Vikasana Bridge Cource 2012

Transcription

1 Vikasana Bridge Cource 2012

2 Definition Learning Objectives Types of movement Muscle Skeletal system Joints Disorders of muscular and skeletal system

3 What is locomotion? Displacement of an animal from one place to another. Locomotory structures in different animal groups Protozoans Pseudopodia, Cilia and Flagella. Coelenterates Tentacles Platyhelminthes Undulatory movements of the body Annelids Setae Arthropods Jointed appendages Echinoderms Tube feet Fishes Fins Birds Wings Amphibians, Reptiles & Mammals Limbs

4 Forms of locomotion Swimming, Crawling, Walking, Running, Climbing, Gliding and Flying. Significances of locomotion Search of food, shelter, mate, favourable climate and to escape from predators.

5 MOVEMENT Definition a process of moving or an act. Examples Streaming of protoplasm in Amoeba. Action of cilia in Paramoecium. Action of flagellum in Euglena. Action of tentacles and arms in animals. Changes in the position of head & appendages. Action of tongue, jaws, eyelids & limbs in Man. Action of heart, lungs, gut & bladder in Man. Backbone of locomotion and movement MUSCLES

6 MUSCLE Basic tissue Mesodermal in origin It contracts or shortens 650 muscles makeup the body. Makes up 40 50% of the body weight. Muscle cells (fibres) are elongated. Sarcoplasm cytoplasm Sarcolemma plasmalemma

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8 FUNCTIONS OF MUSCLE Intake of food Modulation of sound into speech Movement of body parts Maintenance of posture Respiration or Breathing Production of body heat Heart beats Constriction of organs and blood vessels

9 TYPES OF MUSCULAR TISSUE

10 Skeletal Muscle FLESH Attached to bones and contributes to 40% of total body weight Peripherally placed many nuclei. Striated and Voluntary. Myoglobin stores oxygen Red fibres. Smooth Muscle Walls of hollow visceral organs like stomach, uterus, blood vessels Centrally placed single nucleus. Not striated and involuntary. Cardiac Muscle Muscles of Heart Centrally placed single nucleus. Faint cross striations, involuntary, Between adjacent myocytes intercalated discs are present.

11 Skeletal Muscle Structure

12 Skeletal Muscle Structure Epimysium Perimysium Sheath covering the entire muscle Sheath covering the fasciculi or bundles of muscle fibres Endomysium Sheath covering the individual muscle fibres

13 Microstructure of Skeletal Muscle fibre 1. Sarcolemma 2. Sarcoplasm a. Many nuclei b. Many mitochondria c. Sarcoplasmic reticulum d. Transverse tubules e. Myofibrils

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15 SARCOMERE A myofibril is composed of many cylindrical units called sarcomeres. They are bounded by Z-discs. Sarcomere is an unit on contraction. A Sarcomere consists of I bands (Thin filaments only) A band(length of thick filament) H Zone (Thick filament only) Z Line (Attachment site for thin filament) M Line (Attachment site for thick filament)

16 THICK FILAMENT A thick filament is made up of 250 myosin molecules. Each myosin molecule consists of 2 twisted chains Meromyosins Has a head and tail. Head has 2 binding sites for actin and ATP has ATPase and can swing through its hinge binds to actin filament to form cross-bridges

17 THIN FILAMENT A thin filament is made up of 2 twisted F-actin chains Each F-actin is a chain of G-actin molecules. A pair of filaments made up of tropomyosin also closely runs with the thin filament. Troponin is found on tropomyosin at regular intervals. Troponin has Ca ions binding sites. G-actin has a binding site for myosin head.

18 THIN FILAMENT AND THICK FILAMENT

19 Proposed by Hugh Huxley, 1954

20 Step-1 Myosin heads form cross bridges Myosin head is tightly bound to actin in rigor state Cross bridge is at 45 relative to the filament

21 Step-2 ATP binds to myosin ATP binds to nucleotide-binding site on myosin Myosin changes conformation and releases from actin Bridge Course Program for SSLC Students who want to take up Science in I PUC in 2012

22 Step-3 ATP hydrolysis ATP is broken down into ADP + P i Both ADP and P i remain bound to myosin

23 Step-4 Myosin head changes conformation Myosin head rotates and binds to new actin molecule Crossbridge is now at 90 Myosin is in high energy configuration

24 Step-5 Power stroke Release of P i from myosin initiates the power stroke Head rotating on its hinge, pushes the actin filament causing sliding

25 Step-6 Release of ADP At the end of power stroke, myosin head releases the ADP Myosin head is again tightly bound to actin in rigor state Ready to repeat cycle

26 Sarcomere shortens Z to Z distance decreases

27 Skeletal muscle fibre (a & b) and sarcomere at both rest and contraction

28 MODEL OF SARCOMERE CONTRACTION

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30 The Skeletal System (20% of body mass) is made up of bones, ligaments, and tendons. The human skeleton consists of 206 bones. They are responsible for a variety of movements. Functions of the skeletal system Protects vital organs like brain, heart and the lungs. Provides a definite shape to the body. Provides support to the body. Provides a large surface area for the attachment of muscles. Synthesizes RBCs and stores fat, calcium, phosphate etc.,

31 AXIAL SKELETAL SYSTEM APPEND ICULAR

32 Axial skeleton Forms the longitudinal axis of the body. Supports and protects organs of head, neck and trunk. Composed of 80 bones. Consists of four parts. Skull (cranium and facial bones). Vertebral column (vertebrae and discs). Bony thorax (ribs and sternum). Hyoid bone (anchors tongue).

33 HUMAN SKULL- (Cranial-8 and Facial-22)

34 VERTEBRAL COLUMN-(26)

35 THORAX (RIBS-12 AND RIB CAGE)

36 Appendicular Skeleton Forms the limbs and their girdles of the body. It includes bones of limbs and bones that anchor them to the axial skeleton. Composed of 126 bones. Consists of four parts Pectoral girdle (clavicles and scapulae) Upper limbs (arms) Pelvic girdle (sacrum, coccyx) Lower limbs (legs)

37 BIOLOGY

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39 UPPER LIMB (30) AND LOWER LIMB (30)

40 JOINTS Joints are where two or more bones move. Types of Joints Fibrous Fixed or immovable joints Ex- Cranium, Sacrum and coccyx. Cartilaginous Slightly movable joints Ex- Between vertebrae Synovial Freely movable joints Ex- Shoulder, hip and limbs.

41 SYNOVIAL JOINTS These are the most important joints. There are 6 types of synovial joint. 1. Ball & socket hip and shoulder. 2. Hinge knee, elbow and ankle. 3. Pivot radio-ulna, atlas-axis. 4. Saddle Thumb (metacarpal-carpal). 5. Condyloid Wrist. 6. Gliding between carpals.

42 DISORDERS OF MUSCULAR AND SKELETAL SYSTEM Myasthenia gravis Auto immune disorder affecting neuromuscular junction leading to fatigue, weakening and paralysis of skeletal muscle Muscular dystrophy Progressive degeneration due to genetic disorder Tetany Rapid spasms in muscle due to low Ca ions

43 Arthritis Inflammation of joints Osteoporosis Age-related disorder characterized by decreased bone mass and increased chances of fractures. Decreased level of estrogen is a common cause Gout Disease Inflammation of joints due to accumulation of uric acid crystals

44 Myasthenia Muscular Dystrophy Tetany Arthritis Gout

45 Thank You