Anatomy of Joints
List the components of joints
- articular capsule
- synovial fluid
- joint cavity
- articular cartilage
- articular discs and menisci
- tendon
- ligament
Define bursa
bursa: a saclike extension of joint capsule
- growth of osteon: out to in
Identify the structural and functional unit of spongy bone
trabeculae: appears like a sponge
Identify how organic and inorganic mater in osseous tissue provides strength and resilience
- Minerals resist compression; collagen resists tension
- Bone adapts by varying proportions
Describe the articular capsule
- continuous with periosteum
- lined by synovial membrane
Why are bursa close to joints?
to allow joints for smoother movement
List components of compact bone
- canaliculi
- osteon
- central canal
- lamellae
- osteocyte
- blood vessels
- nerves
Describe the locations of spongy bone
- along the bone's lines of stress
- at the epiphysis, the site of red bone marrow production
Define mineralization and describe how bones undergo mineral deposition
- mineralization is a crystallization process
- osteoblasts produce collagen fibers
- minerals (calcium and phosphate) cover fibers and ossify matrix
Identify the layers of synovial membrane
- subintoma: loose areolar/fatty/fibrous
- intima: cells (fibroblasts and macrophages) thinner than paper on pliable membrane
cylinders of connective tissue lined with synovial membrane and wrapped around a tendon
Describe the microscopic composition of compact bone
- osteon: basic structural and functional unit of compact bone
- cylinders formed from layers (lamellae) of matrix around the central canal (osteonic canal)
- collegen fibers alternate between right-and left- handed helices from lamella to lamella
Describe the function of spongy bone
- provides strength with little weight
- effectively disperses forces
Describe how bones elongate
- Gaps fill with bone marrow cells
- Hip can withstand more pressure than the knee
Describe the articular discs and menisci
- jaw, wrist, sternoclavicular and knee joints
- absorbs shock, guides movement, distributes forces
Differentiate bursae from menisci
bursa: thin, fluid-filled membrane; eliminates friction where a ligament would rub against bone
meniscus: made of fibrocartilage; partially covers joint and provides structural support
Describe canaliculi
Tiny cell processes that connect osteocytes to each other and their blood supply
Define contusion
internal bleeding (bruise) primarily within spongy bone
Why do facial features develop earlier than most bones?
- To establish highly integrated functional structures, including:
- sensory organs
- brain protection
Differentiate tendon from ligament
tendon: muscle to bone
ligament: bone to bone
Describe the function of bursae around tendons
- connective tissue with a synovial membrane lining around each individual tendon
- allow for extension of joint capsule
- cover tendons
Describe perforating canals/Volkmann canals
vascular canals that perpendicularly join central canals
Describe the organization of spongy bone in long bones
- compact bone travels along the edge of long bones
- cone expands to house yellow marrow toward the center/shaft/diaphysis of bone
- cone narrows to house red marrow toward the epiphysis/end of bone
Discuss the composition of inorganic matter and organic matter
- bone matrix of osseous tissue: 1/3 organic matter and 2/3 inorganic matter
- organic matter: collagen, glycosaminoglycans, proteoglycans, and glycoproteins
- inorganic matter: 85% hydroxyapatite, 10% calcium carbonate, minerals (fluoride, potassium, magnesium)