubules which causes Calcium to be released from the sarcoplasmic reticulum.
3:The Calcium binds to a structure on the actin that causes its shape to change.
4:The change in shape allows myosin heads to form cross bridges between the actin and myosin.
5:Energy from ATP is used to create a power stroke between the two filaments.
Action Potential
The action potential can be divided into 5 phases:the resting potential,threshold,the raising phase,the falling phase and the recovery phase.
Muscle covering
1:Epimysium:surrounds entire muscle
2:Perimysium:surrounds bundles of muscle fibers
3:Endomysium:surrounds individual muscle fibers
4:External lamina:just bellow endomysium
5:Sarcolemma:muscle cell membrane