A&P Chapter 6
Hematopoiesis-
production of blood cells, which occurs in the red marrow of the bones
axial skeleton consists of
the skull, rib cage, and vertebral column
Long bones-
cylinder-shaped bones that is longer than it is wide; functions as a lever
How does parathyroid hormone affect blood calcium levels and bone density?
decreases bone density ; increases blood calcium
Endosteum-
delicate membranous lining of a bone's medullary cavity
Compact Bone-
dense osseous tissue that can withstand compressive forces
Osteoblast-
cell responsible for forming new bone-
Osteoclast-
cell responsible for reabsorbing bone
Perforating canal-
channel that branches off from the central canal and houses vessels and nerves that extend to the periosteum and endosteum
Canaliculi-
channels within the bone matrix that house one of an osteocyte's many cytoplasmic extensions that is uses to communicate and receive nutrients
Ossification center-
cluster of osteoblasts found in the early stages of intramembranous ossification
Osteogenic cell-
undifferentiated cell with high mitotic activity; the only bone cell that divide; they differentiate and develop into osteoblasts
Epiphyseal Plate-
(AKA growth plate) sheet of hyaline cartilage in the metaphysis of an immature bone; replaced by bone tissue as the organ grows in length
Bone-
(also known as osseous tissue) hard, dense connective tissue that forms the structural elements of the skeleton
Open (compound) Fracture
A fracture in which at least one end of the broken bone tears through the skin; carries a high risk of infection
Closed (simple) Fracture
A fracture in which the skin remains intact
Greenstick Fracture
A partial fracture in which only one side of the bone is broken
Spiral Fracture
Bone segments are pulled apart as a result of a twisting motion
How does calcitonin affect blood calcium levels and bone density?
DECREASES blood calcium levels INCREASES bone density
How does estrogen affect blood calcium levels and bone density?
DECREASES blood calcium levels INCREASES bone density
Aunt Flora fell and fractured her hip due to osteoporosis, what HORMONES should she take?
Estrogen and calcitonin
Growth Hormone
Increases length of long bones, enhances mineralization, and improves bone density
Calcitonin Hormone
Inhibits osteoclast activity and stimulates calcium uptake by bones
Articulation-
Markings where two bone surfaces meet
Vitamin D nutrient
Needed for calcium absorption
calcium nutrient
Needed to make calcium phosphate and calcium carbonate, which form the hydroxyapatite crystals that give bone its hardness
Oblique Fracture
Occurs at an angle that is not 90 degrees
Transverse Fracture
Occurs straight across the long axis of the bone
Impacted Fracture
One fragment is driven into the other, usually as a result of compression
What exactly do osteoclasts and osteoblasts do in your bone?
Osteoblasts- build bone / form new bone Osteoclasts- break down bone
Sex Hormones
Promote osteoblastic activity and production of bone matrix; responsible for adolescent growth spurt; promote conversion of epiphyseal plate to epiphyseal line
Omega- 3 fatty acids
Reduces inflammation that may interfere with osteoblast function
Comminuted Fracture
Several breaks result in many small pieces between two large segments
Calcitriol Hormone
Stimulates absorption of calcium and phosphate from digestive tract
Thyroxine Hormone
Stimulates bone growth and promotes synthesis of bone matrix
Parathyroid Hormone
Stimulates osteoclast proliferation and resorption of bone by osteoclasts; promotes reabsorption of calcium by kidney tubules; indirectly increases calcium absorption by small intestine
Fluoride nutrient
Structural component of bone
Magnesium nutrient
Structural component of bone
Vitamin K nutrient
Supports bone mineralization; may have synergistic effect with vitamin D
Depressed Skull Fracture
a break in the cranial bone, with depression of the bone in towards the brain
Osteon-
basic structural unit of compact bone; made of concentric layers of calcified matrix; also known as Haversian System
Fracture hematoma-
blood clot that forms at the site of a broken bone
Ossification-
bone formation (AKA osteogenesis)
Projection-
bone markings where part of the surface sticks out above the rest of the surface, where tendons and ligaments attach
Irregular bones-
bone of complex shape; protects internal organs from compressive forces
appendicular skeleton consists of
bones of the shoulder, pelvis, and upper and lower extremities
Fracture-
broken bone
Aunt Flora fell and fractured her hip due to osteoporosis, what MINERAL SUPPLEMENTS should she add to her diet?
