Skeletal 4

xiphoid process ossifies at age __

40

sternal angle

indicates second rib, T4-T5 joint, bifurcation of the trachea (into lungs), aortic arch

sternum parts

manubrium, body, sternal angle, xiphoid process, xiphoid process

true ribs

attached directly to costal cartilage, 1-7

false ribs

costal cartilage of the rib connects to another part of costal cartilage or terminates in the muscle, 8-12; does not interact with sternum

floating rib

type of false rib where small end of cartilage anterior does not attach to costal cartilage and end at muscle, 11-12

components of appendicular skeleton

pectoral girdle, upper limb, pelvic girdle, lower limb

pectoral girdle of appendicular skeleton

clavicle, scapula

upper limb of appendicular skeleton

humerus, ulna, radius, carpals, metacarpals, phalanges

function: manipulation of the external world, large range of motion

pelvic girdle of appendicular skeleton

hip bones

lower limb of appendicular skeleton

femur, patella, tibia, fibula, tarsals, metatarsals, phalanges

function: support and stability, locomotion

scapula and clavicle move ____

as a single unit

glenohumeral joint

ball and socket joint that allows wide range of motion

clavicle

supports the shoulder joint, force distribution (esp in falls), protects underlying structures (blood vessels from head to arm)

clavicle clinical significance

most fractured bone in body, if broken muscles will pull arm anteriorly and medially

scapula

anchors the upper limb, force distribution to clavicle, positions shoulder joint

scapula clinical significance

separated shoulder- acromial process is pushed under clavicle, tears the coracoclavicular and acromioclavicular ligaments

radial tuberosity of the radius

muscle attachment of bicep-flexes elbow

olecranon process of the ulna

muscle attachment of triceps-extend elbow

interosseous membrane

connective tissue that keeps parallel bones together (radius and ulna, tibula and fibula)

when rotating your forearm, the radius

rotates around the ulna, which is stationary

carpals

eight wrist bones

midcarpal joint

allows hand to flap up and down, between proximal and distal row of carpals

radiocarpal joint

allows waving/side to side motion of hand, only touches radius directly (not ulna)

carpals + flexor retinaculum

carpal tunnel

flexor retinaculum

bridges semicircle of carpal bones, critical to flex fingers

carpal tunnel syndrome

swelling of flexor retinaculum and tendons in carpal tunnel exerts pressure on median nerve, causing pain

intermetacarpal joints

at proximal ends between metacarpals 2-5

reduction of phalanges at thumb=

likely related to grasping (more strength)

ligaments of the pelvis

support the sacroiliac joint (connects spine to pelvis)

elements of pelvis

ilium, pubis, ischium; immobile and strongly adhered- formed from endochondrial ossification which is fast

sexual dimorphism in pelvis

female pelvis is adapted to childbirth- thinner and lighter bones, large pelvis inlet/outlet, shorter pelvic cavity, broader subpubic angle

head of femur

articulates with acetabulum

neck of femur

common site of fractures

sesamoid bones

small bones embedded/formed inside tendon or muscle to reduce friction and improve leverage

patella

sits in tendon of quadriceps femoris muscle and articulates with the femur

tibia

weight bearing bone of lower limb, medial

lateral malleolus and medial malleolus

bony bulges at ankle

shin splints (medial tibial stress syndrome)

microtears in tendon/muscle or interosseous membrane, inflammation of periosteum or connective tissue, stress fractures

tarsals

seven bones in food that make up the ankle; talus, calcaneus

talus

forms ankle joint

calcaneus

heel bone, attachment for achilles tendon

reduction of phalanges in big toe=

stability and strength

arches of feet

helps distribute force of impact across foot

medial sesamoid and lateral sesamoid

in flexor hallucis brevis (muscle) used to push off the ground when walking