skeletal system A Flashcards
What are the main components of the skeletal system?
Bones, Joints, Cartilages, Ligaments
How is the skeletal system divided into two main divisions?
Axial skeleton and Appendicular skeleton
Name the functions of bones in the human body.
Support of the body, Protection of soft organs, Movement due to attached skeletal muscles, Storage of minerals and fats, Blood cell formation
How many bones does the adult human skeleton typically have?
206 bones
What are the two basic types of bone tissue?
Compact bone and Spongy bone
What is the primary difference between compact bone and spongy bone?
Compact bone is dense and homogeneous, while spongy bone consists of small needle-like pieces with many open spaces.
Give an example of a long bone.
Femur (thigh bone) or Humerus (upper arm bone)
Which bones are generally cube-shaped and contain mostly spongy bone?
Short bones (e.g., carpals and tarsals)
What type of bones are thin, flattened, and usually curved with layers of compact and spongy bone?
Flat bones (e.g., skull, ribs, sternum)
Provide an example of an irregular bone.
Vertebrae and hip bones
What is the diaphysis of a long bone?
The shaft of the bone, composed of compact bone.
What part of the bone covers the external surface of the epiphyses and decreases friction at joint surfaces?
Articular cartilage
What is the medullary cavity, and what does it contain in adults?
The medullary cavity is the cavity of the bone shaft, containing yellow marrow (mostly fat) in adults
Which type of bone marking represents surface features of bones and provides sites of attachment for muscles, tendons, and ligaments?
Projections and processes
What is an osteon (Haversian System)?
A unit of bone consisting of concentric rings of lamellae, lacunae, canaliculi, and a central (Haversian) canal.
What is the central (Haversian) canal responsible for?
Carrying blood vessels and nerves within an osteon
Which type of canal is perpendicular to the central canal and also carries blood vessels and nerves?
Perforating (Volkman’s) canal
What is the function of lacunae in bone tissue?
Lacunae are cavities containing bone cells (osteocytes).
What are canaliculi, and what is their role in bone tissue?
Canaliculi are tiny canals that radiate from the central canal to lacunae and form a transport system for nutrients and waste products.
What happens to the cartilage in epiphyseal plates during bone growth?
New cartilage is continuously formed, while older cartilage becomes ossified (turns into bone)
How does the skeleton change during embryonic development?
In embryos, the skeleton is primarily hyaline cartilage, which is gradually replaced by bone tissue.
What allows for the growth of long bones during childhood?
Epiphyseal plates
What are osteocytes, and what is their role in bone tissue?
Osteocytes are mature bone cells that help maintain bone tissue.
Which type of bone cells are responsible for bone formation?
Osteoblasts
