Bone Fractures
Briefly list the stages of bone healing after a fracture
1. fracture hematoma
2. soft callus
3. hard callus
4. remodeling
What defines bone as a tissue?
Connective tissue consisting of a matrix hardened by minerals, primarily of calcium phosphate
What effect do changes in phosphate levels have in the body?
little effect
Identify and describe the structural and functional types of joints
structural:
- bony
- fibrous
- cartilaginous
- synovial
functional:
- diarthrosis (freely movable)
- amphiarthrosis (slightly movable)
- synarthrosis (little or no movement)
Briefly describe synchondrosis
- hyaline cartilage joints connect to bones
How long do fractures take to heal?
- Typically 8-12 weeks and longer in elderly
What is found in a typical bone?
bone tissue, marrow, blood, cartilage, and periosteum
Why can changes in calcium be serious?
- hypocalcemia: deficiency of calcium in blood
- nervous system becomes excitatory
- symptoms: muscle spasms, tremors, laryngospasm, suffocation
- hypercalcemia: excess calcium in blood
- sodium channels are likely to stay closed
- symptoms: muscle weakness, sluggish reflexes, cardiac arrest
Describe synostosis joints
- gap between two ossified bones
- bony joints
- occurs in fibrous and cartilaginous joints
Describe symphysis joints
- fibrocartilage joins 2 bones
- slight movement possible
List the types of bone fractures
- open, displaced
- greenstick
- comminuted
- linear
- transverse, nondisplaced
- oblique, nondisplaced
- spiral
- colles
- pott
True or false: Bone continually remodels itself.
True
What does calcium phosphate depend on?
- calcitrol
- calcitonin
- PTH hormone regulation
Describe synarthrosis joints
- fibrous joints
- immovable joints
- lines appear serrated
Describe a synovial joint
- joint cavity forms stabilizes interaction between 2 bones
- most are freely movable
Describe the process of fracture healing
1. fracture hematoma: clot forms, then osteogenic cells from granulation tissue
2. soft callus: fibroblasts produce fibers and fibrocartilage
3. hard callus: osteoblasts produce a bony collar in 6 weeks
4. remodeling: in 3-4 months where spongy bone is replaced by compact bone
List the functions of the skeletal system
- support
- protection
- movement
- electrolyte balances
- acid-base balance
- blood formation
What is calcitriol (from Vitamin D) produced by?
- UV radiation and epidermal keratinocytes: conversion of steriod to cholecalciferol
- liver: conversion of cholecalciferol to calcidiol
- kidney: conversion of calcidiol to calcitriol (Vitamin D)
Describe gomphoses joint
- stabilized by fibrous joints made of collagen fibers
- minimal movement from chewing
- ball-and-socket joints
- pivot joint
- saddle joint
- hinge joint
- gliding joint
- condyloid joint
Briefly describe types of treatment for fractures
- closed reduction: align fragments for casting
- open reduction: use of screws and plates
- electrical stimulation: bone growth
- orthopedics: to prevent and correct injuries
Identify and describe general features that comprise bones.
- shaft (diaphysis): cylinder of compact bone
- enlargened ends (epiphyses): layer of compact bone covers spongy bone
- articular cartilage covers joint surface
- periosteum covers shaft: outer fibrous layer of collagen and osteoblasts forming inner osteogenic layer
- epiphyseal plate (growth plate)
Differentiate between the function of the calcitriol and calcitonin hormones in the body
- calcitriol: behaves as a hormone that increases concentration of calcium in blood
- calcitonin: reduces osteoclast activity by approx. 70% and increases osteoblast count and activity
Describe syndesmosis joints
- two bones supported by ligament through interosseous membrane
- greatest range of motion of the fibrous joint types
List what determines the range of motion in a joint
1. structure of articular surfaces
2. strength and tensile strength of ligaments, tendons, and capsule
3. action of muscles and tendons