The Skeletal System Excercise Essay

5. Most connective tissue, including bone, is highly vascular. Which anatomical structures in Mrs. Morgan’s compact bone house blood vessels? What sign or symptom in Mrs. Morgan’s case is directly related to disruption of these structures by her bone fractures? How is the sign or symptom related to these anatomical structures?

Compact bone looks dense and solid, yet it is filled with passageways that serve as conduits for nerves, blood vessels, and lymphatic vessels (Marieb, 181).

Soft callus formation Blood clot is replaced by fibrocartilage and collagen, converting granulation tissue to a soft callus. This is where new blood vessels begin to grow.

The chicken leg bone got more bendable and jelly-like because the acid destroyed the calcium in the bone.

Bone elongation occurs through proliferation and differentiation of the cells located in the cartilage of the epiphyseal growth plates at the ends of the long bones. These plates are present only during the growth period and vanish when sexual maturation is complete. It is the long bones of the skeleton, primarily the legs, which contribute the greatest to final body height. It is at these sites that the pubertal growth spurt first occurs (Tanner, 1962). Longitudinal growth occurs at the epiphyseal plate, a thin layer of cartilage entrapped between epiphyseal and metaphyseal bones, at the distal ends of the long bones (Kronenberg, 2003). In the growth plate, immature cells lie toward the epiphysis, called the resting zone, with flat more mature

Several studies have described the phenomenon of sealed osteons (SO) in secondary bone, yet none has conclusively demonstrated their origin. The aim of this study is to quantify SO in bone and determine their origin. SO occur when the Haversian canal becomes occluded with bone tissue. One study showed that 4-5% of osteons from three amputated tibiae were sealed (Congiu and Pazzaglia, 2011). They theorized that these SO evolved as a physiological response to bone remodeling. However, we found <0.1%) osteons in non-primate bone were sealed, and suggested that the SO that Congiu and Pazzaglia found were a result of pathological

The natural process of healing a fracture starts when the injured bone and surrounding tissues bleed, forming a fracture hematoma. The blood coagulates to form a blood clot situated between the broken fragments. Within a few days, blood vessels grow into the jelly-like matrix of the blood clot. The new blood vessels bring phagocytes to the area, which gradually remove the non-viable material. The blood vessels also bring fibroblasts in the walls of the vessels and these multiply and produce collagen fibres. In this way the blood clot is replaced by a matrix of collagen. Collagen's rubbery consistency allows bone fragments to move only a small amount unless severe or persistent force is applied.

Endochondral ossification, this type of bone development involves cartilage models, which are then replaced with bony tissue. This takes place at the embryonic stages; 8 weeks into development, condroblast secret cartilaginous matrix which will from the hyaline cartilage for bone development. The lacunae trap the condrablast and this is all surrounded by the perichondrium.

The Haversian canal serves as a passageway for blood vessels and nerves. Volkmann’s canal, which is the other type of canal that runs through the osteon, connects the blood and nerve supply of the periosteum to the central canals and medullary cavity. Osteocytes occupy the lacunae at the junctions of the lamellae and are connected to each other and the central canal via a series of hair like channels called canaliculi . Circumferential lamellae are located just beneath the periosteum, which extends the entire circumference of the bone, while interstitial lamellae lie between intact osteons, filling the spaces in between. Spongy bone does not consist of osteons, but does have trabeculae (pores) that align along the lines of

2. Cartilaginous/slightly moveable joints exist at the ends of bone and are covered in hyaline

Bones in the human body form in the process called ossification. There are four stages in ossification, 1.) Embryonic bone formation; 2.) Bone growth throughout life starting in infancy through adulthood; 3.) Bone remodeling, and 4.) Fracture (breaks in the bone) repair.

The bones that are developed from endochondral ossification are referred to cartilaginous bones which occur in long bones and are essential during growth of lengthy bone. It proceeds via condensation of mesenchymal cells and gets differentiated into chondroblasts instead of osteoblasts. A cartilage template is produced by the activity of chondroblasts and serves as a template for the development of long bones such as femur and tibia. The cartilage template becomes surrounded by a membrane called perichondrium, which contains osteoprogenitor cells. As proliferation increases, the template begins to grow. The chondroblasts can secrete an extracellular matrix composed of collagen and proteoglycans. The chondroblasts

Both the osteoblast and osteoclast plays a role in this process. The osteoblast produces new bone tissue whereas the osteoblast resorbed older bone tissue. Bone remodeling are assisted by vitamin A, C and D, and minerals such as calcium, phosphorus and magnesium. It also requires the secretions of calcitonin, growth and parathyroid hormones. The cycle continues until adolescence

Last, but not least, the ability of bone to change its structure and adapt to mechanical loads implies that mechanical forces can regulate bone resorption and formation: increased loads should increase formation and decrease resorption whereas unloading should have the opposite effect. Indeed, immobilization stimulates resorption and suppresses formation (for review, see ref, providing a clear example of “uncoupling” between the two processes. The mechanism for these effects has not been elucidated fully, but, here again, osteoblast lineage cells, osteocytes, and lining cells were proposed to mediate the mechanical signals because their location is best suited to perceive

The skeletal system includes the osseous tissues of the body and the connective tissues that stabilize or interconnect the individual bones. The bone is a dynamic tissue. Throughout the lifespan, bone adjusts to the physiologic and mechanical demands placed on it by the processes of growth and remodeling.