Skeletal System Flashcards
Skeletal System
Dynamic organ system with tissues that grow and change throughout life
Structures of Skeletal System
- Bones
- Cartilage
- Ligaments
- Other supportive connective tissues
Major functions of the Skeletal System
- Framework for the body
- Support body weight
- Attachment for muscles –> movement
- Storage reservoir: Ca2+, Phosphorus
Cartilage
Supporting connective tissue
Cartilage Tissue Characteristics
- Semirigid extracellular matrix (weaker than bone, but more flexible and resilient)
- Cells: chondroblasts, chondrocytes
- Mature cartilage is avascular (nutrient diffusion into tissue)
Chondroblasts
Secrete extracellular matrix (substances surrounding cells)
Chondrocytes
Mature cartilage cells found throughout cartilage, occupy small spaces called lacunae
Types of Cartilage
- Hyaline Cartilage
- Fibrocartilage
- Elastic Cartilage
Hyaline Cartilage
- Most common
- Glassy/shiny
- Found on articular cartilage
Fibrocartilage
- Strongest of the three
- Rigid, tough, does not move a lot
- Supports body weight
- Found in discs in between vertebras
Elastic Cartilage
- Most flexible/mobile
- Lowest in strength
- Found in ear
General Functions of Cartilage
- Supporting soft tissues
- Gliding surface at articulations (joints)
- Precursor model for bone growth
Interstitial Growth
Growth from within (inside) cartilage
Appositional Growth
Growth from outside (periphery) of tissue
Bone
Supporting connective tissue
Bone Tissue Characteristics
- Bones of the skeleton are complex organs containing all four tissue types
- Extracellular matrix is sturdy and rigid due to deposition of minerals (calcification)
General Functions of Bone
- Structural support/body framework
- Protection of more delicate organs
- Movement - attachment site for muscles
- Hemopoiesis - blood cell production in red bone marrow (Produce new RBC)
- Storage of mineral and energy reserves: calcium and phosphate, lipids stored in yellow marrow
What are the four Bone Classifications?
- Long Bones
- Short Bones
- Flat Bones
- Irregular Bones
Long Bones
Longer than they are wide, in appendages
Short Bones
Roughly equal in length and width (Ex. foot, hand, wrist)
Flat Bones
Very broad and thin, spread wide (Ex. Cranium)
Irregular Bones
Doesn’t fit other three characteristics (Ex. hip bone)
Diaphysis
Shaft of bone, circumference is smallest, is most of bone length
Epiphysis
Ends of bones
Metaphysis
Where growth plate is, in between diaphysis and epiphysis
What are the Regions of Long Bones?
Diaphysis, Epiphysis, Metaphysis
Articular Cartilage
To help protect bones
Medullary Cavity
Has yellow bone marrow, contains fat tissue
Spongy Bone
Contains red bone marrow –> Hemopoiesis (very porous, makes RBC)
Endosteum
Inner membrane/layer
Periosteum
Outside of bone, except where articular cartilage is
Bone is highly what?
Vascularized (has a lot of blood vessels)
Innervation
- Nerves accompany blood vessels through the nutrient foramen (hole in bone to travel to deep aspects)
- Innervate bone tissue, periosteum
- Primarily sensory nerves (send info from bone to brain)
