Summary

This document presents an overview of muscles, covering smooth, cardiac, and skeletal muscle types. It explores their functions, composition, and structure. The information is suitable for those studying human biology or related fields at university level.

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Muscles : C K A y // H od f. b...

Muscles : C K A y // H od f. b y o ert rop P Property of.body//HACK: Smooth muscle : C K Controlled by the autonomic nervous system H A (Involuntary) so is not under conscious//control d y. b o Used in all processes that maintain the body’s internal environment. o f rt y Found in the digestive system, it contracts to Found in p e move food through the body. r o blood vessels where it constricts & P to alter the flow of blood as well as dilates, urinary and reproductive systems Property of.body//HACK: Cardiac muscle : C K Found in the heart within the chamberHA y / / d walls where it pumps blood and Oxygen o around the body. f. b o The heart works continuously, y it is not r under conscious e t control. r o p The set rhythm of the heart (on average P 72 bpm at rest) is called autorhythmicity Property of.body//HACK: Skeletal muscle : C K They are striated in nature and cross over the joints and attach to the bones via //H A d y tendons. b o They are controlled by the.somatic nervous system so worko f under conscious rt y or voluntary control. p e P pull r o When stimulated to work, they contract, on the bones and create different body movements. Property of.body//HACK: Common terms : CK A Myo/My – A prefix denoting a relationship H to muscle y / / d Sarco - A prefix denoting flesh or o fleshy tissue, mainly referring to muscle f. b y o e r t r o p P Property of.body//HACK: Muscle composition : C K Water: 75-80% A y Protein (Elastin & Collagen): 20-25% // H od Fat: 1–10% f. b Glycogen: 1% y o ert rop P Property of.body//HACK: Muscle composition : C K A Myocytes (muscle fibers) form the bulk of muscle tissue. H y / / Myocytes are bound together by perimysium, a sheath o of connective tissue. Muscles aredcomposed of long bundles. b of Myocytes containingfthousands of myofibrils. y o Each Myofibril istcomposed e r of numerous sarcomeres o p Sarcomeres r are made up of myofilaments of the proteins P and Actin. Myosin Property of.body//HACK: Structure of a Muscle : C K A y // H od f. b y o ert rop P Property of.body//HACK: How muscles attach to bones : C K A y // H od f. b y o ert rop P Property of.body//HACK: Sliding Filament Theory : K C A A theory that helps explain how the muscles contract H y / / to generate force, based on the sliding movements of thin filaments (actin) alongo d filaments (myosin). thick f. b y o e rt r o p P Property of.body//HACK: Sliding Filament Theory : CK A Cocking: ATP breaks down releasing energy, so myosin’s head gets into a ‘cocked’ position. //H Binding: Calcium ions releaseoind y the Sarcoplasmic f Reticulum so myosin head. b attaches to actin. y o r t Power stroke: Myosin head rotates, pulling the actin towards theecentre of the sarcomere to generate r o p tension/muscle contraction. P Reset: ATP binds to the myosin head, releasing it from the actin binding site. Property of.body//HACK: Types of Muscle Contraction : C K A y // H od f. b y o ert rop P Property of.body//HACK: Types of Muscle Contraction : C K A y // H od f. b y o ert ro p P This means that the muscle is under tension. Contraction: Here the muscle may lengthen, shorten, or remain the same. Property of.body//HACK: Types of Muscle Contraction : C K Concentric: Eccentric: A // H Isometric: contraction contraction where y contraction where d where the muscle the muscle shortens. bo the muscle lengthens remains the same of rt y p e Pro Property of.body//HACK: Law of Reciprocal Inhibition : K C In order for a muscle on one side ofH A to contract y / / a joint effectively (Agonist), the o d System sends a Nervous f. b y o message to the muscle on the opposite side of that e r t joint (Antagonist) to relax. Otherwise, movement r o p P not be possible. would Property of.body//HACK: Law of Reciprocal Inhibition : C K A y // H od f. b y o ert rop P Property of.body//HACK: Law of Reciprocal Inhibition : C K A Fixators/stabilizers: Contracts to stabilize body part that remains fixed y // H Synergist: Contracts to assist o d f. b or modify the Agonist muscles y o e r t ro p P Property of.body//HACK:

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