Chapter 6: Bone Tissue

Canaculi

osteocytes communicate with each other through the smaller veins called caniculis

osteoblasts are responsible for producing

osteogenesis and osteoids

compact bone consists of:

osteon, central canal, lamellae, lacunae, osteocytes, and canaliculi

Bone provides support for?

our body

Periosteum

outer lining of bone - found everywhere, except where bones are going to articulate with each other

sutura=

seam

osteon

basic functional unit of bone

Lamalle

concentric circles

What are the three processes that form joints?

condyle, facet, and head

meta=

between

Collagen fibers make up

1/3 of the bone matrix

Calcium phosphate makes up

2/3 of the bone mass (most abundant), eventually converts to hydroxyapatite crystals

Pneumatized bones

Ethmoid bone - hollow and contain numerous air pockets

what type of ossification is involved in mandible, hip, limb, and clavicle development?

Intramembraneous- mandible and limb Endochondral- hip and clavicle

epi=

above

peri=

around

osteo=

bone

osteogenesis

bone formation (process of making new bone)

Appendicular skeleton consists of?

bones of upper and lower limbs

clasts=

break

Sutural bones (wormian bones)

can be found between sutures of your cranial bone ad in bottom of foot

cytes=

cells

Bone functions as leverage so they can

change direction and force in which a movement occurs

central canal

contains blood vessels and nerves

Bone provides storage of minerals, which

contribute to bone strength

Lacunae

depressions in between concentric lamellae, where you find osteocytes (dark brown)

Epiphysis

ends of long bones (2 one on each side)

In an adult, the epiphysis is separated from the diaphysis by the:

epiphyseal line

Trabeculae

forms branching plates

Long bones

found in upper and lower limbs (humerus, femur, tibia, fibula, radius, ulna, and clavicle) - has diaphysis, 2 metaphyses, 2 epiphysis, and a medullary (marrow) cavity

Blood cell production in skeletal system

has connective tissue termed bone marrow, which is where White and Red blood cells, and platelets are produced

Short bones

has short box-like appearance (carpal and tarsal bones)

osteoclasts (breakdown bone)

huge cell derived from fusion of monocytes (WBC), concentrated in endosteum. - help regulate blood calcium level

where is osteoprogenitor cells found?

inner layer of the periosteum and endosperm (so it surrounds inside and outside of bone)

Endosteum

inner lining of bone and is a thin membrane that lines the medullary cavity

Bone protects?

internal organs (ex. cranial bones protect skull, ribs protect heart and lungs)

spongy bone creates

lightweight nature of bones but doesn't mean its weak

Compact bone (dense bone)

located in outer part of bone

Spongy bone (trabecular or cancellous bone)

located on the inside and surrounds medullary cavity

What are the 7 different types of bones?

long, short, flat, irregular, sesamoid, sutural, and pneumatized,

medulla=

marrow

osteocytes

mature bone cells and maintains bone tissue - maintain daily metabolism, such as the exchange of nutrients and wastes with the blood

Calcium in bone

most abundant mineral in body, reserves that maintains normal concentrations (99% of storage in bone)

Metaphysis

narrow growth zone between the epiphysis and the diaphysis

fissure

narrow slit between adjacent parts of bones through which blood vessels or nerves pass (ex. superior orbital fissue of the sphenoid bone)

Osteoprogenitor cells

only one that undergoes cell division, which develops into an osteoblast. Are considered bone stem cells - heavily involved in the repair of bone in case you have a break

when calcium levels in the blood fall below homeostasis, which bone cells act to raise calcium levels and through what mechanism?

osteoclast; resorption

what hormone is responsible for promoting osteoclast activity?

parathyroid hormone

Sesamoid bones

patella (knecap) - small, round, and flat (think sesame seed)

Tuberosity

projection that has a rough, bumpy surface (ex. Ischial tuberosity of the hip bone)

Crest

prominent ridge or elongated projection (ex. iliac crest of the hip bone)

Epiphysis consists of:

red marrow

what is the correct order in which bone reformation occurs?

resorption, reversal, matrix deposition, mineralization, resting bone

Epicondyle

roughened projection above a condyle (medial epicondyle of the humerus)

foramen

round passageway where blood vessels and nerves go through (ex. foramen magnum)

Diaphysis (shaft)

shaft of the long bones, middle

fossa (=trench)

shallow depression (ex. coronoid fossa of the humerus)

Axial skeleton consists of?

skull, vertebral column, sternum, and ribs

facet

small, flat, slightly concave articular surface (ex. superior articular facet of a vertebra)

Condyle

smooth, rounded articular process at the end of a bone (ex. lateral condyle of the femur)

Flat bones

sternum, ribs, scapula, cranial bones (parietal, occipital, and frontal)

Osteoblasts (bone building)

synthesize and secrete collagen fibers and other organic components needed to build extracellular matrix

Articular cartilage

thin layer of hyaline cartilage covering the part of the epiphysis where the bone forms an articulation (joint) with another bone (on proximal and distal part)

Irregular bones

usually have lots of projections (some facial bones, temporal bone, vertebra, coxal bone, calcaneus (heel bone), and sphenoid bone)

Head

usually rounded articular projection supported on the neck of a bone (ex. head of the femur)

Tubercle

variable sized rounded projection (ex. greater tubercle of the humerus)

The medullary cavity of the diaphysis consists of

yellow marrow, which have adipocytes present (in adults)