What are Muscles?

A Physical Education slideshow highlighting the different types of muscles in the body, their uses, locations etc.

1. MUSCLES

2. WHAT ARE MUSCLES? Muscles are the soft tissues found in the body, which contract and relax to cause movement. They are the fleshy component of our body.

3. HOW DO MUSCLES WORK? Muscles are attached to bones (with the help of tendons) to make the skeleton, and therefore, the body move . The contraction and relaxation of muscles is the cause of movement of the body. They work in pairs.

4. MUSCLE MOVEMENTS Antagonistic pairs of muscles create movement when one (the agonist) contracts and the other (the antagonist) relaxes. Some examples are: the quadriceps and hamstrings in the leg the biceps and triceps in the arm

5. MUSCLE CONTRACTIONS There are mainly three type of muscular contraction: Isometric - During isometric contraction, the muscle remains the same length. Isokinetic - Isokinetic contraction occurs when the speed of the contraction remains constant throughout the movement . Isotonic - Isotonic contraction can be divided into two types: Concentric: the muscle shortens as it contracts. Eccentric: the muscle lengthens but is still under tension.

6. BODY MOVEMENTS In sports, there are many types of movements: Flexion : Bringing two parts of a limb together - bending at the joint . Extension : Moving two parts of a limb away from each other - straightening at the joint . Abduction : Moving limbs away from the center of the body . Adduction : Moving limbs towards the center of the body . Circumduction : The movement of a limb around a joint.

7. FUNCTIONS OF MUSCLES They are the most vital part of our body, as they are the material that most of our body organs are made from, so is essential for most body functions. They are also vital for the overall movement of our body.

8. MUSCLE FIBRES There are two kinds muscle fibers in our body: Slow Twitch : These are efficient but my sluggish fibers. Produce slow and long movements. Good for marathons Fast Twitch : These are powerful but less efficient fibers. Produce fast and sudden movements. Good for sprints

9. TYPES OF MUSCLES There are mainly three types of muscles inside our body: Voluntary Involuntary Cardiac (fall into involuntary)

10. VOLUNTARY MUSCLES Voluntary muscles are ones which can be moved at the conscience of the person. These are muscles which carry out ordinary movements e.g. leg movement, eye rotation etc.

11. EXAMPLES OF VOLUNTARY MUSCLES AND THEIR FUNCTIONS Name of muscle Function Example in sport Triceps Extend the arm at the elbow Press-up, throwing a javelin Biceps Flex the arm at the elbow Pull-up, drawing a bow in archery Deltoids Move the arm in all directions at the shoulder Bowling a cricket ball Pectorals Adduct the arm at the shoulder Forehand drive in tennis Trapezius Hold the shoulders in place, move head back and sideways Holding head up in rugby scrum Gluteals Adduct and extend leg at the hips Pulling back leg before kicking a ball Quadriceps Extend the leg at the knee Kicking a ball jumping upwards Hamstrings Flex the leg at the knee Bending knee before kicking a ball Gastrocnemius Pointing the toes, help to flex the knee Running Latissimus dorsi Adduct and extend the arm at the shoulder Butterfly stroke in swimming Abdominals Flex the trunk across the stomach Pulling the body down when hurdling

12. INVOLUNTARY MUSCLES Involuntary muscles are the ones in our body which work without the will or conscience of the person. These muscles are mostly in the inner part of the body e.g. stomach.

13. CARDIAC MUSCLES Cardiac muscles are one which compose of the circulatory system and its components. They fall under involuntary muscles, but are separately classified as they work non-stop.