M5 Topic 6: Introduction to the Muscular System Flashcards
(18 cards)
Functions of the muscular system
- Producing body movements
- Stabilising body positions
- Storing substances in the body
- Moving substances around the body
- Generating heat
Muscular system producing body movements
When skeletal muscles activate, they generate force that pulls on bones, this creates capacity to move joints
Muscular system stabilising body positions
Skeletal muscle contractions have ability to stabilise joints
E.g. gravity is constantly trying to collapse you
- Many skeletal muscles are resisting gravity force to stabilise posture stay upright
Muscular system storing substances in the body
Often work to close off the opening of an organ to ensure substances are temporarily stored until it is time for release
- Usually smooth muscle tissue involved with this function
Muscular system moving substances around the body
- Cardiac muscle in heart pumps blood around body
- Smooth muscle in walls of intestines propel food through
Muscular system generating heat
Some of the chemical reactions involved in the overall muscle contraction process release heat as a by-product
- Heat from exercise
- Shivers from cold
Common muscle tissue properties
- Electrically excitable
- Contractility
- Extensibility
- Elasticity
Electrical excitement of muscle tissues
PM of muscle cells has ability to establish an AP that can move across the entire PM of that cell
Contractility of muscle tissue
Once excited, muscle cells have the ability to generate force by significantly altering their size and shape
Extensibility of muscle tissue
Muscle tissue has the ability to be stretched (to a point) without being damaged, sort of like an elastic band
Elasticity of muscle tissue
Muscle tissue springs back to its original length once the force that stretches the muscle tissue is removed
What are the 3 types of muscle tissue
- Skeletal
- Cardiac
- Smooth
Skeletal muscle tissue
Cell and tissue have striated appearance
- Multiple nuclei per cell located near edge of cell
- Cylindrical shaped cells
- Can be very long cells, up to 40cm long
Is the activation of skeletal muscle tissue voluntary or involuntary?
Voluntary
- Activation and relaxation of skeletal muscle tissue is under conscious control
Cardiac muscle tissue
Cells have a striated appearance
- Branched cells that usually have one central nucleus
Is the activation of cardiac muscle tissue voluntary or involuntary?
Involuntary
- Cannot choose to contract or relax your heart wall
Smooth muscle tissue
No straited appearance, hence name ‘smooth’ muscle
- Single central nucleus.
- Thin spindle shaped cells.
Is the activation of smooth muscle tissue voluntary or involuntary?
Involuntary
- Cannot choose to contract or relax smooth muscles
