PRELIMINARY HSC PDHPE CQ1 How do the musculoskeletal and cardiorespiratory systems of the body influence and respond to movement?
How do the musculoskeletal and cardiorespiratory systems of the body influence and respond to movement? Students learn about: skeletal system major bones involved in movement structure and function of synovial joints joint actions, eg extension and flexion muscular system major muscles involved in movement muscle relationship (agonist, antagonist) types of muscle contraction (concentric, eccentric, isometric) respiratory system structure and function lung function (inspiration, expiration) exchange of gases (internal, external) circulatory system components of blood structure and function of the heart, arteries, veins, capillaries pulmonary and systemic circulation blood pressure. Students learn to: identify the location and type of major bones involved in movement, eg long bones articulate at hinge joints for flexion and extension identify the location of the major muscles involved in movement and related joint actions perform and analyse movements, eg overarm throw, by examining: bones involved and the joint action muscles involved and the type of contraction analyse the various aspects of lung function through participation in a range of physical activities analyse the movement of blood through the body and the influence of the circulatory and respiratory systems on movement efficiency and performance.
MUSCULAR SYSTEM - watch video 1 The basis of all human movement is muscle action. Muscle consists of cells with contractile filaments that move past each other to change the size of the cell. There are three types of muscle in the human body: skeletal, smooth and cardiac. Smooth and cardiac muscles are voluntary muscles that determine movement over which the human body has no control, for example, a heart beat, or the movement of food through the digestive system. Skeletal muscle is responsible for producing human movement, and groups of muscles in the human body work together to control movement patterns. Muscles enable us to move, breathe and communicate; provide stability so we can stand upright; and serve many internal bodily functions. Muscles come in various shapes and sizes and make up approximately 40% of our body weight. There are approximately 640 muscles in the body, so their ability to convert energy and enable us to function is crucial to our everyday lives.
Types of muscles (3 types) Cardiac these are only found in the heart. The muscle is striated in texture but works involuntarily, so we have little control over the number of times our heart beats. At times, our body may need to increase the intensity of the heart s pumping action usually when undertaking cardiovascular activity. Our heart accommodates these periods of time to ensure adequate oxygen is provided to the body.
Types of muscles (3 types) Smooth These are found in the walls of organs such as the stomach and bladder, and in arteries and veins. They are non-striated, involuntary and have long, slim muscle fibres. Contractions are slow and sustained.
Types of muscles (3 types) - watch video 2 Skeletal These are the most common types of muscles in the body. They are named because of their location; they are attached to the bones of the skeletal system. Skeletal muscles are voluntary and can therefore be controlled to contract and relax. They are striated in texture, contract easily and require rest after exercise. These muscles have tremendous power and strength.
Functions of muscles Muscles can: produce movement to walk, run, jump, breathe, digest and excrete provide stabilisation of posture and internal organs generate heat to maintain body temperature. If you examine a muscle you will find that it is constructed of many smaller bundles of muscle fibres.
Correctly label the following diagram of a muscle fibres composition.
Explain why skeletal muscle is classified as a voluntary muscle
Correctly label the muscular system diagram using the list provided.
muscle relationship (agonist, antagonist) - watch video 3 Muscles work by generating tension that causes change within the cell. The tension created causes a muscle to shorten, lengthen or remain the same length. This is known as muscle contraction. Muscles usually work in paired groups known as the agonist and antagonist. The muscle that is responsible for the shortening action is called the agonist. As the agonist contracts, the other muscle in a pair relaxes and lengthens. This muscle is called the antagonist. Stabilisers are muscles that assist agonist and antagonists in producing particular movements at a joint. For movement to be effective there must be stability in the joint. Stabilising muscles will often contract statically to hold other parts of the body around the joint still.
