Intramembranous ossification is the process in which the flat bones of the cranium ad clavicles are made. This type of ossification is broken up into several different steps. In each of these steps, there are various types of cells that do unique things to aid in ossification. All of these different cells stem from one cell known as a Mesenchymal cell. This cell is a type of stem cell that can differentiate into all of the different connective tissue cells. Differentiation is a characteristic of these cells that allows them to transform into various cells during the growth process; this is aided by methylation. Methylation aids differentiation because it shuts down specific genes in the cells DNA which changes the shape and function and …show more content…
An osteoblast is a “baby” bone cell whose main job is to secrete osteoid which forms the hardened, or calcified, bone matrix. Osteocytes are formed from osteoblasts. Osteocytes are the mature bones cells that have been completely differentiated. They are found in the lacunae of hard bone and have a spider-like appearance due to their canaliculi. Osteoclasts are a different type of cell formed from the mesenchymal cells. These cells are not related to osteoblasts or osteocytes. Their job is to basically “eat” the bone to create cavities and other hallow spaces during bone remodeling. Finally, the cells form differentiate to form fibroblasts and fibrocytes. These fibroblasts and fibrocytes secrete and form the matrix for fibrous connective tissue which is an essential component of the …show more content…
As the matrix hardens, it forms lamella, a tube of the solidified bone matrix, which forms the lamellar bone. Essentially, lamellar bone is lamellae with collagen fibers surrounding each lamella. It is important to know that collagen fibers on one layer, run parallel to the collagen fibers on another layer. For this reason, lamellar bone is very tough. The lamellar bone is located on both sides of the spongy bone and thickens around the trabeculae. The blood vessels are still situated within the spongy bone and form the red marrow. If a lamellae form around a blood vessel, it creates an osteon with a central canal where the blood vessel is
However some of the basic bone functions include storing of crucial nutrients, minerals and lipids, producing red blood cells for the body, protect the organs such as heart, ribs and the brain, aide in movement and also to act as a buffer for pH. With the differences in all of the bones there are four things that remain the same in each bone, their cells. Bones are made up of four different cells; osteoblasts, osteoclasts, osteocytes and bone lining cells. Osteoblasts produce and secrete matrix proteins and then transport the minerals into the matrix. Osteoclasts are responsible for the breaking down of tissue. The osteoblasts and osteoclasts are both responsible for remodeling and rebuilding of bones as we grow and age. The production of osteoclasts for resorption is initiated by the hormone, the parathyroid hormone. Osteocytes are the mature versions of osteoblasts because they are trapped in the bone matrix they produced. The osteocytes that are trapped continue making bone to help with strength and the health of the bone matrix. The bone lining cells are found in the inactive bone surfaces which are typically found in
Stem cells are the building blocks of the human body. Embryos consist of unspecialized stem cells that transform into the various specialized cells in the body such as cardiac, muscle or bone cells. Fetuses also have stem cells. However, the stem cells are divided into types like muscle, bone or nerves and don't perform a specialized function. Surprisingly, adult bodies also contain stem cells. In adults, stem cells are undifferentiated but limited to specific tissue type. When needed, the stem cells transform into the cells needed for repair and maintenance. The most common source of adult stem cells is bone marrow. Researchers also acquire stem cells from umbilical cords. Without stem cells, embryos could not develop into fetuses and adult
Bones are dense and provide support and structure to the body. The two types of bones is compact and spongy bones. Compact bones are dense and tough. Spongy bones are not as dense and are flexable. Bone remodeling occurs n 120-day cycles. Over the first 20 days resorption by osteoclasts occurs. Osteoclasts release proteases, clears away damaged bone, and releases matrix-bound growth factors. Bone formation occurs by osteoblasts over the last 100 days. Osteoblasts fill in bone cavity with bone matrix.
