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AXIAL SKELETON PART I: SKULL
Bony Features
• Projections that help form Joints • Depressions and Openings • Sites of Muscle and Ligament attachment
Features
• Trochanter / Tuberosity
• Tubercle • Crest • Spine • Condyle
• Epicondyle • Ramus • Head • Facet • Fossa • Meatus
• Foramen • Fissure • Malleolus • Notch • Protuberance
Naming Features and Bones
Feature of the (R or L) Bone – Tibial tuberosity of the right tibia – Optic foramen of the sphenoid bone – Head of the left humerus
What are the bones and features of the axial skeleton?
Skeletal Components
• Axial Skeleton – Skull: cranial and facial bones – Vertebral Column – Rib Cage
• Appendicular Skeleton – Upper and Lower Limbs – Attachment girdles: pelvic and
pectoral girdles
Bones of the Axial Skeleton • The skull:
– 8 cranial bones – 14 facial bones
• Bones associated with the skull: – 6 auditory ossicles – the hyoid bone
• The vertebral column: – 24 vertebrae – the sacrum – the coccyx
• The thoracic cage: – 24 ribs – the sternum
What are the bones and features of the cranium?
The Cranial Bones
• Occipital bone • Frontal bone
• Parietal bones (2) • Temporal bones (2)
• Sphenoid • Ethmoid
Features of the Occipital Bone
– External occipital protuberance – Occipital condyles – Foramen magnum – Jugular foramen – Hypoglossal canals
Parietal Bones
Features of the Frontal Bone
– Frontal squama (forehead) – Supraorbital margin (protects eye)
Features of the Temporal Bones
– Zygomatic process – Mastoid process – Styloid process – External auditory (acoustic) canal – Mandibular fossa – Carotid canal – Foramen lacerum
Features of the Sphenoid
– Right and Left Optic canal – Sella turcica
• Hypophyseal fossa
Features of the Ethmoid – Cribriform plate
• Olfactory foramina – Crista galli – Superior nasal conchae – Middle nasal conchae
What are the other features of the skull, as a whole?
Sinuses • Cavities which decrease the weight of the skull:
– lined with mucus membranes – protect the entrances of the respiratory system
Sutures
Immovable joints of the skull: • Lambdoid suture • Coronal suture • Sagittal suture • Squamous suture
What are the differences between the skulls of infants and adults?
The Infant Skull • Has many ossification centers • Fusion is not complete at birth:
– 2 frontal bones – 4 occipital bones – several sphenoid and temporal elements
• Fontanels: – Are areas of fibrous connective tissue (soft spots) – Cover unfused sutures in the infant skull – Allow the skull to flex during birth
The 4 Fontanels
• Anterior fontanel: – frontal, sagittal, and coronal sutures
• Occipital fontanel: – lambdoid and sagittal sutures
• Sphenoidal fontanels: – squamous and coronal sutures
• Mastoid fontanel: – squamous and lambdoid sutures
What are the bones and features of the face?
Features of the Mandible
– Body – Alveolar margin
• processes – Ramus – Mandibular condyle – Mental foramen – Mandibular foramen – Angle – Coronoid process
Features of the Maxillae
– Alveolar margin • processes
– Palatine processes – Maxillary sinuses – Nasolacrimal canal
Palatine Bones
Small Facial Bones • Nasal bone • Vomer • Lacrimal bone
– Lacrimal fossa (sulcus) • Inferior nasal conchae
Features of the Zygomatic Bones
– Temporal process
Functions of the Hyoid Bone • Supports the larynx • Attaches muscles of the larynx, pharynx, and tongue
AXIAL SKELETON PART II: VERTEBRAL COLUMN
What are the bones of the vertebral column?
Axial Skeleton: Vertebral Column
• Cervical Vertebrae – 7 • Thoracic Vertebrae - 12 • Lumbar Vertebrae - 5 • Sacrum • Coccyx
What are the common features of all vertebrae?
Features on all Vertebra
– Body – Spinous process – Transverse process – Vertebral canal – Superior articulating process – Inferior articulating process
– Vertebral arch – Pedicles – Laminae
What are the specialized features and functions of each vertebral group?
