1. BTEC NC Sport & Exercise Sciences
Unit 7
Anatomy for Sport & Exercise

2. Know your Bones?
To revise, try this site…

3. The Muscular System Muscle Tissue
You've got around 650 muscles in your body, and they make up roughly half of your bodyweight. These muscles can be divided into three different groups:
Muscles provide the forces which move our skeleton. But they have other functions too…
Muscle Tissue
Involuntary
Voluntary
Skeletal
Cardiac
Smooth

4. Skeletal (striated) Muscle
Properties:-
Extensibility – ability to lengthen
Highly Elastic – return to normal length after stretch
Contractability - forcibly shortens on nervous/hormonal stimulation

5. Function of Skeletal Muscle
Movement
Posture & Support
Heat Production

6. Basic Muscles of the Human Body
Anterior

7. Basic Muscles of the Human Body
Posterior

8. Muscle Structure

9. Muscle Structure Muscles are attached to bones with tendons.
Tendons are made from collagen fibres.
There is an Origin & Insertion for each muscle.
The Origin is usually proximal. Insertion is distal.
Outer layer is EPIMYSIUM
The muscle itself is made up of many FASSICLES.
Each Fassicle contains many muscle FIBRES (or cells).
Fassicles are covered in and separated by PERIMYSIUM
Perimysium is made from collagen fibres.
Each Fibre is held together by ENDOMYSIUM.

10. Muscle Cell Structure
Each Fibre consists of many MYOFIBRILS.
These are the contractile units of the muscle.
Each Myofibril contains many repeated units called SARCOMERES.
Sarcomeres contain ACTIN & MYOSIN filaments
Actin is the thin filament
Myosin is the thick filament
Troponin and Tropomyosin prevent muscle action.
They bind to Myosin preventing Cross-Bridging.
Calcium Ions (Ca+) released from Sarcoplasmic Reticulum activate the release of Troponin from Myosin.
Myosin heads bind to Actin creating a ‘pulling’ action.
ATP contained in the Sarcoplasm provides energy for release of binding.

11. Sliding Filament Theory

12. Types of Skeletal Muscle Fibre
3 Types exist:
Type 1 –
Slow Oxidative fibres (Slow-twitch fibres)
Type 2(a) –
Fast Oxidative Glycolytic fibres (Fast Twitch fibres)
Type 2(b) –
Fast Glycolytic fibres (Fast Twitch fibres)

13. Type 1 – Slow Oxidative fibres (Slow-twitch fibres)
Red - Rich blood supply, more myoglobin
Slow contraction – due to thin myelin sheath/slow nerve impulse.
Aerobic - Posture & endurance events – Journeying, Hill walking.

14. Type 2(a)– Fast Oxidative Glycolytic fibres (Fast-twitch fibres)
Much Paler – Less myoglobin
Faster contraction – due to thicker myelin sheath.
More fibres in each motor-unit
Mainly Anaerobic – but also Aerobic Capacity
Sprints/400m, Short ‘difficult’ climb, Kayak Sprint

15. Type 2(b) – Fast Glycolytic fibres (Fast-twitch fibres)
White
Fast contraction – due to thick myelin sheath.
Motor Neurone Thicker – large impulse.
Almost entirely Anaerobic
Short Sprints, Powerful climbing moves, strong bursts of power strokes, intense uphill MTB

16. Fatigue Extremely Quickly!
Fibre Type Properties
Quality
Type 1
Type 2a
Type 2b
Contraction Speed
Slow
(80 – 100 ms)
Fast
(40-60 ms)
Very Fast
(< 40ms)
Force Production
Low
High
Very High
Capillary Density
Medium
Oxidative Capacity
Exercise Capacity
Fatigue Quickly
Fatigue Extremely Quickly!

17. Sports Specific Predominance

18. Dependent on sufficient impulse.
Innervation of fibres
‘All or Nothing’ Law
Dependent on sufficient impulse.

19. Muscle Twitch
Muscle Innervation