So far, various techniques have been used for reconstruction and regeneration of maxillary and mandibular bone defects. Autogenous bone grafting, guided bone regeneration (GBR), distraction osteogenesis and nerve transpositioning are among these regenerative techniques (1-8). Decision making for the treatment could be influenced by the type, size and location of the bone defects (2, 3, 9, 10). GBR had high success rate in treating small alveolar defects such as dehiscence or fenestration. Regenerative bony walls around the defect with ingrowing blood vessels can begin osteogenesis (11) larger bone defects with insufficient regenerative walls and an low quality avascular bed need varied amount of autogeneous bone graft from extra oral or intra oral donor sites, however, the patient may suffer from complications in donor site as well as bone graft resorption.(10, 12-15)
Bone contains an inorganic component composed of mineral salts, primarily calcium and potassium, and an organic component made of collagen, a complex protein that is found in various forms in bone and other connective tissues. According to Wolff’s Law, bone is capable of adjusting its strength in proportion to the amount of stress placed on it. When young, healthy people participate in exercise programs for extended periods of time, their bones can become more dense through increased deposition of mineral salts and the number of collagen fibers. On the other hand, if bones are not subjected to mechanical stresses, as in individuals with sedentary lifestyle or
Several surface makers which expressing from mesenchymal stem cells. Basically, these makers are the cell receptors, adhesion molecules, extracellular matrix proteins, cytokines and other molecules that have function as a way of communicating with other cells and to carry out their physiological functions. Thus, these makers are adopted to characterize the homogenous mesenchymal stem cells. However, the Bone marrow-derived stem cells expression of different surface markers which are still controversy. These cells have a negative expression of CD45 which express in Hematopoietic stem cell (HSC) (McKinney-Freeman et al., 2009), CD14 which express in innate immune cells (Cros et al.
Phase III: A phase comprising a mixture of both, active bone resorption, which is compensated by bone formation. This phase is characterized by a disordered skeletal structure, making the bone sponge-like, weak, and deformed.1
Haller (1763) injected a clear fluid into the periosteum showing that “the origin of bone is the artery carrying the blood and in it the mineral elements” putting forward the idea that the cardiovascular system was responsible for bone formation. This was supported by the previous work of Hunter (1754)
Bones of the skeletal system serve as storage compartments for vital minerals like phosphorus and calcium. Excessive calcium in the blood is stored in bones. Calcium is released from the bones into the blood when there are deficient amounts of it in the blood.
The skeletal system consists of 206 bones and has other body attachments that assist in connecting them which are tendons, ligaments, and cartilage. The skeletal system provides vital functions for the human body. The functions this system provides are support, movement, protection, blood cell production, storage for calcium and endocrine regulation. Bone serves as the basic unit of the human skeletal system. Ossification is characterized as a process that produces new bone. This process is also known as bone formation. Bone formation consists of two types of development. They are intramembranous and endochondral formation. Intramembranous ossification takes place when cells within the membrane change and become osteochondral progenitor cells.
During pregnancy the organ systems change in efforts to make room for the growing baby and to support the both the mother and the babies life. The digestive and the urinary systems are impacted primarily due to the growth of the uterus. Because the uterus is growing it may cause heartburn, and the growing uterus puts pressure on the urinary track which may cause the mother to be, to use the bathroom more often. The circulatory system changes because the blood flow increases.
The arrangement of the structures which are present in the fetus will change and be different according to the way of folding . so , before folding if we take from cranial side to caudal side we will have from septum transversum , cariogenic area , oropharynegeal membrane
Describe the microscopic features of osseous tissue that help long bones withstand compressive forces without breaking.
Osteoblasts are cells that form in the marrow of bones. Osteoblasts are vital in forming bones when a foetus is developing and as a child grows. The bone cells don't stop working even once a person has reached adulthood, bone development occurs throughout your whole life. Also, the development of new tissue allows broken bones to repair.
Homeostasis is responsible for keeping biological conditions intact, such as our PH levels and blood pressure. As stated in Chapter 1.1 Overview of Anatomy and Physiology, it is “the state of steady internal conditions maintained by living things.” It also serves as the process that maintains and regulates our natural functioning, in other words. The importance of homeostasis in the body is to make sure that each internal role is functioning correctly. Throughout this paper, we will discuss how homeostasis affects the skeletal system. To understand homeostasis and its effects on the skeletal system, we must first learn the skeletal system itself. The skeletal system is made up of bones and cartilage and functions to support the body, produce blood cells, and store and release minerals and fat.