How many bones are in the human body?

206 bones

What do bones provide?

structure, protection, movement, and storage

Axial skeleton

forms the long central axis

Appendicular skeleton

forms the appendages

Long bones

longer than they are wide

Short bones

rougher & cubelike, for stability and movement

Sesamoid bones

short bones embedded in tendons/joint capsules

Flat bones

thin/flattened/curved bones that shield organs

Irregular bones

don't fit anywhere else

Bone tissue

also called osseous tissue, type of connective tissue

Osteocyte

mature bone cell

Where do osteocytes live?

in cavities called lacunae

What do osteocytes do?

maintain the mineral content of the matrix

Osteoblast

young cells that make new bone tissue

Osteogenic

divide to make new bone cells

Osteoclasts

break down bone for repair/calcium

Osteoid

organic part of the matrix

What makes up an osteoid?

collagen, fibrous protein, and mucopolysaccharide

Mineral salts

inorganic portion of the matrix

Compact/cortical bone tissue

dense

Canaliculi

channels through the matrix that allow passage

Endosteum/Periosteum

line the inner/outer parts of a bone

Haversian canal

the central canal surrounded by concentric tissue

Lamella

rings which are linked together by Volkmann's canals

Spongy bone

found in inner cavity suspended in trabeculae

Articular cartilage

thin layer of hyaline cartilage at the end of long bones

Proximal epiphysis

wide section at the end, filled with spongy bone

Metaphysis

section that grows

Epiphyseal line

thin line of cartilage that flattens with age

Diaphysis

long hollow bone shaft

Nutrient artery

supplies the periosteum with blood

Periosteum

fiborous sheaf of connective tissue containing blood vessels and nerves

Yellow bone marrow

made of adipocytes and stores lipids

Endosteum

layer of bone cells that line the inner cavity

Red bone marrow

site of hematopoiesis

Condyle

rounded projection often covered in hyaline cartilage

Facet

flat/smooth surface that meets another bone

Head

large protuberance of a bone above the neck

Ramus

an arm-like bridge of bone

Crest

a narrow ridge or edge

Spine

a sharp/pointed/slender feature

Tuberosity

a large/round projection with a rough surface

Process

a prominent area

Trochanter

a large/blunt/irregular projection only found on the femur

Tubercle

a small round attachment point for a muscle

Epicondyle

a prominence above a condyle

Line

a very narrow ridge of bone along an edge

Foramen

a large oval/round hole

Fissure

a groove/slit in a bone

Meatus

a long canal

Fossa

a basin-like depression

Groove

a shallow depression or furrow

Notch

similar to a fossa

Sinus

an enclosed cavity within a bone

Bone tissue template

made of cartilage produced by chondroblasts

Longitudinal growth

growing in length

Appositional growth

growing in diameter

When does growth end?

when the epiphyseal growth plate is ossified

Reserve zone

region of the bone closest to the growth plate

Proliferative zone

bone cells moving towards the diaphysis

Hypertrophy/Maturation zone

cells grow and mature quickly

Primary spongiosa

newly deposited bone tissue

Modeling

osteoclasts resorb old bone and osteoblasts produce new bone

Remodeling

destruction of old bone by osteoclasts while osteoblasts produce new bone

What drives bone remodeling?

level of calcium ions + physical demand

Optimal level of ionic calcium

9-11 mg/100 ml

blank flashcard

meant to remind to study calcium cycle

Wolff's Law

describes how bones adapt to mechanical stress

Synergistic Effect

hormonal feedback determines where, wolff's law determines where

Step 1 of bone repair

vasculature and nerves are damaged, blood clots form a hematoma

Step 2 of bone repair

chondrocytes respond and create an internal callus

Step 3 of bone repair

chondrocytes/osteoblasts create an external callus

Step 4 of bone repair

osteoclasts reabsorb dead bone tissue and osteogenic cells divide to make more bone cells

Step 5 of bone repair

the cartilage in the calli is replaced by mineralized bone

How many bones are in the skull?

22 bones

Neurocranium

8 cranial bones that protect the brain

Frontal bone

single bone that creates the forehead and has the glabella

Parietal bones

form the top of the skull

Occipital bone

articulates with the vertebrae

Foramen magnum

allows for passage of the spinal cord

Temporal bones

bilateral, articulate with other bones

Mandibular fossa

a depression that allows the mouth to open/close

Styloid process

muscle/ligament attachment place

Sphenoid bone

butterfly shaped keystone bone

Ethmoid bone

marked by the crista galli

Cribriform plate

allows nerves to pass through the ethmoid bone

Lambdoidal suture

found at the junction of occipital and parietal bones

Occipitomastoid suture

articulation of occipital and temporal bones

Squamosal suture

separates the parietal and temporal bones

Coronal suture

formed where parietal and frontal bones meet

Sagittal suture

joins the two parietal bones

Pterion

centrally located

Viscerocranium: lower anterior portion of the skull

Mandible

jaw bone

Mental protuberance

projection that forms the chin

Mental foramen

small openings that allow for the passage of nerves

Mandibular foramen

tunnel that allows for nerves/vessels for the jaw

Maxilla

upper jaw and base for nose/eyes

Alveolor process

curved margin of the maxilla that holds the teeth

Alveolus

teeth sockets