Biology 111 Muscle and Muscle Tissue PDF

BIOL 111: MUSCLE AND MUSCLE TISSUE Instructor: Dr. Pamela Paynter-Armour  OBJECTIVES Distinguish between the three types of Muscle Tissue Outline the special characteristics and functions of Muscle Tissue Discuss the macroscopic anatomy of muscles...

BIOL 111: MUSCLE AND MUSCLE TISSUE Instructor: Dr. Pamela Paynter-Armour  OBJECTIVES Distinguish between the three types of Muscle Tissue Outline the special characteristics and functions of Muscle Tissue Discuss the macroscopic anatomy of muscles Discuss the microscopic anatomy of muscles  TISSUE AND ORGANIZATION Over 700 skeletal muscles have been named. Muscle tissue is distributed almost everywhere in the body. Responsible for the movement of materials within and throughout the body (McKinley & O'Loughlin, n.d.)  What is the muscular system? The muscular system consists of all the muscles of the body. These make up approximately 42% of total body weight, and are composed of long, slender cells known as fibers. The fibers are different lengths and vary in color from white to deep red. (Nebraska Department of Education, 2017).  3 types of muscle… There are 3 types, classified according to function and appearance:  THREE TYPES OF MUSCLE TISSUE 1. Skeletal muscle tissue:  Attached to bones and skin  Striated  Voluntary (i.e., conscious control)  Powerful (Meeking, 2010).  MUSCLE TYPES CONT’D Skeletal muscle 40% of body mass Multinucleate cells –very long! Contracts rapidly(Donley, 2004)  Skeletal muscles ✓ Are elastic and work ✓ Fast, white muscle in pairs - one flexing fibers contract rapidly, while the other is have poor blood extending. supply, and tire quickly. ✓ Slow, red muscle fibers ✓ They are striated, with contract more slowly, horizontal markings, have better blood and are stimulated to supplies, operate with contract by electrical oxygen, and do not tire impulses from the as easily. (Nebraska nervous system. Department of Education, 2017).  THREE TYPES OF MUSCLE TISSUE 2. Cardiac muscle tissue:  Only in the heart  Striated  Involuntary (Meeking, 2010).  More details in Chapter 18  Cardiac Muscle ✓ The ✓ They are stimulated to myocardium contract by electrical are striated like impulses sent out from skeletal small clumps of muscles, but specialized tissue in the are smaller and heart… the sinoatrial shorter. (sī-nō-Ā-trē-ul) and atrioventricular node (ā-trē-ō-ven-trik-y ə-lər) nodes. (Nebraska Department of Education, 2017).  THREE TYPES OF MUSCLE TISSUE 3. Smooth muscle tissue: In the walls of hollow organs, e.g., stomach, urinary bladder, and airways Not striated Involuntary Slow contracting Individual cells (Donley, 2004)  Smooth muscle ✓ Lines most hollow ✓ Smooth muscles organs of the body, such contract slower than as the intestines, skeletal muscles, but stomach, and uterus. can remain ✓ They help move contracted longer, substances through and are not as tubular areas such as dependent on blood vessels and the oxygen. small intestines, ✓ They are stimulated contracting by electrical impulses automatically and or hormones, and use rhythmically. carbohydrates for energy. (Nebraska Department of Education, 2017). Copyright © 2010 Pearson Education, Inc. Table 9.3  (Donley, Copyright © 2010 Pearson Education, Inc. 2004)  SPECIAL CHARACTERISTICS OF MUSCLE TISSUE  Excitability (responsiveness or irritability): ability to receive and respond to stimuli  Contractility: ability to shorten when stimulated  Extensibility: ability to be stretched  Elasticity: ability to recoil to resting length (Meeking, 2010).  MUSCLE FUNCTIONS 1. Movement of bones or fluids (e.g., blood) 2. Maintaining posture and body position 3. Stabilizing joints and Support 4. Heat generation/Temperature regulation (especially skeletal muscle) (Meeking, 2010). 5. Storage of materials (McKinley & O'Loughlin, n.d.)  