Anatomy & Physiology
Skeletal System
I. Functions of the Skeletal System
A. ______the body
B. ______of vital organs
C. Provide ______for movement
D. ______storage (calcium & phosphate)
E. ______cell formation
II. Bone Structure
A. Microscopic anatomy
1. ______– complex series of canals & ______that run through the dense bone matrix and supply ______to the osteocytes (bone cells)
a. ______(Haversian canal) – elongated cylinder that runs ______to the long axis of the bone. Arteries, veins, & nerves run through the osteons.
b. ______– rings or layers of bone matrix.
c. ______– space in the bony matrix where the osteocyte resides.
d. ______– small channels that connect lacuna (and neighboring osteocytes) to each other and provide a means for passing nutrients & wastes between cells.
e. Matrix composition – ______& ______
2. Types of bone tissue
a. ______bone – relatively solid part of bone. Make bones hard & strong. Usually found on the ______of the bone.
b. ______bone – network of bony struts that form a “honeycomb” of flat bony pieces. Allows bones to be lightweight. Found on the ______of the bones.
1) ______– interlocking plates or struts.
2) ______(red or yellow) - fills the spaces between the trabeculae.
B. Gross anatomy
1. ______– expanded ends. Compact bone on the exterior. Spongy bone fills the interior. The joint surface of each epiphysis is covered with a layer of ______.
2. ______– shaft of the bone. Composed of a thick layer of compact bone.
a. ______– hollow shaft of the diaphysis. It is filled with marrow.
b. ______on a bone is normally applied along the axis of the diaphysis.
3. ______– tissue that fills the spaces of spongy bone & medullary canals.
a. ______– ______tissue (blood cell forming).
1) found in ______the spongy bone & medullary canals of ______
2) found in the ______bones of ______.
b. ______– fat. Found in the medullary canals of the ______bones of ______.
4. ______cartilage – ______cartilage that covers the ends of bones & provides a smooth articulating surface between the two bones of a joint.
5. ______– fibrous, tough, vascular layer that covers the outer surface of a bone.
a. Actively involved in bone ______& ______.
b. Allows attachment surface for tendons & ligaments.
6. ______– covers the internal bone surface of the medullary canal. Similar to periosteum.
C. Bone Development (______)
1. Formation of bones from the hardening of ______cartilage models of the future bones.
2. ______the process of bone formation. Has 2 phases.
a. ______ossification
1) Begins at the center of the ______of the hyaline “bone” around the ______month of development.
2) A bone collar forms around the diaphysis of the hyaline model.
3) Hyaline bone becomes ossified with ______.
4) Ossification proceeds from the center of the diaphysis toward the two epiphyses.
5) The hyaline bone continues to grow & elongate, thus preventing the ossification from reaching the epiphyses for ______years.
b. ______ossification
1) Around ______, both of the epiphyses begin calcifying the cartilage from the inside outward.
2) Primary & secondary ossification usually finishes around ______years of age.
3) The junction of P & S ossification forms a gagged line called the ______.
c. Hyaline cartilage remains at the ends of the bones as ______cartilage.
D. Bone Remodeling
1. The continual breaking down of calcium salts by ______and the relaying of calcium salts by ______.
2. We recycle _____% to _____% of our bones every week to repair and strengthen the bones and to maintain calcium balance in our blood.
E. Hormonal effect on bone growth & remodeling
1. ______gland – secretes the hormone ______, which stimulates ______& decreases blood calcium levels. Makes bones stronger.
2. ______– secretes the hormone ______, which stimulates ______activity & increases blood calcium levels. This makes the bones weaker.
3. Anterior Pituitary – secretes ______, which stimulates bone growth & elongation.
F. Classification of bones
1. ______– almost all bones of appendages
2. ______– carpals & tarsals
3. ______– ribs, scapula, cranial bones, sternum
4. ______– vertebrae, coxal, facial
5. ______– small bones with no bony attachments (E.g. patella)
III. Skeletal System Disorders
A. Bone Fractures
1. ______– bone breaks cleanly, but does not penetrate the skin.
2. ______– broken ends of the bone penetrate through the skin.
3. ______– bone broken into many pieces & fragments.
4. ______– bone is crushed inward.
5. ______– broken bone ends forced into each other.
6. ______– ragged break occurs when excessive twisting is applied to the bone.
7. ______– bone breaks incompletely much like a green twig.
B. Skeletal Disorders
1. ______– decreased osteoblast activity due to the body’s inability to absorb calcium. Usually seen in the ______although exercise & proper calcium intake in middle years can delay the onset of this disorder. Factors that speed up the effects of osteoporosis are: ______. More often seen in ______.
2. ______– Vit. _____ deficiency causes soft bones due to a reduction in calcium. Causes ______legs and other skeletal disformities.
3. ______– excessive GH secretion ______closure of the epiphyseal plates. Results in a ______.
4. ______– excessive GH secretion ______ closure of the epiphyseal plates. Results in ______.
IV. Joints / Articulations
A. General info
1. Joints are ______.
2. Three functional types: ______movable (synarthrosis); ______moveable (amphiarthrosis); ______moveable (diarthrosis)
B. Synarthroses (______movable joints)
1. Occur between bones that come in close contact with each other.
2. A thin layer of fibrous connective tissue separates the bones.
3. Examples are:
C. Amphiarthroses (______moveable joints)
1. Joints are limited to a few degrees of movement.
2. Occur in areas where the bones are connected by disks of fibrocartilage or by thick ligaments.
3. Examples are:
D. Diarthroses (______moveable joints)
1. Joints are able to move in ______directions and with ______degrees of movement.
2. Bones have a layer of ______(hyaline) cartilage at the ends & are held together by ligaments.
3. Articulating bones are separated by a fluid filled joint cavity – the ______cavity – that allows for substantial freedom of movement.
4. The articular capsule is a double layers capsule that surrounds the ends of the bones with a protective fibrous layer and a inner synovial membrane.
5. ______fluid is a slippery lubricant that fills the synovial joint.
6. Synovial joints that bear greater weight (E.g. knee) contain ______pads & fluid filled sacs (______) also help to pad the joints from extrinsic wear.
E. Types of freely moveable joints
1. ______– most freely moveable type. Able to move in 3 planes. Ex: ______
2. ______- nearly flat surfaces are able to glide over one another in 2 planes. Ex: ______.
3. ______- oval surface of one bone fits on the complementary concave surface of the other bone. Ex:______.
4. ______– convex surface of one bone fits into the concave surface of the other bone thus limiting them to 1 plane of movement.
Ex: ______.
5. ______– cylindrical surface of one bone rotates within a ring formed by the other bone. Movement limited to rotation.
Ex: ______.
6. ______– cones with both concave & convex shaped articular surfaces. Allows for a wide variety of movements. Only one example –
V. Joint Disorders
A. ______– chronic joint disorder due to the wearing down of the articular cartilage due to age. Often called “______” arthritis. Accounts for ______% of all arthritis.
B. ______arthritis – autoimmune disease whereby the immune system attacks its own tissues and destroys the articular cartilage. Onset usually begins in the ______’s and can eventually lead to disfigurement and crippling.
C. ______– the build up of ______crystals in the joints. The crystals are painful and can wear away at the articular cartilage.
D. ______– inflammation of a bursa due to injury or excessive friction in a joint.
E. ______– inflammation of the tendon sheaths of a joint due to overuse.