calcium and phosphorus
short bone examples
carpals of the wrists and tarsals of the ankles
External callus-
collar of hyaline cartilage and bone that forms around the outside of a fracture
Epiphyseal line-
completely ossified remnant of the epiphyseal plate
Hypercalcemia-
condition characterized by abnormally high levels of calcium
Hypocalcemia-
condition characterized by abnormally low levels of calcium
Yellow Marrow-
connective tissue in the interior cavity of a bone where fat is stored
Red Marrow-
connective tissue in the interior cavity of a bone where hematopoiesis takes place
flat bone examples
cranial bones, shoulder blades, sternum, and the ribs
Short bones-
cube shaped bone that is approximately equal in length, width, and thickness; provides limited motion
Orthopedist-
doctor who specializes in diagnosing and treating musculoskeletal disorders and injuries
long bones in the legs
femur, tibia, and fibula
Internal callus-
fibrocartilaginous matrix, in the endosteal region, between the two ends of a broken bone
Periosteum-
fibrous membrane covering the outer surface of bone and continuous with ligaments
head example:
head of femur
Medullary Cavity-
hollow region of the diaphysis; filled with yellow marrow
long bones in the arm
humerus, ulna, and radius
effects on osteoclasts (calcitonin)
inhibits
effects on osteoclasts (estrogen)
inhibits
Articulation example:
knee joint
Diploë-
layer of spongy bone, that is sandwiched between two the layers of compact bone found in flat bones
Central canal-
longitudinal channel in the center of each osteon; contains blood vessels, nerves, and lymphatic vessels; also known as the Haversian Canal
Closed reduction-
manual manipulation of a broken bone to set it into its natural position without surgery
Perichondrium-
membrane that covers cartilage
long bones in the fingers
metacarpals and phalanges
long bones in the toes
metatarsals and phalanges
effects on osteoblasts (PTH)
no affect
Hole-
opening or depression in a bone
Skeletal System-
organ system composed of bones and cartilage that provides for movement, support, and protection
sesamoid bone examples
patella
Osteocyte-
primary cell in mature bone; responsible for maintaining the matrix
Intramembranous ossification-
process by which bone forms directly from mesenchymal tissue
Remodeling-
process by which osteoclasts resorb old or damaged bone at the same time as and on the same surface where osteoblasts form new bone to replace that which is absorbed
Endochondral ossification-
process in which bone forms by replacing hyaline cartilage
Modeling-
process, during bone growth, by which bone is resorbed on one surface of a bine and deposited on another
Secondary ossification center-
region of bone development in the epiphyses
Zone of calcified matrix-
region of the epiphyseal plate closest to the diaphyseal end; functions to connect the epiphyseal plate to the diaphysis
Reserve zone-
region of the epiphyseal plate that anchors that plate to the osseous tissue of the epiphysis
Proliferative zone-
region of the epiphyseal plate that makes new chondrocytes to replace those that die at the diaphyseal end of the plate and contributes to longitudinal growth of the epiphyseal plate
Zone of maturation and hypertrophy-
region of the epiphyseal plate where chondrocytes from the proliferative zone grow and mature and contribute to the longitudinal growth of the epiphyseal plate
Primary ossification center-
region, deep in the periosteal collar, where bone development starts during endochondral ossification
Lamellae (compact bone)
rings of bone matrix within an osteon
Cartilage-
semi-rigid connective tissue found on the skeleton in areas where flexibility and smooth surfaces support movement
Nutrient foramen-
small opening in the middle of the external surface of the diaphysis, through which an artery enters the bone to provide nourishment
Sesamoid bones-
small, round bone embedded in a tendon; protects the tendon from compressive forces
Lacuna-
spaces in a bone that house an osteocyte
Trabeculae-
spikes or sections of the lattice-like matrix in spongy bone
projection example:
spinous process of the vertebrae
effects on osteoblasts (calcitonin)
stimulates
effects on osteoblasts (estrogen)
stimulates
effects on osteoclasts (PTH)
stimulates
Open reduction-
surgical exposure of a bone to reset a fracture
Why are drugs such as Fosamax, Actonel, and Boniva effective at treating osteoporosis?
they prevent further breakdown of the bone
Flat bones-
thin and curved bones; serves a point of attachment for muscles and protects internal organs
Articular Cartilage-
thin layer of cartilage covering epiphysis; reduces friction and acts as a shock absorber
Spongy bone-
trabeculated osseous tissue that supports shifts in weight distribution
Diaphysis-
tubular shaft that runs between the proximal and distal ends of a long bone
Osteoid-
uncalcified bone matrix secreted by osteoblasts
irregular bones examples
vertebrae, facial bones
Epiphysis-
wide section at each end of a long bone; filled with spongy bones and red marrow