Muscles 19/11/2018 Do it now : (Write in the inner circle) Do it now : (Write in the inner circle) Everything you know about muscles The names of any muscles What you know about muscle fibres.
Quick Quiz. Muscles 19/11/2018 Skeletal, Cardiac, Smooth Cardiac What are the three types of muscle? What type of muscle is the heart made out of? What would you use involuntary muscles for? Where in the body would you find smooth muscle? Skeletal, Cardiac, Smooth Cardiac Digestion, Circulation, Bladder, lungs Heart, lungs, Gastrointestinal tract.
Muscles Outcomes: Keywords Cardiac Smooth Skeletal involuntary 19/11/2018 Muscles LO – to understand the structure and arrangement of muscles. Outcomes: All: will revise the different types of muscle. Most: Understand why the different muscle groups are structured this way. Some: will know what the arrangement of muscles in the body are. Keywords Cardiac Smooth Skeletal involuntary
Muscles! If you got 4 marks on the quiz do this. Write a description of Smooth muscle. If you got 1 mark on the quiz do this. Write out a description of Cardiac Muscle Write out a description of skeletal muscle. Challenge: What are involuntary muscles? How are they controlled Start Here Get here!
Cardiac (Heart) Muscle Cardiac muscle is found only in the heart and is responsible for pumping blood and nutrients around the body It contracts without you having to think about it so it is involuntary Has a striated (striped) appearance and single nuclei Does not fatigue All of its parts contract in synchronous wave (think of the arms in a Mexican wave going around and around synchronously) because the cells are interconnected Generates its own nervous impulses (myogenic).
Smooth Muscle Involuntary Muscle Smooth muscle is found in the walls of all the hollow organs of the body (except the heart) Smooth muscle gets its name because there are no visible striations (stripes) It functions by contracting to reduce the size of all these organs. Examples below. Regulates the flow of blood in the arteries Moves blood through the gastrointestinal tract Expels urine from the bladder Regulates the flow of air through the lungs.
Skeletal Muscle Skeletal muscle is attached to the skeleton (who would have thought it)? Also known as striated (striped) muscle or voluntary muscle It is known as voluntary muscle because you can control these muscles consciously This muscle type can contract at great speed, but it fatigues quickly Main function = movement and posture Has a high concentration of enzymes and mitochondria which are necessary for energy production It has multiple nuclei.
Muscle groups competition Work in groups of 3-4. One person can come up at a time to look at the labelled diagram. Use your memory to fill out your blank diagram!
Muscle fibres.
One thick filament is surrounded by six thin filaments One thick filament is surrounded by six thin filaments. The thin filaments are made mainly of two entwined strands of the protein actin; the thick filaments are bundles of a protein called myosin:
Watch the video and number the processes to put them in order. Each myosin molecule consists of a tail and a head, entwined in pairs so that the heads protrude as shown above. Where the thick and thin filaments overlap the myosin heads would just luuurrrve to bind to the actin molecules (i.e. they have an actin binding site), but in relaxed muscle they are prevented from doing so by a rod-shaped protein called tropomyosin. Attached to the tropomyosin is the troponin complex, consisting of three protein molecules: one binds to the actin, another to the tropomyosin, and the third to calcium ions. The binding of calcium ions causes the troponin complex to move the tropomyosin out of the way, allowing myosin heads to bind to the actin: this initiates contraction. Watch the video and number the processes to put them in order.
6 1 5 2 4 7 3
Muscles Do it now : (Write in the outer circle) Do it now : (Write in the outer circle) Everything you have learned today that you didn’t already know.