The Appendicular Skeleton · Copyright © 2009 Pearson Education, Inc., publishing as Pearson...

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

C h a p t e r

8

The

Appendicular Skeleton

PowerPoint® Lecture Slides

prepared by Jason LaPres

Lone Star College - North Harris

Copyright © 2009 Pearson Education, Inc.,

publishing as Pearson Benjamin Cummings


An Introduction to the Appendicular

Skeleton

The Appendicular Skeleton

126 bones

Allows us to move and manipulate objects

Includes all bones besides axial skeleton

The limbs

The supportive girdles


An Introduction to the Appendicular

Skeleton

Figure 8–1 The Appendicular Skeleton.


The Pectoral Girdle

Also called the shoulder girdle

Connects the arms to the body

Positions the shoulders

Provides a base for arm movement

Consists of

Two clavicles

Two scapulae

Connects with the axial skeleton only at the

manubrium


The Pectoral Girdle

The Clavicles

Also called collarbones

Long, S-shaped bones

Originate at the manubrium (sternal end)

Articulate with the scapulae (acromial end)


The Pectoral Girdle

Figure 8–2 The Clavicle.


The Pectoral Girdle

The Scapulae

Also called shoulder blades

Broad, flat triangles

Articulate with arm and collarbone

Anterior surface: the subscapular fossa


The Pectoral Girdle

The Scapulae

Structures of the scapula

Body has three sides:

– superior border

– medial border (vertebral border)

– lateral border (axillary border)

Body has three corners:

– superior angle

– inferior angle

– lateral angle


The Pectoral Girdle

The Scapulae

The scapular head

Holds glenoid cavity

Which articulates with humerus

To form shoulder joint

Processes of the glenoid cavity

Coracoid process:

– anterior, smaller

Acromion:

– posterior, larger

– articulates with clavicle

– at the acromioclavicular joint


The Pectoral Girdle

Figure 8–3 The Scapula.


The Pectoral Girdle

The Scapulae

Posterior features of the scapula

Scapular spine:

– ridge across posterior surface of body

Separates two regions:

– supraspinous fossa

– infraspinous fossa

3D Rotation of Scapula, Clavicle, and Humerus

08ScapClavHum_3DROT_3D.mov


The Upper Limbs

The upper limbs consist of the arms,

forearms, wrists, and hands

Note: arm (brachium) = 1 bone, the humerus


The Upper Limbs

The Humerus

Also called the arm

The long, upper arm bone

Articulates with the pelvic girdle


The Upper Limbs

The Humerus

Tubercles of the proximal epiphysis

Separated by the intertubercular groove:

– greater tubercle:

» lateral

» forms tip of shoulder

– lesser tubercle:

» anterior, medial


The Upper Limbs

The Humerus

Head:

Rounded, articulating surface

Contained within joint capsule

Anatomical neck:

Margin of joint capsule

Surgical neck:

The narrow metaphysis


The Upper Limbs

The Humerus

The Shaft

Deltoid tuberosity:

– a bulge in the shaft

– attaches deltoid muscle

Radial groove:

– for radial nerve

– posterior to deltoid tuberosity


The Upper Limbs

The Humerus

The distal epiphysis

Medial and lateral epicondyles:

– for muscle attachment

Condyle of the humerus:

– articulates with ulna and radius

Articular regions of the condyle

Trochlea:

– coronoid fossa and olecranon fossa

– articulates with ulna

Capitulum:

– radial fossa

– articulates with radius


The Upper Limbs

Figure 8–4a The Humerus.


The Upper Limbs

Figure 8–4b The Humerus.


The Upper Limbs

The Forearm (also called the antebrachium)

Consists of two long bones

Ulna (medial)

Radius (lateral)


The Upper Limbs

The Ulna

The olecranon

Superior end of ulna

Point of elbow

Superior lip of trochlear notch

Articulates with trochlea of humerus

The coronoid process

Inferior lip of trochlear notch


The Upper Limbs

The Ulna

Articulations with the humerus

Forearm extended:

– olecranon enters olecranon fossa

Forearm flexed:

– coronoid process enters coronoid fossa

Other articulations

Radial notch:

– articulates with head of radius

– forms proximal radio-ulnar joint

Ulnar head:

– prominent styloid process

– attaches to articular disc between forearm and wrist


The Upper Limbs

Figure 8–5a The Radius and Ulna.


The Upper Limbs

The Ulna

Interosseous membrane

A fibrous sheet

Connects lateral margin of ulnar shaft to radius


The Upper Limbs

The Radius

Lateral bone of forearm

Disk-shaped radial head above the neck

Radial tuberosity below the neck, attaches biceps

Articulations of the radius

Ulnar notch:

– distal end

– articulates with wrist and radius

Styloid process:

– stabilizes wrist joint


The Upper Limbs

Figure 8–5b The Radius and Ulna.


