Post on 23-Feb-2016
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The Skeletal SystemPart 2
The Appendicular SkeletonHonors Anatomy & Physiology
The Appendicular Skeleton
The Pectoral Girdle(Shoulder)
2 pectoral girdlesattach bones of upper limbs to axial
skeletoneach: 1 clavicle 1 scapula
Clavicle
S-shaped, (medial ½ convex anteriorly, lateral ½ concave anteriorly) slender bone
lies horizontally across anterior thorax superior to 1st rib
Clavicle
medial end = sternal end is rounded & articulates with the manubrium @ sternoclavicular joint
Clavicle
lateral end = acromial end is flatarticulates with acromion of the
scapula to form acromialclavicular joint
Clavicle
last bone to stop growing1 of most frequently fx’d bones (2
curves) usually from fall on outstretched arm
or see compression fx in auto accidents from shoulder strap which can cause damage to median n. (between clavicle & 2nd rib)
Scapula
aka shoulder blade, angel bonelarge, triangular, flat bonein superior part of posterior thorax
between levels of 2nd & 7th ribs
spine: prominent ridge that runs diagonally across posterior surface
Scapula
lateral edge: acromion a flattened expanded process, easily felt as hi pt of shoulder (tailors use it as landmark to measure length of arm)
glenoid cavity: inferior to acromion, smooth, shallow depression that accepts head of humerus in shoulder joint
Scapula
Upper Limb
6 parts:1. Humerus2. Ulna3. Radius4. Carpals5. Metacarpals 6. Phalanges
Joints:ShoulderElbowWristHand
Humerus
longest & largest bone of upper limbarticulates proximally with scapula &
distally with ulna & radiushead: rounded proximal end
articulates with glenoid cavity of scapula to form glenohumeral joint
Humerus
Humerus
distal end:capitulum: rounded knob on lateral
aspect that articulates with head of radius
trochlea: medial to capitulum, spool-shaped, articulates with ulna
Humerus
Ulna
medial aspect of forearmlonger than radiusproximal end: olecranon (prominence
in elbow)distal end: head, styloid process
(posterior)
Radius
lateral aspect of forearm
proximal end: head of radius: articulates with capitulum
distal end: styloid process (palpable proximal to thumb)
Ulna & Radius
connect @ 3 places
1. interosseous membrane
2. proximal end3. distal end
Carpals
proximal to the hand, distal to radius & ulna
8 small bones joined by ligaments
articulations w/each other called intercarpal joints
Carpal Tunnel
Phalanges
14 bones of the digits (each hand)#’d I to V beginning with thumbthumb is the pollex has only 2
phalanges, other digits have 3joints between phalanges called
interphalangeal joints
Pelvic Girdle
2 hip bones (os coxa) which unite anteriorly at pubic symphysis and posteriorly with the sacrum @ sacroiliac joint
Pelvic Girdle
Functions:provides sturdy
support for vertebral column
connects lower limb to axial skeleton
Newborn Pelvis
3 bones on each side:
1. Ilium◦ superior
2. Pubis◦ anterior &
inferior3. Ischium posterior &
inferior
Ilium
largest of the 3 hip bonesdistinguishing features:1. Iliac Crest along superior surface1. Sacroiliac Joint (SI Joint) between sacrum and ilium
Ilium
Ischium
ramus of ischium fuses with pubisdistinguishing features:
1. Ischial Tuberosity what you feel when someone sits on
your lap
Ischium
Pubis
Acetabulum ◦formed by ilium, ischium, & pubis◦is the “socket” half of the hip joint
Pubic Symphysis◦joint between the 2 hip bones
True Pelvis/ False Pelvis
Pelvic Brim: line that distinguishes between true & false palvis
Male Pelvis
generally male bone heavier & stronger & have larger surface marker (because larger muscles attach)
Pelvis:◦deeper false pelvis, smaller, narrower◦pelvic brim heart-shaped◦acetabulum larger, faces posterior◦obturator foramen round
Female Pelvis
generally bones lighter & thinnerPelvis:
◦false pelvis shallow, widers◦pelvic brim larger, more oval◦acetabulum smaller & faces anterior◦obturator foramen oval
Male or Female?
Male or Female?
Lower Limb
30 bones in each:1 femur1 patella 1 tibia1 fibula7 tarsals5 metatarsals14 phalanges
Femur
longest, heaviest, & strongest bone in the body
proximally articulates with the acetabulum to form hip joint◦Head of the Femur: “ball” part of joint
small, central depression: fovea capitis◦Greater Trochanter
prominence felt & seen @ side of hip
Femur
Femur
distally articulates with:◦Patella◦Tibia
Patella (kneecap)
small, triangular, sesamoid bonedevelops in tendon of quadriceps
femoris muscleParts:Base: broad, superior endApex: pointed, inferior end
Patella
Tibia
“shin bone”larger, medial, weight-bearing bone of
lower legproximally articulates with femur &
fibuladistally articulates with fibula &
tarsals
Tibia
medial malleolus forms prominence that is palpable & visible on medial ankle
Fibula
parallel & lateral to the tibia & considerably smaller
head of fibula on proximal end
lateral malleolus at distal end
Tibia & Fibula
Tarsals
7 bones:1 calcaneous: heel bone, largest of
the tarsals
Metatarsals
5 bones between tarsals & phalanges#’d I to V from medial lateral
Phalanges
14 bones that make up the 5 digits#’d I to V medial to lateralHallux: great or big toe has 2 large
heavy phalanges
Arches of the Foot
2 arches in foot: 1. allows the foot to support weight of
body by distributing weight over the soft & hard tissues
2. provide leverage while walkingfully developed by age 12 - 13
Arches of the Foot
2 longitudinal arches (medial & lateral
1 transverse arch
Development of the Skeletal System
all skeletal tissue arises from mesoderm1st bone: skull in 4th wkU/S ~ 24 – 25 wks:
Medical Terminology
1. Clubfoot:◦ inherited deformity in which baby is born with
foot twisted inferiorly & medially◦ 1/1000 births◦ tx: casts or wraps, surgery may be indicated
Medical Terminology
2. Genu valgum: knees
abnormally close together with increased space between ankles
aka “knock-knee”
Medical Terminology
3. Genu varum:knees abnormally
separatedwith lower limbs
bowed mediallyaka “bowleg”