1 / 22

1. Infancy & Childhood : G rowth Hormone: Thyroid Hormone :

Chapter 6 … III. Bone Formation and Development … E. Hormonal Regulation of Bone Growth In Children. 1. Infancy & Childhood : G rowth Hormone: Thyroid Hormone : 2. During puberty: Test. and Estrogens :  adolescent growth spurts induces epiphyseal closure– end growth.

floridaj
Télécharger la présentation

1. Infancy & Childhood : G rowth Hormone: Thyroid Hormone :

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 6 …III. Bone Formation and Development …E. Hormonal Regulation of Bone Growth In Children 1. Infancy & Childhood: • Growth Hormone: • Thyroid Hormone: 2. During puberty: Test. and Estrogens: •  adolescent growth spurts • induces epiphyseal closure– end growth

  2. F. Bone Remodeling in Adults - When: - Amount: 5-10% annually in an adult • Function: 1) 2) 3) 1. Importance of Calcium • Nerve • Muscle • Blood Clotting • Cell division

  3. Control of Remodeling …2. Hormones That Influence Osteoclasts Controls - Affected by Ca+ blood levels - Negative Feedback Loops • Parathryroid Hormone– determines when to remodel • Parathyroid Gland cells: If low blood Ca+2, PTH increases  Activates Osteoclasts  Ca+2 blood levels increase b) Calcitonin • Much less involved • Functions in oposition to PTH 3. Where to Remodel: determined by mechanical stresses • Gravity • Exercise 4. Other Factors: UV light & Vitamine D

  4. IV. Bone Repair- Fractures • Classification by complexity, location, and other features: • Closed (Simple) vs. Open (Compound): • Completeness of break:

  5. F. Types of Fractures … Table 6.2.1

  6. Table 6.2.2

  7. Table 6.2.3

  8. G. Bone Repair • Treating Fractures • Reduction = realignment • Immobilization The Body’s Process of Repair 1. Fracture Hematoma (immediate – 1st day or 2) • Swollen • Painful • Inflamation Figure 6.13.1

  9. G. Bone Repair … 2. Fibrocartilage Callus (few days – 1-2 weeks) • New capillaries grow • Phagocytes clean up the dead • Fibroblasts & osteogenic cells come in and collagen fibers are produced to span the break • Chondrocytes develop and produce fibrocartilage • Externally bulging cartilage matrix forms Figure 6.13.2

  10. Repair … 3. Bony callus of Spongy Bone - few weeks – 2 to 3 months • Osteoblastsbegin forming spongy bone that invades cartilage Figure 6.13.3

  11. Repair … 4. Bone remodeling - (up to several months after bony callus) • Excess material on outside and inside removed • Resembles original with slight bulge Figure 6.13.4

  12. Homeostatic ImbalancesSTUDENTS DO • Rickets • Osteoporosis

  13. END

  14. Participating . . . 2a. List 2 reasons why bones are remodeled in adults? Regulate blood calcium, compensate for stress, also to repair fractures, renew matrix 2b. Why do exercisers have denser and stronger bones? • Bones develop over longer time periods in exercisers • Bone remodeling adds bone tissue to compensate for the stress of exercise • Exercisers need more calcium for their muscles a b

  15. Participating… 4. Which of the following might help delay or even prevent the effects of osteoporosis? Why? • Being sure to include plenty of calcium in the diet. • Getting regular exercise. • Resting bones as often as possible.

  16. Hematoma Externalcallus Bonycallus ofspongybone Internalcallus(fibroustissue andcartilage) Newbloodvessels Healedfracture Spongybonetrabecula Bone remodeling Hematomaformation Fibrocartilagecallus formation Bony callusformation Participate: 3. List 4 steps of bone repair. 1. Hematoma (blood-filled swelling) is formed 2. Break splinted by fibrocartilage to form a callus 3. Fibrocartilage callus replaced by a bony callus 4. Bony callus is remodeled to form a permanent patch

  17. Hormonal Control of Blood Ca – raising Ca concentration Imbalance Calcium homeostasis of blood: 9–11 mg/100 ml Falling blood Ca2+ levels Imbalance Figure 6.11

  18. Hormonal Control of Blood Ca – raising Ca concentration Imbalance Calcium homeostasis of blood: 9–11 mg/100 ml Falling blood Ca2+ levels Imbalance Thyroid gland Parathyroid glands Parathyroid glands release parathyroid hormone (PTH) Figure 6.11

  19. Hormonal Control of Blood Ca – raising Ca concentration Imbalance Calcium homeostasis of blood: 9–11 mg/100 ml Falling blood Ca2+ levels Imbalance Thyroid gland Parathyroid glands Parathyroid glands release parathyroid hormone (PTH) PTH Figure 6.11

  20. Hormonal Control of Blood Ca – raising Ca concentration Imbalance Calcium homeostasis of blood: 9–11 mg/100 ml Falling blood Ca2+ levels Imbalance Thyroid gland Osteoclasts degrade bone matrix and release Ca2+ into blood Parathyroid glands Parathyroid glands release parathyroid hormone (PTH) PTH Figure 6.11

  21. Hormonal Control of Blood Ca – raising Ca concentration Calcium homeostasis of blood: 9–11 mg/100 ml Falling blood Ca2+ levels Thyroid gland Osteoclasts degrade bone matrix and release Ca2+ into blood Parathyroid glands Parathyroid glands release parathyroid hormone (PTH) PTH Figure 6.11

  22. Surgical Neck- most common break point Control of Remodeling …Response to Mechanical Stress • Determine WHERE remodeling occurs • Wolff’s law – bones remodel in response to stresses

More Related