The Upper Limbs

Eight carpal bones

Four proximal carpal bones

Four distal carpal bones

Allow wrist to bend and twist


The Upper Limbs

The Four Proximal Carpal Bones

Scaphoid

Near styloid process

Lunate

Medial to scaphoid

Triquetrum

Medial to lunate bone

Pisiform

Anterior to triquetrum


The Upper Limbs

The Four Distal Carpal Bones

Trapezium

Lateral

Trapezoid

Medial to trapezium

Capitate

Largest

Hamate

Medial, distal


The Upper Limbs

Figure 8–6 Bones of the Wrist and Hand.


The Upper Limbs

Metacarpal Bones

The five long bones of the hand

Numbered I–V from lateral (thumb) to medial

Articulate with proximal phalanges

Phalanges of the Hands (14 total finger bones)

Pollex (thumb) Two phalanges (proximal, distal)

Fingers Three phalanges (proximal, middle, distal)


The Upper Limbs

Figure 8–6a Bones of the Wrist and Hand.


The Upper Limbs

Figure 8–6b Bones of the Wrist and Hand.


The Pelvic Girdle

Made up of two hip bones (coxal bones)

Strong to bear body weight, stress of

movement

Part of the pelvis

Coxal bones

Made up of three fused bones

Ilium (articulates with sacrum)

Ischium

Pubis


The Pelvic Girdle

Coxal Bones

The acetabulum

Also called the hip socket

Is the meeting point of the ilium, ischium, and

pubis

Is on the lateral surface of the hip bone (coxal

bone)

Articulates with head of the femur (lunate surface)

Acetabular notch

A gap in the ridge of the margins of the

acetabulum


The Pelvic Girdle

Figure 8–7a The Right Coxal Bone.


The Pelvic Girdle

Figure 8–7b The Right Coxal Bone.


The Pelvic Girdle

Marks of the Ilium

Greater sciatic notch

For sciatic nerve

Iliac crest

Upper brim

Iliac fossa

Depression between iliac crest and arcuate line


The Pelvic Girdle

Marks of the Ischium

Ischial spine

Above lesser sciatic notch

Ischial tuberosity

Posterior projection you sit on

Ischial ramus

Meets inferior ramus of pubis

Superior ramus

Meets pubic tubercle


The Pelvic Girdle

Marks of the Pubis

Pubic symphysis

Gap between pubic tubercles

Padded with fibrous cartilage

Obturator foramen

Formed by ischial and pubic rami

Attaches hip muscles

Pectineal line

Ridge of superior ramus of pubis

Continues to iliac crest as arcuate line (both of the ilium)


The Pelvic Girdle

Figure 8–7 The Right Coxal Bone.


The Pelvic Girdle

Coxal Bones

Articulations of the pelvic girdle

Sacroiliac joint

– Articulation of posterior auricular surface of ilium

– With the sacrum

– Stabilized by ligaments of iliac tuberosity

The Pelvis

Consists of two coxal bones, the sacrum, and the coccyx

Stabilized by ligaments of pelvic girdle, sacrum, and lumbar

vertebrae

3D Rotation of Pelvis

08Pelvis_3DROT_3D.mov


The Pelvic Girdle

Figure 8–8a The Pelvis.


The Pelvic Girdle

Figure 8–8b The Pelvis.


The Pelvic Girdle

Divisions of the Pelvis

True pelvis

Encloses pelvic cavity

Pelvic brim:

– upper edge of true pelvis

– encloses pelvic inlet

Perineum region:

– inferior edges of true pelvis

– forms pelvic outlet

– perineal muscles support organs of pelvic cavity

False pelvis:

Blades of ilium above arcuate line


The Pelvic Girdle

Figure 8–9a Divisions of the Pelvis.


The Pelvic Girdle

Figure 8–9b Divisions of the Pelvis.


The Pelvic Girdle

Figure 8–9c Divisions of the Pelvis.


The Pelvic Girdle

Comparing the Male Pelvis and Female Pelvis

Female pelvis

Smoother and lighter

Less prominent muscle and ligament attachments

Pelvis modifications for Childbearing

– enlarged pelvic outlet

– broad pubic angle (>100°)

– less curvature of sacrum and coccyx

– wide, circular pelvic inlet

– broad, low pelvis

– ilia project laterally, not upwards

Male and Female Pelvis

08MFPelvis_NA_SWF.html


The Pelvic Girdle

Figure 8–10 Anatomical Differences in the Pelvis of a Male and a

Female.


