Human Biology Muscle Tissue PDF

ITBC – Course 6BM Human Biology Muscle tissue Nothing from this presentation may be published without explicit permission from the director of the Institute Applied Biosciences and Chemistry  Goal of the Human Biology lessons Insight and knowledge about the 4 bas...

ITBC – Course 6BM Human Biology Muscle tissue Nothing from this presentation may be published without explicit permission from the director of the Institute Applied Biosciences and Chemistry  Goal of the Human Biology lessons Insight and knowledge about the 4 basic tissues Epithelial tissue & skin Connective tissue Muscle tissue Nervous tissue Insight and knowledge about organs and organ systems Urinary system Digestive system & Endocrine system Respiratory system & Circulation 2 All pictures are derived from the following book (unless indicated differently): Mescher, Anthony. Junqueira's Basic Histology: Text and Atlas, Fifteenth Edition. McGraw-Hill Education This lesson: muscle tissue Junqueira’s basic histology Chapter 10 3 Muscle tissue: 3 types Skeletal muscle tissue - Striated Striated - Multinucleoted Multinucleated (fusion of many cells) - movement Organized into long muscle fibers Voluntary movements Cardiac muscle tissue - striated Also striated - oneOne ornuclei or two two nuclei Branched cells, connected via intercalated discs -involuntary movements Involuntary, rhythmic movements 4 Muscle tissue: 3 types Smooth muscle tissue - no striation No striations - oneOne nucleus per cellper nucleuscell Elongated cells with tapering ends Involuntary movements Locations?? stomach, skin, intestines 5 Muscle tissue general to contract it need calcium Parts of muscle cells get the prefix sarco- Cytoplasm → sarcoplasm cytoplasm of muscle cells - calcium ER → sarcoplasmic reticulum Cell membrane → sarcolemma 6 Skeletal muscle tissue Development from myoblasts Generation of long (1 mm to 30 cm!) muscle cells/muscle fibers development of Cylinder shape (diameter muscle cells reserve cells -regeneration 10-100 µm) Satellite cell: ‘reserve’ cell (limited) regeneration after damage 7 Organization of a skeletal muscle (I) important to know Muscle cell (-fiber) endo - inside of this muscle bundle Endomysium Very thin layer connective tissue Capillaries + nerve endings Perimysium Thin connective tissue layer around a bundle of muscle fibers Functional unit in which muscle fibers work together Innervated by 1 nerve 8 Organization of a skeletal muscle (II) Epimysium Dense connective tissue (i) Surrounds the entire muscle Contains nerves, blood + lymph vessels that branch out and enter the muscle Fascia Dense connective tissue (i) is continuous with tendon Movement is transferred via the connective tissues 9 Skeletal muscle tissue 10 Organization of a skeletal muscle fiber (cell) Highly organized Myofibrils → long bundles of protein filaments: 1. Thick filament Myosin proteins 2. Thin filament Actin proteins (+ troponin & tropomyosin) movement via calcium 11 Organization of a skeletal muscle fiber (cell) Myofibrils organized in repetitive units Z-line to Z-line = sarcomere (functional unit) Actin and myosin slide past each other → movement Contraction: Z-lines get closer together Draw or explain the sarcomere 12 13 Organization of a skeletal muscle fiber (cell) Infoldings of sarcolemma: T-tubules Branched sarcoplasmic reticulum (SR) Triad (T-tubule + 2x SR) Mitochondria 14 Contraction of a muscle fiber signal important substance Neuromuscular junction (NMJ) → acetylcholine (neuro- transmitter) → depolarisation sarcolemma (t-tubules) → release Ca2+ from SR → initiation contraction cycle 15 Sliding filament model → contraction cycle Video: https://www.youtube.com/watch?v=sIH8uOg8ddw you can get the signal Also fun and useful: Crash course Muscles https://www.youtube.com/watch?v=Ktv-CaOt6UQ 16 Cardiac muscle tissue Cells are: Branched Striated Connected via intercalated discs Surrounded by endomysium Surrounded by many capillaries Groups cardiac muscle cells: Surrounded by perimysium (is continuous with connective tissue of the heart → endocardium and epicardium) Picture from chapter 11 17 Cardiac muscle tissue Signal transfer comparable with skeletal muscle, slightly less organized Many mitochondria (up to 40%) → aerobic respiration Use fatty acids (are stored inside the cell) 18  Cardiac muscle tissue Intercalated discs: connections between cells Strong adhesion desmosomes Communication gab junctition 19 Smooth muscle tissue Individual cells Many gap junctions Endomysium Basal lamina + collagen fibers Transfers contractile forces Slow contraction Using actin and myosin No striation 20  Smooth muscle tissue Cells pack closely together → unity Organization in layers with different alignment spindle shape nucleus; no striate lumen 21 Smooth muscle tissue Dense bodies → similar to Z-line Do not remember Use different proteins instead of troponin and tropomyosin (namely calmodulin and MLCK) 22 Muscle tissue: movement initiated by Skeletal muscle tissue Motor nerves → acetylcholine (ACh) Cardiac muscle tissue Autonomic nervous system → pacemaker heart Smooth muscle tissue Autonomic nervous system Hormones/secretions (uterus, GI-tract) influences by 23  Summary 24 End of this lesson Are there any questions? 25 Next lesson Nervous tissue: Chapter 9 26 Sources Junqueira’s basic histology 15th ed., Anthony L. Mescher, McGraw-Hill Education Functionele histologie, Junqueira L.C., Carneiro J., 13th edition, Elsevier gezondheidszorg 27