Lecture 3 - Intro to the Skeletal System Flashcards
what are the five main functions of bone tissue?
- supports and protects soft tissue
- supports and generates the shape of the body
- provides attachment for muscles, tendons, and ligaments
- dynamic mineral storage
- makes bone marrow
connective tissue in medullary cavity where blood formation occurs
red marrow
connective tissue in medullary cavity where adipose is stored
yellow marrow
bone is composed of:
calcium phosphate (minerals = inorganic) and type I collagen (protein = organic)
bone cells are embedded in a:
mineralized matrix
bone is covered by other connective tissue such as:
periosteum and endosteum
bone remodels itself under the influence of:
forces
bone is anisotropic, which means:
it has different strength depending on its orientation
how are bones classified?
by location and shape
what are the two main types of bone?
spongy (cancellous/trabecular) bone and compact (cortical) bone
- open network of struts surrounded by blood
- shape and direction depend on external forces
- 20% of bone in all the body, 80% of bone remodelling (due to assoc. with vasculature)
these are all characteristics of what type of bone?
spongy/trabecular bone
- relatively dense and solid (lamellae = layers)
- thickness and density also depends on external forces
- 80% of bone in all the body, 20% of bone remodelling
these are all characteristics of what type of bone?
compact/cortical bone
epiphysis
the end of a bone
diaphysis
the shaft of a bone
highly vascularized connective tissue and contain mesenchymal stem cells
endosteum and periosteum
contain many sensory nerves (where pain is felt)
periosteum
where does appositional growth occur?
periosteum and endosteum
contains red marrow and yellow marrow
medullary cavity
what is articular cartilage?
hyaline-like cartilage at the ends of bone, remnants of bone growth
what are osteoblasts?
immature bone cell which secretes matrix
what is the function of osteoblasts?
bone forming
what are osteocytes?
mature bone cells that live in the lacunas
what is the function of osteocytes?
to maintain the matrix
canals that allow osteocytes to communicate
canaliculi
what are osteoclasts?
bone cells which come from blood which reabsorb the matrix
what is the function of osteoclasts?
bone reabsorbing
secretes acidic substance which break down bone
osteoclasts