Chapter 8 Bone and Bone Tissue A+P Lap 4

skeletal system

consists of both fused and individual bones which are supported and supplemented by associate connective tissue

cartilage, tendons, and ligaments

what are some examples of parts of the skeletal system?

20%, 270, 206

The skeletal system accounts for about...% of our body weight. At birth, humans have....bones but fully grown adults have....bones.

provides support and a structural framework of the body

protection for more delicate tissue

provides mineral storage: calcium and phosphorus

blood cell production

movement of the body

electrolyte balance and acid/base balance

what are some functions of bones?

the thoracic cage protects the heart and lungs

what is one way the skeletal system protects delicate tissue?

calcium, phosphorus, yellow bone marrow, adipose (fat) tissue, triglycerides (energy)

what are some examples of minerals that the skeletal system provides storage to?

red bone marrow

what is part of blood cell production?

What are some components of long bones?

Femur, humerus, tibia, radius, metacarpals, metatarsals, phalanges, and diaphysis (shaft), both proximal and distal epiphyses, and medullary cavity lined with endosteum containing either red or yellow (fatty) bone marrow

diaphysis

part of the long bone, the long central shaft of the bone

metaphysis

area between the diaphysis and epiphysis and contains either the epiphyseal plate OR the epiphyseal line (the site of length-wise growth of long bones)

articular cartilage

special type of hyaline cartilage that covers the ends of epiphyses. This provides a smooth surface which forms a movable articulation

medullary cavity

this is also called the marrow cavity. where red and yellow bone marrow is stored

endosteum

the inner lining of the medullary cavity of long bone

periosteum

the otuer covering around bone

Sharpey's fibers

connective tissue consisting of bundles of strong collagen fibers connecting the periosteum to a bone

N/A

Look over the long bone diagram

flat bones

thin, flat often curved bones protect organs. they provide a larger surface area for the attachment of muscles

skull, ribs, breastbone, shoulder blades

what are some examples of flat bones?

short bones

about as broad as they are long, these tend to be shaped like cubes

carpal bones of the wrist and the tarsal bones of the ankle

what are some examples of short bones?

irregular bones

often clustered in groups, these bones come in various sizes and shapes

the vertebrae and facial bones

what are some examples of irregular bones?

sesamoid bones

small bones embedded in tendons

knee cap

what is an example of a sesamoid bone?

osseous tissue

another word for bone tissue

cells, fibers, and extracellular material, or matrix

if bone tissue is like all connective tissue, then it should consist of...

osteoblasts, osteoclasts, and osteocytes

what are some types of bone cells?

osteoblasts

help form bone by secreting substance that comprise the bone's matrix

osteoclasts

dissolve unwanted or unhealthy bone

osteocytes

mature osteoblasts that have become entrapped in the hardened bone matrix. osteocytes sense mechanical stressors on bone as well as chemical changes. They then signal osteoblasts and osteoclasts to begin the bone remodelling or repair process. Besides playing this key role in bone repair, osteocytes also contribute to the maintenance of bone density, while assiting with regulation of blood vessels of calcium and phosphate

consists of collagen fibers and crystalline salts

(primarily calcium and phosphate), the matrix of the bone is hard and calcified

What is consisted of the bone's matrix?

also incredibly strong, has a strenght rivaling that of steel and reinforced concrete

bone is also....

tensile strength

collagen fibers in the matrix make bone highly resistant to stretching forces

compressional strength

calcium salts allow bones to resist strong squeezing forces

torsional strength

bone lacks the ability to endure twisting. Most bone fractures result when....forces are exerted on an arm or leg.

heredity, nutrition, hormones, and execise

a number of factors affect bone growth and maintenance including:

spongy/cancellous bone

some osseous tissue is light and porous....this is found in the ends of long bones and in the middle of most other bones, it is always surrounded by the more durable compact bone

compact bone

another osseous tissue, it is dense and solid. Its density offers strength, which is why it forms the shafts of long bones and outer surfaces of other bones

trabeculae

spongy, or cancellous bone consists of a latticework of bone called.....This design adds strength w/o adding weight. The cavities between the trabeculae are filled w/ red bone marrow. The red marrow supplies spongy bone with blood and also produces red blood cells.

matrix in the trabeculae

are arranged along the lines of greatest stress in a way that offers maximum strength. If the stress a bone is exported to changes, the trabecular will realign themselves to compensate

matrix in the compact bone also called the osteon

layers or matrix are arranged in concentric, onion-like rings, around a central canal. This is also called....

lamellae

layers of matrix are arranged in concentric, onion-like rings

haversian or osteonic canal

central canal that is surrounded around lamellae

compact bone

consists of an elaborate network of canals and passageways containing nerves and blood vessels.

allows bone injuries to heal quickly despite the hardiness of the bone's matrix

the fact that bone cells are so well supplied w/ oxygen and nutrients...

N/A

Go over the diagrams of long bone and compact bone in journal

bone marrow

a type of soft tissue that fills the medullary cavity of long bones as well as the spaces of spongy bone

red bone marrow

charge with producing red blood cells, nearly all of a child's bones contain red bone marrow

yellow bone marrow

overtime, red marrow is gradually replaced w/ fatty yellow marrow. because its marrow cells are saturated with fat, yellow marrow no longer produces blood cells. However, incases of severe, chronic blood loos or anemia, yellow marrow can change back into red marrow

ribs, sternum, vertebrae, skull, pelvis, and the upper parts of both the humerus (arm) and femur (thigh). All other bones contain yellow marrow

in an adult, red bone marrow can be found ONLY...

intramembraneous ossificiation

ossification of fibrous connective tissue (usually in the skull and face)

endochondral ossification

ossification of cartilage (long bones)

ossification

the process by which bone tissue is formed

First stage of endochondral ossification

early in the life of a fetus, long bones composed of cartilage. They serve as models for bone development.

2nd stage of endochondral ossification

osteoblasts start to replace the chondrocytes (cartilage cells). The osteoblasts coat the diaphysis in a thin layer of bone, after which they produce a ring of bone that encircles the diaphysis, soon, the cartilage begins to calcify.

stage 3 of the endochondral ossification

blood vessels then penetrate the cartilage, and a primary ossification center develops in the middle of the diaphysis

stage 4 of the endochondral ossification

the bone marrow cavity fills with blood and stem cells. ossification continues - proceeding from the diaphysis toward each epiphysis and the bone grows in length. Eventually, secondary ossification centers appear in the epiphyses.

bone growth

bone lengthening and bone widening are part of ....?

bone lengthening

occurs at the epiphyseal plate for a fixed period

bone widening

continues throughout the lifespan

simple

a fracture where one in which the bone remains aligned and the surrounding tissue is intact.

compound

one in which the bone pierces the skin. Damage to surrounding tissue, nerves, and blood vessels may be extensive. Because the bone breaks through the skin, there is an increased risk for infection

greenstick

one in which the fracture is incomplete, similar to when a green stick breaks. This type of fracture typically occurs in young children, mainly because their bones are softer and more flexible than adult bones, causing the bone to splinter rather than break completely

commminuted

the bone breaks into pieces. Because considerable force is required to fragment bone, these fractures tend to occur after high-impact trauma, such as a car accident

spiral

the fracture line spirals around the bone, the result of a twisting force. The jagged bone ends often make this type of fracture difficult to reposition.

first step in fracture repair

initial hematoma (blood) transforms into granulation tissue

second step in fracture repair

granulation tissue transforms into a soft callus

third step in fracture repair

a hard callus forms around the tissue

fourth step in fracture repair

remodelling replaces the callus tissue with bone