Muscular system Flashcards
The functions of Muscle system
- Provides voluntary movement of body
- Maintain Posture
- Produces heat
- Provides movement of internal organs
- Causes involuntary actions
Voluntary movement produced by the body
- Enables breathing, blinking, and smiling
- Allows you to hop, skio or do push-ups
The movements of internal organs provided by muscular system
- Moves food through digestive tract
- Enables bladder control
What involuntary actions does muscular system cause?
- Reflex actions
- Adjusts opening of pupils
- Causes hair to stand on
end
Properties of muscle
- Excitability
- Contractility
- Extensibility
- Elasticity
capacity of muscle to respond to a stimulus
Excitability
ability of a muscle to shorten and generate pulling force
Contractility
muscle can be stretched back to its original length
Extensibility
ability of muscle to recoil to original resting length after stretched
Elasticity
Characteristics of muscle tissue
- Made up of contractile fibers
- Provides movement
- Controlled by nervous system
consciously controlled
Voluntary
not under conscious
control
Involuntary
Two main types of colored muscle fibers
- Red (slow) fibers
- White (fast) fibers
- greater number of mitochondria
- contain high concentration of myoglobin
- react at a slow rate; do not undergo fatigue even with sustained contraction
Red (slow) fibers
Example of red fibers
- Postural muscles
muscles which are opposed to gravity
Postural muscle
-contain little myoglobin/mitochon
- react rapidly and undergo anaerobic respiration
-generate force quickly but not for long durations
White (fast) fibers
Example of white fibers
Fingers and eye movements
postural muscles that are capable of rapid contraction at times
Intermediate fibers
Example of intermediate fibers
Calf muscle
supports leg but also capable of running, walking, jumping
Calf muscle
Differences between red and white fibers
- Number of mitochondria and concentration of myoglobin
- stimulate muscle fibers to contract
- Neuron axons branch so that each muscle fiber is innervated
- Form a neuromuscular junction
Motor neurons
- Muscles require large amts of energy
- Extensive vascular network delivers necessary oxygen and nutrients and carries away metabolic waste produced by muscle fibers
Capillary beds surround muscle fibers
Location of skeletal muscle type
attached to bone
Location of cardiac muscle type
Heart
Location of smooth muscle type
Walls of internal organs + skin
Function of skeletal muscle type
Movement of bone
Function of cardiac muscle type
Beating of heart
Function of smooth muscle type
Movement of internal organs
Control mode of skeletal muscle type
Voluntary
Control mode of cardiac and smooth muscle type
Involuntary
Shape of skeletal muscle type
Long + slender
Shape of cardiac muscle type
Branching
Shape of smooth muscle type
Spindle shape
Characteristics of skeletal muscle type
- Striated- light and dark bands
- Many nuclei
Characteristics of cardiac muscle type
- Striated
- One or two nuclei
Characteristics of smooth muscle type
- Non-striated
-One nucleus (visceral)
Contain two types of protein filaments
Myofibril