Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The skeletal system 1. SUPPORT • Attachment for tendon, framework for body 2. PROTECTION • Ex: cranial bones protect brain 3. ASSISTANCE IN MOVEMENT • Work with muscles 4. MINERAL HOMEOSTASIS • calcium 5. BLOOD CELL FORMATION • hemopoiesis in red bone marrow of select bones 6. TRIGLYCERIDE STORAGE • Potential energy reserve in adipose cells of yellow bone marrow • 1. diaphysis: shaft • 2. epiphyses: ends • 3. metaphysis: between diaphysis and epiphysis. Contains epiphyseal plate (hyaline cartilage) in growing bone. Replaced by bone around 18-21 = epiphyseal line 4. Articular cartilage: covers ends of bone to reduce friction • 5. periosteum: surrounds bone everywhere there isn’t articular cartilage; bone growth in thickness, • assists in fracture repair, serves as an attachment point for ligaments and tendons 7. endosteum: lines the medullary cavity 6. Medullary cavity (marrow cavity): inside diaphysis that contains fatty yellow bone marrow Compact bone tissue • Strong/light • Makes up most of diaphysis Parts of compact bone OSTEON: repeating unit of the structures 1. Perforating (Volkmann’s) canals: transverse, for blood vessels and nerves 2. Central (haversian) canals: connect with perforating canals; run longitudinally; for blood vessels and nerves 3. Concentric lamellae: rings around central canals 4. Lacunae: spaces between lamellae 5. Canaliculi: fluid-filled; radiating from lacunae in all directions. Spongy bone tissue Does NOT contain osteons Sometimes red bone marrow Forms most of epiphyses and narrow rim around medullary cavity of diaphyses Looks spongy; is not soft Makes up most of short, flat, and irregulary shaped bones Choices: spongy or compact 1. What type of bone tissue is made up of osteons? 2. What type of bone tissue would the patella be made up of? Calcium in bone • Bones, neurons, muscle cells, blood clotting, depend on Ca+2 in blood. • Too high – heart stops • Too low – osteoporosis, breathing stops Calcium homeostasis • Stimulus: low blood calcium levels • Receptors: cells of parathyroid gland • Control center: nucleus of parathyroid cells (parathryoid hormone – PTH) • Effectors: osteoclasts activated – releases calcium from bone A negative feedback system • Stimulus: high blood calcium levels • Receptors: Cells in thyroid gland • Control center: nucleus of thyroid cells (secrete calcitonin). • Effectors: osteoclasts inhibited: bone absorbs calcium What type of feedback system?