MUSCULAR system Learning Objectives To be able to name the 3 types of muscle and explain their role within the human body. To be able to name and locate the major skeletal muscles and explain their specific role. Content 1.1.7 Classification and characteristics of muscle types: voluntary muscles of the skeletal system; involuntary muscles in blood vessels; cardiac muscle forming the heart; and their roles when participating in physical activity and sport 1.1.8 Location and role of the voluntary muscular system to work with the skeleton to bring about specific movement during physical activity and sport, and the specific function of each muscle (deltoid, biceps, triceps, pectoralis major, latissimus dorsi, external obliques, hip flexors, gluteus maximus, quadriceps, hamstrings, gastrocnemius and tibialis anterior) 1.1.9 Antagonistic pairs of muscles (agonist and antagonist) to create opposing movement at joints to allow physical activities (e.g. gastrocnemius and tibialis anterior acting at the ankle –plantar-flexion to dorsiflexion; and quadriceps and hamstrings acting at the knee, biceps and triceps acting at the elbow, and hip flexors and gluteus maximus acting at the hip – all flexion to extension)

Types of muscle There are 3 types of muscle in our body: Cardiac Involuntary Voluntary (Skeletal)

Cardiac Muscle This is muscle found only in the heart. Cardiac muscle contracts to pump blood through and out of the heart to be circulated around the body. When our heart rate increases during exercise, the cardiac muscle contracts more frequently to allow more blood to be circulated per minute.

Involuntary Muscle These are found in the walls of organs in the body. For example: In the walls of arteries where they control the flow of blood. This affects the delivery of oxygen and removal of carbon dioxide. In parts of the digestive tract which squeeze food further along while extracting vital nutrients. Regulating the flow of air through the lungs. Involuntary muscles react to changes in the body so they know when to contract. Therefore, we don’t have to consciously control them.

Voluntary (Skeletal) Muscle These are the muscles that create movement and maintain our posture. They only move when we tell them to so they are under our conscious control. Muscles can only pull, they cannot push, therefore they work in pairs to create movement in opposing directions.

TASK Research the main skeletal muscles to label the figure on your worksheet.

Voluntary (Skeletal) Muscle Although paired muscles produce movements in opposing directions, they aren’t working against each other like a tug of war. They work together to allow the movements instead. For example: The triceps relax allowing the biceps to pull and move the elbow joint one way (flexion / bending). The biceps relax allowing the triceps to pull and move the elbow the other way (extension / straightening).

Voluntary (Skeletal) Muscle The muscle that contracts (pulls) to produce a movement is called the agonist. The muscle that relaxes to allow the movement is called the antagonist.

TASK (in pairs) For each of the muscles on the worksheet; Work out the movement they cause. Describe when this movement occurs in a sporting action.