Skeletal System 1 Flashcards
Number of bones in human body?
206 bones
Two divisions of skeletal bones?
Axial & appendicular skeleton
Number of Axial skeletal bones?
80 bones across the brain, spine, ribs, vertebra, thorax
Number of bones in appendicular skeletal system?
126 - arms, legs, limbs and parts of pelvis
Five functions of the skeletal system?
Support, protection, movement, storage of minerals & fat and blood cell production
What are the four classifications of bone?
short, long, flat, irregular & sesamoid
Short bones description & example?
Cube shaped, spongy bone with thin layer of compact bone - carpals (wrist)
Long bones description & example?
Longer in length than width, curved at ends - humerus
Flat bones description & example?
Thin bilayer of compact bone tissue filled with spongy - sternum
Irregular bones description & example?
Complex shaped, vary in sponge and compact tissue - vertebrae
Sigmoid bones description & example?
Special bones developed in places of abrasion or tension such as palms and knees - patella
What is the Diaphysis?
Bone’s main body
What is the Metaphysis?
Between the epiphysis and diaphysis and contains cartilage growth plates
What is the Epiphysis?
Distal ends of long bones
What is the Periosteum?
Outer layer of bone bilayer of tough connective tissue which covers, and protects the bone
What is the Medulla Cavity?
Hollow cavity within the diaphysis which house yellow marrow and blood vessels
What is the Endosteum?
Inner layer of bone thin membrane lining medullary cavity
What is Articular Cartilage?
Hyaline cartilage covering Epiphysis to reduce friction and abrasion to connecting joints
What is compact bone?
Forms body of the bone, and outer covering of epiphysis
What is spongy bone?
Found inside the epiphysis
What is osseous tissue made of?
15% water, 30% collagen and 55% crystallized mineral salts
How much of bone is compact and spongy?
80% compact & 20% spongy
What is the structural unit of compact bone?
Osteons
What is the osteon?
A group of hollow tubes (lamellae) of bone matrix arranged like the growth rings of a tree trunk.
What is the central canal & location?
Containing blood vessels which are surrounded by tree-rings of extracellular bone matrix hollow tubes called lamellae in compact bone
What are between the lamellae?
Small gaps called lacuna which house osteocytes
What does the central canal contain?
Nerves fibers & a network of blood vessels
What surrounds the central canal?
Lamellae embedded with collagen fibers that each run-in directions according to the greatest force and provide resistance to twisting force and tensile strength.
What basic structure do spongy bone exhibit?
Honeycomb structure of flat bones called trabeculae & between them red bone marrow
What are the four bone cell types?
Osteoproginator cells, osteoblasts, osteocytes, & osteoclasts
What are Osteoproginator cells?
Only bone cells that divide and form osteoblasts
What are Osteoblasts?
Young bone cells that build bones and surround themselves in bone extracellular matrix and get stuck in their secretions to form osteocytes
What are osteocytes?
Mature bone cells found in lacuna surrounded by matrix and maintain bone tissue nourishment and waste exchange
What are osteoclasts?
Formed from WBC monocytes & destroy bone matrix
What two materials do bones consist of?
Inorganic & organic materials
What is & functions of inorganic material?
Minerals that provide bones with hardness
What is & functions of organic material?
Carbs, proteins, & provide bones with flexibility and strength
Bone composition of youth?
Higher organic = flexibility
