Bone tissue Flashcards

Study of the tissues of the body and how tissues are arranged into organs.

• Collected
• Fixed (formalin, paraformaldehyde, etc.)
• Sectioned
• Stained (H&E, methylene blue, etc.)
• Imaged (Brightfield, fluorescence)

Hematoxylin

basic stain that binds to acids

purple

ex. nucleus and RNA

Eosin

acidic stain that binds to basic

pink

ex. cytoplasm

skeletal bone are complex organs

primarily connective tissues

• Support and protection of more delicate organs
• Movement – attachment site for muscles
• Hematopoiesis – blood cell production in red bone marrow
• Storage of mineral and energy reserves

greater length than width

ex. femur

nearly equal length and width

ex. tarsal bones

thin surfaces

ex. frontal lobe

complex shapes

ex. vertebra

develop within tendons

elongated cylindrical shaft

• Knobby, enlarged regions at each end
• Strengthens joints
• Attachment site for tendons and ligamen

• Region between diaphysis and epiphysis
• Contains epiphyseal (growth) plat

• Thin layer of hyaline cartilage covering the epiphysis
• Reduces friction and absorbs shock in moveable join

• Hollow, cylindrical space in diaphysis
• In adults, it contains yellow bone marro

Two layers of compact bone, with spongy bone (diploe) sandwiched between

strong, flexible connective
tissue that protects your joints and bones
• Also supports soft tissues

• Solid and relatively dense
• External surfaces of long and flat bones

• Open lattice of narrow plates called trabeculae
• Internal surface of bones

the osteon - Haversian system -small

Carries vessels and nerves in center of osteo

Run perpendicular to and help connect
multiple central canals; Passageways for blood vessels and nerv

Housed in lacunae between lamellae

spaces within bone which contain osteocytes

Tiny, interconnecting channels that extend between
lacunae and allow osteocytes to connect and communica

Rings of bone around central cana

Abundant extracellular matrix:
• 15% water
• 30% collagen fibers*
• 55% crystallized mineral salts
◦ Calcium phosphate
◦ Calcium hydroxide
◦ Other:
• Calcium carbonate
• Magnesium
• Fluoride
• Potassium
• Sulfate

• Unspecialized bone stem cells from mesenchyme
• Only bone cells to undergo cellular division
• Inner portions of periosteum, endosteum and the
blood vessel canal

bone builders

• Mature bone cells
• Maintains metabolism

• HUGE cells which derived from up to 50 monocytes
• Within endosteum
• Release lysozymes and acids to resorb bone
• Bone Crushers
• Helps regulate serum (blood) calcium levels

blood cell production

blood vessels and adipocytes

• Develops from mesenchyme
• Produces flat bones of the skull, some facial bones, mandible, and central portion of clavicle

• Begins with hyaline cartilage model
• Produces majority of bones in the body

as interstitial growth (occurs at the
epiphyseal plate)

as appositional growth (occurs at the
periosteum)

Near the epiphysis; composed of small chondrocytes

Chondrocytes proliferate; align into stacks

Chondrocytes stop proliferating, but enlarge
(hypertrophy)

Minerals are deposited, which kills the chondrocytes

Matrix of bone is deposited on the remaining calcified
cartilage matrix

bone is constantly renewing and get stronger with exercise

Involves bone resorption via osteoclast and new bone formation via osteoblast

Supply the diaphysis of a long
bone; usually just one nutrient artery and vein per bone

Supply the diaphyseal side
of the epiphyseal plate

Supply the epiphyses

Supply blood to the external
circumferential lamellae and superficial osteons

• Growth hormone stimulates cartilage growth at epiphyseal
plate
• Thyroid hormone stimulates osteoblasts
• Calcitonin (↓)/parathyroid (↑) hormone impact blood
calcium

• Vitamin A activates osteoblasts
• Vitamin C required for collagen synthesis
• Vitamin D stimulates calcium absorption from GI tract into
blood so that calcium is available for bold building

• Mechanical stress stimulates increase in bone density by increased osteoblast activity
• Bones of athletes become thicker and stronger as the result of repetitive and stressful exercise
• Bones lose mass with age, but this can be slowed or reversed with weight-bearing exercise

pulling a bone off from the rest of the bones

wrist fracture

bone is crushed into many pieces

Broken ends of the bone protrude through the skin

bone is broken into 2 or more pieces

Fractured bone parts are out of anatomic alignment

Partial fracture; one side of bone breaks—the other side is bent

Fine crack in which sections of bone remain aligned

fracture is parallel to the long axis of the bon

fracture is at an angle

no break through skin

Thin fractures due to repeated, stressful impact such as running

• Manual realignment
• Casting/splinting
• Skin intact

• Realignment with surgery
• Screws, plates, rods, pins, wires
◦ Open reduction internal fixation
◦ Open reduction external fixation
General Fracture Repair
BMD 310 - Clinical Anatomy and Histology

• Blood vessels crossing fracture line break
• Blood clots resulting in a fracture hematoma
within 8 hrs after injury
• Nearby bone cell death
• Swelling, inflammation
• Last up to several week

Formation of a fibrocartilaginous callus and then a bony callus (spongey bo

• Dead portion of original bone resorbed by osteoclasts
• Compact bone will replace spongy bone surrounding the fracture site

10m in the US

calcium and bone mass is lost

middle aged and older, women

treatment: diet, exercise, medication