7 The Skeleton: Part B Appendicular Skeleton
Revised by Dr. Par Mohammadian Overview of the Skeleton
Axial (Ch 7a) The Skull The Vertebral Column The Thoracic Cage Appendicular (Ch 7b) The Pectoral (Shoulder) Girdle The Upper limb The Pelvic (Hip) Girdle The Lower limb Developmental Aspects (Ch 7b) Overview of Appendicular Skeleton
The Pectoral (Shoulder) Girdle (Attaches upper limbs to body trunk) Clavicle Scapula The Upper limb Arm (humerus) Forearm (ulan, radius) Hand (carpus, palm, fingers) The Pelvic (Hip) Girdle (Attaches lower limbs to body trunk) Ilium Ischium Pubis The Lower limb Thigh Leg Foot Pectoral Girdle (Shoulder Girdle)
Acromio- clavicular joint Clavicles (anteriorly) and scapulae (posteriorly) Attach upper limbs to axial skeleton Provide attachment sites for muscles that move upper limbs Clavicle Scapula Articulated pectoral girdle Clavicles (Collarbones; little keys)
S-shaped; sternal end articulates with sternum medially acromial end articulates laterally with scapula Anchor muscles Act as braces to hold the scapulae and arms out laterally Sternal (medial) end Posterior Anterior Acromial (lateral) end Larger and stronger in those who perform manual labor or athletes using their shoulder and arm muscles. Right clavicle, superior view Right clavicle, inferior view
Figure 7.25cThe pectoral girdle and clavicle. Acromial end Anterior Trapezoid line Sternal end Posterior Conoid tubercle Right clavicle, inferior view 2013 Pearson Education, Inc. Scapulae (Shoulder Blades; shovel)
On dorsal surface of rib cage, between ribs 2 and 7 Flat and triangular, with 3 borders and 3 angles Several large fossae named according to location Suprascapular notch Acromion Superior border Coracoid process Superior angle Glenoid cavity Subscapular fossa Lateral border Medial border Inferior angle Right scapula, anterior aspect Coracoid (beaklike) process Suprascapular notch
Figure 7.26bThe scapula. Coracoid(beaklike) process Suprascapular notch Superior angle Acromion Supraspinous fossa Glenoid cavity at lateral angle Spine Infraspinous fossa Medial border Lateral border Right scapula, posterior aspect 2013 Pearson Education, Inc. Right scapula, lateral aspect
Figure 7.26cThe scapula. Supraspinous fossa Acromion Supraglenoid tubercle Supraspinous fossa Coracoid process Infraspinous fossa Subscapular fossa Spine Glenoid cavity Posterior Anterior Infraspinous fossa Infraglenoid tubercle Subscapular fossa Inferior angle Right scapula, lateral aspect 2013 Pearson Education, Inc. Overview of Appendicular Skeleton
The Pectoral (Shoulder) Girdle Clavicle Scapula The Upper limb Arm (humerus) Forearm (ulan, radius) Hand (carpus, palm, fingers) The Pelvic (Hip) Girdle (Attaches lower limbs to body trunk) Ilium Ischium Pubis The Lower limb Thigh Leg Foot 30 bones form skeletal framework of each upper limb
The Upper Limb 30 bones form 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 2013 Pearson Education, Inc. Humerus Largest, longest bone of upper limb
Articulates superiorly with glenoid cavity of scapula Articulates inferiorly with radius and ulna Greater tubercle Head of humerus Greater tubercle Lesser tubercle Anatomical neck Inter- tubercular sulcus Surgical neck Radial groove Deltoid tuberosity Deltoid Tuberosity (V-shaped) Medial supracondylar ridge Coronoid fossa Lateral supracondylar ridge Olecranon fossa Radial fossa Medial epicondyle Lateral epicondyle Capitulum Trochlea Anterior view Posterior view Bones of the Forearm Ulna (elbow) Medial bone in forearm
Radial notch of the ulna Head Neck tuberosity Olecranon Trochlear notch Coronoid process Proximal radioulnar joint Interosseous membrane Ulna Radius Ulnar notch of the radius Head of ulna Ulnar styloid process Distal Radial styloid Anterior view Posterior view Neck of radius Head of Ulna (elbow) Medial bone in forearm Forms major portion of elbow joint with humerus Radius (rod) Lateral bone in forearm Head articulates with capitulum of humerus and radial notch of ulna Interosseous membrane connects radius and ulna along their entire length Proximal portion of ulna, lateral view
