MUSCLE TISSUE. Larry Johnson Texas A&M University

Transcription

1 MUSCLE TISSUE Larry Johnson Texas A&M University

2 Objectives Histologically identify and functionally characterize each of the 3 types of muscle tissues. Describe the organization of the sarcomere as seen in light and electron microscopy. Identify the endomysium, perimysium, and epimysium CT sleeves in muscle. Relate the functional differences of the three muscle cell types. From: Douglas P. Dohrman and TAMHSC Faculty 2012 Structure and Function of Human Organ Systems, Histology Laboratory Manual

3 MUSCLE FUNCTION: GENERATION OF CONTRACTILE FORCE DISTINGUISHING FEATURES: HIGH CONCENTRATION OF CONTRACTILE PROTEINS ACTIN AND MYOSIN ARRANGED EITHER DIFFUSELY IN THE CYTOPLASM (SMOOTH MUSCLE) OR IN REGULAR REPEATING UNITS CALLED SARCOMERES (STRIATED MUSCLES, e.g., CARDIAC AND SKELETAL MUSCLES)

4 MUSCLE DISTRIBUTION: SKELETAL STRIATED MUSCLES MOSTLY ASSOCIATED WITH THE SKELETON

5 MUSCLE DISTRIBUTION: SKELETAL STRIATED MUSCLES MOSTLY ASSOCIATED WITH THE SKELETON CARDIAC STRIATED MUSCLES ASSOCIATEWD WITH THE HEART

6 MUSCLE DISTRIBUTION: SKELETAL STRIATED MUSCLES MOSTLY ASSOCIATED WITH THE SKELETON CARDIAC STRIATED MUSCLES ASSOCIATEWD WITH THE HEART SMOOTH FUSIFORM CELLS ASSOCIATED WITH THE VISCERA, RESPIRATORY TRACT, BLOOD VESSELS, UTERUS, ETC.

7 MUSCLE HISTOLOGICAL INDENTIFICATION: SKELETAL MUSCLE VERY LONG CYLINDRICAL STRIATED MUSCLE CELLS WITH MULTIPLE PERIPHERAL NUCLEI

8 MUSCLE HISTOLOGICAL INDENTIFICATION: SKELETAL MUSCLE VERY LONG CYLINDRICAL STRIATED MUSCLE CELLS WITH MULTIPLE PERIPHERAL NUCLEI CARDIAC MUSCLE SHORT BRANCHING STRIATED MUSCLE CELLS WITH CENTRALLY LOCATED NUCLEI

9 MUSCLE HISTOLOGICAL INDENTIFICATION: SKELETAL MUSCLE VERY LONG CYLINDRICAL STRIATED MUSCLE CELLS WITH MULTIPLE PERIPHERAL NUCLEI CARDIAC MUSCLE SHORT BRANCHING STRIATED MUSCLE CELLS WITH CENTRALLY LOCATED NUCLEI SMOOTH MUSCLE CLOSELY PACKED SPINDLE-SHAPED CELLS WITH A SINGLE CENTRALLY PLACED NUCLEUS AND CYTOPLASM THAT APPEARS HOMOGENEOUS BY LIGHT MICROSCOPY

10 MUSCLE HISTOLOGICAL INDENTIFICATION: SKELETAL MUSCLE VERY LONG CYLINDRICAL STRIATED MUSCLE CELLS WITH MULTIPLE PERIPHERAL NUCLEI Myoepithelial cells CARDIAC MUSCLE SHORT BRANCHING STRIATED MUSCLE CELLS WITH CENTRALLY LOCATED NUCLEI SMOOTH MUSCLE CLOSELY PACKED SPINDLE-SHAPED CELLS WITH A SINGLE CENTRALLY PLACED NUCLEUS AND CYTOPLASM THAT APPEARS HOMOGENEOUS BY LIGHT MICROSCOPY

11 Muscle Tissue Muscle cells specialized for contraction with apparatus of actin and myosin proteins. 3 types: Skeletal Muscle Smooth Muscle Cardiac Muscle Longitudinal sections - Peripheral nuclei - Striations - No branching Cross section - Peripheral nuclei - Massive cytoplasm Longitudinal sections - Central nuclei (often fusiform) - Meshwork appearance of cells - No striations Cross section - Central nuclei - Low cytoplasm to nucleus ratio Longitudinal sections - Central nuclei (often elongated) - Striations - Branching cells - Intercalated discs Cross section - Central nuclei - High cytoplasm to nucleus ratio

