A&P Chapter 6-9

support, protection, assistance in movement,  mineral homeostasis, blood cell production, and triglyceride storage

calcium and phosphorus

Homeostatic contributions; provide support, protection, production of blood cells, storage of minerals and triglycerides

Bone (osseous tissue)cartilage dense connective tissues, epithelium, adipose tissue and nervous tissue make up 18% of weight of the human body

the construction of new bone tissue and the breaking down of old bone tissue

composed of bones and their cartilages ligaments and tendons

the study of bone structure and the treatment of bone disorders

skeletal structural framework supports soft tissues, provides attachment points for tendons of most skeletal muscles

skeletal function that protects most important internal organs from injury

skeletal muscles attach to bones; upon muscle contraction they pull on bones to produce movement

On demand, bone releases minerals in to the blood to maintain critical mineral balances (homeostasis) and distribute the minerals to other parts of the body

Bone tissue mineral storage calcium and phosphorus strengthen bones, stores 99% of the body's calcium

red bone marrow consist of developing blood cells adipocytes fibroblast, and macrophages within a network of reticular fibers

produces red blood cells, white blood cells and platelets in the process called hemopoiesis

developing fetus, adult bones, hip bones ribs, breastbone, vertebrae, skull, ends of  bones, of the arm, and thigh

potential chemical energy reserve, with increasing age much of the red bone marrow turns yellow, Vitamin A makes it yellow

consists mainly of adipose cells, which store triglycerides

longer than they are wide, act as levers and shock absorbers mostly compact bone with spongy bone at the ends.

thighs, legs, toes, upper arms, forearms, and fingers

diaphysis, epiphyses, metaphyses, articular cartilage, periosteum, medullary cavity, endosteum.

the bones shaft or body (long cylindrical, main portion of the bone) contains the medullary marrow cavity (in adults the MC contains the yellow bone marrow)

the proximal and distal ends of the bone

the regions between the diaphysis and the epiphyses contains the epiphyseal growth plate or epiphyseal line

a layers of hyaline cartilage that allows the diapysis of bone to grow in length; last part to turn into bone always actively to change cartilage into bone until hit puberty

when the bone ceases to grow in length (age 18-24) is the replacement of the epiphyseal plate into a boney structure

thin layer of hyaline cartilage that cover the part of the epiphysis where the bone forms an articulation joint with another bone reduces friction and absorbs shock at freely moveable joints

surround the external bone surface wherever it is not covered by articular cartilage protects the bone assists in fracture repair, helps nourish bone tissue, and serves as an attachment point for ligaments and tendons

Outer fibrous layer of dense irregular connective tissue; inner osteogenic layer consists of cells some cells enable bone growth in thicknes but not in length

thick bundles of collagen fibers that  extend from the periosteum into extracellular bone matrix provide attachment of the periosteum to the underlying bone

a hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow in adults

is a thin membrane that lines the internal bone surface facing the medullary cavity, contains a single layer of cells and a small amount of connective tissue

Contains an abundant extracellular matrix that surrounds widely separated cells

15% water 30 % collagen fibers and 55% crystallized mineral salts

osteogenic cells, osteoblasts, osteocytes and osteoclasts

unspecialized stem cells derived from mesehchyme found along the inner portion of the periosteum in the endosteum, and in the canals within the bone that contain blood vessels, the only bone cells that goes through cell division, give rise to all bone cells

the tissue from which almost all connective tissue are formed

producing

bone-building cells, synthesize and secrete collagen fibers and other organic components needed to build the extracellular matrix of bone tissue, initiates calcification, surrounds themselves within their own extracellular matrix become osteocytes

in the name of a bone cell or any other connective tissue cell means that the cell secretes extracellular matrix

mature bones cells the main cells in bone tissue and MAINTAIN its daily metabolism such as the exchange of nutrients and wastes with blood

in the name of a bone cell or any other tissue cell means that the cell maintains the tissue

Bone-destroying cells that contain lysomes and phagocytic vacuoles that demineralize bone tissue, help regulate blood calcium level. are target cell for drug therapy to treat osteoporosis

Part of normal development, maintenance, and repair  of bone

in a bone cell means that the cell breaks down extracellular matrices

Strongest form of one tissue. Provide protection and support and resists the stresses produced by weight and movement. Found beneath the periosteum of all bones and make up the bulk of the diaphyses of long bones

Allows blood vessels, lymphatic vessels, and nerves from the periosteum to penetrate compact bones

Run longitudinally through the bone

Around the central canals are rings of calcified extracellular matrix much like the rings of a tree trunk

Contain osteocytes. Small spaces between lamellae.

Small channels filled with extracellular fluid. Inside contains slender fingerlike processes of osteocytes. Connects lacunae with one another and with the central canals, provides routes for nutrients and oxygen to reach the osteocytes and for the removal of wastes

Compact Bone Tissue and Spongy Bone tissue

Osteons/ Haversian systems: Repeating structural unitis

(resembles a stack of logs) Consists of a central (haversian) canal, with arranged lamellae, lacunae, osteocytes, and canaliculi. they are aligned in the same direction along lines of stress which helps the long bone resist bending or fracture. Changes over time in response to the physical demands placed on the skeleton

Area between osteons. Fragments of older osteons that have been partially destroyed during bone rebuilding or growth

Rings of hard calcified matrix found just beneath the periosteum and in the medullary cavity

Does not contain osteons, Consists of lamellae trabeculae surrounding many red bone marrow-filled spaces.

