Chapter 8: The Appendicular Skeleton
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Transcript Chapter 8: The Appendicular Skeleton
Chapter 8:
The Appendicular Skeleton
BIO 210 Lab
Instructor: Dr. Rebecca Clarke
Appendicular Skeleton
Allows us to move and manipulate objects
Includes all bones besides axial skeleton:
the limbs
the supportive girdles
Pectoral (shoulder)
Pelvic
Appendicular Skeleton
Figure 8–1
Pectoral Girdle
Also called the shoulder girdle
Positions shoulder joints
Connects the arms to the body
Provides base for muscle attachment
Helps move upper limbs
Pectoral Girdle
Figure 8–2a
Pectoral Girdle
Consists of:
2 clavicles
2 scapulae
Connects with axial skeleton only at the manubrium (clavicle
articulations)
Clavicle
Also called collarbone
Long, S-shaped bone
Originates at manubrium (sternal end)
Articulates with scapula (acromial end)
Relatively fragile so fractures common
Clavicle
Sternal End:
Square, flat surface
Articulates with
manubrium; only ones
between axial skeleton
and pectoral girdle
Acromial End:
Flatter, broader end
Articulates with
acromion of scapula
Figure 8–2b, c
Scapula
Also called shoulder blade
Broad, flat triangle
Articulates with arm and collarbone
Skeletal muscles support/position
Extreme mobility
Not much strength
Scapula: Posterior Surface
Body
Broad, flat, triangular area
Has 3 borders/ margins
Superior
Medial
Lateral
Figure 8–3c
Scapula: Posterior Surface
Spine
Large ridge across posterior
surface
Shoulder blade
Supraspinous fossa
Depression superior to spine
Infraspinous fossa
Depression inferior to spine
Figure 8–3c
Scapula: Posterior Surface
Acromion
Large, posterior extension at
lateral end of spine
Articulates with clavicle
(acromial end)
Figure 8–3c
Scapula: Lateral View
Glenoid fossa (cavity)
Cup-shaped, lateral depression
Articulates with humerus
Forms shoulder joint
Figure 8–3c
Scapula: Lateral View
Coracoid process
Smaller, anterior projection
superior to glenoid cavity
Near clavicle vs coronoid process
on mandible near nose)
Figure 8–3c
Scapula: Anterior Surface
Subscapular fossa
Depression on smooth,
anterior side of body
Figure 8–3a
Bones of the Upper Limbs
Brachium (arm)
Antebrachium (forearm)
Ulna
Radius
Carpals (wrist)
Metacarpals (hand)
Phalanges (fingers)
Humerus
Only bone in brachium (arm)
Extends from scapula to elbow
Articulates with pectoral girdle
on proximal end (head) – with glenoid fossa of scapula
on distal end – with radius and ulna (bones of antebrachium)
Humerus
Head
Large, ball-shaped structure on
proximal end
Greater tubercle
Larger, rounded projection on
lateral/posterior surface of
epiphysis
Lesser tubercle
Smaller projection on
medial/anterior surface
Intertubercular groove
Separates tubercles
Figure 8–4
Humerus
Anatomical neck
Narrow groove between base of head
and tubercles
Margin of joint capsule
Surgical neck
At metaphysis
Where fractures often occur
Deltoid tuberosity
Rough ridge on-anterior surface of
shaft
Where deltoid muscle attaches
Figure 8–4
Humerus
Condyle
= rounded projection for muscle
attachment
Distal epiphysis where humerus
articulates with radius and ulna
“Knuckles” on anterior surface of
humerus
Figure 8–4
Humerus
Lateral epicondyle
Medial epicondyle
More prominent than lateral one
Trochlea (“pulley” or “spool”)
In center of condyle (middle
“knuckle)
