The+Bones

=From the Top of the Skeleton=

The Skull (cranial)
There are 207 bones in the adult body. Starting with the skull which is part of the axial skeleton we have the the frontal bone. The frontal bone forms the forehead. It is classified as a flat bone and there is only one in the body. It forms the superior portion of the orbit and contains two frontal sinuses. It articulates with the parietal bones along the coronal suture, the lacrimal bones, and the zygomatic bones. The frontal bone protects the brain. The next bone is the parietal bone which is also classified as a flat bone. There are two found in the body. They articulate anteriorly with the frontal bone, laterally with the temporal bones, posteriorly the occipital bone and between bones at sagital suture. The parietal bones also protect the skull. Another flat bone of the skull is the occipital bone. There is one large one in the back of the skull. Bing the base of the skull makes this bone very important. Not only does it also protact the brain but it allows the spinal cord to go through the brain through the foramen magnum (the large hole in the bone). There are occipital condyles (large rounded process on the end of a bone) which allow the head to nodd. There are two bumps on the bottom of the occipital bone. The next three bones are classified as irregular bones. There are two temporal bones in the skeleton. The temporal bone is home to the zygomatic process, the styloid process (not to be confused with the styloid processes of the radius and the ulna), the mastoid process, and the external auditory meatus which opens to inner portions of the ear. The temporal bones is the attachment site for the neck muscles and the tounge. It extends to the zygomatic bone. The fossa articulates with the mandibular condyle to form the temporomandibular joint. The temporal bone helps to protect the muscles in the head. The next bone is the sphenoid bone. There is only one in the skeleton. It has two dips surrounding the spinal cord opening then part of the spinal cord. It is butterfly shaped from the front, bat-shaps from the back and contains two sinuses. It's not really visible from the outside. The sphenoid bone is crucial to the skull. It connects to the internal bones structure of the skull. It isthe foundation or "key stone". It contributes to the posterior walls of the orbit and a bit to the lateral skull. It provided protection the spinal cord and the bottom side of the brain. It contains the sella turcica which is a saddle-shaped depression that protects the pituitary gland. The ethmoid is another important bone. It is very delicate but very complex. It is a cuboidal-shaped bone which makes up the internal bony structure between the orbits and the nasal bones. The perpendicular plate forms the top part of the nasal septum. This bone provides protection for the brain, orbits and nasal cavity. The zygomatic bones is also part of the cranial skeleton.

The Lower Region of the Skull
The mandible is another flat bone. It's the largest and strongest facial bone. It is curved and has two small holes (the mental foramen and mandibular foramen). It's the only bone in the skull that can move. The mandible articulates with the tempoal bone at the temporomandibular joint to allow for chewing and speech and the (TMJ) or the mandibular condyle. The mandible houses the lower teeth and the lower jaw. The maxillary (the maxilla fused) or the upper jaw is two irregular fused boned. They are part of the orbits. The maxillary is the upper jaw and provides sockets for the teeth of the upper jaw. It houses the maxillary sinuses. The fused frontal processes allow for articulation with the frontal, lacrimal bones and laterally with the nasal bones. The palatine bones are also part of the facial skeleton. There are two in the body. The horizontal plates complete the posterior portion of the hard palate. The L- shaped palatine bones fuse medially via their horizontal plates. the palatine bones contribute to the walls of the nasal cavities. The volmer, nasal bone, lacrimal bone and ramus are also part of the facial skeleton. The hyoid bone is part of the neck. It is the bone that supports the tounge. The Hyoid bone is the bone that breaks when one is strangled.
 * The Mandible, Maxillary and Palatine (facial)**

Moving Down the Vertebral Column
There are three types of vertebrae in the vertebral. The include: cervical vertebrae, thoracic vertebrae, and lumbar vertebrae. All of which are classified as irregular bones. They provide a sturdy, yet flexible structures support for the upper body. A means of transferring weight to lower limbs, but also houses and protects the vertebral column from its' point of exit to its' termination (the coccyx). The cervical vertebrae consist of the atlas which allows the head to nodd and which holds the head on it's axis (no pun intended). It also consists of the axis which allows the head to spin and turn from side to side. There are seven cervical vertebrae in the vertebral column. They are the smallest of the vertebrae. Next, the thoracic vertebrae. There are twelve in the vertebral column. The costal and transverse processes are required. They are associated facets for articulation with the head and neck. They articulate with the cervical vertebrae and the lambar cyne (rib cage). The thoracic vertebrae are heart shaped. There are five kidney shaped lumbar vertebrae. They articulate with the sacrum and the thoracic vertebrae, These vertebrae provide the main support of the body weight. The Sacrum is also an irregular bone. It is five fused vertebrae to make one bone. The dorsal sacrol crest represens the fuses spirous process of S1-S4. The sacrum articulates with the perlvic girdle. the body of the sacrum is a large discoid shape with a vertebral arch. The pedicles are short and bony, lamina are the flattened plates and the vertebral foramen is the hole that the spinal cord passes through. The spinous process is the midline posterior projection and the transverse process is lateral from the pedicles. The coccyx or the tailbone is also an irregular bone. It consists of 3-5 vertebrae. It is usually four fused vertebrae that decrease in size going down. There is superior articulation with the sacrum, There is attachment for some pelvic gluterall muscles.

