Nathaniel Matulessya Period 2
Muscular System
Major Functions of the muscular system
3 types of muscles & their function
Names of all skeletal muscles
Sarcomere
Neuromuscular junction
Sliding filament theory
Action potential in muscle fiber
Muscle coverings
Smooth
Skeletal
It is located in the skeletal muscles
The main function of the skeletal muscle is to move bones at the joint and to maintain your posture.
Striated
Has many neucli
Voluntary
compresses and relaxes rapidly when it is in contact with a motor neuron.
Cardiac
It is located in walls of the hollow viscera and in the blood vessels
The main function is the movement of the viscera, peristalsis, and vasoconstriction
Not striated
Has 1 nucleus
Involuntary
compresses and relaxes slowly.
It is located in the wall of the heart
The main function is the pumping of the heart
Striated
Has 1 nucleus
Involuntary
network of cells compressing as a unit.
Pectoralis major
Deltoid
Extensor digitorum:
Biceps brachii
Sternocleidomastoid
External oblique
Temporalis
Frontal
Orbicularis Oculi
Zygomaticus
Masseter
Orbicularis Oculi
Sternocleidomastoid
muscle contraction releases calcium from the sarcoplasmic reticulum and it exposes binding sites on thin filaments
from there the exposed binding sites on actin allow the muscle contraction cycle to start
myosin heads bind to actin, forming cross-bridges, connecting myosin to acting
the ADP and it releases from myosin and cross-bridge pulls the thin filament
the new ATP binds to myosin, breaking the connection to actin
the ATP splits, which provides power to "cock" the myosin heads and store energy for the next power stroke.
Forehead
Temple
Area around your eye
Area near the cheek bone
Area near the jaw line
Area around the lips
Area near the neck
Movement of bones at joints, maintenance of posture
Movement of viscera, peristalsis, vasoconstriction
Pumping action of the heart
Prime mover
Synergist
Antagonist
the prime mover is the function that does most of the work
the synergist helps the prime movers and actually supports the prime mover
the antagonist is the villain to the prime mover, they oppose all the actions from the prime mover
a synapse between a motor neuron and a muscle fiber that it regulates
contract only when stimulated by a motor neuron
the neuron communicates with the muscle fiber by way of chemicals called neurotransmitters, which are released at the synapse
made up of many units called sarcomeres, joined end-to-end
a sarcomereextends from one Z line to the next
I bands (light bands) aremade up of actin filaments, which are anchored to the Z lines
A bands (dark bands) are made up of overlapping thick and thin filaments
in the center of the A band is the H zone, which consists of myosin filaments only
the M line, in the center of the H zone, consists of proteins that hold the myosin filaments in place
Each muscle fiber is a single, long, cylindrical muscle cell
Fibers respond to stimulation by contracting
Cell membrane of a muscle fiber is the sarcolemma
Cytoplasm of a muscle cell is the sarcoplasm; it contains many mitochondria and nuclei
Sarcoplasm contains parallel myofibrils, which are active in muscle contraction
Thick filaments in myofibrils consist of the protein myosin
Thin filaments in myofibrils are mainly composed of the protein actin, but also contain troponinand tropomyosin
Fascia blends with the epimysium, the layer of connective tissue around each skeletal muscle
The perimysium extends inward from the epimysium; it surrounds bundles of skeletal muscle fibers, called fascicles, within each muscle
Covered by a connective tissue layer called endomysium