Question

which of the following is the single most important stimulus for epiphyseal plate acti infancy and childhood? parathyroid hormone calcium growth hormone thyroid hormone question 6 (1 point) bones are covered and lined by a protective tissue called periosteum. the inner (osteo consists primarily of cartilage and compact bone osteoblasts and osteoclasts marrow and osteons chondrocytes and osteocytes

Explanation:

• First question: Growth hormone is crucial for the activity of the epiphyseal plate (growth plate) in infancy and childhood as it promotes bone growth by stimulating chondrocyte (cartilage cell) division in the epiphyseal plate. Parathyroid hormone mainly regulates calcium levels. Calcium is a mineral, not a hormonal stimulus for the epiphyseal plate. Thyroid hormone has roles in metabolism and development but is not the single most important for epiphyseal plate activity compared to growth hormone.
• Second question: The inner layer (osteogenic layer) of the periosteum contains osteoblasts (bone - forming cells) and osteoclasts (bone - resorbing cells). Cartilage is not part of the inner periosteum. Marrow is inside the bone cavity, and osteons are the structural units of compact bone. Chondrocytes are cartilage cells, and osteocytes are mature bone cells found within the bone matrix, not in the inner periosteum.

Answer:

• First question: growth hormone
• Second question: osteoblasts and osteoclasts