The Rib Cage (thoracic cage)
The rib cage or the thoracic cage consists of the sternum, true ribs, false ribs, and floating ribs. The sternum is very important. It is classified as flat shaped. The monubrium is the superior portion of the sternum. The sternum articulates with two pairs of ribs and with the clavicles. It helps connect the ribs. The location of the Xiphoid process is also at the end of the sternum respectively. It is also home if the jugular notch. All types of ribs are flat. There are seven pairs of true ribs. They are attached directly to the sternum via costal cartilages. Their job is to protect the heart, lungs, and the guts. There are 8-20 false ribs depending on the person. The attachment to the sternum is indirect. There is vertabral articulation. Costal cartilages link one another. There are two pairs of floating ribs. They are not attached to the sternum. They have articulation with vertebrae. There is no articulation anteriorly. It has a head, neck, tubercle, shaft, a costal groove, and an angle. These parts all make up the typical rib in the thoracic cage/ the protection of the guts and such.

The Appendicular Skeleton
The Appendicular skeleton first starts with the clavicle bone and the scapula which are part of the pectoral girdle. There are two clavicle (collar) bones in the body. They are flat and S-shaped. They have sternal and acromial ends. They articulate with the scapula laterally and tje anteriorly with the manabrium of the sternum. They serve as support for the shoulder blades, allow arms to hang down by the sides of the body by keeping the shoulder blades back, prevent pectural girdles from getting out of place easily and provide movement for the limbs and shoulders. They act as a brace for the scapula and the arms (they anchor the arms to the body). The scapula (shoulder blade) looks like an inverted triangle. The scapula is a flat bone and has superior, medial, and lateral borders. The acromion, glenoid cavity, and coracoid process are all located on the scapula. It has inferior, lateral, and superior angles. They are weak bones and they fracture easily. They articulate with the clavicle bones and indirectily to the vertebral column via muscles. They provide the movement of the shoulders. The humerus is the next bone down the line. There are two of them in the body. They are classified as long bones. They are the largest bones of the upper limb. They contain the detoid tuberosity, an oblique radial groove, two condyles and the trochlea. They articulate with the radius, ulna and scapula. The shaft and proximal head articulate with the glenoid cavity. They have greater and lesser tubercles. The radius is the long bone parallel to the ulna. There are two in the body. They form a narrow head proximally. They have a prominent distal projection which is the radial styloid process. It's another site of attachment for wrist ligaments. It's thin at its' proximal end and wide distally. The radius articulates with the capitulum of the humerus. It broadens distally to create a fairly large area of articulation with the scaphoid and lunate carpal bones of the wrist. The radius supports the forearm and contributes to the wrist joint. The ulna is the longest of the two forearm bones and the one that forms the bony structure of the elbow. It is parallel to the radius and is also a long bone. It articulates with the proximal end and olecranon and coronoid process. It also articulates with the trochlea of the humerus and broadens to form the head. The styloid process of the ulna is also located here. It helps to support the forearm.

The Wrist and Hand
The carpals or wrist bones are irregular. There are eight of them or two rows of four. They make up the structure of the wrist (carpus). The eight wrist bones are the scaphoid, lunate, triquestrum, pisiform, trapezium, trapezoid, capitate, and hamate. The scaphoid and lunate bones articulate with the distal end of the radius while the distal row of carpal bones (TM, TD, C, H) articulate with the metacarpals. They make up the structure of the wrist. The metacarpals of the hand are short bones. There are five of them. They form the palm of the hand. The metacarpal is the shortest. The distal ends of metacarpals 2-5 can easily be recognized as your knuckles when you form your hand into a fist. They connect the carpal bones and the wrist. The phalanges are also short bones or small long bones. They are numbered #1-5 starting with the thumb. There are three phalanges for each finger (proximal, medial, and distal) plus two for the thumb making a grand total of twenty-eight for the whole body (fourteen each hand). They connect to the metacarpals. They form the fingers.

The Pelvic (hip) Girdle
The pelvic gidle connects lower limbs to the vertebral column. There is a compound pair of coxa bones which articulate anteriorly at the symphasis pubis and posteriorly with the sacrum. Each coxal bone consists of three separate bones during childhood but are securely fused in adulthood. These three bones are the ilium, ischium, and the pubis. The ilium is the largest and uppermost flaring portion of the coxal bone. The ilian crest is part of the ilium. It is the prominence of the hips. When you put your hands on your hips that is what you are feeling. It has the socket which articulates with the head of the femur which is called the acetabulum. The hole in each coxal bone is called the obturator foramen. The ischium is the lowest L-shaped portion of the coxal bone. It has an ischial spine. The pubis is the anterior portion of the coxal bone (bladder).

The Lower Limbs
The Femur or the thigh bone is the largest, longest and strongest bone in the entire skeleton. The head is supported by the neck. The greater and lesser trochanters are projections that attach to the thigh and buttock muscles. The femur shaft broadens distally and forms the medial condyle and lateral condyle which articulate with the tibia. The medial and leteral condyles are slightly concave facets which articulate with corresponding femur medial and lateral condyles. There are two femur bones in the body (upper leg). There is also the patella or the knee cap (sesmoid bone). The two tibia (shin bones) bones are strong long bones as well. They are the second largest bones in the body. They contain the tibial-medial and lateral condyles which are bony projections that have slightly concave facets. The tibial tuberosity is present. The medial malleolus (bulge of the ankle) is also present. The fibula is the thin bone that is lateral to the tibia. It also has a head and a laterall malleolus (lateral ankle bone bulge). It is very easy to break and sometimes goes unnoticed. The foot is just like the hand. Instead of carpals it has tarsals. It has seven tarsals or ankle bones. Body weight is carried on the two largest tarsals. Talus is the uppermost tarsal which articulates with the tibia and fibula. The Calcaneus is the heel bone. The foot has two cuneiform bones (medial, intermediate, lateral)a cuboid bone, and a navicular bone which makes fourteen tarsals (seven each foot). The foot also has metatarsals. five for each foot and ten altogether. Finally the foot has fourteen phalanges on each foot for a grandtotal of twenty eight in the feet. They make up the toe bones (digits). The phalanges of the foot help support the weight of the body.