Where trochlear notch of ulna
rotates during forearm flexion
Capitulum
Forms a “cap” over the radius
Figure 8–4
Humerus
Coronoid fossa
On anterior surface
Articulates with coronoid process of
ulna
Olecranon fossa
On posterior surface
Articulates with olecranon of ulna
Figure 8–4
Antebrachium (Forearm)
Consists of 2 long bones:
Ulna (medial)
Radius (lateral)
“Rotates”
Site of radial pulse
Figure 8–5
Ulna
Olecranon (process)
Large, curved projection (like
cobra head) on proximal end
“U” for ulna
Articulates in olecranon fossa
of humerus
Superior lip of trochlear notch
Point of elbow
Figure 8–5
Ulna
Trochlear notch
Anterior curved surface of
proximal epiphysis
Articulates with trochlea of
humerus
Coronoid process
Inferior lip of trochlear notch
Articulates in coronoid fossa of
humerus
Figure 8–5
Ulna
Head
Much smaller, distal epiphysis
(near wrist)
Articulates with radium and carpal
(wrist) bones
Styloid process
Medial pointed extension at distal
epiphysis
On posterior, lateral surface of
head
Figure 8–5
Ulna: Articulations
with the Humerus
Forearm extended:
Olecranon enters olecranon fossa
Forearm flexed:
Coronoid process enters coronoid fossa
Radius
Head
Disc-shaped proximal epiphysis
Articulates with humerus
Neck
Narrow region between head and
tuberosity
Radial tuberosity
Structure at proximal end of diaphysis
below neck
Marks attachment site of biceps brachii
muscle
Figure 8–5
Radius
Shaft
Curves and broadens
Distal portion much larger
than distal portion of ulna
Styloid process
Lateral pointed extension at
distal epiphysis
Stabilizes wrist joint
Figure 8–5
Carpal Bones
Allow wrist to bend and twist
8 bones
“Sam likes to push the toy car hard.”
Carpal Bones
Scaphoid
Trapezium
Lunate
Trapezoid
Triquetrum
Capitate
Pisiform
Hamate
Wrist and Hand Bones
Figure 8–6
Metacarpal Bones
5 long bones of the hand
Numbered I–V from lateral (thumb) to medial
Articulate with proximal phalanges
Phalanges (Phalanx=singular)
Finger bones
I (lateral)
Pollex (thumb):
2 phalanges (proximal, distal)
II -V
3 phalanges (proximal, medial or middle, distal)
Pelvic Girdle
Functions
Weight-bearing
Locomotion
Bones more massive than those of pectoral girdle
Strong to bear body weight
Pelvic Girdle
Made up of 2 hip bones (coxal bones or pelvic bones)
Each hip bone is made up of 3 fused bones:
Ilium (articulates with sacrum)
Ischium
Pubis
Pelvic Girdle
Figure 8–7
Pelvic Girdle: Ilium
Largest hip bone
Superior part of coxae
Fused to ischium
(posteriorly) and pubis
(anteriorly)
Articulates with sacrum
– attaches pelvic girdle
to axial skeleton
Figure 8–7
Pelvic Girdle: Ilium
Iliac crest
Superior border
Anterior superior iliac
spine (ASIS)
Anterior inferior iliac
spine (AIIS)
Posterior superior iliac
spine (PSIS)
Posterior inferior iliac
spine (PIIS)
Figure 8–7
Pelvic Girdle: Ilium
Iliac fossa
Depression on anterior aspect
Sacroiliac joint
Between posterior superior and
inferior spines; where ilium and
sacrum articulate
Greater sciatic notch
Inferior to PIIS
Passageway for large sciatic nerve
Figure 8–7
Pelvic Girdle: Ischium
Posterior-inferior part of
coxae
Ischial spine
Inferior to greater sciatic notch
At posterior-superior end
Lesser sciatic notch
Inferior to ischial spine
Ischial tuberosity
Thickened posterior-inferior part
Bears body weight when seated
(“sit bone”)
Figure 8–7
Pelvic Girdle: Pubis
