Week 8 Ch 7: Skeleton - bones and joints

provides internal framework that supports the body; protects internal organs; helps fight disease by producing wbc; makes movement possible by working in concert with muscle contraction and relaxation; stores calcium

what are the functions of bone?

long, short, flat, irregular

what are the 4 major types of bone?

206 bones

how many bones does skeleton consist of?

long bone

diaphysis or shaft; medullary cavity; epiphyses; periosteum; endosteum

diaphysis

long hollow tube of compact bone

medullary cavity

hollow space inside the diaphysis, contains yellow marrow

epiphyses

spongy (cancellous) bone containing red bone marrow

periosteum

strong, fibrous membrane covering bone except at joint surfaces; contains osteoblasts and osteoclasts, blood and lymphatic vessels, nerve fibers

endosteum

thin membrane that lines medullary cavity; contains osteoblasts and osteoclasts

red bone marrow

found in spongy bone at ends of long bone and at centre of other bone; manufactures blood cells

yellow bone marrow

found in central cavities (medullary) of long bones; storage site for fat

compact bone and spongy bone

what are the 2 types of osseous tissue?

osseous tissue

hardest form of CT; composed of matrix, collagen, mineral salts; contains osteoblasts, osteoclasts, osteocytes

ossification

conversion of cartilage to bone; cartilage beings to turn into bone during fetal development; continues after birth until late teens or early 20’s; bone resorption and formation continue

spine

sharp projection

crest

distinct ridge at the edge of a bone

process

large projection of a bone

condyle

rounded projection

epicondyle

small projection above a condyle

head

rounded knob-like end separated from the rest of the bone by a slender region, the neck

foramen

an opening in bone that allows the passage of nerves and/or blood vessels

sinus

cavity or hollow space; an air-filled chamber found in some skull bones

fossa

a depression on a bone surface

meatus

a short, air-filled channel or passageway

axial, appendicular

what are 2 main groups of bone?

axial skeleton

consists of 80 bones; includes head and trunk

appendicular skeleton

126 bones; forms the framework for the extremities and the shoulders and hips

cranium

comprised of 8 bones; frontal, paired parietal, occipital, paired temporal, sphenoid and ethmoid bone

facial bones

compromised of 14 bones; mandible, paired maxillae, paired zygomatic bones, paired lacrimal, paired palatine, paired inferior nasal conchae, vomer, paired nasal bones

frontal bone

forms the forehead, anterior skull’s roof and roof of eye socket

parietal bones (2)

form most of the top and side walls of the cranium

temporal bones (2)

sides and base of skull; ear canals, eardrum, mastoid process

ethmoid bone

light fragile bone between eyes; forms part of the medial wall of the eye orbit, a small portion of the cranial floor and most of the nasal cavity roof

sphenoid bone

lies at the base of the skull anterior to the temporal bones and forms part of the eye socket; contains the sella turcica, saddlelike depression, that holds the pituitary gland

occipital gland

forms the posterior and part of the base of the skull

sutures

flat, immovable joint joining skull bones; lambdoidal, sagittal, squamous, coronal

lambdoidal suture

joins the occipital bone to the parietal bones in the posterior cranium

sagittal suture

joins the parietal bones along the superior midline of the cranium

squamous suture

joins the temporal bone to the parietal bone on lateral surface

coronal suture

joins the frontal bone to the parietal bones along the coronal plane

mandible

only movable bone of the skull

maxillae

fuse in the midline to form the upper jaw bone, including the front part of the hard palate

zygomatic bones

form the prominence of the cheek

lacrimal bones

anterior medial wall of the orbital cavity

palatine bones

form the posterior of the hard palate

vomer

forms the inferior part of the nasal septum

nasal bones

form the bridge of the nose

inferior nasal conchae

extend horizontally along the lateral sides of the nasal cavities

ear ossicles

three tiny bones in each middle ear

hyoid bone

u-shaped bone located just below the mandible; has only muscle attachments

fontanels

soft spots, areas of the skull where bone formation is incomplete

spine or vertebral column and chest/thorax

what are the bones of the trunk?

vertebral column

bony sheath of CT, houses spinal cord; 5 groups of bones named according to location from superior to inferior; 4 normal curves

lordosis, kyphosis, scoliosis

what are 3 abnormal curves of vertebral column?

