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