What are the histological features of bone? BIOL 2010 Human Anatomy & Physiology I What are the histological features of bone? Types of bone cells: (Most likely to have “osteo”) _____________ Cells from endosteum and inner periosteum __________ Cells forming matrix __________ Cells “trapped” in matrix __________ Multinucleated cells “remodel” matrix

What are the other categories of bone besides the shapes (ex What are the other categories of bone besides the shapes (ex. Long, irregular etc.)? Bone is classified depending on the arrangement of cells and matrix. Types: ________ ~ Collagen fibers are __________ arranged ________ ~ Collagen fibers are arranged _________

What are the other categories of bone besides the shapes (ex What are the other categories of bone besides the shapes (ex. Long, irregular etc.)? Types: __________ (_______) ~ Network of mineralized bone (_____________) with many spaces ~ ___________ fills up these spaces in life

Types: Cancellous (spongy) Referring back to our discussion of striae and collagen fibers, what direction do you suppose the trabeculae align in relation to stress?

What are the other categories of bone besides the shapes (ex What are the other categories of bone besides the shapes (ex. Long, irregular etc.)? Types: _________ ~ Dense _______ bone that is mineralized (mature) with numerous units (________) arranged around ___________ _________ Compare this photomicrograph to the diagram and locate the listed structures

Discuss with your neighbor and predict an answer. Take 5!!! Compact bone has a specialized canal system for the transport of nutrients and waste products. Why isn’t such a system necessary in cancellous bone? Discuss with your neighbor and predict an answer.

OK Mary, we know about your cartilage… so how does your bone grow? 2 patterns of ossification: (compared in table 6.2) __________________ ______________ Originally _________ tissue __________ Originally ________ that is ossified Note: Both types start as ________ ______, which is remodeled as it matures

How does your bone grow? Intramembranous Ossification fontanels How does your bone grow? Intramembranous Ossification Occurs during _______ __________ and “finishes” by 2 years of age Woven bone fibers connect and thicken forming ________ (cancellous bone) Outer layer of __________ create outer layer of ________

How does your bone grow? Endochondral Ossification Occurs during fetal development and “finishes” by “______________” Hyaline _______ ______ formed Presence of blood vessels on periphery cause “_________” to become “_______” Internal chondrocytes die and are replaced by ________ and ______ cells

How does your bone grow? Endochondral Ossification Hyaline cartilage model formed… everything is “__________” Blood vessels invading ______________ stimulate __________ cells to become ______________ Perichondrium now becomes _______________ New osteoblasts form ________ _________

How does your bone grow? Buds of connective tissue from ___________ invade cartilage model. Bring in osteogenic cells. Then what happens? Osteoblasts form bone as ______ _______ enlarges Bone growth progresses towards ___________ medullary cavity enlarges

How does your bone grow? Osteoblasts form bone in __________ __________ center, beginning of ___________

How does your bone grow? When bone is mature epiphyseal plate is ossified and becomes epiphyseal ______

Discuss with your neighbor and predict an answer. Take 5!!! During endochondral ossification, calcification of cartilage results in the death of chondrocytes. Later in the process, ossification of the bone matrix does not result in the death of osteocytes. Why is this so? Discuss with your neighbor and predict an answer.

Can bone display interstitial growth? How does your bone grow? Can bone display interstitial growth? We’ve talked about bone growth in length… what about diameter? Appositional _________ and _________

How does your bone grow?

How does your bone grow? Factors affecting bone growth: _________ Proteins Vitamins D & C _________ Growth hormone Thyroid hormone Sex hormones Needed for _______ portion of _______ Needed for ___ ________ and _______ formation ___________ overall growth Stimulates bone ________ and works with _____ Stimulates bone growth BUT also closure of __________ ______

What different types of bone injuries are there? Fractures Bones can succumb to stress… resulting in a fracture Fractures categorized based on: 1) __________ _________ damage Need a good picture 5pts. e.c. _______ Open wound extends to fracture No perforation of soft tissue Closed… soft tissue damage

What different types of bone injuries are there? Fractures Fractures categorized based on: 2) ________ of bone damage _________ > or = 2 fragments NOT in 2 fragments

What different types of bone injuries are there? Fractures Fractures categorized based on: 3) _______ of bone damage Ex. _________ _________ Others: Displaced and non-, depressed, epiphyseal, and avulsion

How do bones heal? Bone repair in 5 steps or less… 1) __________ forms (blood confined in a space or organ) Clot formation includes protein mesh of _______ Why? 2) __________ ____ forms Clot is replaced by internal callus… Fibers, then cartilage, then bone

How do bones heal? 3) _______ ______ forms Forms cartilage, then bone support 4) __________ ________ in external and internal calluses 5) ___________ of bone Clean up dead bone, reshape medullary cavity and compact bone of external callus

How do bones heal? Fractures Rate of healing is dependent in part on ______ _____ on the bone. Which person will heal more quickly? Why? Also on _______ activity. Sometimes electrical current applied to speed healing process.

How does the Skeletal System regulate Ca & P? Ca and P homeostasis _________: needed for nerve cell action, muscle contraction, blood clotting and more ________: needed as a component of ATP, DNA and RNA Why are these elements important?

How does the Skeletal System regulate Ca & P? Ca and P homeostasis regulated in part via 2 hormones: ______ (parathyroid hormone) comes from _________ _______ __________ minor role… secreted by ________ _______

How does the Skeletal System regulate Ca & P? PTH +PTH = blood Ca via bone and kidney activities Calcitonin minor role… +Calcitonin = blood Ca