Chapter 5 Skeletal System Flashcards
Name the five functions of the Skeletal system
support, storage of minerals (Calcium salts), Blood cell production, Protection, leverage
what is periosteum?
fibrous outer covering of the bone
what is endosteum?
simple cubodial epithelium lining the inside of the marrow cavity
The matrix of the bone is made up of what?
2/3 calcium phosphate and 1/3 collagen fibers
cells make up what percentage of bone tissue?
2-3%
Osteocytes are?
mature cells of bone tissue, basic content of bone
osteoblasts are?
active cells found on the bones inner and outer surffaces (Build up bones)
osteoprogenitor cells are found where?
in the periosteum and endosteum of the bone (mesenchymal cells)
Osteoclasts are?
giant multinucleated cells that perform osteolysis (dissolve bone matrix)
what happens if osteoclasts are more active?
the bone becomes weaker and blood calcium levels rise
compact bone is?
relatively dense and solid tissue that makes up the walls of most bones
spongy bone is?
an airy tissue made up of interconnected struts and plates of bone tissue
what is the cortex?
(outer region) of a typical bone is primarily compact bone
A long bone is divided into what three regions?
Epiphyses, diaphysis, metaphysis.
what is the epiphyses?
ends of long bones. filled with spongy bone
what is diaphysis?
the shaft. compact bone collar that resists tension and compression along the axis of the bone
what is the medullary cavity?
space in the shaft that contains the yellow marrow, which is the fat storage marrow
what is the metaphysis?
the connecting region between the epiphysis and diaphysis
what are the functions of the periosteum?
isolates and protects the bones from surrounding tissues, provides a route and a place for attachment for circulatory and nervous supply, actively participates in bone growth and repair, attaches the bone to the connective tissue network of the deep fascia.
what are the two layers of the periosteum?
fibrous layer (outer; contains fibroblasts)and cambium layer (AKA osteogenic layer)
before 6 weeks of development the framework of the body is what?
mesenchyme and cartilage
what is osteogenesis?
bone formation. the result of ossification
what is ossification?
bone replacing existing tissue
what is calcification?
process of depositing calcium salts into tissues, and is part of the ossification process
what are the two types of ossification?
intramembranous and endochondral
what is intramembranous ossification?
process of converting fibrous CT into bone
what is endochondral ossification?
formation of bone from a hyaline cartilage modeled that has already formed by 6 weeks of gestation
what is nociceptor?
pain receptors
what does the parathyroid (PTH) hormone do?
acts to increase overall availability of calcium ions in the blood.
what is calcitonin?
the antagonist of PTH found in children and pregnant women
what are growth hormoes and thyroxines?
thyroid hormones that increase osteoblast activity.
what are the six bone classifications?
long bones, flat bones, sutural bones, irregular bones, short bones, sesamoid bones
