U2 L2 Flashcards
What is the adult human skeleton made up of?
206 bones
This accounts for about 14 percent of total body weight.
How many bones do humans start with at birth?
About 300 bones
Several bones fuse together as growth occurs.
What are bones primarily composed of?
Calcium
Bone tissue also includes living cells, fat cells, and blood vessels.
What is a major concern for older individuals related to bones?
Osteoporosis
Caused by a diet low in calcium leading to brittle bones.
What are the main functions of the skeletal system?
Structural support, protection, growth centre for cells, reservoir of minerals, movement
Each function plays a vital role in maintaining body integrity.
What does the skeletal system provide for soft tissue?
Structural support
What does the skeletal system protect?
Vital organs
Where are red blood cells and platelets made?
In bones
What does the skeletal system act as a reservoir for?
Minerals such as calcium and phosphorus
How do muscles facilitate movement in relation to bones?
Muscles attach to bones by tendons, and contract to move bones
What are the two basic types of bone tissue?
Compact (Cortical) Bone and Spongy (Cancellous/Trabecular) Bone
Compact bone resists bending; spongy bone has a sponge-like appearance and contains bone marrow.
What are the two main parts of the human skeletal system?
Axial skeleton and appendicular skeleton
How many bones are in the axial skeleton?
80 bones
What structures comprise the axial skeleton?
Vertebral column, skull, rib cage
How many bones are in the appendicular skeleton?
126 bones
What does the appendicular skeleton consist of?
Movable limbs and their supporting structures (girdles)
List the six major regions of the appendicular skeleton.
- Pectoral girdle
- Arms & forearms
- Hands
- Pelvis
- Thighs & legs
- Feet & ankles
What are long bones commonly found in?
Arms and legs
Example: femur.
Where are short bones most commonly found?
Wrists
Example: carpal bone.
What are flat bones and where can they be found?
Flat and thin; found in the roof of the skull
What are irregular bones?
Bones of different shapes and sizes
Example: sphenoid bone or vertebrae.
What are sesamoid bones?
Unusual, small, flat bones wrapped within tendons
Example: patella.
What is the diaphysis of a long bone?
The shaft of the bone
What is the epiphysis of a long bone?
The very ends of the long bone
