the process of laying down new bone by osteoblasts. It occurs in bone, cartilage or fibrous connective tissue. new bone growth…
Bones grow in three stages during life. The bone starts growing in the embryo at around 8 weeks. Ossification is the word for the formation of bone. There are osteoblasts that help form the bone and osteoclasts that eat away at old bone. Bones start off as cartilage, but then is replaced by bone. Connective tissue forms a sheet where the bones are going to be. These connective tissue sheets are highly invested with blood vessels. Some of the cells in the connective tissue sheets differentiate into osteoblasts. These osteoblasts begin laying down the bone extracellular matrix, called spongy bone. These osteoblasts get trapped within the hard matrix and are then called osteocytes. As time goes more and more osteoblasts form from the connective tissue sheets. The connective tissue sheets, as they become major producers of osteocytes, are no longer called connective tissue sheets. They are now called the bone's periosteum. But the newer osteoblasts made by the periosteum cannot enter the spongy bone. So, they begin to accumulate on the edges of the spongy…
10. what are the small spaces in the bone tissue that are holes in which osteocytes live…
Why is bone remodeling necessary when a person reaches adulthood? It renews osseous tissue before deterioration sets in, it heals injured bone, it redistributes bone along lines of mechanical stress…
*Despite their simple appearance, bones are complex and dynamic living tissues that are remodeled continuously.…
Bone is a specialised, strong, flexible connective tissue and is the main component of the adult skeleton. Unlike hyaline and fibrocartilage, bone is supplied with nerves and blood vessels. Epiphyseal veins carry the blood away from the long bones of the body and periosteal arteries, which are also accompanied by nerves, carry blood to the bones. It provides support and gives the structural framework to the body, it acts as a protective cover for internal organs such as the heart, brain and lungs, it provides sites of attachment for muscles, it stores minerals such as calcium and phosphate and it contains cavities where bone marrow produces blood cells. Bone is made up of two main components, cells and the bone matrix. There are four different types of cells in the bone; osteogenic, osteocytes, osteoblasts and osteoclasts of which…
The femur is formed through the endochondral ossification process. This is where bone replaces the cartilage. There are six steps in this type of ossification and they are as follows; one the development of cartilage model, two the growth of the cartilage model, three the development of the primary ossification center, four the development of the medullary cavity, five the development of the secondary ossification centers, and six the formation of articular cartilage and the epiphyseal plate…
Your 80 year-old great aunt, Persis, was placing a canning jar on the top shelf of her pantry when she stepped awkwardly off the stool and twisted her leg at the hip. She felt a sharp pain in her hip and, after collapsing to the floor, found she could no longer stand. She was taken to the emergency room where an X ray showed that the neck of her femur was fractured. More detailed X ray images revealed reduced bone mass in the head and neck regions of the injured femur, in the ends of other long bones of the body and in the vertebrae. Surgery was necessary to repair the fractured femur and a biopsy of the bone tissue indicated that the composition of the osteoid was normal. Healing of the fractured femur is proceeding slowly.…
Osteoblasts create bone, while Osteoclasts break them down. The osteoblast is found on the surfaces of bone and is involved with bone deposition. The osteoclast is usually found in depressions (Howship's lacunae) at the surfaces of bony tissue and is associated with bone resorption; it is a large multi-nucleated cell derived from blood monocytes…
Spongy bone is the internal while the compact are the external layer. Osteogenic cells are the stem cell of the bones. The osteoblast are the matrix-synthesizing cell that is responsible for bone growth while the osteocyte is mature bone cells that monitor and maintain the mineralized bone matrix. Osteocytes are bone reabsorbing cells.…
The skeletal system is made up of cartilage and bone. Both bone and cartilage are connective tissues, that is, they are composed of cells in a matrix with intracellular fibers. Just imagine connective tissue as a gelatin salad with grapes and coconut. The grapes would represent cells, the gelatin the support material for matrix, and the pieces of coconut the intracellular fibers. By changing the amounts of each ingredient and adding extra substances, we can produce a material that is very hard like bone and can withstand weight or softer like cartilage which can be used as a cushioning material.…
1. The skeleton is a metabolically active organ that undergoes continuous remodeling throughout life. Bone remodeling involves the removal of mineralized bone by osteoclasts followed by formation of bone matrix through the osteoblasts that subsequently become mineralized. The remodeling cycle consists of three constructive phases resorption, during which osteoclasts digest bone; reversal, when mononuclear cells appear on bone surface; and formation, when osteoclasts lay down new bone until the reabsorbed bone is completely replaced. Bone remodeling serves to adjust bone architecture to meet changing mechanical needs and helps to repair micro damages in bone matrix preventing the accumulation of old bone. It also plays an important role in maintaining plasma calcium homeostasis.…
In the story "Bones" by J. Lee Engfer, we meet a young, 27 year old, self diagnosed hypochondriac named Lea who acts as if she doesn't appreciate life. Lea in the beginning of the story is a pessimist but towards the end we see a change in her ideas and thinking until she becomes optimistic about her life. We also meet a young spirited older woman named Thea who is vivacious and fun loving with a sense of style which makes her almost 1940's Hollywood-esque, with the neck scarves and painted on eyebrows. The story is a small look into Lea's life. We learn key points about her such as her mother passing away, and her self-diagnosed hypochondria. It's Halloween and Lea and her friend Thea go for a walk to Lake Harriet near Thea's house. Lea has an epiphany about her life. The theme of the story is about living your life to the fullest. The idea that Lea is a hypochondriac could have an even deeper meaning, such as Lea representing the oppression of society in today which is seen almost everywhere with people who do not make an effort to make their lives worthwhile.…
“It is not that adults produce children, but more importantly that children produce adults” (Peter De Vries). In the novel, Salvage the Bones, Jesmyn Ward takes the readers on a quest through the life of Esch. Esch is only fifteen years old when she realizes that her life is collapsing in on her. She is the only girl in a world full of men; from her drunken father to the love of her life, Manny. Esch’s mother died when she was giving birth to her seven year old brother, Junior, forcing her to take care of this damaged family. Skeetah, one of Esch’s three brothers, is occupied with the care and upkeep of his pit bull, China, and her puppies. Skeetah engages the family in his dog-fights while his friends take interest in Esch at…
The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia and kneecap forming the knee joint. By most measures the femur is the strongest bone in the body. The femur is also the longest bone in the body.Using the AP view of the hip, angle formed by axis of femoral shaft and line drawn along axis of femoral neck passing through center of head of femur. At birth, the femoral neck shaft angle is 140degrees. In adult, the femoral neck shaft angle is 120-135degrees. We analysed the Femoral Neck Shaft Angle in 50 dry human femur bones.…