Muscular System Flashcards
Muscular system
System composed of all the muscles of the body and concerned with movements of the total body as well as well as movements within the body
Contractility
Ability of muscle tissue to shorten or contract
Extensibility
Ability of muscle tissue to be extended or stretched within limits
Elasticity
Ability of muscle tissue to return to its original state after being stretched
Irritability
The susceptibility of muscle tissue to react to external stimuli
Tonus
State in which muscle is partially contracted allowing it to react instantly when stimulated
Nervous control: involuntary
Muscles NOT subject to the control of the will
1. Cardiac and smooth muscle are of the type.
Nervous control: voluntary
Muscle subject to the control of the will
1. Skeletal muscle is of this type
Smooth muscle
It is located comprising the walls of the internal organs as well as the blood vessels of the body
1. It does not appear striated.
Smooth muscle
Long spindles that are think in the center and tapered at the ends.
1 nuclei per cell
Cardiac muscle
It is located in the heart
It appears striated
1 nuclei per cell
Skeletal muscle
Composed of very long cells (up to 4 cm)
Multinucleate
1 nucleus is needed to carry out cellular functions
Sacro
Muscle
Sarcolemma
Cell membrane
Sarcoplasm
Cytoplasm
Myofilaments
Is a special type of organelle is found within skeletal muscle cells
What are the two types of myofilaments found in the myofibril
Actin and myosin
Arranged in patterns that appears as alternating light and dark bands
Fascia
Connective tissue located surrounding muscles and between adjacent muscles
Fascia function
Permits gliding of 1 muscle over another
Provides pathway for passage of vessels and nerves
Function
Extensor digitorum
Shape
Trapezius
Location
Tobialis anterior
Number of heads of origin
Biceps brachii
Structure (direction of fibers)
External oblique
Organ
Non-movable point of attachment
Insertion
Moveable point of attachment
Action
Movement a particular muscle produces
Innervation
Nerve supply to a muscle
Muscle attachments
Bone Cartilage Skin Fascia Tendons Aponeurosis
Blood supply of muscle
Skeletal muscles are involved in movement and are very active organs
They require a substantial amount of blood
Nerve supply of muscle: Motor or efferent
Nerve fibers carry nerve impulses from receptors (muscle spindles) in the muscle to the central nervous system (brain and spinal cord)
Nerve supply of muscle: sensory or afferent
Nerve fibers carry nerve impulses from central nervous system to muscle
Prime mover or agonist
A muscle that directly produces the desired movement
1. Ex when the extensor digitorum muscle extends the digits, it is acting as a prime mover or agonist
Antagonist
A muscle that produces a movement opposite to that of a prime mover or agonist
Example The flexor digitorum profundus which flexes the digits is antagonist to the extensor Digitorum
Synergist
A muscle that adds a little extra force to help the prime mover or agonist perform the desirable movements
Example of this includes the flexor digitorum profundus muscle which is assisted by the flexor digitorum superficialis when flexing the digits
Fixators
Muscle that maintain body position while a part is moving
This occurs in the shoulder one the muscle (serrated anterior) holds the scapula at an angle so that the humerus can move
The muscle that flexes the scapula is acting as fixator
