Ligaments
Cartilage
Bones
Fibrous
Joints
Cartilaginous
Tendons
Marrow
Synovial
The Skeletal System
consists of inflexible layers of dense connective tissue, holds the bones tightly together
Semisolid CT; Nasal Septum, Growth Plates, Developing Bone, Costal Cartilage, Articular Cartilage (Joints)
allow only slight movement and consist of bones connected entirely by cartilage
Dense CT, Attach Bones to Muscles
3 Types: Fibrous, Cartilaginous, Synovial
Loose CT, 2 Types: Red and Yellow
freely movable joints
Bones, Cartilage, Marrow, Ligaments, Tendons, & Joints
Dense CT, Attach Bone to Bone
Solid CT, 206
Functions of Bone
Site of Hematopoiesis
Movement
Protection
Framework
Storage
Provide the structure for the body; contains hard, mineralized extracellular matrix that's strong against gravity
Attachment points for muscles, act as lever to facilitate movement
Framework, Protection, Movement, Site of Hematopoiesis, Storage,
guards our many delicate tissues and structures (cranial bones-brain, vertebra-spinal cord, rib cage-heart and lungs, pelvis-lower organs)
stores calcium and phosphorus in the extracellular matrix stores energy in the form of fat in yellow bone marrow
blood cell production takes place in the red bone marrow
Short Bones
Irregular Bones
Classification of Bone
Long Bones
Flat Bones
Complex; Vertebrae, Coxa, Other Bones of the Skull
Square; Carpals, Tarsals, Patella
Long Bones, Short Bones, Flat Bones, & Irregular Bones
Thins, Curved; Roof of Skull, Scapulae, Sternum, Ribs
Elongated; upper and lower limbs
Periosteum
Articular Cartilage
Epiphyseal Line
Macroanatomy of Bones
Diaphysis
Medullary Cavity
Epiphysis
hollow space in the diaphysis – filled with yellow bone marrow (adipose ct) in adults (red in children)
hyaline – covers the joint surface of the epiphysis – reduces friction and absorbs shock
expanded knobby region on either end – the joint/articular ends
long shaft – major weight support and leverage for muscles
Epiphysis, Diaphysis, Articular Cartilage, Epiphyseal Line (Growth Plate), Medullary Cavity, & Periosteum
remnant of the growth plate that fuses in adults
tough sheath that covers the outer surface=dense irregular ct – protects from surrounding structures and serves as an anchor for ligaments and tendons
Osteoblasts
Microanatomy of Bones
Compact Bone
Osteocytes
Organic ECM
Extracellular Matrix
Inorganic ECM
Cells
Osteogenic Cells
Osteoclasts
Spongy Bone
2 components: Organic & Inorganic
(“osteoid”) = collagen fibers; imparts elastic and bendability to bones
(mineral) = calcium phosphate; imparts rigidity and stiffness to bones
break down/resorb bone
(dense or cortical) = RESISTS bending – arranged in layers (lamellae) – OUTER layer (80% of bone)
(calcaneus/trabecular) = ABSORBS stress - porous, filled with bone marrow – INNER layer (20% of bone)
Cells, Extracellular Matrix, Spongy, & Compact
bone stem cells capable of differentiation
Osteogenic Cells, Osteoblasts, Osteocytes, Osteoclasts
mature bone cells, “stuck” in lacunae
build bone & secrete ECM, arranged in lines
Cartilaginous Joints
Sutures
Types of Cartilaginous Joints
Examples of Synovial Joints
Types of Fibrous Joints
Symphyses
Fibrous Joints
Syndesmoses
Gomphoses
Synovial Joints
Synchondroses
Joint (Articulation)
lock bones together with dense fibers
fibrocartilage pads between bones – resists compression and tension, absorbs shock
Fibrous, Cartilaginous, Synovial
Shoulder, Hip, Elbow, Knee, Fingers and toes, Jaw, Neck
bones connected by cartilage pads
Gomphoses, Sutures, Syndesmoses
allows the brain/skull to grow but have interlocking irregular edges to increase the strength
have hyaline cartilage between the bones
between radius and ulna, tibia and fibula – shafts of the long bones are bound by “interosseous membrane” so they can slightly pivot around each other
bones separated by a space filled with fluid Highly mobile Held together by ligaments and a CT capsule
tooth to jaw = “peg in socket” (also between temporal bone and styloid process)
Synchondroses & Symphyses
