Human Skeleton - Bones, Cartilage, Joints

musculoskeletal system

system of muscles, joints, tendons, ligaments providing movement, form, strength, warmth, protection

skeleton

made of bone & is the support system for the body

skeleton is divided into 2 parts

axial & appendicular

axial skeleton

made up of the skull, hyoid, rib cage, sternum, vertebrae, sacrum; 80 bones in total

appendicular skeleton

made up of the shoulder bones, pelvic bones, arms/legs (including hands/feet); 126 bones in total

skull

boney housing for brain; closed system, except the Foramen of Magnum, where the spinal cord exits

8 bones in the skull

frontal, occipital, ethmoid, sphenoid, 2 parietal, 2 temporal

facial bones

maxilla, 2 zygomatic, mandible, nasal, palatine, inferior nasal concha, lacrimal, vomer

cranial bones of auditory system

2 incudes, 2 mallei, 2 stapes

hyoid

lone bone found under the chin

spinal column

7 cervical, 12 thoracic, 5 lumbar, sacrum

appendicular skeleton

shoulder girdle, 2 clavicles, 2 scapula, pelvic girdle, 2 hip bones

upper extremity

2 humeri, 2 radii, 2 ulnae, 16 carpals, 10 metacarpals, 28 phalanges

hand bones

ulna, radius, carpal bones, metacarpal bones, phalynx bone

carpal bones of hand

lunate, triquetrum, pisiform, hamate, scaphoid, trapezium, trapezoid, capitate

phalynx bone of hand

proximal, middle, distal phalanges

lower extremity

2 femurs, 2 tiniae, 2 fibulae, 2 patellae, 14 tarsals, 10 metatarsals, 28 phalanges

foot bones

tarsal, metatarsal, phalanges

tarsal bones of foot

calcaneus, talus, navicular, cuboid, cuniform

phalanges bones of foot

proximal, intermediate, distal phalanges

bones

give bodies shape, protect organs, support weight; work with muscles & tendons to help the body move

bone marrow

produces blood cells for the body

long bones

bones longer than wide (named for elongated shape, not size); found in limbs (femur & humerus)

tubular bones

long bones

short bones

roughly cube shaped bones (carpal bones of wrist & tarsal bones of ankle)

sesamoid bones

a short bone shaped like a sesame seed formed within tendons; patella is largest of this bone in the body

cuboidal bones

short bones

flat bones

consist of layer of spongy bone between two thin layers of compact bone; cross-section is flat, not rounded; have marrow but lack of bone marrow cavity; skull & ribs

irregular bones

bones not fitting into any other category; vertebrae; several are found in the face

closed fracture

does not involve a break in the skin

colles’ fracture

occurs in wrist & affects the distal radius bone

comminuted fracture

more than 2 separate bone components (fragments)

compound fracture

projects through skin with possibility of infection

compression fracture

vertebrae collapse due to trauma, tumor, or osteoporosis

epiphyseal fracture

occurs when matrix is calcifying & chondrocytes are dying; usually seen in children

greenstick fracture

only one side of shaft is broken & other is bent; common in children

transverse fracture

spread along length of bone & produced by twisting stress Lefort fractures

Le Fort I fractures

horizontal; usually result from blunt force trauma occurring low on the maxillary alveolar rim in a downward direction

Le Fort II fractures

pyramidal; usually result from a blow to the lower or mid maxilla; has a pyramid shape & extends from the nasal bridge at or below the nasofrontal suture through the frontal process of the maxilla

Le Fort III fractures

transverse; create a total cranial facial separation - the lower face is no longer attached to the skull; can follow impact to the nasal bridge or upper maxilla

cartilage

type of flexible connective tissue that is non-vascular; found in many areas of the body, including in joints between bones

conditions that affect cartilage

chondrosis, chondritis, chondromalacia

chondrosis

when cartilage breaks down/deteriorates; often seen with osteoarthritis

osteoarthritis

when cartilage wears away & the bones of a joint rub against each other causing inflammation

chondritis

inflammation of cartilage

costochondritis

chondritis in the cartilage of the ribs

chondromalacia

condition where the cartilage becomes soft; often seen in the knee joint at the patella

3 types of joints

fibrous, cartilaginous, synovial

most common types of synovial joints

ball-and-socket, hinge, pivot

ball-and-socket

allow a full range of movement; shoulder/hip

hinge

allow only bending & straightening; knee/elbow

pivot

allow swivel & bending; neck

Salter-Harris fractures

physeal fractures; occur through a growth plate (physis); specific to children who are relying on the growth plate to continue to support their growth to full height

Salter-Harris fracture type I

occurs through the growth plate; fracture line extends within the growth plate or through the physis

Salter-Harris fracture type II

most common Salter-Harris fracture; occurs through both the metaphysis & growth plate

Salter-Harris fracture type III

fracture in the joint extending through the growth plate and epiphysis; this type of fracture is rare; most commonly found at the distal end of tibia

Salter-Harris fracture type IV

fractures extend through the growth plate, epiphysis, metaphysis

Salter-Harris fracture type V

usually the result of a crushing or compression injury of the growth plate; the force is transmitted through the epiphysis & physis; very rare

discs

sits between 2 vertebra & made of fibrocartilaginous material; 24 in human spine

annulus fibrosus

outer rim of disc - protective covering; made of strong material

mucoprotein gel

nucleus pulposus; jelly like substance that moves inside the annulus fibrosus & re-distributes itself to absorb the impact as the spine is subjected to pressure

vertebral body

specifically designed for loadbearing

vertebral arch

exists to protect the spinal cord

transverse processes

designed to allow for ligament attachment, providing stability

facet joints

connected to the vertebrae above & below; composed of 2 articular processes of adjacent vertebrae