Chapter 6 Bone Tissue Flashcards
Structure of a long bone
Define diaphysis
Shaft of the bone
What are the 6 important functions of the skeletal system?
- Support. 2. Protection. 3. Assists in body movement
- Stores and releases salts of calcium and phosphorous
- Participates in blood cell production (hemopoiesis)
- Stored triglycerides in adipose cells of yellow marrow
Structure of a long bone
Define epiphyses
Both ends of the bones at the joints.
Structure of a long bone
Define metaphyses
Region between diaphysis and epiphyses
Structure of a long bone
Define periosteum
Connective tissue surrounding the diaphysis
Structure of a long bone
Define medullary cavity
Hollow space within diaphysis
Structure of a long bone
Define endosteum
Thin membrane lining the medullary cavity
Bones contain 4 types of cells Define osteoprogenitor cells Osteoblasts Osteocytes Osteoclasts
Osteoprogenitor - bone stem cells, differentiate
Osteoblasts - bone-building cells that secrete matrix
Osteocytes - mature bone cells
Osteoclasts - remodel bones and cause them to release calcium
Define compact bone
Provides protection and support
Define spongy bones
Lightweight and provides tissue support
Periosteal arteries and veins enter the _______ through _________ ___________.
The diaphysis through Volkmann’s canals
Nutrient artery enters the center of the _________ through a ________ __________. Nutrient veins exit the same canal.
Diaphysis through a nutrient Foramen.
What is ossification/osteogenesis?
The process of bone formation.
What 4 situations do bones form?
- During embryological and fetal development
- When bones grow before adulthood
- When bones remodel
- When fractures heal
Ossification takes place in 2 forms.
Intramembranous and endochondral
When does intramembranous ossification occur?
In flat bones when a connective tissue membrane is replace by bone.
When does endochondral ossification occur?
It replaces cartilage with bone in a developing embryo and fetus.
Also occurs epiphyseal plates of long bones as they grow in length.
What cells cause bones to thicken?
Osteoblasts and osteoclasts
What are the 3 different phases and 4 steps involved in the healing process of a fracture?
Reactive phase - the early inflammatory phase
Reparative phase - formation of a fibrocartilaginous callus first, bony callus second
Bone remodeling phase - last step as the bony callus is remodeled
Some common fractures include…
Open (compound) - bone presses against or through skin
Comminuted - little pieces of bone between fracture
Green stick - happens in children, one side breaks, the other bends
Impacted - top portion impacts into bottom portion
Potts - break of the distal end of the fibula
Coles - break in the distal radius with posterior displacement
Bones store ____% of the body’s calcium. The parathyroid gland secretes ____________ when calcium levels drop. This causes ________ to stimulate and increase bone resorption and ________ is released. Also stimulates the production of _________ by the kidneys to increase calcium absorption in the intestines.
99% Parathyroid hormone (PTH) Osteoclasts Calcium Calcitriol
Older individuals, especially post-menopausal women, experience a ___________ in bone mass when _______ outpaces _______.
Decrease in bone mass when resorption outpaces deposition
