Protection – Bone marrow and organs. (axial skel has cranial bones & thoracic cage.)
Leverage – long bones esp. Long bones give more power for effort
Storage – Minerals and lipids.
Minerals - calcium and phosphate.
Lipids – energy reserves in areas filled with yellow marrow.
Name and describe the major bones shape categories and give an example of a bone in each.
Long Bones – femur
Short Bones – talus
Irregular Bones – sphenoid
Sesamoid Bones – patella
Flat Bones – occipital bone
Sutural Bones – often found within the sutures of flat bones in skull
How does its tissue arrangement differ from cancellous (spongy) bone?
Compact or dense bone is
organized in osteons and is stronger and heavier than spongy bone.
Stronger so it can withstand more stress than spongy bone.
found on the surface of all bones.
slower to form.
Name the 4 types of bone cells and describe what each one does
Osteoprogenator Cells – Stem cells which can divide quickly. Important for growing and healing.
Osteoblast Cells – produce bone matrix – collagen and other organic bone components (osteoid)
Osteocyte – Mature bone cells that sit in lacunae. They maintain the bone matrix
Osteoclast – Macrophages (a monocyte (mononuclear phagocytic WBC) that has left circulation and settled and matured in tissue. There are a variety of macrophages found throughout the body.) These are the “cleanup” cells.
What is intramembranous ossification?
bone developes directly from mesenchyme or fibrous connective tissue.
happens in ossification center
bone grows from center outward forming spicules.
Blood vessels grow into area and become trapped as bone develops.
Osteons and periosteum forms
What is an osteoid?
prebone; resembles bone
What cells are involved in intramembranous ossification?
What is endochondral ossification? (Always)
most common process of bone formation.
bone is formed within hyaline cartilage
gradual process that continues as long as cartilage remains.
As long as growth plate has cartilage, bone can lengthen.
What are the 5 steps of Endochondral ossification?
1. Chondrocytes enlarge near ctr of shaft, calcium is added to the matrix and chondrocytes cant get nutrients so they start dying
2. increased blood vessel growth in perichondrium, perichondrium cells chg to osteoblast producing a periosteum
3. Primary ossification ctr develops near middle of model - capillaries and fibroblast move into ctr of cartilage
4. Remodeling begins - osteoclasts carve out a marrow cavity, spongy remodels to compact, epiphyseal cartilage growth continues
5. Development of bone in epiphysis - blood vessels enter epiphysis allowing 2nd ossification ctr to begin forming. Same process as primary EXCEPT spongy bone is left in epiphyses.
What could be results of epiphyseal plate damage?
the amount of cartilage at the growth plate could be reduced thus will be converted to bone sooner than normal.
What are the 4 steps in healing a fractured bone?
1. Blood clot forms to stabilize break
2. fibroblasts move in from periosteum forming external callus, fibroblast from endosteum form internal callus, fibroblasts produce collagen to knit bone together
3. Callus convert to bone - osteoblast replace cartilage w/ bone, external and internal callus tissues connect
4. osteoblasts and clasts remodel area, attempting to regain orig shape.
Explain how bones gain diameter
by osteoprogenators and osteoblasts. Marrow cavity is enlarged by osteoclasts
What is bone remodeling?
part of normal bone maintenance where the organic and mineral components of the bone matrix are being recycled. Also takes place to reshape after injury.
List the facial bones
inferior nasal concha
what bone and structure does the condylar process of the mandible fit into?
mandibular fossae of temporal bones
What do paranasal sinuses do?
lighten skull and resinate sound
what are the names of the normal curves of the vertebral column and where is each located?
Cervical curve - Anterior Curve
Thoracic Curve - posterior curve
Lumbar Curve - anterior curve
Sacral Curve - posterior curve
Name 3 abnormal vertebral curves
kyphosis- hump back
lordosis - bending backwards
scoliosis - side to side curving
What pairs of ribs articulate directly with the sternum?
pairs 1 - 7
Which ribs do not articulate with the sternum at all?
prs 11 and 12. they are called floating ribs
name the joint between the pelvic girdle and the axial skeleton
What 2 bones and parts of these bones make up the ankle?
Tibia and the medial malleolus
Fibula and the lateral malleolus
What is the heel bone called?
What are the cells involved in remodeling process and what do they do?
Osteoclast - clean-up
Osteoblast - build
osteocytes - maintain
What vitamins are needed for bone growth and what happens in the case of deficiency?
Vit C (needed for collagen) - deficiency = scurvy (brittle bones)
Vit D (needed for calcium absorption) - deficiency = rickets (soft bones
Calcium (needed to harden bones)
What are some of calcium's uses?
What are the 2 hormones involved in restoring calcium balance and what do each do?
Calcitonin - used to lower calcium in blood by decreasing absorption in GI tract, kidneys allow more loss, keep bones from releasing store calcium into system.
Parathyroid hormone - stimulates osteoclasts to release calcium from bone, decrease rate of excretion at kidneys, increase rate of absorption in GI tract
calcitriol - Active form of Vit. D - allows for greater absorption in GI tract and in kidneys
What is the bones role in blood cell production?
All types of blood cells are produced in red bone marrow
What is a comminuted fracture?
What is a stress fracture?
Cracking in bone due to repeated stress
projection or bump
small, articular surface
passage or opening
smooth rounded articular process
open area within a bone
expanded articular end of an epiphysis
lg rough projection
small rounded projection
extension of bone that makes an angle with the rest of the structure