MUSCLE TISSUE TERMINOLOGY Prefixes: myo or mys = muscle Prefix: sarco = reference to muscle Examples Cytoplasm = sarcoplasm ER = sarcoplasmic reticulum Cell membrane = sarcolemma (Donley, 2004)  SKELETAL MUSCLE http://ts4.mm.bing.net/th?id=H.4566204271559383pid=15.1  SKELETAL MUSCLE Each muscle is served by one artery, one nerve, and one or more veins (Meeking, 2010). Muscle cells fuse together during development (up to 30 cm long) Nuclei are usually peripheral (Donley, 2004)  Parts of a muscle Each muscle has 3 parts: Body – the main portion Origin – the fixed attachment Insertion - the point of attachment to the part of the body moved by this muscle ❖ In this picture, the origin of the muscle is the scapula attachment; a tendon provides the insertion on the ulna and radius bones. Parts of a muscle… A tendon is a means of attachment, connecting the muscle to the bone. They vary in length, from less than an inch to more than a foot. A wide sheet-like tendon is called an aponeurosis (ap ah nyu ROH siss). (Nebraska Department of Education, 2017). MACROSCOPIC ANATOMY  Structure of a Skeletal Muscle Epimysium Perimysium Endomysium Muscle Fascicles Muscle fibers Myofibrils Thick and thin filaments 9-4 (Shier, Butler, and Lewis, n.d.).  MUSCLE SHEATH-ENDOMYSIUM Innermost connective tissue layer- Mainly reticular fibers and basal lamina Surrounds each muscle fiber Help bind together neighboring muscle fibers Support capillaries near fibers (McKinley & O'Loughlin, n.d.) 10-24 (McKinley & O'Loughlin, n.d.)  MUSCLE SHEATH-PERIMYSIUM Surrounds the bundles of muscle fibers called fascicles. Has a dense irregular connective tissue sheath which contains extensive arrays of blood vessels and nerves that branch to supply each individual fascicle (McKinley & O'Loughlin, n.d.) (McKinley & O'Loughlin, n.d.)  MUSCLE SHEATH- EPIMYSIUM A layer of dense irregular connective tissue that surrounds the whole skeletal muscle (McKinley & O'Loughlin, n.d.) 10-28 (McKinley & O'Loughlin, n.d.) 29  DEEP FASCIA An expansive sheet of dense irregular connective tissue separates individual muscles binds together muscles with similar functions forms sheaths to help distribute nerves, blood vessels, and lymphatic vessels fill spaces between muscles (McKinley & O'Loughlin, n.d.) 10-30  SUPERFICIAL FASCIA  An extensive sheet of areolar connective tissue and adipose Also called subcutaneous tissue or hypodermis Separates muscle from skin Superficial to the deep fascia (McKinley & O'Loughlin, n.d.) 10-31 (McKinley & O'Loughlin, n.d.) 32 SKELETAL MUSCLE: ATTACHMENTS  Muscles attach: Directly—epimysium of muscle is fused to the periosteum of bone or perichondrium of cartilage Indirectly—connective tissue wrappings extend beyond the muscle as a ropelike tendon or sheetlike aponeurosis (Meeking, 2010). Copyright © 2010 Pearson Education, Inc.  Muscle Attachments Tendon attaches the muscle to bone, skin, or another muscle. Tendons usually have a thick, cordlike structure. Sometimes forms a thin, flattened sheet, termed an aponeurosis (McKinley & O'Loughlin, n.d.) Copyright © 2010 Pearson Education, Inc.  Blood Vessels and Nerves Extends through both the epimysium and perimysium. Blood vessels deliver to the muscle fibers both nutrients and oxygen needed for the production of ATP (adenosine triphosphate). Also remove waste products produced by the muscle fibers (McKinley & O'Loughlin, n.d.) Copyright © 2010 Pearson Education, Inc. MICROSCOPIC ANATOMY  Skeletal Muscle Fiber Sarcolemma Sacroplasm Sarcoplasmic reticulum Transverse tubule Triad Cisterna of sarcoplasmic reticulum Transverse tubule Myofibril Actin filaments Myosin filaments Sarcomere 9-5 (Shier, Butler, and Lewis, n.d.).  MICROSCOPIC ANATOMY OF A SKELETAL MUSCLE FIBER Cylindrical cell 10 to 100 m in diameter, up to 30 cm long Multiple peripheral nuclei Many mitochondria Glycosomes for glycogen storage, myoglobin for O2 storage Also contain myofibrils, sarcoplasmic reticulum, and T tubules (Meeking, 2010).  MICROSCOPIC ANATOMY Multinucleated cells Occurs during development Myoblasts: embryonic cells Most fuse into one cell Satellite cells Myoblasts that do not fuse Can aid in repair and regeneration in adults (McKinley & O'Loughlin, n.d.) (McKinley & O'Loughlin, n.d.) 10-41  MYOFIBRILS AND MYOFILAMENTS Myofibrils: Long cylindrical organelles About 1-2 micrometers in diameter Extend length of muscle fiber Shorten during contraction Contain myofilaments ~80% of cell volume Exhibit striations: perfectly aligned repeating series of dark A bands and light I bands (Meeking, 2010).  MYOFILAMENTS: 2 TYPES Actin (thin) filament: long bead like strands (twisted double strand of pearls); tropomyosin & troponin on beaded strand Myosin (thick) filament: rod-like tail with two globular heads (Career and Technical Education, n.d.).  