BIOL 235 Chapter 6 questions and answers all are graded A+

What is osteology? - Answer-The study of bone structure and the treatment of bone disorders Describe the protection function of the skeletal system - Answer-The skeleton protects internal organs from injury Describe the support function of the skeletal system - Answer-The skeleton is a structural framework for the body (it supports soft tissues and provides attachment points for tendons) Describe the mineral homeostasis (storage/release) function of the skeletal system - Answer-Bones store minerals (calcium and phosphorus) that contributes to bone's strength Bones release minerals into the blood to maintain homeostasis and distribute minerals throughout the body Describe how the skeletal system aids in movement - Answer-Skeletal muscles attach to bones, contract, and pull on bones for movement Describe the triglyceride storage function of the skeletal system - Answer-Yellow bone marrow consists of adipose cells that store triglycerides (a potential chemical energy reserve) Describe the blood cell production function of the skeletal system - Answer-Red bone marrow produces red/white blood cells, and platelets (marrow changes to yellow with age) What is a long bone? - Answer-A bone that has greater length than width What is the diaphysis? - Answer-The shaft of a long bone (body, main portion) What are the epiphyses? - Answer-The proximal and distal ends of a long boneWhat are the metaphyses? - Answer-Regions between the diaphysis and epiphyses of long bones (in growing bones, each contains a growth plate) What is an epiphyseal plate/line? - Answer-A layer of hyaline cartilage that allows diaphysis of a long bone to grow in length Once the bone stops growing (age 14-24), cartilage is replaced by bone (creating an epiphyseal line) What is articular cartilage? - Answer-A layer of hyaline cartilage that covers the epiphysis at joints to reduce friction/absorb shocks (avascular, so damage repair is hard) What is a periostium? - Answer-The connective tissue sheath and blood supply that surrounds the remainder of a long bone's surface (has an outer fibrous layer and inner osteogenic layer) Help protect bone, aids in fracture repair, nourishes tissue, and acts as attachment point (attached to underlying bone by Sharpey's fibres) What is a medullary (marrow) cavity? - Answer-A hollow space in the diaphysis of a long bone that contains fatty yellow bone marrow and blood vessels (helps minimize bone weight) What is an endosteum? - Answer-A thing membrane that lines the medullary cavity in a long bone Why is bone classified as a connective tissue? - Answer-Bone tissue contains an abundant extracellular matrix (contains water, collagen, and crystal mineral salts) that surrounds widely separated cells Mineral salts combine to form hydroxyapatite crystals which then participate in calcification What are osteoprogenitor cells? - Answer-Unspecialized bone cells that undergo division (develop into osteoblasts), found along periosteum, endosteum, and canals What are osteoblasts? - Answer-Bone-building cells that excrete collagen to build extracellular matrix, initiate calcification (become osteocytes when they are trapped in extracellular matrix) What are osteocytes? - Answer-Mature bone cells (main cells in bone tissue) that maintain metabolism through exchange (cells don't divide, just maintain and monitor tissue)What are osteoclasts? - Answer-Huge osteogenic cells concentrated in the endosteum (plasma membrane is folded) Participates in resorption (breakdown of extracellular matrix, a normal part of development, maintenance and repair of bone) What is compact bone tissue? - Answer-The strongest form of bone tissue found beneath periosteum of all bones, makes up most of diaphyses of long bones (has few spaces) What is an osteon (Haversian system)? - Answer-A structural unit of compact bone (aligned parallel to diaphysis), helps shaft resist bending or fracture under lots of force What is a central (Haversian) canal? - Answer-Part of an osteon, surrounded by concentric lamellae (mineralized extracellular matrix) that contains blood vessels and nerves Interstitial lamellae are fragments of old, destroyed osteons Perforating (Volkmann's) canals: blood vessels/nerves from the periosteum penetrate compact bone through these canals What are lacunae? - Answer-Spaces between concentric lamellae (have osteocytes) What are canaliculi? - Answer-Small channels in compact bone, radiating in all directions from lacunae (filled with extracellular fluid) and connect lacunae to each other/to central canals, provides routes for nutrients/oxygen and waste removal What is spongy bone tissue? - Answer-Interior part of short, flat, sesamoid bones (protected by compact bone) with light tissue (located where stress is applied from many angles) Also called trabecular/cancellous bone tissue Trabeculae: lamellae set in an irregular pattern of columns located along lines of stress (support/protect red bone marrow) Explain the blood/nerve supply of bones - Answer-Blood vessels pass into bones from the periosteum (periosteal arteries enter diaphysis through Volkmann's canals) Nerves accompany blood vessels (periosteum has many that can detect pain)Explain the nutrient artery/veins - Answer-Nutrient artery: passes through nutrient foramen in diaphysis (then branches) Nutrient veins: veins that carry blood away from the long bones (accompany artery) Explain the metaphyseal and epiphyseal arteries/veins - Answer-Metaphyseal artery: supply red marrow and bone of the metaphyses (veins go opposite direction) Epiphyseal artery: supply red marrow and bone of the epiphyses (veins go opposite direction) Explain the process of ossification (osteogenesis) - Answer-The process by which bone forms (happens in 4 places) Initial formation is in an embryo/fetus, then growth happens during infancy, childhood/adolescence until adulthood, then bone remodelling and repair of fractures happen throughout life