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The Skeletal System. http://www.octc.kctcs.edu/gcaplan/anat/Notes/API Notes H Skeletal System.htm. Terminology. 1 Condyle – Rounded prominence 2 Facet – Smooth articular surface 3 Fissure – Narrow opening 4 Foramen – Opening or hole through bone 5 Fossa – Depression or groove.
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The Skeletal System http://www.octc.kctcs.edu/gcaplan/anat/Notes/API Notes H Skeletal System.htm
Terminology • 1Condyle – Rounded prominence • 2Facet – Smooth articular surface • 3Fissure – Narrow opening • 4Foramen – Opening or hole through bone • 5Fossa – Depression or groove
FISSURE FISSURE http://www.octc.kctcs.edu/gcaplan/anat/images/Image180.gif
6Process – Any bone projection • 7Spine – A narrow or pointed projection • 8Trochanter – A large, blunt process http://www.octc.kctcs.edu/gcaplan/anat/Notes/API Notes H Skeletal Features.htm
9).Tubercle – A small, rounded process • 10).Tuberosity – A rounded, elevated area of a bone that is usually roughened
Types of bones • 4 types of bones. • Long bones - longer than they are wide. • Short bones - equal in length and width. • Flat bones - thin and flat. • Irregular bones do not fit into any of these categories.
IRREGULAR BONES http://www.personal.psu.edu/users/j/m/jmh595/Irregular%20bones.htm
Bone Structure • The shaft of the long bone is called the diaphysis. • The extreme ends of the bones are known as the epiphyses. • The diaphysis is between the two epiphyses.
Epiphysis of one bone meets the epiphysis of another bone is called a joint. • Cartilage in joint known as the articular cartilage.
Bone - covered by a layer of connective tissue (periosteum). • Provides nourishment attaches ligaments and tendons.
Two types of bone tissue in the diaphysis. • Compact bone is tightly packed and forms the walls of the diaphysis. • Spongy bone is less compact and is found in the diaphysis.
Within the spongy bone is red marrow. • Within the diaphysis is a chamber called the medullary cavity. • This cavity has yellow marrow which is used for energy storage.
Leukemia • Red marrow - makes red blood cells (hematopoiesis), white blood cells, and platelets. • When white blood cells can’t fight off infection, leukemia develops. • Treatment for leukemia - injecting new bone marrow into the patient.
*Bone cells • There are three types of bone cells. • 1Osteoblasts - come from embryonic cells and found on surface of bone tissue. • They lay bone down around themselves - become surrounded by bone matrix. • Then they are called 2osteocytes.
3Osteoclasts are found in the bone tissue and are involved with secretion of a substance that breaks down the bones. • Osteoclasts help to break down the bone so that osteoblasts can lay new bone. • This is how a bone grows.
Under the microscope • Osteocytes are found in spaces called lacunae, which are found between lamellae. • These lamellae are layered in circles around canals known as Haversian canals.
Bone Growth • 2 forms of development. • 1Intramembranous bones - cells develop between sheetlike layers of connective tissue. • 2Endochondral bones - masses of cartilage are later replaced by bone tissue.
Intramembraneous bones - bones of the skull. • Connective tissue appears where the bones will eventually be. • Some of that connective tissue differentiates into the osteoblasts, which lay down bone.
In endochondral bone (most other bones) - masses of cartilage have same basic shape as future bones. • The cartilage cells die - osteoblasts replace them. • Happens in two stages - primary and secondary ossification centers.
When bone nears end of early development, a narrow band of cartilage remains between epiphyses and the diaphysis (epiphyseal plate) • These are growth plates - located at each end of the bone. • Determines how long your bones will be.
Growth plate injuries can happen. • This is when the growth plate area is broken. • In severe cases (only in children), it can stunt growth of the bone. • When these growth plates close, you are done growing.
Osteoblasts and osteoclasts - lay down bone and breaking down bone. • Once the epiphyseal plate is gone - done growing. • The osteoblasts and osteoclasts are important in broken bones.