Sarcolemma Mitochondrion Myofibril Dark A band Light I band Nucleus (b) Diagram of part of a muscle fiber showing the myofibrils. One myofibril is extended afrom the cut end of the fiber. (Meeking, 2010). THIN AND THICK MYOFILAMENTS Banding I-band: light band Actin filaments Bisected by z-line A-band: dark band Overlap of actin and myosin myofilaments Bisected by H-band H-band (zone) no actin here in relaxed fiber (McKinley & O'Loughlin, n.d.) 10-45  THIN AND THICK MYOFILAMENTS Banding M-line: Middle of H-band (zone) in relaxed fiber Thin protein meshwork Attachment for thick filaments Z-line (Z-disc) Thin protein structure Connectins: anchor thin filaments Titin: attach thin, thick filaments to z-disc Attachment for thin filaments (McKinley & O'Loughlin, n.d.) 10-46 (McKinley & O'Loughlin, n.d.) 47  Sarcomere I band A band H zone Z line M line (Shier, Butler, and Lewis, n.d.). 9-6  SARCOMERE Smallest contractile unit (functional unit) of a muscle fiber The region of a myofibril between two successive Z discs Composed of thick and thin myofilaments made of contractile proteins (Meeking, 2010).  FEATURES OF A SARCOMERE Thick filaments: run the entire length of an A band Thin filaments: run the length of the I band and partway into the A band Z disc: coin-shaped sheet of proteins that anchors the thin filaments and connects myofibrils to one another H zone: lighter mid region where filaments do not overlap M line: line of protein myomesin that holds adjacent thick filaments together (Meeking, 2010).  Thin (actin) filament Z disc H zone Z disc Thick (myosin) I band A band I band M line filament Sarcomere (c) Small part of one myofibril enlarged to show the myofilaments responsible for the banding pattern. Each sarcomere extends from one Z disc to the next. Sarcomere Z disc M line Z disc Thin (actin) filament Elastic (titin) filaments Thick (myosin) filament (d) Enlargement of one sarcomere (sectioned lengthwise). Notice the myosin heads on the thick filaments. Copyright © 2010 Pearson Education, Inc. (Meeking, 2010).  ULTRASTRUCTURE OF THICK FILAMENT Composed of the protein myosin Myosin tails contain: 2 interwoven, heavy polypeptide chains Myosin heads contain: 2 smaller, light polypeptide chains that act as cross bridges during contraction Binding sites for actin of thin filaments Binding sites for ATP ATPase enzymes (Meeking, 2010).  ULTRASTRUCTURE OF THIN FILAMENT Twisted double strand of fibrous protein F actin F actin consists of G (globular) actin subunits G actin bears active sites for myosin head attachment during contraction Tropomyosin and troponin: regulatory proteins bound to actin (Meeking, 2010).  Longitudinal section of filaments within one sarcomere of a myofibril Thick filament Thin filament In the center of the sarcomere, the thick filaments lack myosin heads. Myosin heads are present only in areas of myosin-actin overlap. Thick filament Thin filament Each thick filament consists of many A thin filament consists of two strands myosin molecules whose heads protrude of actin subunits twisted into a helix at opposite ends of the filament. plus two types of regulatory proteins (troponin and tropomyosin). Portion of a thick filament Myosin head Portion of a thin filament Tropomyosin Troponin Actin Actin-binding sites Heads Tail Active sites ATP- Actin for myosin binding Flexible hinge region subunits attachment site Myosin molecule Actin subunits Copyright © 2010 Pearson Education, Inc. (Meeking, 2010).  (McKinley & O'Loughlin, n.d.) Copyright © 2010 Pearson Education, Inc. SARCOPLASMIC RETICULUM (SR) Network of smooth endoplasmic reticulum surrounding each myofibril Pairs of terminal cisternae form perpendicular cross channels Functions in the regulation of intracellular Ca2+ levels (Meeking, 2010).  T TUBULES Continuous with the sarcolemma Penetrate the cell’s interior at each A band–I band junction Associate with the paired terminal cisternae to form triads that encircle each sarcomere (Meeking, 2010).  T-TUBULES Action potential travels along sarcolemma, down T-tubule This causes calcium to be released from sarcoplasmic reticulum(Donley, 2004)  Part of a skeletal muscle fiber (cell) I band A band I band Z disc H zone Z disc Myofibril M line Sarcolemma Triad: T tubule Terminal Sarcolemma cisternae of the SR (2) Tubules of the SR Myofibrils Mitochondria Copyright © 2010 Pearson Education, Inc. (Meeking, 2010).  