Figure 7.28cdRadius and ulna of the right forearm. Olecranon (elbow) Trochlear notch View Coronoid process Radial notch Proximal portion of ulna, lateral view Ulnar notch of radius Articulation for lunate Articulation for scaphoid Radial styloid process Head of ulna Ulnar styloid process View Distal ends of the radius and ulna at the wrist 2013 Pearson Education, Inc. Posterior view of extended elbow Anterior view at the elbow region
Figure 7.27cdThe humerus of the right arm and detailed views of articulation at the elbow. Humerus Capitulum Head of radius Radial tuberosity Radius Coronoid fossa Medial epicondyle Trochlea process of ulna Radial notch Ulna Olecranon Lateral Head Neck Posterior view of extended elbow Anterior view at the elbow region 2013 Pearson Education, Inc. Hand: Carpus, Metacarpus, and Phalanges
Carpus (Wrist) Eight bones in two rows Proximal rowlateral to medial Scaphoid, lunate, triquetrum, and pisiform Trapezium, trapezoid, capitate, and hamate Only scaphoid, lunate, and triquetrum form wrist joint (Sally left the party to take Cindy home.); carpel tunnel syndrome: overuse of tendons causes inflammation-> swelling->compression of nerve Metacarpus (Palm) Five metacarpal bones (#1 to #5 -thumb ->little finger) form the palm Phalanges (Fingers) Fingers numbered 15 starting at thumb (pollex) Digit #1 (Pollex) has 2 bones - no middle phalanx Digits #2 5 have 3 bonesdistal, middle, and proximal phalanx Anterior view of right hand Posterior view of right hand
Figure Bones of the right hand. Phalanges Distal Middle Proximal Metacarpals Head Sesamoid bones Shaft Base Carpals IV III II V Hamate I Carpals II III IV I V Trapezium Carpals Capitate Hamate Pisiform Trapezoid Capitate Triquetrum Scaphoid Triquetrum Lunate Lunate Ulna Radius Ulna Anterior view of right hand Posterior view of right hand 2013 Pearson Education, Inc. Overview of Appendicular Skeleton
The Pectoral (Shoulder) Girdle Clavicle Scapula The Upper limb Arm (humerus) Forearm (ulan, radius) Hand (carpus, palm, fingers) The Pelvic (Hip) Girdle (Attaches lower limbs to body trunk) Ilium Ischium Pubis The Lower limb Thigh Leg Foot 2013 Pearson Education, Inc. Pelvic (Hip) Girdle Two hip bones (coxal bones or os coxae) and sacrum
Attach lower limbs to axial skeleton with strong ligaments Transmit weight of upper body to lower limbs Support pelvic organs Less mobility but more stable than shoulder joint Three fused bones form coxal bone Ilium, ischium, and pubis Bony pelvis formed by coxal bones, sacrum, and coccyx 2013 Pearson Education, Inc. Figure Pelvis. Hip Bone Three regions Ilium Ischium (hip) Pubis (sexually mature)
Superior region of coxal bone Auricular surface articulates with sacrum (sacroiliac joint) Ischium (hip) Posteroinferior part of hip bone Pubis (sexually mature) Anterior portion of hip bone Pubis bones join at pubic symphysis joint 2013 Pearson Education, Inc. Acetabulum (vinegar cup; receives the head of femur) Greater sciatic
Figure 7.31aThe hip (coxal) bones. Ilium Anterior gluteal line Ala Posterior gluteal line Iliac crest Anterior superior iliac spine Posterior superior iIiac spine Inferior gluteal line Anterior inferior iliac spine Posterior inferior iliac spine Acetabulum (vinegar cup; receives the head of femur) Greater sciatic notch Ischial body Ischial spine Pubic body Lesser sciatic notch Pubis Ischium Ischial tuberosity Obturator foramen Inferior pubic ramus Ischial ramus Lateral view, right hip bone 2013 Pearson Education, Inc. Figure 7.31c The hip (coxal) bones.