Anterior-inferior part of
coxae
Pubic symphysis
Joint where anterior medial
surfaces of pubic bones are
interconnect by
fibrocartilage pad
Limits movement between
pubic bones of left and right
hipbones
Figure 8–7
Pelvic Girdle: Acetabulum
Also called the hip socket
Large, concave socket on
lateral surface of os coxae
Meeting point of ilium,
ischium, and pubis
Articulates with head of
femur
Figure 8–7
Pelvic Girdle: Obturator Foramen
Large space encircled by
pubis and ischium
Closed by sheet of collagen
fibers
Provides base for hip muscles
Figure 8–7
Pelvis
Consists of:
2 hip bones
Sacrum
Coccyx (of axial skeleton)
Stabilized by ligaments of pelvic girdle, sacrum, and lumbar
vertebrae
Pelvis
Figure 8–8
Pelvic Openings
Pelvic inlet – (anterior) space enclosed by pelvic brim
Pelvic outlet – opening bounded by coccyx and ischial
tuberosities
Figure 8–9
Pubic Angle
Inferior angle between pubic bones
Figure 8–10
Bones of the Lower Limbs
Femur (thigh)
Patella (kneecap)
Tibia and fibula (leg)
Tarsals (ankle)
Metatarsals (foot)
Phalanges (toes)
Femur
Longest, heaviest bone
Transfers body weight to ground
Articulates with:
coxae at acetabulum
tibia at knee joint
Figure 8–11
Femur
Head
Large, round proximal end
Articulates at acetabulum
Neck
Narrow connector between head and
shaft
Joins shaft at angle
Figure 8–11
Femur
Greater trochanter
Large process at superior end of shaft
Lesser trochanter
Smaller process inferior to neck on
medial /posterior side
Figure 8–11
Femur
Lateral condyle
Large, rounded, lateral projection at
distal epiphysis
Articulates with lateral condyle of
tibia
Medial condyle
Large, rounded, medial projection at
distal epiphysis
Articulates with medial condyle of
tibia
Figure 8–11
Femur
Intercondylar fossa
Depression between condyles on
posterior side
Figure 8–11
Femur
Patellar surface
Flattened area between condyles on
anterior side
Figure 8–11
Patella
Large sesamoid bone
Forms within tendon of quadriceps femoris
(extends/straightens the knee)
Figure 8–12
Tibia
Larger, medial bone; supports body weight
Also called the shinbone
Figure 8–13
Tibia
Lateral condyle
Lateral projection at proximal
epiphysis
Articulates with lateral condyle
of femur
Medial condyle
Medial projection at proximal
epiphysis
Articulates with medial condyle
of femur
Figure 8–13
Tibia
Tibial tuberosity
Roughened area on anterior
surface
Inferior to condyles
Attachment for patellar
ligament
Figure 8–13
Tibia
Anterior margin
Ridge that begins at tibial
tuberosity and extends distally
along anterior surface (“shin
bone”)
Medial malleolus (“little
mallet”)
Projection on medial side at
distal epiphysis
Figure 8–13
Fibula
Slender, lateral bone of lower leg
Figure 8–13
Fibula
Head
Articulates with proximal tibia
Lateral malleolus
Projection on lateral side at
distal epiphysis
Articulates with distal tibia
Provides lateral stability to
ankle
Figure 8–13
Tarsal Bones
Allow ankle to bend and twist
7 bones
Ankle and Foot Bones
Figure 8–14a
Tarsal Bones
Talus
Cuneiforms (3)
Calcaneous
Navicular
Cuboid
Note: movement more
restricted than wrist/hand
Metatarsal Bones
5 long bones of the foot
Numbered I–V from medial (big toe) to lateral
Articulate with proximal phalanges
Phalanges
Toe bones
I (lateral)
Hallus (big toe):
2 phalanges (proximal, distal)
II -V
3 phalanges (proximal, medial or middle, distal)