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Sacral promontory
Ala
Body of
first
sacral
vertebra
Transverse
ridges (sites
of vertebral
fusion)
Apex
Anterior
sacral
foramina
Coccyx
(a) Anterior view
Figure 7.21a
Ala
Sacral
canal
Body
Facet of
superior
articular
process
Auricular
surface
Median
sacral
crest
Posterior
sacral
foramina
Coccyx
Lateral
sacral
crest
Sacral
hiatus
(b) Posterior view
Figure 7.21b
Thoracic Cage
• Composed of
• Thoracic vertebrae
• Sternum
• Ribs and their costal cartilages
• Functions
• Protects vital organs of thoracic cavity
• Supports shoulder girdle and upper limbs
• Provides attachment sites for many muscles, including
intercostal muscles used during breathing
Sternum (Breastbone)
• Three fused bones
• Manubrium
• Articulates with clavicles and ribs 1 and 2
• Body
• Articulates with costal cartilages of ribs 2 through 7
• Xiphoid process
• Site of muscle attachment
• Not ossified until ~ age 40
Ribs and Their Attachments
• 12 pairs
• All attach posteriorly to thoracic vertebrae
• Pairs 1 through 7
• True (vertebrosternal) ribs
• Attach directly to the sternum by individual
costal cartilages
Ribs and Their Attachments
• Pairs 8 through12
• False ribs
• Pairs 8–10 also called vertebrochondral ribs
• Attach indirectly to sternum by joining costal
cartilage of rib above
• Pairs 11–12 also called vertebral (floating) ribs
• No attachment to sternum
Jugular notch
Clavicular notch
Manubrium
Sternal angle
Body
Xiphisternal
joint
Xiphoid
process
True
ribs
(1–7)
False
ribs
(8–12)
Sternum
Intercostal spaces
Costal cartilage
Costal margin
L1
Vertebra
Floating ribs (11, 12)
(a) Skeleton of the thoracic cage, anterior view
Figure 7.22a
Structure of a Typical Rib
• Main parts:
• Head
• Articulates posteriorly with facets (demifacets) on
bodies of two adjacent vertebrae
• Neck
• Tubercle
• Articulates posteriorly with transverse costal facet of
same-numbered thoracic vertebra
• Shaft
Transverse costal facet
(for tubercle of rib)
Angle
of rib
Superior costal facet
(for head of rib)
Body of vertebra
Head of rib
Intervertebral disc
Neck of rib
Tubercle of rib
Shaft Sternum
Crosssection
of rib
Costal groove Costal cartilage
(a) Vertebral and sternal articulations of a
typical true rib
Figure 7.23a
Articular facet
on tubercle of rib
Spinous process
Shaft
Ligaments
Neck of rib
Head of rib
Transverse
costal facet
(for tubercle
of rib)
Body of
thoracic
vertebra
Superior costal facet
(for head of rib)
(b) Superior view of the articulation between a
rib and a thoracic vertebra
Figure 7.23b
Appendicular Skeleton
• Bones of the limbs and their girdles
• Pectoral girdle attaches the upper limbs to the
body trunk
• Pelvic girdle secures the lower limbs
Pectoral Girdle (Shoulder Girdle)
• Clavicles and the scapulae
• Attach the upper limbs to the axial skeleton
• Provide attachment sites for muscles that
move the upper limbs
Acromioclavicular
joint
Clavicle
Scapula
(a) Articulated pectoral girdle
Figure 7.24a
Clavicles (Collarbones)
• Flattened acromial (lateral) end articulates
with the scapula
• Cone-shaped sternal (medial) end articulates
with the sternum
• Act as braces to hold the scapulae and arms
out laterally
Sternal (medial)
end
Posterior
Anterior
Acromial (lateral)
end
(b) Right clavicle, superior view
Figure 7.24b
Scapulae (Shoulder Blades)
• Situated on the dorsal surface of rib cage,
between ribs 2 and 7
• Flat and triangular, with three borders and
three angles
• Seven large fossae, named according to
location
Acromion
Suprascapular notch
Superior border
Coracoid
process
Glenoid
cavity
Lateral border
Superior
angle
Subscapular
fossa
Medial border
(a) Right scapula, anterior aspect
Inferior angle
Figure 7.25a
Suprascapular notch
Coracoid process
Superior
angle
Supraspinous
fossa
Spine
Infraspinous
fossa
Acromion