Anterior gluteal line Ilium Anterior superior iliac spine Posterior gluteal line Anterior inferior iliac spine Posterior superior iliac spine Inferior gluteal line Posterior inferior iliac spine Acetabulum Greater sciatic notch Ischial body Pubic body Ischial spine Lesser sciatic notch Pubic tubercle Ischium Inferior pubic ramus Ischial Tuberosity (when we sit ) Ischial ramus Obturator foramen Lateral view, right hip bone 2013 Pearson Education, Inc. Medial view, right hip bone
Figure 7.31bThe hip (coxal) bones. Ilium Iliac crest Iliac fossa Anterior superior iliac spine Posterior superior iliac spine Posterior inferior iliac spine Anterior inferior iliac spine Body of the ilium Arcuate line Auricular Surface (ear shaped) Superior pubic ramus Greater sciatic notch Ischial spine Pubic tubercle Lesser sciatic notch Obturator foramen Articular surface of pubis (at pubic symphysis) Ischium Ischial ramus Inferior pubic ramus Medial view, right hip bone 2013 Pearson Education, Inc. Figure 7.31d The hip (coxal) bones.
Auricular surface Ilium Anterior superior iliac spine Iliac fossa Anterior inferior iliac spine Posterior superior iliac spine Arcuate line Posterior inferior iliac spine Superior pubic ramus Greater sciatic notch Ischial spine Pubic tubercle Lesser sciatic notch Ischium Articular surface of pubis (at pubic symphysis) Inferior pubic ramus Ischial ramus Obturator foramen Medial view, right hip bone 2013 Pearson Education, Inc. Comparison of Male and Female Pelves
Female pelvis Adapted for childbearing True pelvis (inferior to pelvic brim) defines birth canal Cavity of true pelvis is broad, shallow, and has greater capacity Male pelvis Tilted less far forward Adapted for support of male's heavier build and stronger muscles Cavity of true pelvis is narrow and deep 2013 Pearson Education, Inc. Table 7.4 Comparison of the Male and Female Pelves (1 of 3)
2013 Pearson Education, Inc. Table 7.4 Comparison of the Male and Female Pelves (2 of 3)
2013 Pearson Education, Inc. Table 7.4 Comparison of the Male and Female Pelves (3 of 3)
2013 Pearson Education, Inc. Overview of Appendicular Skeleton
The Pectoral (Shoulder) Girdle Clavicle Scapula The Upper limb Arm (humerus) Forearm (ulan, radius) Hand (carpus, palm, fingers) The Pelvic (Hip) Girdle Ilium Ischium Pubis The Lower limb Thigh Leg Foot Carries entire weight of erect body
The Lower Limb Carries entire weight of erect body Subjected to exceptional forces if jump or run Three segments of lower limb Thigh Leg Foot 2013 Pearson Education, Inc. Bones Of The Thigh Patella (knee cap)
Neck Fovea capitis Greater trochanter Head Femur (=thigh) Largest and strongest bone in the body Length ~ of person's height Articulates proximally with acetabulum of hip and distally with tibia and patella Inter- trochanteric crest Lesser trochanter Intertrochanteric line Gluteal tuberosity Apex Linea aspera Anterior Facet for lateral condyle of femur Facet for medial condyle of femur Medial and lateral supra- condylar lines Lateral condyle Popliteal surface Lateral epicondyle Surface for patellar ligament Intercondylar fossa Posterior Medial condyle Patella (kneecap) Lateral epicondyle Adductor tubercle Medial epicondyle Patellar surface Patella (knee cap) Sesamoid bone in quadriceps tendon Anterior view Posterior view Femur (thigh bone) Bones Of The Leg Tibia (shin bone) Medial leg bone
Intercondylar eminence Lateral condyle Medial condyle Tibia (shin bone) Medial leg bone Receives weight of body from femur; transmits to foot; not covered by muscles Fibula Not weight bearing; no articulation with femur Several muscles originate from fibula Articulates proximally and distally with tibia Tibia and fibula connected by interosseous membrane Head Tibial tuberosity Superior tibiofibular joint Interosseous membrane Anterior border Fibula Tibia Inferior tibiofibular joint Medial Malleolus (medial bulge of ankle) Lateral malleolus Inferior articular surface Anterior view Inferior articular surface Posterior view
Figure 7.33bThe tibia and fibula of the right leg. Articular surface of medial condyle Articular surface of lateral condyle Medial condyle Head of fibula Interosseous membrane Tibia Fibula Medial malleolus Lateral malleolus Inferior articular surface Posterior view 2013 Pearson Education, Inc. Lateral condyle Lateral condyle Fibula articulates here Tibial
