Skeletal System Overview
What is the first step in bone remodeling?
Activation, when osteoblasts are basically activated to start bone remodeling
What is different about adult bone marrow compared to infant bone marrow
All bone marrow in a child is red until aging causes more of it to change into yellow bone marrow
What is compact bone, where is it found, and what is its function?
Compact bone is dense and composed of osteons; it forms on the diaphysis of long bones - it provides strength and protection to the bone
What is the 4th and final step in bone remodeling?
Formation, osteoblasts create new bone cells until resorbed (the old absorbed) bone is completely replaced
What is the 2nd step in bone remodeling?
Reabsorption, when osteoclasts break down old bone
What is the 3rd step in bone remodeling?
Reversal, osteoclasts start to die and osteoblasts are activated
What is spongy bone, where is it found, and what is its function?
Spongy bone is lighter and honeycomb in design. It is found on the ends of long bones and in vertebrae. - the function is to make the whole bone lighter and to house red bone marrow in the spaces
Where is red bone marrow found (in adults)?
Spongy bone of skull, ribs, sternum, pelvis, vertebrae, and epiphysis of long bones
What is the function of red bone marrow?
blood cell formation
Osteoblasts
bone forming cells
Examples of long bones
bones of arms & legs,except wrist, ankle & patella
What are long bones?
bones that are longer than they are wide; has a cavity that contains yellow bone marrow
What are sesamoid bones?
bones that develop from tendons, made to reinforce and decrease stress on said tendons; circular/rounded in shape
What are irregular bones?
bones that do not fit one of the preceding categories - its function is to protect internal organs
Osteoclasts
break down and absorb bone
How are bones classified?
by their shape
Examples of short bones
carpals and tarsals
What are short bones?
cube shaped bones that mainly contain spongy bone with a thin covering of compact bone
Where is yellow bone marrow found (in adults)?
in the medullary cavity of long bones
What are the different bone classifications?
long, short, flat, irregular, sesamoid
Osteocytes
mature bone cells
What type of cells make up bones?
osteocytes, osteoblasts, and osteoclasts
Example of sesamoid bones
patella (kneecap)
Ossification
process of bone formation
Examples of flat bones
skull, ribs, sternum
What are the two types of bone tissue?
spongy bone and compact bone
What is the function of yellow bone marrow?
stores fat for energy
Functions of the skeletal system include:
support, permission of movement, blood cell formation, protection of internal organs, mineral storage, fat storage, and hormone production
What are flat bones?
thin, flat, and slightly curved; a thin layer of spongy bone is sandwiched between two layers of compact bone
Examples of irregular bones
vertebrae, facial bones, and hyoid
What is bone remodeling?
Bone tissue is removed by osteoclasts, and then new bone tissue is formed by osteoblasts.
What are the differences between infant/fetus skeletons and adults skeletons?
Child's bones are more flexible while adults are harder and more brittle Babies have more bones at birth but they eventually fuse together into adulthood, decreasing the number of bones