Quizzam 4 4

• Integument: The skin and its appendages, forming a protective covering.

• Vasoconstriction: Narrowing of blood vessels to reduce blood flow.

• Vasodilation: Widening of blood vessels to increase blood flow.

• Granulation tissue: New connective tissue formed during wound healing.

• Regeneration: Replacement of damaged tissue with the same type of cells.

• Fibrosis: Formation of scar tissue.

• Hematopoiesis: Production of blood cells in bone marrow.

• Epiphysis: End part of a long bone.

• Metaphysis: Region between epiphysis and diaphysis, includes growth plate.

• Epiphyseal line: Remnant of the growth plate in adults.

• Diaphysis: Shaft of a long bone.

• Endosteum: Thin membrane lining the bone’s internal cavity.

• Periosteum: Outer covering of bone.

• Osteoprogenitor cells: Bone stem cells that develop into osteoblasts.

• Osteoblasts: Cells that build bone.

• Osteocytes: Mature bone cells that maintain bone.

• Osteoclasts: Cells that break down bone.

• Bone formation: The process of forming new bone tissue.

• Calcification: Deposition of calcium salts in tissues.

• Bone resorption: Breakdown of bone tissue by osteoclasts.

• Intramembranous ossification: Bone development from mesenchymal tissue.

• Endochondral ossification: Bone development from cartilage.

• Interstitial growth: Growth in length of cartilage and bone.

• Appositional growth: Growth in width of cartilage and bone.

• Chondroblasts: Cartilage-forming cells.

• Chondrocytes: Mature cartilage cells.

• Mechanical stress: Physical force affecting bone growth and remodeling.

• Calcitonin: Hormone that lowers blood calcium levels.

• Parathyroid hormone (PTH): Hormone that raises blood calcium levels.

• Vitamin D3: Precursor to active vitamin D.

• Calcidiol: Intermediate in vitamin D metabolism.

• Calcitriol: Active form of vitamin D, regulates calcium absorption.

• Bone fracture: A break in a bone.

• Fibrocartilaginous callus: Temporary repair tissue in bone healing.

• Hard callus: Hardened repair tissue in bone healing.

• Bone remodeling: Replacement of old bone with new bone.

• Osteopenia: Reduced bone density.

• Osteoporosis: Severe bone density loss, increasing fracture risk.

Study Questions:

1. Layers in the integument: Epidermis, dermis, hypodermis.

2. Layers of the epidermis: Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (only in thick skin), stratum corneum.

3. Accessory structures in integument: Hair, nails, sweat glands, sebaceous glands.

4. Functions of accessory structures: Hair provides protection, nails protect fingertips, glands regulate temperature and moisture.

5. Functions of integument: Protection, sensation, temperature regulation, vitamin D synthesis.

6. Selective absorption by skin: Lipid-soluble substances can pass through; water-soluble substances cannot.

7. Temperature regulation: Blood vessel dilation/constriction and sweat production.

8. Sensory receptors in skin: Mechanoreceptors, thermoreceptors, nociceptors.

9. Steps of skin repair: Inflammation, clot formation, granulation tissue formation, regeneration or fibrosis.

10. Function restored vs. not restored: Regeneration restores function; fibrosis forms scar tissue without full function.

11. Functions of bones: Support, movement, protection, mineral storage, blood cell production.

12. Minerals stored in bone: Calcium, phosphate.

13. Regions of long bones: Epiphysis, metaphysis, diaphysis.

14. Growth plate: Epiphyseal plate.

15. Inside bone covering: Endosteum.

16. Outside bone covering: Periosteum.

17. Four bone cells & functions:

    • Osteoprogenitor: Stem cells.

    • Osteoblasts: Build bone.

    • Osteocytes: Maintain bone.

    • Osteoclasts: Break down bone.

18. Bone formation: Intramembranous and endochondral ossification.

19. Bone flexibility & rigidity: Collagen provides flexibility; minerals provide rigidity.

20. Bone resorption: Osteoclasts break down bone.

21. Intramembranous ossification steps: Mesenchymal cells → osteoblasts → spongy bone → compact bone.

22. Intramembranous ossification location: Skull, clavicles.

23. Endochondral ossification steps: Cartilage model → calcification → primary ossification center → secondary ossification center → bone replaces cartilage → epiphyseal plate closure.

24. Epiphyseal lines form: After growth stops in adulthood.

25. Cells in cartilage: Chondroblasts, chondrocytes.

26. Two ways cartilage grows: Interstitial and appositional growth.

27. Interstitial growth effect on bones: Increases length.

28. Five zones of interstitial growth: Resting, proliferative, hypertrophic, calcified, ossification.

29. Appositional growth effect on bones: Increases width.

30. Effect of mechanical stress: Increased stress strengthens bones; decreased stress weakens bones.

31. Hormones affecting bone growth: Growth hormone, thyroid hormone, sex hormones, PTH, calcitonin.

32. Homeostasis when calcium is too high: Thyroid releases calcitonin → osteoblasts deposit calcium in bone.

33. Hormone stimulating osteoblasts: Calcitonin, from the thyroid gland.

34. Homeostasis when calcium is too low: Parathyroid releases PTH → osteoclasts break down bone to release calcium.

35. Hormone stimulating osteoclasts: PTH, from the parathyroid gland.

36. Steps of Vitamin D3 synthesis:

    • UV light converts precursor in skin to Vitamin D3.

    • Liver converts it to calcidiol.

    • Kidneys convert it to calcitriol.

37. Process begins: Skin.

38. Organs involved: Skin, liver, kidneys.

39. End hormone and function: Calcitriol; increases calcium absorption.

40. Effect of calcitriol on calcium homeostasis: Increases blood calcium levels.

41. Common bone fractures: Simple, compound, comminuted, spiral, greenstick.

42. Steps of bone repair: Fracture hematoma → fibrocartilaginous callus → hard callus → bone remodeling.

43. Effect of aging on bones: Reduced density, increased fragility.

44. Hormone affecting postmenopausal women: Estrogen.