Sesamoid bones, such as the patellae, are small and round, and are located in tendons. . Running down the center of each osteon is the central canal, or Haversian canal, which contains blood vessels, nerves, and lymphatic vessels. These are 1 the , the —the spine—and much of the , and 2 the , to which the pelvic hip and pectoral shoulder girdles and the bones and cartilages of the limbs belong. Inside this is the which has an inner core of bone marrow, it contains nutrients and help in formation of cells, made up of yellow marrow in the adult and red marrow in the child.
Long bones, such as the femur, are longer than they are wide. Many of these fuse together as the infant grows. The shaft is composed of compact bone surrounding a central medullary cavity. These bones tend to have more complex shapes, like the vertebrae that support the spinal cord and protect it from compressive forces. Anatomy of a Flat Bone. Medullary Cavity Long bones all have a long cavity inside the diaphysis called the medullary cavity. The femur thigh bone is a good example of a long bone.
When a bone is injured or fractured, the progenitor cells of the osteogenic layer call upon reviving cell reproduction in the form of both osteoblasts and chondrocytes. Lesson Summary Let's review what we've learned… A long bone is a largely cylindrical bone with a slightly curved shape, a shaft that's longer that it is wide, and extremities that are generally expanded. The Fibula is the third longest bone in your body, measuring in at 15. Also, in the human body t … here are 350 bones when you are first born but by the time your an adult some of your bones would have fused together to make only 206 bones. Bone Markings The surface features of bones vary considerably, depending on the function and location in the body. The hydroxyapatite crystals give bones their hardness and strength, while the collagen fibers give them flexibility so that they are not brittle. Chapter Review A hollow medullary cavity filled with yellow marrow runs the length of the diaphysis of a long bone.
Cartilage is a tough yet flexible material not quite as hard as bone. This is right next to the tibia. They are separate at birth, but later in life, they are fused together to form one structure, the sacrum. In this joint a large projection of the ulna, the olecranon, fits into the well-defined olecranon fossa, a depression of the humerus. Bad habits like excessive consumption of alcohol, drugs, fast food leading to weight gain and smoking can affect the health seriously. A short bone is a somewhat irregularly shaped bone that has relatively equal dimensions. Blood and Nerve Supply The spongy bone and medullary cavity receive nourishment from arteries that pass through the compact bone.
The third general function of the skeleton is that of. The structure of the within the head and neck and the upper part of the shaft of the femur would do credit to an engineer who had worked out the weight-bearing problems involved in the maintenance of upright posture. The outside sheath of the periosteum contains nerve ending called nociceptors which respond to stimuli or signals from the and. The function of the tarsal bone is that they are your toes!! Don't think of a short bone as simply a shorter version of the dumbbell-shaped long bone, though. Their shapes are due to the functions they fulfill within the body e. In this article the parts of the skeleton are described in terms of their sharing in these functions. Although thus attached to the ulna, the head of the radius is free to rotate.
The open spaces of the trabeculated network of spongy bone allow spongy bone to support shifts in weight distribution, which is the function of spongy bone. It consists of a relatively few large bones, the , the bone, two temporal bones, two parietal bones, and the. Of these functions, support is the most primitive and the oldest; likewise, the axial part of the skeleton was the first to evolve. The red marrow in adults and older individuals is restricted to vertebrae and heads of tibia and femur. Achondroplasia is a cartilage disorder which leads to dwarfism. There are also other bone cells, like bone lining cells.
Short People Some people are jokingly accused of being 'vertically challenged,' as if that's a bad thing. Bone Classifications Table 1 Bone classification Features Function s Examples Long Cylinder-like shape, longer than it is wide Leverage Femur, tibia, fibula, metatarsals, humerus, ulna, radius, metacarpals, phalanges Short Cube-like shape, approximately equal in length, width, and thickness Provide stability, support, while allowing for some motion Carpals, tarsals Flat Thin and curved Points of attachment for muscles; protectors of internal organs Sternum, ribs, scapulae, cranial bones Irregular Complex shape Protect internal organs Vertebrae, facial bones Sesamoid Small and round; embedded in tendons Protect tendons from compressive forces Patellae Chapter Review Bones can be classified according to their shapes. Anatomy of a Long Bone. The osteogenic cells of the periosteum are responsible for determining the width of each bone of the body. Keep in mind, however, that the term describes the shape of a bone, not its size. They are one of five types of : long, , , and. The epiphyses, which are wider sections at each end of a long bone, are filled with spongy bone and red marrow.
It's made up of compact bone that overlays cancellous bone. In fact, out of all bones in the body, the chest bones are the most packed together, showing the level of criticality of the functions they perform. Flat bones are thin, but are often curved, such as the ribs. They form many gliding joints with each other to increase the flexibility of the wrist. Irregular bones such as those of the face have no characteristic shape. But they're holding 'hands' with one another and reaching out to the cells on the surface and they're not dead you hope.
This is because cartilage is present in those areas. The long bones of the human leg comprise nearly half of adult height. You must have noticed that some very old people have bigger earlobes and bigger nose-ends. Mainely, there are three types of bone cells,Osteoblast, Osteoclast, and Osteocytes. The Humerus is the fourth largest bone in the body, measuring in at 14. The human skeleton, like that of other , consists of two principal subdivisions, each with origins distinct from the others and each presenting certain individual features.
It is located between the elbow joint and the shoulder. Bone markings depend on the function and location of bones. The three types of cartilage, described above, differ in the relative amounts of these three main components. Protection The skeleton provides mechanical protection for many of the body's internal organs, reducing risk of injury to them. It consists of a very hard virtually solid mass of bony tissue arranged in concentric layers Haversian systems.