The Pelvic Girdle

Figure 8–10a Anatomical Differences in the Pelvis of a Male and a

Female.


The Pelvic Girdle

Figure 8–10b Anatomical Differences in the Pelvis of a Male and a

Female.


The Lower Limbs

Functions of the lower limbs

Weight bearing

Motion

Note: leg = lower leg; thigh = upper leg


The Lower Limbs

Bones of the Lower Limbs

Femur (thigh)

Patella (kneecap)

Tibia and fibula (leg)

Tarsals (ankle)

Metatarsals (foot)

Phalanges (toes)


The Lower Limbs

The Femur

The proximal epiphysis

Femoral head:

– articulates with pelvis at acetabulum

– attaches at fovea capitis

The neck:

– Narrow area between head and trochanters

– Joins shaft at angle


The Lower Limbs

The Femur


Trochanters:

– greater trochanter and lesser trochanter:

» tendon attachments

– intertrochanteric line (anterior) and intertrochanteric crest

(posterior):

» mark edge of articular capsule


The Lower Limbs

The Femur

The shaft

Linea aspera:

– most prominent ridge of shaft

– attaches hip muscles

– joins epicondyles


Medial epicondyle and lateral epicondyle:

– above the knee joint

Medial condyle and lateral condyle:

– separated by intercondylar fossa and patellar surface

– form part of knee joint


The Lower Limbs

Figure 8–11 The Femur.


The Lower Limbs

Figure 8–11a The Femur.


The Lower Limbs

Figure 8–11b The Femur.


The Lower Limbs

The Patella

Also called the kneecap

A sesamoid bone

Formed within tendon of quadriceps femoris

Base attaches quadriceps femoris

Apex attaches patellar ligament


The Lower Limbs

Figure 8–12 The Right Patella.


The Lower Limbs

The Tibia

Also called the shinbone

Supports body weight

Larger than fibula

Medial to fibula


The Lower Limbs

The Tibia


Medial and lateral tibial condyles:

– separated by intercondylar eminence

– articulate with medial and lateral condyles of femur

Tibial tuberosity:

– attaches patellar ligament


The Lower Limbs

The Tibia

The shaft

Anterior margin:

– sharp ridge of shinbone


Medial malleolus:

– medial projection at the ankle


The Lower Limbs

The Fibula

Attaches muscles of feet and toes

Smaller than tibia

Lateral to tibia


The Lower Limbs

The Fibula

Articulations with tibia

Fibula/tibia articulations:

– head

– inferior tibiofibular joint

Interosseous membrane:

– binds fibula to tibia

Lateral malleolus:

– lateral projection of ankle


The Lower Limbs

Figure 8–13 The Tibia and Fibula.


The Lower Limbs

Figure 8–13a The Tibia and Fibula.


The Lower Limbs

Figure 8–13b The Tibia and Fibula.


The Lower Limbs

The Ankle

Also called the tarsus

Consists of seven tarsal bones

Bones of the ankle

Talus:

– carries weight from tibia across trochlea

Calcaneus (heel bone):

– transfers weight from talus to ground

– attaches calcaneal (Achilles) tendon

Cuboid:

– articulates with calcaneus


The Lower Limbs

The Ankle

Bones of the ankle

Navicular:

– articulates with talus and three cuneiform bones

Medial cuneiform

Intermediate cuneiform

Lateral cuneiform


The Lower Limbs

Figure 8–14a Bones of the Ankle and Foot.


The Lower Limbs

Metatarsal Bones of the Foot

Five long bones of foot

Numbered I–V, medial to lateral

Articulate with toes


The Lower Limbs

Phalanges of the foot

Phalanges

14 bones of the toes

Hallux

Big toe or great toe, two phalanges (distal,

proximal)

Other four toes

Three phalanges (distal, medial, proximal)


The Lower Limbs

Figure 8–14a Bones of the Ankle and Foot.


The Lower Limbs

Arches of the Feet

Arches transfer weight from one part of the

foot to another

The longitudinal arch

Calcaneal portion:

– lateral

Talar portion:

– medial

The transverse arch

Formed by a difference in curvature between

medial and lateral borders of the foot


The Lower Limbs

Figure 8–14b Bones of the Ankle and Foot.


Individual Skeleton Variation

Studying the Skeleton

Reveals characteristics

Muscle strength and mass (bone ridges, bone

mass)

Medical history (condition of teeth, healed

fractures)

Sex and age (bone measurements and fusion)

Body size


Individual Skeleton Variation

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