THE TRIAD The triad is a diagnostic feature of skeletal muscle It is composed of two lateral cisternae on either side of a T-tubule. It is not found in cardiac or smooth muscle (Donley, 2004)  TRIAD RELATIONSHIPS T tubules conduct impulses deep into muscle fiber Integral proteins protrude into the intermembrane space from T tubule and SR cisternae membranes T tubule proteins: voltage sensors SR foot proteins: gated channels that regulate Ca2+ release from the SR cisternae (Meeking, 2010).  CONTRACTION The generation of force Shortening occurs when tension generated by cross bridges on the thin filaments exceeds forces opposing shortening (Meeking, 2010).  SLIDING FILAMENT THEORY OF MUSCLE CONTRACTION In the relaxed state, thin and thick filaments overlap only slightly During contraction, myosin heads bind to actin, detach, and bind again, to propel the thin filaments toward the M line As H zones shorten and disappear, sarcomeres shorten, muscle cells shorten, and the whole muscle shortens (Meeking, 2010). Copyright © 2010 Pearson Education, Inc. (Donley, 2004)  Molecular characteristics of contractile filaments Myosin II Each thick filament contains more than 200 myosin molecules (Donley, 2004) Copyright © 2010 Pearson Education, Inc.  Myosin head ATPase activity Actin binding Molecular hinge Copyright © 2010 Pearson Education, Inc. (Donley, 2004)  Actin thin filament 2 strands of F actin formed from globular or G actin Tropomyosin- double stranded long filament that wraps around F actin Troponin TnI- inhibits myosin-actin interaction TnT- binds to tropomyosin TnC- binds to calcium (Donley, 2004) Copyright © 2010 Pearson Education, Inc.  (Donley, 2004) Copyright © 2010 Pearson Education, Inc.  (Donley, 2004) Copyright © 2010 Pearson Education, Inc.  t http://www.ottahaveit.com/gotItGuy.png ot i G OR Copyright © 2010 Pearson Education, Inc.  Review C.T. attachments between muscle and bone Endomysium (surrounds each muscle fiber), Epimysium (... whole muscle) Perimysium (... fascicle) Copyright © 2010 Pearson Education, Inc. Review Each thick filament is made of 200 to 500 myosin molecules– each in turn has Each bead is a globular (G) actin with an active site; capable of binding the head of a myosin Muscle cells shorten because their individual Sarcomere________________ shorten Copyright © 2010 Pearson Education, Inc.  References Career and Technical Education. (n.d.). Muscle and Muscle Tissues. Retrieved from http://cte.unt.edu/content/files/_HS/curriculum/ Muscle_and_Tissues.ppt Donley. (2004).Muscle Tissue. Retrieved from https://www.google.tt/#q=muscle+and+muscle +tissue+ppt Copyright © 2010 Pearson Education, Inc.  References cont’d McKinley & O'Loughlin. (n.d.). Muscle Tissue and Organization. Retrieved fromhttp://www.google.tt/url?sa=t&rct=j&q=&esrc=s&frm= 1&source=web&cd=10&ved=0CFsQFjAJ&url=http%3A% 2F%2Ffaculty.orangecoastcollege.edu%2Fhapp%2Fpres entations%2Fbio220%2FMcKinley%2FCh10%2520Muscl e%2520Tissue.ppt&ei=K-dfUr67Ko3- 8QSmmoGgAw&usg=AFQjCNE_1QdYorcXKbsiOpdBYs5 N98IVzw Meeking, J. (2010). Muscles and Muscle Tissue. Retrieved from Copyright © 2010 Pearson Education, Inc.  References Cont’d Nebraska Department of Education. (2017). Anatomy – Muscular System. https://www.education.ne.gov/wp- content/uploads/2017/07/175-Anatomy-Muscular- system.ppt Shier, D., Butler, J. and Lewis, R. (n.d.). Muscular System. Retrieved from http://www.google.tt/url?sa=t&rct=j&q=&esrc=s&frm=1&s ource=web&cd=10&ved=0CFoQFjAJ&url=http%3A%2F% 2Fwww.rtmsd.org%2Fcms%2Flib%2FPA01000204%2FC entricity%2FDomain%2F170%2Fchapt09_lecture.ppt&ei= NOtfUt7hIoKE9QScsoCgDg&usg=AFQjCNHpXAt5DsPap 6KoLqVL1erYlylg5Q Copyright © 2010 Pearson Education, Inc.  References Cont’d University of Tennessee at Martin. (n.d.). Chapter 11– Muscular Tissue. Retrieved from http://www.google.tt/url?sa=t&rct=j&q=&es rc=s&frm=1&source=web&cd=1&ved=0CC UQFjAA&url=http%3A%2F%2Fwww.utm.ed u%2Fstaff%2Fdonalds%2Fa-p- 1%2Flecture-notes%2Fch11-Muscular- tissue.ppt&ei=z- NbUryiJYiGkQf7t4CIAw&usg=AFQjCNFCd QI5oZ7wjTC3z9HDi9RO39YHXQ&bvm=bv.5 3899372,d.eW0 Copyright © 2010 Pearson Education, Inc.