Skeletal System

Axial skeleton includes

skull, ossicles, hyoid, ribs, and spine

Appendicular skeleton includes

collarbone, arms, legs, and hips

5 functions of skeletal system

support, protection, movement, storage, and blood cell formation

Compact bone

dense smooth bone, comprised of osteons, comprising the shaft and exterior of the bone

Spongy bone

composed of small needlelike pieces of bone and lots of open space

Diaphysis

shaft of longs bones composed of compact bone

Epiphysis

ends of the long bone consisting of a thin layer of compact bone enclosing an area filled with spongy bone

Periosteum

a fibrous connective tissue membrane that covers and protects the diaphysis

Articular cartilage

covers the external surface of the epiphysis and decreases friction at the joint surfaces

Yellow bone marrow

fat stored in the diaphyses of adult long bones

Red bone marrow

produces blood cells and is found in the spongy bone of flat bones and the epiphyses of some long bones in adults

Osteoblasts

Bone building cells

Osteocytes

mature bone cells

Ossification

formation of bone

Osteoclasts

bone-destroying cells in bone that break down bone matrix and release calcium ions into the blood

Maxillae

upper jaw

Mandible

lower jaw

Cervical vertebrae

7 vertebrae in the neck (C1-C7)

Thoracic vertebrae

12 vertebrae in chest area; attachment for 12 ribs (T1-T12)

Lumbar vertebrae

5 vertebrae in the lower back (L1-L5)

Sacrum

fusion of 5 vertebrae forming the posterior wall of the pelvis

Coccyx

tailbone; fusion of 3-5 small, irregular vertebrae

Sternum

breastbone

True ribs

1st 7 pairs of ribs that attach directly to the sternum by cartilage

False ribs

last 5 pairs of ribs that attach indirectly or are not attached to the sternum

Floating ribs

Bottom 2 false ribs that have no sternal attachment

Clavicle

collar bone

Scapula

shoulder blade

Humerus

upper arm bone

Radius

forearm bone on the thumb side

Ulna

forearm bone on the little-finger side

Carpals

8 bones of the wrist area

Metacarpals

bones in the palm of the hand

Phalanges

finger and toe bones

Pelvic bones

hip bones

Femur

thigh bone

Tibia

shinbone

Fibula

lower leg bone that lies alongside the tibia and forms the outer part of the ankle

Patella

kneecap bone

Tarsals

7 bone that make up the ankle

Calcaneus

large tarsal bone also known as the heel bone

Metatarsals

5 bones that make up the sole of the foot

Frontal bone

forms the forehead, the bony projections under the eyebrows, and the superior part of each eye's orbit

Parietal bones

paired bones that form most of the superior and lateral walls of the cranium

Temporal bones

bones that lie inferior to the parietal bones

Occipital bone

most posterior bone in the cranium

Sphenoid bone

bat-shaped bone that spans the width of the skull and forms part of the floor of the cranial cavity

Zygomatic

cheekbones; also form portion of the lateral walls of the orbits

Nasal bones

bridge of the nose

Haversion Canal

central canal of the osteon, houses the blood vessels to nourish the bone

Intramembranous ossification

type of ossification that occurs in the soft spots of a baby's head

Endochondral ossification

type of ossification that occurs in a long bone to allow for both growth as well as repair of the bone

Long bones

longer than they are wide, these types of bones act as levers to aid in movement

Short bones

tend to be cube shaped, these types of bones provide support and stability with little movement

Sesamoid bones

shaped like a sesame seed and embedded in a tendon, these types of bones modify pressure, reduce friction, and occasionally alter the direction of muscle pull

Flat bones

thin and flat with roughly parallel surfaces, these types of bones have a large surface area for the attachment of skeletal muscles.

irregular bones

complex shapes with short, flat, notched, or ridged surfaces, these types of bones provide protection of tissue and muscle attachment points

hyoid bone

a U-shaped bone in the neck that supports the tongue.

ischium

the curved bone forming the base of each half of the pelvis.

ilium

part of the hip bone

pubic bone

one of the three sections of the hipbone

ball and socket joint

shoulder and hip; 360 degrees of rotation

hinge joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane

saddle joint

type of joint found at the base of each thumb; allows grasping and rotation

condyloid joint

biaxial (wrist, fingers, toes)

pivot joint

neck and elbow

fibrous joint/suture

connect bones without allowing any movement (like sutures)

Cartlaginous joints

joints held up by cartilage, limited movement

synovial joints

freely movable joints

fracture

broken bone

simple fracture

bone is broken cleanly; the ends do not penetrate the skin

compound fracture

break in the bone where the bone comes through the skin; open fracture

comminuted fracture

fracture in which the bone is splintered or crushed; common in older individuals

compressed fracture

Bone is crushed, common in porous bones (osteoporosis)

greenstick fracture

bone breaks incompletely; common in children

osteroporosis

A condition in which the body's bones become weak and break easily; common in older individuals

Osteoarthritis

inflammation and wearing of the bone and joint cartilage

Hypermobilty

abnormal movement of joints due to weakened cartilage, damaged cartilage/tendons/ligaments, or malformed bone

scoliosis

sideways curvature of the spine