APPENDICULAR SKELETON HONORS ANATOMY CHAPTER 7 PART II
Jan 17, 2016
APPENDICULAR SKELETON
HONORS ANATOMYCHAPTER 7 PART II
The Appendicular Skeleton
Includes:1. limb bones2. bones that connect limbs to axial
skeleton› shoulder girdle› pelvic girdle
The Pectoral Girdle(Shoulder)
2 pectoral girdles attach bones of upper limbs to
axial skeleton each: 1 clavicle 1 scapula
Pectoral Girdle
does not form complete belt-like bony structure
anteriorly: clavicles attached to sternum
laterally: clavicles attach to scapulae posteriorly:
› scapula attach to vertebral column via muscle attahments
Clavicle
S-shaped, (medial ½ convex anteriorly, lateral ½ concave anteriorly) slender bone
lies horizontally across anterior thorax superior to 1st rib
Clavicles
Functions:1. anchor muscles2. hold upper limbs and scapula out
laterally away from the narrow superior part of thoracic cage
Clavicle
medial end = sternal end is rounded & articulates with the manubrium @ sternoclavicular joint
Clavicle
lateral end = acromial end is flat articulates with acromion of the
scapula to form acromialclavicular joint
Clavicle
last bone to stop growing 1 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 bone large, triangular, flat bone in superior part of posterior
thorax between levels of 2nd & 7th ribs
spine: prominent ridge that runs diagonally across posterior surface
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: Shoulder Elbow Wrist Hand
Humerus
longest & largest bone of upper limb
articulates proximally with scapula & distally with ulna & radius
head: 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
Forearm (Antebrachium)
2 parallel bones: Ulna & Radius articulate:
› proximally with humerus elbow› distally with carpal bones wrist› with each other along their length
radioulnar joint
Ulna
medial aspect of forearm› (in anatomical position: pinky finger
side) longer than radius proximal end: olecranon
(prominence in elbow) distal end: head, styloid process
(posterior)
Ulna
Radius
lateral aspect of forearm
proximal end: head of radius: articulates with capitulum
distal end: styloid process (palpable proximal to thumb)
Radius
Hand
includes:1. Carpals
› wrist
2. Metacarpals› palm
3. Phalanges › digits
Carpals
proximal to the hand, distal to radius & ulna
8 small bones joined by ligaments
articulations w/each other called intercarpal joints
Phalanges
14 bones of the digits (each hand) #’d I to V beginning with thumb thumb is the pollex has only 2
phalanges, other digits have 3 joints between phalanges called
interphalangeal joints
Pelvic (Hip) Girdle
attaches lower limbs to axial skeleton› transmitting full weight of trunk to lower
limbs supports visceral organs of pelvic
cavity attachment to axial skeleton
(compared to shoulder girdle) stronger via strongest ligaments in body
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 &
inferior
3. Ischium posterior &
inferior
Ilium
largest of the 3 hip bones distinguishing features:1. Iliac Crest along superior surface (hands
akimbo resting on them)2. Sacroiliac Joint (SI Joint) between sacrum and ilium
Ilium
Ischium
ramus of ischium fuses with pubis distinguishing features:
1. Ischial Tuberosity what you feel when someone sits
on your lap
Ischium
Pubis
Pubic Symphysis› anterior joint between the 2 hip
bones
Acetabulum
point of fusion of all 3 pelvic bones a deep hemispherical socket
True Pelvis/ False Pelvis
Pelvic Brim: line that distinguishes between true & false pelvis
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 & thinner Pelvis:
› false pelvis shallow, widers› pelvic brim larger, more oval› acetabulum smaller & faces anterior› obturator foramen oval
Male or Female?
Male or Female?
Lower Limb carries the weight of the entire erect
body so bones are thicker & stronger than
comparable bones in upper limb
Lower Limb
30 bones in each: 1 femur 1 patella 1 tibia 1 fibula 7 tarsals 5 metatarsals 14 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: Proximal End
Femur: Distal End
broadens lateral & medial condyles› articulation points with tibia
each flanked superiorly: lateral & medial epicondyles› sites of muscle attachments
Femur distally articulates with:
› Patella› Tibia
Patella (kneecap)
small, triangular, sesamoid bone develops in tendon of quadriceps
femoris muscle Parts: Base: broad, superior end Apex: 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
Interosseous membrane between tibia and fibula: is less flexible but more stable than radius and ulna
Foot
Functions:1. supports body weight2. acts like a lever to propel body forward
as we walk or run
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 lateral
Hallux: 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