Complete the following table for muscles, their origin, insertion and the actions the cause. Muscle Origin Insertion Actions Deltoid Clavicle and scapula Humerus Abducts, flexes, extends, medially and laterally rotates arm Biceps brachii Scapula Radius Flexes and supinates forearm; flexes arm Triceps Scapula and humerus Ulna Extends forearm and arm Latissimus dorsi Trapezius Pectorals Major Minor Erector spinae Lower 6 thoracic vertebrae, all lumbar vertebrae, lower 4 ribs, iliac and sacral crests Occipital bone, spines of C7 and all thoracic vertebra Ribs 2 6, clavicle and sternum Ribs 3 5 Vary along vertebral spines and transverse processes, ribs and iliac crest Humerus Clavicle and scapula Humerus Scapula Vary along vertebral spines and transverse processes, ribs and jaw Extends, adducts and medially rotates arm; draws arm downward and backward; depresses scapula Elevates clavicle; extends head; adducts, rotates upward, elevates and depresses scapula Flexes, adducts and medially rotates arm; pulls rib cage upwards With ribs fixed: draws scapula forward and downward With scapula fixed: draws rib cage superiorly Maintains erect posture; extends vertebral column Acts on one side to: bend vertebral column laterally; extend head and rotate face to side Gluteus maximus Iliac crest, sacrum and coccyx Femur Extends and laterally rotates thigh Hamstrings: group Ischium and femur (biceps femoris) Tibia and fibula (biceps femoris) Flexes leg and extends thigh of 3 muscles Quadriceps: group of 4 muscles Femur (semitendinosus and semimembranosus) Iliac spine (rectus femoris) Tibia (semitendinosus and semimembranosus) Common insertion to patella and tibia through the patella ligament Extends leg and flexes hip (rectus femoris) Femur (vastus group) Extends leg (vastus group) Gastrocnemius Lateral and medial sides of femur Calcaneous via Achilles tendon Plantar flexes foot; flexes leg Soleus Fibula and tibia Calcaneous via Achilles tendon Plantar flexes foot Tibialis anterior Tibia First metatarsal Dorsiflexes and inverts foot Rectus abdominus Pubic crest Xiphoid process and ribs 5 7 Flexes and rotates lumbar vertebra; fixes and depresses ribs; stabilises pelvis External obliques Lower 8 ribs Iliac crest and linea alba As pair flexes vertebral column, compresses abdominal wall Singular trunk rotation and lateral flexion
Muscles - watch video 3 Muscles can be classified functionally into three groups: agonists (prime movers) the agonist muscle provides the main force that causes the desired movement antagonists (muscles that react) the muscle that opposes or reverses a particular movement stabilisers (synergists and fixators) the muscle that aids agonists by promoting the same movement or by reducing unnecessary movement or undesired action. When a synergist immobilises the head of a muscle or a bone, it is called a fixator.
Activity/task - Participate in the following exercises (if possible) and complete the table Exercise Muscles Location Point of origin Point of insertion Bicep curl Biceps, triceps, wrist flexors scapula radius Deep squat Quadriceps, hamstrings, glutes, tibialis anterior, gastrocnemius Bench press Pectorals, deltoids, triceps, biceps Lateral pull down Lattisimus dorsi, deltoids, triceps, biceps Lunge walk Quadriceps, hamstrings, glutes, tibialis anterior, gastrocnemius Sit-up Rectus abdominus, transverse abdomin Upright row Trapezius, tric, bi, delt, serrate Prone alternating Trap, delt, pect, bi, tric reverse fly Leg press calf raise Gastrocnemius, tib anter, hams
Types of muscle contraction (concentric, eccentric, isometric) Isotonic contractions Body movement occurs when there is a shortening of a muscle with the agonist lengthening at the same time. In this case both the agonist and antagonist will be contracting or creating tension. Where the muscle is shortening the contraction is classified as a concentric contraction. The antagonist will be lengthening but will still be creating tension to control the movement. This contraction while extending is known as an eccentric contraction.
Isotonic Contraction
Types of muscle contraction (concentric, eccentric, isometric) - watch video 4 Isometric contractions These occur where the muscle generates force against a fixed resistance that does not move. There is no significant change in the muscle length. An example of this would be doing a calf stretch against a wall. Other sporting examples include an athlete performing a crouch start before a sprint, with muscles tensed waiting for the starter s gun. Rock climbers will often perform isometric muscle contractions as they keep parts of their bodies still while searching for a new hand or foothold.
Isometric Contraction
Revision/Homework task Answer/complete the following statements/questions: Analyse the following movements, eg overarm throw, by examining: bones involved and the joint action, and the muscles involved and the type of contraction Identify the agonist and antagonist in the following actions: A. extension of the elbow B. rotation of the shoulder C. flexion of the hip D. hyperextension of the hip E. rotation of the neck Explain the different types of contraction that muscles are able to perform.
Revision/Homework task Answer/complete the following statements/questions: Identify some sport-based movements where isometric contractions are required. Describe how skeletal muscles produce movement by pulling on bones. Define the role of the agonist, antagonist and stabiliser in the production of movement. Describe the movements that are possible at the shoulder joint and the muscles involved in producing these movements. Movements: abduction, adduction, rotation, circumduction Identify the agonists, antagonists and stabilisers.
Revision/Homework task Answer/complete the following statements/questions: - watch video 5 Identify which of the following is the muscle of the arm that both flexes the elbow and supinates the forearm: triceps brachii biceps brachii deltoid brachialis Explain the difference between an isotonic contraction and an isometric contraction. Suggest three exercises and three sporting activities that produce both types of contraction. Discuss the reasons why AFL players may be prone to injuries such as shoulder dislocations and hamstring tears.