cervical vertebrae (c1-c7)

located in the neck; 1st vertebrae, atlas, support head; 2nd vertebrae, axis, serves as pivot when you turn your head; develops at 3 months when baby lifts/hold up head

thoracic vertebrae (t1-t12)

located in the chest; longer, stronger than cervical; have longer spinal processes, attached to ribs at posterior end

lumbar vertebrae (l1-l5)

located in the small of the back; larger, heavier than those above them - supports more weight; curve develops when child starts to walk

sacral vertebrae

5 separate bones in the child; fuse to form the single in the adult; posterior part of pelvis

coccygeal vertebrae

tail bone; consist of 4-5 tiny bones in the child; fuse to form a single bone in the adult

thorax

12 pairs of ribs; sternum or breastbone

xiphoid process

small tip at inferior end of sternum; cartilage in youth, bone in adults; landmark for CPR to locate region for chest compressions

upper division

shoulder girdle; upper extremity

lower division

pelvis; lower extremity

shoulder girdle

clavicle, scapula

upper extremity

arm - humerus, forearm - radius and ulna, wrist - 8 carpal bones, hand - 5 metacarpal bones, fingers - 14 phalanges

pelvic bone

begins its development as 3 separate bones - ilium, ischium, pubis

acetabulum

formation of ilium, ischium, pubis at the hip joint

lower extremity

thigh bone or femur, longest and strongest bone in body; patella or kneecap articulates with the femur and tibia; tibia and fibula are 2 bones in lower leg

foot

stronger and less mobile than those of the hand; 7 tarsal bones associated with ankle and foot; 5 metatarsal bones form the framework of the instep and the ball of the foot; 14 phalanges of the toes are counterparts of those in the fingers

osteopenia

bone mineral density is lower than normal

osteoporosis

bones become fragile and break easily; most often involves the spine, pelvis and long bones; more common in post menopausal women (decrease of estrogen hormone)

osteitis deformans (paget’s disease)

bones experience alternating periods of resorption and regrowth; result is deformed bones - prone to fracture; etiology and cure are unknown

osteomalacia (rickets in children)

characterized by bowing of legs; softening of bones due to vit D deficiency; can result in osteopenia or osteoporosis

osteogenesis imperfecta (brittle bone disease)

genetic disorder of impaired collagen production - bones fracture easily

osteosarcoma

tumors result from growing bone cells, usually in children - most common and serious malignant bone neoplasm

chondrosarcoma

tumors resulting from cartilage cells, usually in adults - second most common cancer of skeletal tissues

osteomyelitis

inflammation of the bone caused by pyogenic bacteria - not as common due to antibiotics

tuberculosis

bone usually originates as pulmonary tuberculosis - pott disease (of the spine)

kyphosis

exaggeration of the thoracic curve - hunchback

lordosis

excessive lumbar curve - swayback

scoliosis

lateral curvature of the vertebral column; most common, occurs during the rapid growth period of teens - more often in girls

cleft palate

faulty union of the maxillary bones; surgery can easily correct

flatfoot

tendons and ligaments of the foot are weakened and the curve of the arch flattens

open fracture

broken bone protrudes through the skin or an external wound leads to a broken bone

closed fracture

simple fracture with no open wound

impacted fracture

the broken ends of the bones are jammed into each other

comminuted fracture

there is more than one fracture lone and the bone is splintered or crushed

oblique fracture

the break occurs at an angle across the bone

spiral fracture

the bone has been twisted apart

greenstick fracture

one side of the bone is broken and the other is bent

transverse fracture

the fracture goes straight across the bone

articulation or joint

area of junction or union between two or more bones - every bone except the hyoid connects to at least one other bone

synarthrosis - fibrous joint

bones are held together by fibrous connective tissue; sutures of the skull; joint is immovable

amphiarthrosis

connect by cartilage; joint between the pubic bones of the pelvis and the joints between each vertebrae; joint is slightly movable

diarthrosis - synovial joints

these joints have a potential space between them (joint cavity) which contains a small amount of lubricant; joint is freely movable

ball and socket joint

permits the widest range of movement

hinge joints

allow movement in only 2 directions - flexion and extension

gliding

two flat bone surfaces slide over each other with little change in angle; tarsal and carpal bones

hinge

convex surface of one bone fits into the concave surface of another - allows movement along one axis only

pivot

rounded portion of one bone fits into a ring of another; rotation only