The Functions of the Skeletal System & Microscopic Anatomy of the Bone

PLTW- Human Body Systems

bone marrow

the softer connective tissue that fills the interior of most bone

yellow marrow

contains adipose tissue that can serve as a source of energy

hematopoiesis

formation of blood cells, takes place in red Bone marrow to produce your bodies RBC, WBC, and blood platelets

flat bone

thin, flattened, and curved; they provide protection for organs and serve as places for muscle attachment (skull bones, ribs, sternum)

long bone

longer than they are wide, found in limbs; they help facilitate movement (femur, tibia, fibula, humerus)

short bone

are equal in length, width, and thickness; cube-like shape (carpals, tarsals)

irregular bone

complex shapes; different shapes and functions (vertebrae, sacrum, skull bones)

sesamoid bone

small, round bones embedded within tendons; they help protect tendons from stress and improve leverage (patella)

diaphysis

the tubular shaft that runs between the proximal and distal ends of the bone

epiphysis

the wider section at each end of the bone, filled with spongy bone

red marrow

fills the spaces in the spongy bone

medullary cavity

the hollow region in the diaphysis, filled with yellow marrow

epiphyseal line

bone stops growing, and turns into this from epiphyseal plate

endosteum

delicate membranous lining, where bone growth/repair/remodeling occur

periosteum

the outer surface of the bone is covered by this fibrous membrane

blood vessels

bring in nutrients and carry out waste products

articular cartilage

a thin layer of cartilage that reduces friction and acts as a shock absorber

spongy bone

(cancellous bone/trabecular bone) very porous as it has holes or open spaces that help make the bone lighter than it would be if solid

compact bone

(cortical bone) surrounds spongy bone; made up of lamellae

osteons

circular structures; contains osteocytes

Haversian canal

a passageway for blood vessels and nerves

lamella

concentric layers or rings that surround the central canal

lacunae

small spaces in the lamellae that houses the osteocytes

canaliculi

osteocytes are connected to each other by this

osteogenic cells

undifferntiated stem cells with high mitotic activity and they are the only bone cells that divide

osteoblasts

the bone cells responsible for forming new bone and is found in the growing portions of bone; do not divide

osteocytes

the primary cell of mature bone and the most common typ

osteoclasts

the cell responsible for bone resorption, or breakdown

non-displaced fracture

a bone is broken, but the broken pieces remain in their normal, aligned position

closed fracture

a bone break where the skin remains intact, meaning the broken bone does not pierce through the skin

open fracture

a bone break where the broken bone pierces through the skin, creating an open wound

linear fracture

a complete, straight break in a bone that runs perpendicular to the bone’s long axis

oblique fracture

a break occurs at an angle to the bone’s long axis, often due to a twisting or angled imapct

spiral fracture

a bone fracture where the break spirals around the bone, resembling a spiral staircase

stress fracture

a small crack or severe bruising within a bone, caused by overuse or stress

transverse fracture

a break where the fracture line runs horizontally across the bone

comminuted fracture

a break where the bone is shattered into 3 or more fragments

greenstick fracture

a bone fracture in kids, bone bends and cracks on one side, but does not break completely

fracture

a crack or break in the bone

compression force

occurs when a physical force presses inward on an object, causing it to become compacted

bone remodeling

the replacement of old bone tissue by new bone tissue and continues after birth into adulthood

hematoma formation

blood vessels in the broken bone tear and hemorrhage, forming a mass of clotted blood (hematoma) that forms between the broken bones

fibrocartilaginous callus formation

new blood vessels grow into the hematoma in the damaged area;

phagocytic cells

a type of cell within the body capable of eating other small cells and particles to clear away

fibrocartilaginous callus

composed of collagen fiber, cartilage, bone fragments; replaces the blood clot at the fracture site where osteoblasts form spongy bone

bony callous formation

fibrocartilaginous callus is converted into a new mass called a bony callus of spongy bone

bone remodeling

bony callus is remodeled by osteoclasts and osteoblasts; compact bone is added to create bone tissue similar to original bone

tailbone

coccyx

axial

head, neck, chest, trunk

appendicular

limbs

maxilla

the bone that holds your teeth in the upper jaw

radiology

branch of medicine that uses imaging

histology

study of tissues