Anatomy - Skeletal System
How does bone damage repair itself?
- blood clotting - connects broken ends forming spongy bone and replacting cartilaginous callus - bone remdeling occurs
What are the two types of ossification?
- intramembranous - endochondral
What are the 4 main types of bones?
- long - short - flat - irregular
How many bones do we have?
206
How often does your skeleton rebuild itself?
7-10 years
What is the first step in bone remodeling?
Activation
What run through each osteon?
Haversian canal
What does the sesame look like?
a sesame seed
Examples of endochondral ossification
all other bones
What are examples of long bones?
arms, legs, hands, feet
What function is in red bone marrow of certain bones?
blood cell formation
What is intramembranous ossification?
bone that develops from a fibrous mambrane
What is endochondral ossification?
bones that develops by replacing cartilage
What is a fracture?
break
How are bones classified?
by shape and location
What is the new matrix mineralized with?
calcium and phosphorus
How is connective tissue in our bones?
cartilage and dense connective tissue cover the bone's external surface
What are osteoclasts?
cells that break down bone tissue
What are osteoblasts?
cells that repair the bone that the osteoclasts broke down
Example of intramembranous ossification
clavicle and skull bone
irregular bones are _____?
everything else
What forms when the bone connects itself?
fibrocartilagious callus
What are depressions for?
for blood vessels and nerves to run through
What is ossificiation essential for?
for bone growth from childhood up until early adulthood
What is ossification used for later in life?
for bone remodeling and repair
What is ossification key for?
for forming your skeleton as an embryo
What is the fourth step in bone remodeling?
formation
What form when the blood clots happen?
hematoma
What are examples of irregular bones?
hip bones, vertebrae, some facial bones
What function is critical for helping maintain homeostasis?
hormone production
How is epithelial tissue in our bones?
in its blood vessels, which provide nourishment
How is nervous tissue in our bones?
in its nerves
Where is spongy bone found?
interior of bone
How can you tell that a bone is an irregular bone?
it have a highly specialized shape and structure
What detects the bones function?
its shape
What is immobilization?
keeping bone stable so it has time to heal itself
Where are osteocytes located?
lacunae - between lamellae
What are osteons made of?
lamellae
Flat bones have a _____ surface area
large
What do long bones act as?
levers
Where are long bones located?
limbs
Longer bones are _______?
longer than they are wide
What does red bone marrow do?
makes red blood cells
What happens during reversal?
mesenchymal stem cells are along the burrow or pit where they are proliferate and differentiate into osteoblasts
Short bones are _______?
more cubed shape
What function helps the skeletal muscles that are connected to cones via tendons and use bones as levers at joints
movement
What do pre-osteoclasts fuse to form?
multi-nucleated osteoclasts
What do flat bones look like?
often have a bit of a curve
Spongy bone is less _____ than compact bone?
organized
What happens during formation?
osteoblasts mature at the surface of the burrow/pit and release osteoid at the site, forming a new soft non-mineralized matrix
What does resorption do?
osteoclasts release enzymes that allow them to digest calcium phosphate and return it to the blood for various uses
In resorption what happens with the compact bone?
osteoclasts will burrow a tunnel
In resorption what happens with the spongy bone?
osteoclats dig out a cavity
What does activation do?
osteocytes release chemical signals to tell osteoclasts to go to the remodeling sites
What is compact bone made out of?
osteons
Where is compact bone found?
outside of the bone
Where is the sesame located in the body?
patella
3 bone markings
projection, surfaces, and depressions
What function guards the body's most vital organs
protection
What is the last step in bone remodeling?
quiescence (resting)
What is reduction?
realignment of broken bone ends
What is treatment?
reduction and immobilization
What is the second step in bone remodeling?
resorption
What is the third step in bone remodeling?
reversal
What is Haversian canal?
runs through the middle of each osteon and contains small blood vessels for nourishment and nerve fibers for signaling
What is the special kind of short bone?
sesame
What happens during resting?
sites, with resting lining cells, remain dormant until the next cycle
How is muscle tissue in our bones?
skeletal muscle tissue
What do short bones provide?
stability and support with little movement
What are examples of flat bones?
sternum, scapulae, ribs, and pelvis, also some cranial bones
What function stores minerals like calcium and phosphate, which can be released into blood when needed
storage
What does yellow bone marrow do?
stores energy on the form of fat
What function holds up your entire body?
support
What are osteocytes?
tells other bone cells where to go and what to do
What do short bones look like?
tend to be wide as they are long
What do long bones look like?
tend to have a long shaft with earthier end being a bit wider
What are osteons?
the basic structural unit; long cylinders that act as tiny weight-bearing pillars in the bone
What would happen if bones didn't remodel themselves?
the calcium in our bones would crystallize and make bones more brittle
What is ossification?
the process of bone tissue formation
What happens to the osteoclasts after they are done digesting the calcium phosphate?
they disappear
Flat bones are ______?
thin and flat
What is trabeculae?
tiny bone struts that are key for helping the bone resist stress
What is lamellae filled with?
tiny salt and collagen fibers that allow the bone to resist torsion stress
Why do flat bones have such a large surface area?
to attach to the muscle
what are surfaces for?
to form joints
What does spongy bone shave that compact bone doesn't?
trabeculae
What are projection for?
where muscles and ligaments attach
What are examples of short bones?
wrists and ankles
Does spongy bone have osteons?
Nope