Formative Assessment 3

Some Facts about Muscles Muscles convert chemical energy into mechanical energy to create a force, and this allows us to move. Skeletal muscle is primarily attached to bones, and it moves the skeleton. It is said to be striated because of its obvious striped appearance. Contraction is under our direct control and so the movement of the muscle is said to be voluntary. Cardiac muscle Cardiac muscle – forms the walls of the heart. This muscle is striated and, because contraction occur without us knowing, it movement is said to be involuntary. Smooth muscle is located on the walls of our internal structures, such as the stomach, blood vessels, and intestines. It is non-striated, and it movement is usually involuntary. Types of Contraction There are 3 main types of muscular contraction, isotonic, isometric. Isotonic contraction the muscle fibres produce a tension, or force, as they lift the load through the range of movement. The muscle length changes (shortens and lengthens) as tension develops, so there are two possible types of isotonic contractions. Concentric isotonic contraction, the muscle shortens to pull on bones and bring them closer together, as when you picked the heavy book Eccentric isotonic contraction the muscle lengthens as when you put the book back down. Isometric occurs when tension develops in the muscle, but it neither shortens nor lengthens. Agonist Pairs Usually it is the action of muscles in groups that causes use to move. Often muscles move in pairs at joints AGONIST This the prime mover and creates the movement by contracting ANTAGONIST This is the muscle that relaxes during the movement can help with controlling movement. Lab Activity Perform the following exercises and complete the table below to show you understanding of Agonist and Antagonist Pairs.Where there is more than one same answer provided 1 will be higher on the table and 2 will be lowerExampleBiceps 1Biceps 2 Agonist Antagonist Type of Muscle contraction Up phase Bicep curl Biceps 1 Triceps 1 Concentric 1 Wall sit Quadriceps 1 Hamstrings 1 Isometric Down phase Press ups Pectoralis major Latissimus Dorsi 1 Eccentric 1 Up phase Dips Triceps 2 Biceps 2 Concentric 2 Down phase leg extension Quadriceps 2 Hamstrings 2 Eccentric 2 Up phase Upright rows Trapezius Latissimus Dorsi 2 Concentric 3 Muscles and their Movements Match the Muscles with the main anatomical movement that they create. Biceps elbow flexion Triceps Elbow extension Trapezius shoulder retraction, elevation and depression Latissimus dorsi Create movement and cause shoulder adduction Deltoid Responsible for shoulder abduction Pectorials Create flexion of the shoulder joint Quadriceps Primary function is to extend the knee Hamstrings Primary function flexion of the knee joint Gluteals Hip extension is this muscles main function Abdominals Forward trunk flexion. Erector spinae Hyperextension is the main function of this muscle Gastrocnemius ankle joint to plantaflex Soleus also assists in plantaflexion Tibialis anterior allow dorsiflexion at the ankle joint Muscles