Chapter 6 Bones and Skeletal Tissue Flashcards
What are the functions of the bones? Shelley Possibly Might Make a B or C
Support Protection Movement Mineral Storage Blood Cell Formation
Function-Support forms (Shelley)
the framework that supports the body and cradles the soft organs
Function-Protection (Possibly)
provides case for the brain, spinal cord and vital organs
Function-Movement (Might)
provides levers for muscles
Function-Mineral Storage is a (Make a)
reservoir for minerals, especially calcium and phosphorus
Function-Blood Cell Formation is where (B or C)
most blood cell formation happens
Hematopoiesis occurs within the
marrow cavities of the bones
Classification of Bones Axial skeleton includes bones of the
skull vertebral column rib cage
Axial skeleton bones
protect, support or carry other body parts
Classification of Bones Appendicular skeleton includes the bones of the
upper and lower limbs shoulder hip
Bones of the limbs help us
move from place to place and manipulate our environment
Bones are classified as shapes such as
long flat short irregular
Compact bones are
dense, and look smooth
Spongy (cancelleous) bones are
a honeycomb of small needle-like or flat pieces called trabeculae
what does trabeculae mean?
Little beams
Open spaces between trabeculea are
filled with marrow
Long bones are
longer than they are wide
Long bones have
a shaft and two ends
Long bones are primarily made up of
compact bones
Examples of long bones are
all the bones in the limbs except the patella, wrist and ankle bones
Long bones consists of a ______ and an _______.
Diaphysis and Epiphysis
Diaphysis is the tubular shaft that forms
the long axis of bone
Diaphysis is composed of
compact bone that surrounds the medullary cavity
Epiphysis is the expanded
ends of long bones
Epiphysis is composed of what 2 bones?
Compact (exterior) and spongy (interior)
The epiphysis line separates the
diaphysis from the epiphysis
Epiphysis joint surface is covered with
articular (hyaline) cartilage
Periosteum is the
white double-layered protective membrane around diaphysis
Periosteum outer fibrous layer is
dense irregular tissue
Periosteum inner osteogenic layer is
on the bone surface, primarily composed of osteoblasts and osteoclasts
Sharpey’s fibers are collagen fibers that
secure the periosteum to bone
Endosteum is the delicate membrane covering the
internal surface of the bone
Osteocytes are
mature bone cells
Osteocytes lie in
lacunae at junctions of lamellae
Canaliculi are hair-like canals that
nutrients and wastes pass through
Identify all components of microscopic structure of compact bone
Intramembranous ossification
bone develops from a fibrous membrane
Endochondral ossification
bone forms by replacing hyaline cartilage
Stages of Intramembranous Ossification (4)
- an ossification center appears in the fibrous connective tissue membrane
- bone matrix (osteoid) is secreted within the fibrous membrane
- woven bone and periossteum form
- bone collar of compact bone forms and red marrow appears
Stages of Eddochondral Ossification (5)
- formation of bone collar
- cavitation of the hyaline cartilage shaft
- invasion of internal cavities by the periosteal bud, and spongy bone formation
- formation of the medullary cavity; appearance of secondary ossification centers
- ossification of the epiphyses
Osteogenic zone is when
new bone formation occurs
Osteoclasts degrage the spongy bone, that results in medulalry cavity growing longer as bone grow, this happens in the
osterogenic zone
Hormonal control of blood calcium steps (4)
- rising blood calcium levels trigger the thyroid to release calcitonin
- calcitonin stimulates calcium salt deposit in bone
- falling blood calcium levels signal the parathyroid glands to release PTH
- PTH signals osteoclasts to degrade bone matrix and release calcium into the blood
Define Wolff’s Law
a bone grows or remodels in response to the forces or demands placed on it
Bone fractures are classified by: (4)
- the position of the bone ends after the fracture
- the completeness of the break
- the orientation of the bone to the long axis
- whether or not the bones ends penetrate the skin
compound bone fracture is when
the bone penetrates the skin
a simple bone fracture is when
the bone ends do not penetrate the skin
Common types of fractures:
comminuted
bone fragments into three or more pieces
comminuted fractures are common
in the elderly
Common types of fractures:
spiral
ragged break when bone is excessively twisted
spiral fractures are a common
sports injury
Common types of fractures:
greenstick
imcomplete fracture where one side of the bone breaks and the other side bends
greensticks fractures are common
in children
commuicated fracture
spiral fracture
greenstick fracture
4 stages in the healing of a bone fracture
- hematoma formation
- fibrocartilaginous callus formation
- bony callus formation
- bone remodeling
Bones become so fragile in osteoporosis, that _______ can cause fractures.
sneezing
Paget’s disease is characterized by
excessive bone formation and breakdown