Glenoid
cavity
at lateral
angle
Medial border
Lateral border
(b) Right scapula, posterior aspect
Figure 7.25b
Acromion
Supraspinous fossa
Supraglenoid
tubercle
Coracoid
process
Supraspinous
fossa
Infraspinous
fossa
Posterior
Spine
Glenoid
cavity
Infraspinous
fossa
Infraglenoid
tubercle
Subscapular
fossa
Subscapular
fossa
Anterior
(c) Right scapula, lateral aspect
Inferior angle
Figure 7.25c
The Upper Limb
• 30 bones form the skeletal framework of each upper
limb
• Arm
• Humerus
• Forearm
• Radius and ulna
• Hand
• 8 carpal bones in the wrist
• 5 metacarpal bones in the palm
• 14 phalanges in the fingers
Humerus
• Largest, longest bone of upper limb
• Articulates superiorly with glenoid cavity of
scapula
• Articulates inferiorly with radius and ulna
Greater
tubercle
Lesser
tubercle
Intertubercular
sulcus
Head of
humerus
Anatomical
neck
Deltoid
tuberosity
Lateral
supracondylar
ridge
Radial
fossa
Capitulum
(a) Anterior view
Coronoid
fossa
Medial
epicondyle
Trochlea
Figure 7.26a
Bones of the Forearm
• Ulna
• Medial bone in forearm
• Forms the major portion of the elbow joint with the
humerus
• Radius
• Lateral bone in forearm
• Head articulates with capitulum of humerus and with
radial notch of ulna
• Interosseous membrane connects the radius and ulna
along their entire length
Radial
notch of
the ulna
Head
Neck
Radial
tuberosity
Olecranon
process
Trochlear
notch
Coronoid
process
Proximal
radioulnar
joint
Interosseous
membrane
Ulna
Head of
radius
Neck of
radius
Radius
Ulnar notch
Radius
of the radius
Head of ulna
Styloid
Styloid
process of ulna
process
Distal radioulnar
Styloid process
of radius
joint
of radius
(a) Anterior view
(b) Posterior view
Figure 7.27a-b
Olecranon process
Trochlear notch
View
Coronoid process
Radial notch
(c) Proximal portion of ulna,
lateral view
Ulnar notch of radius
Articulation
for lunate
Articulation
for scaphoid
Styloid
process
View
Styloid
Head
of ulna process
(d) Distal ends of the radius and
ulna at the wrist
Figure 7.27c-d
Humerus
Capitulum
Coronoid
fossa
Medial
epicondyle
Trochlea
Coronoid
process of
ulna
Radial notch
Ulna
(c) Anterior view at the elbow region
Head of
radius
Radial
tuberosity
Radius
Humerus
Olecranon
process
Olecranon
fossa
Lateral
epicondyle
Medial
epicondyle
Head
Ulna
Neck
Radius
(d) Posterior view of extended elbow
Figure 7.26c-d
Hand: Carpus
• Eight bones in two rows
• Proximal row
• Scaphoid, lunate, triquetrum, and pisiform
proximally
• Distal row
• Trapezium, trapezoid, capitate, and hamate
distally
• Only scaphoid and lunate articulate with
radius to form wrist joint
Hand: Metacarpus and Phalanges
• Metacarpus
• Five metacarpal bones (#1 to #5) form the
palm
• Phalanges
• Each finger (digit), except the thumb, has three
phalanges—distal, middle, and proximal
• Fingers are numbered 1–5, beginning with the
thumb (pollex)
• Thumb has no middle phalanx
Phalanges
• Distal
• Middle
• Proximal
Sesamoid
bones
Carpals
• Trapezium
• Trapezoid
• Scaphoid
Radius
(a) Anterior view of left hand
Metacarpals
• Head
• Shaft
• Base
Carpals
• Hamate
• Capitate
• Pisiform
• Triquetrum
• Lunate
Ulna
Carpals
• Trapezium
• Trapezoid
• Scaphoid
Radius
(b) Posterior view of left hand
Figure 7.28a-b
Pelvic (Hip) Girdle
• Two hip bones (each also called coxal bone or os
coxae)
• Attach the lower limbs to the axial skeleton with strong
ligaments
• Transmit weight of upper body to lower limbs
• Support pelvic organs
• Each hip bone consists of three fused bones: ilium,
ischium, and pubis
• Together with the sacrum and the coccyx, these
bones form the bony pelvis
Base of sacrum
Iliac fossa
Coxal
bone
llium
(os coxae
or hip
Pubic
bone)
bone
Iliac crest
Sacroiliac
joint
Anterior
superior
iliac spine
Sacral
promontory
Sacrum
Coccyx
Anterior inferior
iliac spine
Pelvic brim
Acetabulum
Pubic tubercle
Pubic crest