12 Slide 11: Skeletal muscle (longitudinal and cross sections) Muscle fibers with peripheral nuclei Capillary Cross sections of muscle fibers with peripheral nuclei

13 Slide 052: Skeletal muscle (longitudinal and cross sections) Muscle fibers with peripheral nuclei Capillary Cross striations (A and I bands)

14 Slide 052: Skeletal muscle (longitudinal and cross sections) Muscle fibers with peripheral nuclei Capillary Cross striations (A and I bands) The increase in muscle mass during exercise results from stimulating formation of new myofibrils and enlargement in the diameter of individual muscle fibers (hypertrophy = increase in size).

15 CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE EPIMYSIUM - COARSE CT EPIMYSIUM

16 CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE EPIMYSIUM - COARSE CT PERIMYSIUM - LESS COARSE CT PERIMYSIUM EPIMYSIUM

17 CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE EPIMYSIUM - COARSE CT PERIMYSIUM - LESS COARSE CT ENDOMYSIUM - DELICATE CT PERIMYSIUM EPIMYSIUM ENDOMYSIUM

18 CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE EPIMYSIUM, PERIMYSIUM, and ENDOMYSIUM

19 Slide 11: Skeletal muscle (longitudinal and cross sections) Epimysium Perimysium Endomysium

20 Slide 052 Skeletal muscle (longitudinal and cross sections) Perimysium Endomysium with its capillaries

21 CONNECTIVE TISSUE connect LAYERS OF SKELETAL MUSCLE ENDOMYSIUM

22 CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE PERIMYSIUM

23 CONNECTIVE TISSUE LAYERS OF SKELETAL MUSCLE PERIMYSIUM 052 ENDOMYSIUM

24 Striations in skeletal muscle 052 Skeletal muscles have striations, peripheral nuclei, same thickness throughout their length and do not branch. Specialized for powerful and rapid contraction. Voluntary. Found attached to the skeleton.

25 Slide 12: Skeletal muscle (phosphotungstic acid/hematoxylin) Sarcomere: Z line to Z line Z line is In the I band I band A band

26 STRIATED MUSCLE CARDIAC SKELETAL A A BAND = dark band ANISOTROPIC = DOES ALTER POLARIZED LIGHT (BIREFRINGENT)

27 STRIATED MUSCLE CARDIAC SKELETAL A I A BAND = dark band ANISOTROPIC = DOES ALTER POLARIZED LIGHT (BIREFRINGENT) I BAND = light band ISOTROPIC = DOES NOT ALTER POLARIZED LIGHT

28 STRIATED MUSCLE (SKELETAL) A I SARCOMERES ARE ORGANIZED FOR RAPID AND HIGHLY CONTROLLED CONTRACTION

29 SKELETAL MUSCLE cell structure

30 SKELETAL MUSCLE

31 SKELETAL MUSCLE

32 INTERMEDIATE FILAMENTS FUNCTION in muscle cells MYOFIBRIL ORGANIZATION MUSCLE cells

33 INTERMEDIATE FILAMENTS FUNCTION in muscle cells MYOFIBRIL ORGANIZATION MUSCLE cells Cell =

34 CONTRACTION OF THE SARCOMERE THIN FILAMENT ACTIN (F-ACTIN) TROPOMYOSIN TROPONIN T - ATTACHES TO TROPOMYOSIN C - BINDS CALCIUM IONS I - INHIBITS ACTIN-MYOSIN INTERACTION The stoppage of the neural impulse and depletion of free calcium ends the actinmyosin crossbridge cycle in skeletal muscle. ATP is required in this process.