Short, flat, and irregular bones and the interior of the epiphyses in long bones

Offer resistance along lines of stress, support and protect red bone marrow, and make bones lighter for easier movement

Accompanied by nerves enter the diaphysis through many perforating (Volkmann's) canals. Supply the periosteum and outer parts of the compact bone

Near the center of the diaphysis; Divides in the medullary cavity into proximal and distal branches. Supplies both the inner part of the compact bone tissue of the diaphysis and the spongy bone tissue and red marrow as far as the epiphyseal plats

An opening in the shaft of the bone allowing an artery to pass into the one

BOTH supply the ends of long bones, which arise from arteries that supply the associated joint

Enter the Epiphyses of long bone and supply the red bone marrow and bone tissue of the epiphyses

Long bones are supplied by periosteal, nutrient, metaphyseal, and epiphyseal arteries; veins accompany the arteries.

Nerves accompany blood vessels in bone; the periosteum is rich in sensory neurons. Some of which carry pain sensations.

Depends on its collagen fibers

Provided by collagen fibers and other organic molecules resistance to being stretched or torn apart

Bone formation develops by either ENDOCHRONDRAL ossification or INTRAMEMBRANOUS (dermal) ossificationbegins during the fourth week of prenatal development.

Bone development first through a cartilaginous stage. Begins in a primary center in the shaft of the cartilage model with hypertrophy of chondrocytes (cartilage cells) and calcification of the cartilage matrix. The cartilage model is then vascularized, osteogenic cells form a bony collar around the mode, and osteoblasts lay down bony matrix around the calcareous spicules. The formation of most bones

Forming directly as a bone. (Facial bones, most cranial bones, and the clavicle)

Ossification from primary centers occurs before birth; from secondary centers in the epiphyses, it occurs during the first 5 years.

both supply the red bone marrow and bone tissue of the metaphyses

enter the metaphyses of a long bone

depends on the crystallized in organic mineral salts

Provided by collagen fibers and other organic molecules. Resistance to being stretched or torn apart.  

ossification center – mesenchymal cells differentiate into        osteoblasts that secrete matrix that fuses into spongy bone; mesenchymal cells invade and form blood vessels; periosteum develops; layer of spongy bone inside periosteum becomes compact bone

mesenchymal cells differentiate into chondroblasts which lay down matris (= hyaline cartilage); a fibrous membrane(perichondrium) forms around this”model”;the cartilage model grows; at center of diaphysis, chondrocytes enlarge and secrete Ca salts to make matrix hard and thereby isolating themselves; they die; a nutrient artery penetrates perichondrium and invades matrix and branch off into capillaries; fibroblasts follow into ossification center and differentiate into osteoblasts which lay down matrix, forming spongy bone; osteoclasts form medullary cavity which fills with red bone marrow; area inside periosteum (formerly called perichondrium) becomes a bony collar which forms lamellae of compact bone; each epiphysis has its own ossification ctr which repeats this process after birth

appositional and longitudinal from the epiphyseal plate (the place where the diaphysis and epiphysis meet); this plate calcifies at end of puberty and becomes the epiphyseal line and longitudinal growth stops

Effect: stimulates liver to secrete somatomedin and causes cartilage to proliferate at epiphyseal plate (bone elongation)Mechanism: Increase osteoblast activity

Effect: stimulate bone growth Mechanism: increase osteoblast activity

Effect: promotes Ca+ deposition Mechanism: decrease osteoclast activity and decreases blood calcium levels

Effect: increases Ca levels by encouraging bone resorption by osteoclasts Mechanism: increase osteoclast activity and increases blood calcium levels

Effect: promotes epiphyseal plate growth and closure Mechanism: increase osteoblast activity

Effect: increases bone loss; in children can impair bone growth Mechanism: increases osteoclast activity

inhibits osteoprogenitor cells from differentiating into osteoblasts when there are chronically high levels of serotonin

Fracture hematoma, fibro cartilaginous callus, bony callus, bone remodeling

• §  Once you stabilize the area you will have a clot called a hematoma it stabilizes and activates the osteoblast and clasts
• §  Phagocytes remove cellular debris and fibroblasts deposit collagen to form a fibro cartilaginous callus
• §  Which is followed by osteoblasts forming a bony callus of spongy bone
• §  Final sstep spongy bone is replaced by compact bone
• §  Bone heals more rapidly than cartilage because its bloods supply is more plentiful

• o   Partial complete is all the way through the bone
• o   Closed simple
• o   Open punctures through the skin

• o   Bone resorption by osteoclasts outpaces bone deposition by osteoblasts
• o   Since female bones are generally smaller and less massive than males to begin with old age has a greater adverse effect in females
• o   There are two principals effects of aging on bone tissue
• §  Loss of bone mass
• ·         Loss of calcium from bones is one of the symptoms in osteoporosis 
•   Brittleness 
• - Collagen fibers have decreased
• -Bone can also become cancerous and is a fast growing, osteosarcoma

the loss of calcium and other minerals from bone extracellular matrix.