The Skeletal System By Kevin Beneduce and Taylor Goldman

General Overview of Bones 206 bones in our body (most humans are born with around 300 total bones in the body but most of them fuse together during growth) Most bones begin as hyaline cartilage and harden over time Bones support our body Protect our organs Provide attachment points for muscles, tendons and ligaments

General Overview cont’d Store nutrients such as Phosphorus and Calcium Adult bones are made of 60 % calcium compound and 40 % collagen Bone marrow produces blood cells The skeleton controls and directs internal pressure See page one of reference sheet

Axial Skeleton Comprised of bones that make up our skull, vertebral column, the ribs and the sternum Support and protect organs that allow us to hear, taste and smell 33 stacked vertebrae encase the spinal cord 7 disks that protect the cervical vertebrae 24 ribs, sometimes people are born with an extra set of ribs See page two of reference sheet

Appendicular skeletons Consists of about 126 bones The appendicular bones primarily include the pectoral girdles, the upper limbs, the lower limbs and the pelvic girdle Pectoral girdle- Two shoulder blades (scapulae) and two collar bones (clavicles) Pelvic girdle- two hip bones which are each comprised of three fused bones (ilium ischium pubis) Upper and lower limbs- see reference sheet

Long Bone Any bone that is significantly longer than it is wide Ex- Femur, Tibia, Fibula, Humerus, Radius, Ulna and the phalanges Long bones have a compact hard outside with a spongy bone marrow filled inside Bone marrow is responsible for the creation of Erythrocytes (red blood cells), leukocytes (white blood cells) and platelets

Joint Articulation Any place where two bones meet and movement occurs Gliding - one bony surface glides on another without angular or rotatory movement. Angular - occurs only between long bones, increasing or decreasing the angle between the bones. Circumduction - occurs in joints composed of the head of a bone and an articular cavity, the long bone describing a series of circles, the whole forming a cone. Rotation - a bone moves about a central axis without moving from this axis.

Osteoperosis Bone mineral density is reduced Bone microstructure is disrupted Abundance and diversity of non- collogenous proteins are altered Most prevalent in post-menopausal women (due to estrogen deficiencies) There are no specific symptoms but bone fractures and breaks are much more likely to occur

Osteoporosis cont’d Calcium, Vitamin D and Bisphosphonates can be taken as supplements, both for prevention and aid Fall prevention is necessary because bones are fractured and broken more easily then normal 10 million people are affected by this disease in the U.S. 8 million are women, 2 million are men

Rickets The softening of bones Rickets is most common in children Usually caused by a vitamin D or calcium deficiencies (due to malnutrition) Bowed legs, “knock-knees”, spinal, cranial and pelvic deformities are common Treatments- intake of HGH (human growth hormone), phosphates and vitamin D. Exposure to ultraviolet B light (sunshine when the sun is highest in the sky), cod liver oil, halibut-liver oil, and viosterol are all natural sources of vitamin D.

Fibrodysplasia Ossificans Progressiva Extremely rare bone disease (only affects about 2500 people and only 600 of them are known) FOP is when bones continues to grow in places it shouldn’t ie. on muscles or in joints Causes swelling, intense pain and lack of movement FOP is believed to be a genetic disorder (nucleotide substitution)