1. Bio 449Lecture 15 - Endocrinology III / Muscle IOct. 4, 2010 Endocrinology III Hypothalamic-pituitary system (cont'd) Hormonal control of growth (conclusion) Temporal patterns of GH release Hypo- and hypersecretion Muscle I Functions and types of muscle Structure of skeletal muscle Myofiber structure Sarcomere structure Contraction of the sarcomere Cross-bridge cycling Length-tension relationship Terms to Know Anabolism IGF-I Osteoblast Osteoclast Chondrocyte Epiphyseal plate Gigantism Acromegaly Dwarfism Smooth muscle Striated muscle Skeletal muscle Cardiac muscle Muscle Tendon Readings Lectures 15-16:Chapter 11, pages 396-401 Chapter 12 Muscle fiber (myofiber) Sarcolemma Mitochondria Sarcoplasmic reticulum Myofibril Sarcomere Thick filament Thin filament Z-disc (or Z-line) Actin Myosin Cross-bridge Contraction Sliding-filament theory

2. Hypothalamic-pituitary system Hormonal control of growth

3. Bone growth Fig. 23-16 Epiphysis Diaphysis Epiphyseal plate Diaphysis Compact bone Osteoblast Chondrocyte Cartilage Bone growth Newly calcified bone Direction of growth Osteoblasts Old chondrocytes Chondrocytes Dividing chondrocytes

4. Acromegaly Fig. 23-14

5. Poodles!

6. Muscle Physiology Functions and Types of Muscles

7. Functions of muscle Fig. 12-2 Flexion Extension Biceps muscle contracts (flexor) Triceps muscle relaxes Triceps muscle contracts (extensor) Biceps muscle relaxes

8. Functions of muscle Fig. 12-2 Peristalsis Vasoconstriction Hydrostatic Pressure

9. Types of muscle Fig. 12-1 Nucleus Muscle fiber (cell) Striations Skeletal muscle

10. Types of muscle Fig. 12-1 Muscle fiber Nucleus Striations Cardiac muscle Intercalated disk

11. Types of muscle Fig. 12-1 Muscle fiber Nucleus Smooth muscle

12. Muscle structure Fig. 12-3 Skeletal muscle Muscle fascicle: bundle of fibers Muscle fiber Connective tissue Tendon Nerve and blood vessels Nucleus

13. Muscle structure Fig. 12-3 T-tubules Sarcoplasmic reticulum Sarcolemma Mitochondria Myofibril Thick filament Thin filament Nucleus ULTRASTRUCTURE OF MUSCLE

14. Muscle structure Myofibril Z disk Sarcomere Thin filaments Tropomyosin Troponin Actin chain G-actin molecule Myosin tail Myosin heads Myosin molecule Thick filaments Hinge region Titin M line Myosin crossbridges M line Fig. 12-3

15. Cross-bridge cycle Fig. 12-9 ADP Actin moves Cytosolic Ca 2+ Tropomyosin shifts, exposing binding site on actin TN Power stroke Initiation of contraction Troponin G-Actin Tropomyosin blocks binding site on actin Myosin head TN Relaxed state. Myosin head cocked. Pi 1 2 3 4 5

16. Sarcomere contraction Fig. 12-8