Ch 7 The Skeletal System (Part 1) Flashcards
What is the skeletal system made of?
bones, cartilages, and ligaments
What is cartilage?
lessen friction in joints and allow for expansion of bony frame
What are ligaments?
connect bone to bone at joints
What are tendons?
connect bone to muscle
What are the functions of the bone and their characteristics?
1) Support - holds up the body
2) Protect - soft tissue like brain
3) Movement - by coordinated action of muscle and bone
4) Electrolyte Balance - by storage of calcium and phosphate
5) Acid Base Balance - buffers blood against pH changes by absorbing/releasing alkaline (basic) salts
6) Blood Formation - red bone marrow is major producer of blood cells
What are the classifications by shape and their characteristics?
1) Long - femur, thigh bone, leg, arm
2) Short - carpal, wrist, ankle
3) Flat - parietal bone from roof of skull
4) Irregular - sphenoid bone from skull, vertebrae
What is the long shaft of a bone called?
diaphysis
What are the 2 expanded ends of a bone called?
epiphysis
What does articular cartilage do?
reduces friction
What is the medullary cavity?
shaft of long bone that has a hallow center
What is marrow?
soft connective tissue
What are the 2 membranes?
periosteum and endosteum
What is the periosteum membrane?
- on outside of bone
- glistening white double membrane
- has osteoblasts and osteoclasts
What are osteoblasts?
builders, make bone
What are osteoclasts?
construction, collapse, break down bone
What is the endosteum membrane?
- on inside of bone
- delicate connective tissue
- lines canals in bone
What is a compact bone?
- primarily in diaphysis
- tough, tightly packed, no spaces
What is a spongy bone?
- primarily in ephiphyses
- covered by thin layer of compact bone
- numerous branching bone plates with spaces between
- spaces reduce bone’s weight
What is trabeculae?
the spaces between the branching bone plates
What is an osteon?
structural unit, tiny support pillars
What is a central canal?
central tube with nerves and blood vessels, connect with perforating canals at right angles
What is a perforating canal?
the channel between each central canal to connect them
What is endosteum?
the lining of canals
What are osteocytes?
mature cells in lacunae
What are canaliculi?
connect lacunae with each other and the central canal, allow for passage of nutrients and wastes
What are lamellae?
concentric rings within the osteon
What are the 2 types of bone?
intramembranous and endochondral
What is intramembranous bone?
- forms broad, flat bones of skull
What is the special connective tissue cells?
- Differentiate into osteoblasts > become active > deposit bony matrix around themselves
What is endochondral bone?
- develops from masses of hyaline cartilage
- cartilage acts like a model
What is the bone development?
- hyaline cartilage model forms bone collar
- cavity forms in hyaline cartilage
- periosteal bud invades > spongy bone
- medullary cavity forms (spongy bone broken down)
- epiphysis ossify > only growth plates remain as cartilage > site of future long bone growth
T or F: Bone is not static.
True
What are the 2 steps in remodeling?
1) bone deposit - new bone continually laid down by osteoblasts
2) bone resorption - old bone continually broken down by osteoclasts, mostly done to get calcium