35 CALCIUM REGULATION TRANVERSE (T) TUBULE (INVAGINATION OF SARCOLEMMA) TRANSMIT DEPOLARIZATION OF MEMBRANE DEEP INTO THE CELL SARCOPLASMIC RETICULUM (SER OF CELL) RELEASE CA ++ FOR CONTRACTION - THEN RECOVER CA ++ AFTER CONTRACTION TRIAD = (T TUBULE AND TWO ENDS OF SER)

36 EM 29 : Skeletal muscle 052

37 EM 46 and 47 : Skeletal muscle

38 STIMULATION OF MUSCLE CELLS

39 Slide 13: Skeletal Muscle muscle spindles (trichrome) Intrafusal muscle fibers Muscle spindle: (stretch receptors) Nerve fibers

40 INNERVATION OF MUSCLE MUSCLE SPINDLE MUSCLE Intracapsular SPINDLE fibers

41 SMOOTH MUSCLE

42 SMOOTH MUSCLE Has a PAS + basement membrane

43 Slide 35: Urinary bladder Muscularis externa (smooth muscle) Smooth muscle fibers with central nuclei Smooth muscles are fusiform with tapered ends, single, central nuclei, and no striations. Involuntary. Found in sphincters and sheets of internal visceral organs and glands.

44 Slide 63: Appendix Smooth muscle layer arrangement in tubular organs Submucosa The layering of smooth muscle in the gut is responsible for contractions which mix and propel luminal contents forward. Muscularis externa

45 EM 49: Smooth muscle Actin Myosin

46 SMOOTH MUSCLE

47 MUSCULAR ARTERY

48 Skeletal Muscle Smooth muscle

49 CARDIAC MUSCLE IS STRIATED MUSCLE INTERCALATED DISC FASCIA ADHERENS MACULAE ADHERENS GAP JUNCTIONS - LATERAL PORTION

50 CARDIAC MUSCLE INTERCALATED DISC The intercalated discs enables coordinated function via gap junctions to facilitate energy and calcium conductance between neighboring myocytes.

51 pulmonary artery in the lungs of a rat INTERCALATED DISC

52 pulmonary artery in the lungs of a rat INTERCALATED DISC nucleus mitochondria

53 Slide 14: Heart & EM 48: Heart Intercalated discs

54 CARDIAC MUSCLE Diad located at Z line Diad = (T tubule + one end of SER)

55 REGENERATION OF MUSCLE Which type of muscle cells can be replaced in adults? SMOOTH LOTS SKELETAL SOME CARDIAC NONE

56 Clinical Correlation Ischemic heart disease is one of the most significant health problems in the US. Coronary artery thrombosis usually precedes and precipitates a myocardial infarct, resulting in the death of cardiac myocytes. Eventually scar tissue is formed and there is some loss of contractility. Image taken from adultstemcellawareness.wordpress.com Lacking muscle mesenchymal satellite cells, adult mammalian cardiac muscle has little potential to regenerate after injury. Damage is replaced by proliferating fibroblasts and connective tissue growth, forming myocardial scars.

57 Summary of MUSCLE shapes and excitations of types

58 Many illustrations in these VIBS Histology YouTube videos were modified from the following books and sources: Many thanks to original sources! Bruce Alberts, et al Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY. Bruce Alberts, et al Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY. William J. Banks, Applied Veterinary Histology. Williams and Wilkins, Los Angeles, CA. Hans Elias, et al Histology and Human Microanatomy. John Wiley and Sons, New York, NY. Don W. Fawcett Bloom and Fawcett. A textbook of histology. W. B. Saunders Company, Philadelphia, PA. Don W. Fawcett Bloom and Fawcett. A textbook of histology. Chapman and Hall, New York, NY. Arthur W. Ham and David H. Cormack Histology. J. S. Lippincott Company, Philadelphia, PA. Luis C. Junqueira, et al Basic Histology. Lange Medical Publications, Los Altos, CA. L. Carlos Junqueira, et al Basic Histology. Appleton and Lange, Norwalk, CT. L.L. Langley, et al Dynamic Anatomy and Physiology. McGraw-Hill Book Company, New York, NY. W.W. Tuttle and Byron A. Schottelius Textbook of Physiology. The C. V. Mosby Company, St. Louis, MO. Leon Weiss Histology Cell and Tissue Biology. Elsevier Biomedical, New York, NY. Leon Weiss and Roy O. Greep Histology. McGraw-Hill Book Company, New York, NY. Nature ( Vol. 414:88,2001. A.L. Mescher 2013 Junqueira s Basis Histology text and atlas, 13 th ed. McGraw Douglas P. Dohrman and TAMHSC Faculty 2012 Structure and Function of Human Organ Systems, Histology Laboratory Manual - Slide selections were largely based on this manual for first year medical students at TAMHSC

59 The end!