Skeletal System Worksheet Guide

Skeletal System Worksheet List the functions of the skeletal system: Support Protection Assistance in movement Mineral homeostasis Blood-cell production Triglyceride storage What are the components of the skeletal system? Bones Cartilage Tendons ligaments What are the three kinds of cartilages found in our body and what are their significant properties? Give examples of where you would find each of them. 1. Hyaline cartilage: most abundant cartilage and provides support through flexibility a. Found in costal cartilage and intervertebral disc 2. Elastic cartilage: contains many elastic fibers and able to tolerate repeated bending a. Found in external ear 3. Fibrocartilage: resists strong compression and strong tension and an intermediate between hyaline and elastic a. Found in meniscus Articular cartilage Proximal epiphysis metaphysis Spongy bone 1.Epiphyseal line 2.Compact bone 3.Spongey bone 4.Medullary cavity endosteum diaphysis periosteum Nutrient artery Metaphysis Distal epiphysis Name the different kinds of bone cells and list their functions: 1. 2. 3. 4. Osteogenic cells: mitotic potential-can divide Osteoblasts-bonebuilding cells Osteocytes- mature bone cells Osteoclasts-huge cells-bone resorption Articular cartilage Define: 1. Compact bone: dense outer layer that looks smooth and solid to the naked eye 2. Spongy Bone: internal network of bone, also called trabecular bone Label the parts of the compact bone: osteon periosteum Circumferential lamellae lamella lamella Spongy bone Blood vessel central canal What are the two methods of bone formation? How do they differ from each other? The two methods are intramembranous ossification and endochondral ossification. Intramembranous ossification forms directly within mesenchyme arranged in sheet-like layers that resemble membranes while endochondral ossifcication, bones froms within hyaline cartilage that develops from mesenchyme. What is appositional growth and what is interstitial growth? Interstitial growth- chondrocytes within cartilage divide and secrete new matrix Appositional growth- chondroblasts in surrounding perichondrium produce new cartilage by actively secreting matrix Label the zones of cartilage in the epiphyseal plate: Zone 1: zone of resting cartilage Zone 2: zone of proliferating cartilage Zone 3: zone of hypertrophic cartilage Zone 4: zone of calcified cartilage Zone 5: zone of ossification Which side of the epiphyseal plate does cartilage grow and which side does the bone formation take place? On the epiphyseal side, cartilage is formed and on the diaphyseal side is where bone formation takes place. What is bone remodeling? It is the ongoing replacement of old bone tissue by new bone tissue. It involves bone resorption. List the factors that affect bone remodeling: Adequate dietary intake of minerals and vitamins as wells as hormones minerals What is calcium homeostasis and how is it maintained in our body? levels of calcium in the blood are maintained by controlling the rates of calcium resorption from bone into blood and of calcium deposition from blood into bone Ca2+ exchange is regulated by hormones, the most important is parathyroid hormone, its actions help elevate blood Ca2+ level PTH indirectly stimulates osteoclasts to break down bone and release Ca2+ into the blood. In the kidneys, PTH increases ca2+ reabsorption from the urine. It also promotes the formation of active vitamin D which increases ca2+ absorption from the small intestine. What is osteoporosis? What are its causes? How is it treated? Osteoporosis is characterized by low bone mass and deterioration of the microscopic architecture of the bony skeleton. It causes low calcium and an estrogen deficiency. Treatments include supplemental calcium, vitamin D, weight-bearing and resistance exercise, and estrogen replacement. What is the role of following hormones in the skeletal system: 1. Thyroid hormone: promote bone growth by stimulating osteoblasts and ensures that the skeleton retains proper proportions 2. Insulin: promotes bone growth by increasing the synthesis of bone proteins 3. Estrogen: cause of sudden “growth spurt” that occurs during the teenage year, promote changes in females such as widening of the pelvis and shut down growth at epiphyseal plates 4. Testosterone: cause of sudden “growth spurt” that occurs during the teenage year, promote changes in females such as widening of the pelvis and shut down growth at epiphyseal plates (same as estrogen).