1. The muscular system

2. The Muscular System
Muscles work in conjunction with the skeleton to help us move and perform basic functions
Most muscles are arranged in pairs called “antagonistic” – they work as opposites of each other
Muscles are never completely at rest
There are approx700 muscles in the body
Muscle makes up 1/5th of a persons total body weight

3. Functions of a muscle Movement Maintain posture Produce heat
Contract after stimulation from either – Chemical, Mechanical, Electrical or heat source
Muscles are approx. 70% water and 25% solids (the most important are proteins Actin & Myosin)

4. Muscle groups
Muscles are often grouped together and named by a system according to:
Function – flexors/extensors
Attachment – sterno-cleido mastoid
Shape – trapezius
Formation – biceps/triceps
Position - intercostals

5. How a muscle works Muscles have the following points of attachment:
Origin – bone to which they are attached and don’t move
Insertion – bone to which muscle attach and does move
In order to contract, muscle fibres need adequate supplies of blood, oxygen, nutrients and waste removal systems

6. How a muscle works
Discuss in pairs the origin and insertion of each of the following muscles;
Biceps
Gastrocnemius
Hamstrings

7. How a muscle works
Energy is brought to the muscles via the blood stream
It is stored as glycogen until needed
When required the glycogen combines with oxygen from the blood starting off a chemical chain reaction
The result is energy and waste being produced

8. Types of muscle tissue Voluntary (striated) Under conscious control
Contain collagen and elastin fibres
Make up approx 40% of body weight
Each fibre is linked to the CNS
Fatigues easily if overused
Reactions are quick and immediate

9. Types of muscle tissue Involuntary (smooth, visceral)
Not under conscious control
Found in the walls of internal organs (stomach, bowel) & Respiratory system
Doesn’t fatigue
Contraction is slower but more even

10. Types of muscle tissue Cardiac Only found in the heart
Not under conscious control
Doesn’t fatigue
Strongest type of muscle tissue
Self regulating contraction

11. Muscle contraction
Muscles contract (shorten) to exert a force when stimulated by the CNS
The motor nerve carries the impulse to a motor neuron in the muscle fibres
The more fibres that are stimulated the shorter the muscle will become & therefore the stronger the contraction

12. Types of muscle contraction
Concentric
Muscle actively shortens & thickens
Origin & insertion move closer together
Produces heat in the muscles
Can be used in all ranges of movement
Try this yourself

13. Types of muscle contraction
Eccentric
Muscles lengthen
Origin & insertion move further away (against gravity)
Heat is produced
Used in all ranges of movement
Try this yourself

14. Types of muscle contraction
Isometric
Muscles contract becoming harder but stay the same length
Sometimes known as static contraction
Isotonic
Muscles move against constant resistance
This is how muscles work in weight training
Try these!

15. Muscle tone State of partial contraction of muscle
Linked to the maintanence of posture etc
Always present in some fibres (even at rest)
Weakest during sleep
Only lost when the motor nerve supply is interrupted
Poor tone indicated undersized muscles which fatigue easily. Contractions are slow & weak
Excessive tone indicates tense muscles due to over development

16. How would you measure the tone of your clients muscles?
Muscle tone
How would you measure the tone of your clients muscles?

17. Effects of temperature
Warm – faster contractions due to the chemical process being quicker.
tone is reduced as temperature rises as more of the fibres relax
Cold – chemical process slows down so does contraction speed
Involuntary increase in muscle tone eventually results in “shivering”

18. Muscle fatigue Caused by an inadequate blood supply
Due to over worked muscles – contractions slow & weaken, eventually stopping
Muscle fibres do not all contract at the same time but do so in series
As a result of fatigue there is a build up of lactic acid, waste products and carbon dioxide

19. Tendons Dense, connective tissue Connects muscles to bone
Certain tendons are covered with a protective tube to allow for smooth and easy movement e.g. in the wrist
Vary in length and size

20. Ligaments Connects bone to bone Provides support to structures
Made of bundles of fibres laying parallel to each other
Not very flexible
Together they flex head
Individually turn the head towards the shoulder