Figure 7.33cdThe tibia and fibula of the right leg. Lateral condyle Lateral condyle Fibula articulates here Tibial tuberosity Line for soleus muscle Anterior view, proximal tibia Posterior view, proximal tibia Parts of fractured fibula X ray of fracture of the fibula Foot: Tarsus, Metatarsus, Phalanges
7x tarsal bones Body weight carried primarily by talus and calcaneus (heel bone) Other tarsal bones: cuboid, navicular, and medial, intermediate, and lateral cuneiform bones Metatarsals: 5x metatarsal bones (#1 to #5 from hallux to little toe) Enlarged head of metatarsal 1 forms "ball of the foot" Phalanges 14 bones of toes Digit #1 (Hallux) has 2 bones - no middle phalanx Digits #25 have 3 bonesdistal, middle, and proximal phalanx Phalanges Distal Middle Proximal I II III Metatarsals IV Medial
Figure 7.34aBones of the right foot. Phalanges Distal Middle Proximal I II III Metatarsals IV Medial cuneiform V Intermediate cuneiform Lateral cuneiform Navicular Cuboid Tarsals Talus Trochlea of talus Calcaneus Superior view 2013 Pearson Education, Inc. Medial Talus malleolar facet Navicular Intermediate cuneiform
Figure 7.34bBones of the right foot. Talus Medial malleolar facet Navicular Intermediate cuneiform Sustentac- ulum tali (talar shelf) First metatarsal Calcaneus Medial cuneiform Calcaneal tuberosity Medial view Intermediate cuneiform
Figure 7.34cBones of the right foot. Lateral malleolar facet Navicular Intermediate cuneiform Lateral cuneiform Talus (ankle) Calcaneus Cuboid Fifth metatarsal Lateral view 2013 Pearson Education, Inc. Arches Of The Foot Medial longitudinal arch Transverse arch
Maintained by interlocking foot bones, ligaments, and tendons; Allow foot to bear weight; Three arches: Medial longitudinal arch Transverse arch Lateral longitudinal arch Lateral aspect of right foot Overview of the Skeleton
Axial (Ch 7a) The Skull The Vertebral Column The Thoracic Cage Appendicular (Ch 7b) The Pectoral (Shoulder) Girdle The Upper limb The Pelvic (Hip) Girdle The Lower limb Developmental Aspects (Ch 7b) 2013 Pearson Education, Inc. Developmental Aspects: Fetal Skull
Infant skull has more bones than adult skull Skull bones such as mandible and frontal bones are unfused Skull bones connected by fontanelles Unossified remnants of fibrous membranes Ease birth and allow brain growth Four fontanelles Anterior, posterior, mastoid, and sphenoidal 2013 Pearson Education, Inc. Fontanelle ( soft spot)
Figure 7.36abSkull of a newborn. Frontal suture Frontal bone Anterior Fontanelle ( soft spot) Ossification center Parietal bone Posterior fontanelle Occipital bone Superior view Frontal bone Sphenoidal fontanelle Parietal bone Ossification center Posterior fontanelle Mastoid fontanelle Occipital bone Temporal bone (squamous portion) Lateral view 2013 Pearson Education, Inc. Congenital Abnormalities Of Skull
Cleft palate No medial fusion of right and left halves of palate 2013 Pearson Education, Inc. Developmental Aspects: Growth Rates
At birth, cranium huge relative to face At 9 months, cranium is adult size Mandible and maxilla are foreshortened but lengthen with age Arms and legs grow at faster rate than head and trunk, leading to adult proportions Human newborn Human adult 2013 Pearson Education, Inc. Newborn 2 yrs 5 yrs 15 yrs Adult
Figure 7.39bDifferent growth rates of body parts determine body proportions. Newborn 2 yrs 5 yrs 15 yrs Adult 2013 Pearson Education, Inc. Developmental Aspects: Spinal Curvature
Primary thoracic and sacral curvatures obvious at birth Give spine a C shape Convex posteriorly Secondary curvatures Cervical and lumbarconvex anteriorly Appear as child develops (e.g., lifts head, learns to walk) 2013 Pearson Education, Inc. Developmental Aspects: Old Age
Intervertebral discs thin, less hydrated, and less elastic Risk of disc herniation increases Several centimeter height loss common by 55 Costal cartilages ossify Rigid thorax causes shallow breathing and less efficient gas exchange All bones lose mass, so fracture risk increases 2013 Pearson Education, Inc.