Pubic symphysis
Ischium
Pubic arch
PLAY
Animation: Rotatable pelvis
Figure 7.29
Hip Bone
•
Three regions
1. Ilium
•
Superior region of the coxal bone
•
Auricular surface articulates with the sacrum
(sacroiliac joint)
2. Ischium
•
Posteroinferior part of hip bone
3. Pubis
•
Anterior portion of hip bone
•
Midline pubic symphysis joint
Anterior gluteal
Ilium
line
Ala
Posterior
Iliac crest
gluteal line
Posterior
Anterior
superior
superior
iIiac spine
iliac spine
Posterior inferior
Inferior
iliac spine
gluteal line
Greater sciatic
Anterior inferior
notch
iliac spine
Ischial body
Acetabulum
Ischial spine
Pubic body
Lesser sciatic
notch
Pubis
Ischium
Inferior ramus
Ischial
of pubis
tuberosity
Obturator foramen
Ischial ramus
(a) Lateral view, right hip bone
Figure 7.30a
Ilium
Iliac crest
Iliac fossa
Posterior
superior
iliac spine
Posterior
inferior
iliac spine
Auricular
surface
Greater sciatic notch
Ischial spine
Lesser sciatic notch
Obturator
foramen
Ischium
Anterior
superior
iliac spine
Anterior inferior
Body of
iliac spine
the ilium
Arcuate line
Superior ramus
of pubis
Pubic tubercle
Articular surface
of pubis (at pubic
symphysis)
Ischial ramus
Inferior ramus
of pubis
(b) Medial view, right hip bone
Figure 7.30b
Comparison of Male and Female Pelves
• Female pelvis
• Adapted for childbearing
• True pelvis (inferior to pelvic brim) defines birth
canal
• Cavity of the true pelvis is broad, shallow, and
has greater capacity
Comparison of Male and Female Pelves
• Male pelvis
• Tilted less forward
• Adapted for support of male’s heavier build
and stronger muscles
• Cavity of true pelvis is narrow and deep
Comparison of Male and Female Pelves
Characteristic
Female
Male
Bone thickness
Lighter, thinner, and
smoother
Heavier, thicker, and more
prominent markings
Pubic arch/angle
80˚– 90˚
50˚– 60˚
Acetabula
Small; farther apart
Large; closer together
Sacrum
Wider, shorter; sacral
curvature is accentuated
Narrow, longer; sacral
promontory more ventral
Coccyx
More movable; straighter
Less movable; curves ventrally
Table 7.4
Table 7.4
Table 7.4
The Lower Limb
• Carries the weight of the body
• Subjected to exceptional forces
• Three segments of the lower limb
• Thigh: femur
• Leg: tibia and fibula
• Foot: 7 tarsal bones in the ankle, 5 metatarsal
bones in the metatarsus, and 14 phalanges in
the toes
Femur
• Largest and strongest bone in the body
• Articulates proximally with the acetabulum of
the hip and distally with the tibia and patella
Neck
Fovea
capitis
Greater
trochanter
Head
Intertrochanteric
crest
Lesser trochanter
Intertrochanteric
line
Gluteal tuberosity
Linea aspera
Apex
Anterior
Facet for
medial
condyle
of femur
Facet for lateral
condyle of femur
Lateral
condyle
Medial and
lateral supracondylar lines
Surface for
patellar
Posterior
ligament
(a) Patella (kneecap)
Intercondylar fossa
Lateral
epicondyle
Medial condyle
Adductor
tubercle
Medial
epicondyle
Lateral epicondyle
Patellar surface
Anterior view
Posterior view
(b) Femur (thigh bone)
Figure 7.31
Bones of the Leg
• Tibia
• Medial leg bone
• Receives the weight of the body from the femur and
transmits it to the foot
• Fibula
• Not weight bearing; no articulation with femur
• Site of muscle attachment
• Connected to tibia by interosseous membrane
• Articulates with tibia via proximal and distal tibiofibular
joints
Lateral condyle
Head
Proximal tibiofibular
joint
Intercondylar eminence
Medial condyle
Tibial tuberosity
Interosseous membrane
Anterior border
Fibula
Tibia
Distal tibiofibular
joint
Lateral malleolus
Articular surface
Medial malleolus
(a) Anterior view
Figure 7.32a
Articular surface
of medial condyle
Medial condyle
Articular surface of
lateral condyle
Head of fibula
Interosseous
membrane
Tibia
Fibula
Articular surface
Medial malleolus
Lateral malleolus
(b) Posterior view
Figure 7.32b