Muscular & Skeleton system

Question 1

Function of bones and roles in sport

Answer 1

•Shape & support = the bones of the axial and appendicular skeleton provide the body with shape and support for the lungs, heart and vital organs
•Protection = the skeleton protects delicate parts of the body like the brain
•Movement = All sporting actions require muscles to move bones at joints
•Mineral Storage = Calcium and phosphorus are stored in the bones

Question 2

What are the 5 Synovial Joints

Answer 2

•Hinge
•Ball & Socket
•Condyloid
•Gliding
•Radio-Ulna

Question 3

The types of planes and definitions

Answer 3

• Sagittal plane — It divides the body into left and right parts from the midline to the outside e.g. Flexion, Extension , Plantar & Dorsi flexion
• Frontal plane — It divides the body into front and back parts e.g. Abduction and Adduction
• Transverse plane — It divides the body into upper and lower parts e.g. Horizontal Flexion & Extension and Rotation

Question 4

Types of Contractions

Answer 4

• Concentric : Muscle shortens under tension - occurs in the agonist
• Eccentric : Muscle lengthens under tension - occurs in the antagonist and only occurs if the antagonist is acting as a break to control the movement
• Isometric : An increase in muscle tension but no change in its length and always occurs in the fixator muscle - occurs in other muscles if they are working against a resistance they cannot overcome

Question 5

Define the motor neuron

Answer 5

Nerve cell which conducts a nerve impulse to a group of muscle fibres

Question 6

Define motor unit

Answer 6

Made up of the motor neurone and the muscle fibre stimulated by its axon

Question 7

Define Action potential

Answer 7

Positive charge inside the nerve and muscle cells which conduct the nerve impulse down the neurone and into the muscle fibres

Question 8

Describe the role of a motor unit

Answer 8

1) Nerve impulse initiated in the motor neuron cell body
2) Nerve impulse conducted down the axon of the motor neurone by a nerve ACTION POTENTIAL to the SYNAPTIC CLEFT
3) NEUROTRANSMITTER called ACETYLCHOLINE a secreted into the nerve impulse across the gap
4) If the electrical charge in above a THRESHOLD the muscle fibre will contract
5) This happens in an “all or none” law

Question 9

Structural and Functional features of a Slow Oxidative muscle fibre (Type 1)

Answer 9

Structural features
• High myoglobin content
• High capillary density
• Small neurone size
Functional features
• Longer to fatigue
• Low force production
• High aerobic capacity