Lab #2: Basic Histology of the Skeletal System Flashcards
The skeleton is divided into two major subdivisions
the axial and appendicular skeleton
Axial skeleton
consists of all the bones along the midline of the body, including all the bones of the skull, neck, thorax, and abdomen. Can be paired or unpaired.
Appendicular skeleton
consists of all the bones pertaining to the upper and lower limbs, these bones are always paired
Paired bones
one on each side of the body
Unpaired bones
one directly along the midline
Shapes of bone
long, short, irregular, flat
Osteon
the basic organizational unit of osseous tissue
Both spongy bone and compact bone contain ______.
Osteons
Osteons in compact vs spongy bone
Compact bone contains numerous, densely-packed osteons, while the osteons in spongy bone are scattered throughout the trabeculae and spicules
A single osteon is comprised of _____________.
multiple lamellae (circular layers) surrounding a central canal, which houses blood vessels and nerves
Osteocytes
mature bone cells
Osteoblasts
immature bone cells
Osteocytes sit in between ______.
the lamella and small gaps in the bone matrix, called lacunae
Canaliculi
minute channels in the hard bone matrix that osteocytes communicate through
Osteoblasts produce ______.
collagen fibers during bone formation
Long bones
cylindrical bones of the limbs that are longer than they are wide
Diaphysis
long central portion of the long bone
Epiphysis
the complex end piece of each long bone
Diaphysis houses the medullary cavity, which contains ______.
yellow bone marrow and is lined by a thin epithelium, the endosteum
Each epiphysis contains _____.
spongy bone filled with red bone marrow
Epiphyseal line
the line where the diaphysis and epiphysis fused together
Epiphyseal line
the line where the diaphysis and epiphysis fused together
Living bone tissue is encased by a thin layer of ______.
dense connective tissue, called the periosteum
There is a thin layer of _______ on the epiphyses that cushions the long bones wherever they meet at the synovial joints
articular cartilage
Nutrient foramina
little holes in the compact bone created by blood vessels and nerves
Deep to the periosteum is a layer of _____.
compact bone, with spongy bone deep to the compact bone
Organization of Flat Bones
- No medullary cavity
- Structured like a sandwich with multiple layers: flat bones are covered with a periosteum, followed by a layer of compact bone tissue on both sides, then spongy bone in the center
diploë
The deep spongy bone in the middle of flat bones