Characteristics of Cervical Vertebrae
C1–C7 – Atlas (C1) – Axis (C2)
• Specialized features: – Bifid spinous process (C2–C7) – Transverse foramen (C1–C7)
Characteristics of Thoracic Vertebrae
T1–T12 • Specialized features:
– Costal facets
Characteristics of Lumbar Vertebrae L1–L5 • Specialized features:
– Large body – Stumpy spinous process
Characteristics of the Sacrum and Coccyx • Females curvature is more ‘shallow’ • The adult sacrum:
– consists of 5 fused sacral vertebrae – fuses between puberty and ages 25–30 – leaving transverse lines
• Mature coccyx: – consists of 3 to 5 fused coccygeal vertebrae
AXIAL SKELETON PART II: VERTEBRAL COLUMN
What are the components of the thoracic cage?
Axial Skeleton: Thorax
• 12 pair of ribs – True Ribs (7) – False Ribs (3) – Floating Ribs (2)
• Sternum
Features of the Sternum • Manubrium • Body • Xiphoid process
APPENDICULAR SKELETON PART I: PECTORAL GIRDLE
Appendicular Skeleton
• Pectoral Girdle – Clavicle and Scapula
• Upper Extremity – Humerus, Radius, Ulna, Carpals,
Metacarpals, Phalanges
• Pelvic Girdle – Ilium, Ischium, Pubis
• Lower Extremity – Femur, Tibia, Fibula, Tarsals,
Metatarsals, Phalanges
The Pectoral Girdle • Connects arms to the body • Consists of:
– 2 clavicles – 2 scapulae
Clavicle • Look for the tapered, wide end
– That part goes toward the shoulder (lateral) • Look for the side (top/bottom) that is ‘rougher’ for muscle attachment
– That is the inferior part
Features of the Clavicle – sternal end – acromial end
Scapula
(shoulder blade) • Look for the side that has a ‘handle
– That part is the most posterior and superficial – The featureless side is deep
• Look for the circular, smooth fossa or cavity – That is the cup of the shoulder joint, it points laterally
Features of the Scapula
– Glenoid cavity – Coracoid process – Acromion – Spine – Medial border – Lateral border – Inferior angle – Subscapular fossa
APPENDICULAR SKELETON PART II: UPPER LIMBS
What are the bones and features of the arm?
The Upper Limbs
• Arm – humerus
• Forearm – radius – ulna
• Wrist – carpal bones
• Hand – metacarpals – phalanges
Humerus
(upper arm bone) • Look for the rounded ‘head’
– That part is superior, and medial (shoulder joint) • On the bottom (distal end), look for the big dip (like a soup ladle)
– That is posterior
Features of the Humerus – Head – Anatomical neck – Greater tubercle – Lesser tubercle – Intertubecular groove – Deltoid tuberosity
– Medial epicondyle – Lateral epicondyle – Trochlea – Capitulum – Olecranon fossa
Ulna
(medial forearm bone) • Look for the ratchet ‘head’
– That part is proximal (part of the elbow joint) • On the side of the lower part of the ratchet, find the groove that drops
downward – That surface faces laterally (toward the radius)
Features of the Ulna
• Olecranon process • Coronoid process • Trochlear notch • Radial notch • Styloid process
Radius (lateral forearm bone) • Look for the golf tee ‘head’
– That part is proximal • Lay the bone on the table, look at the distal end (wide part). Turn the bone
so that the end tapers up, like a ski jump – That surface faces anteriorly
Features of the Radius
• Head – Radial tuberosity – Ulnar notch – Styloid process
Carpal Bones
Proximal bones: • Scaphoid bone:
– near styloid process • Lunate bone:
– medial to scaphoid • Triquetrum:
– medial to lunate • Pisiform bone:
– anterior to triquetrum
Distal bones: • Trapezium:
– lateral • Trapezoid bone:
– medial to trapezium • Capitate bone:
– largest • Hamate bone:
– medial, distal
Metacarpal Bones
• The 5 long bones of the hand • Numbered I–V from lateral (thumb) to medial • Articulate with proximal phalanges
Phalanges of the Hands
• Pollex (thumb): – 2 phalange bones
• proximal, distal • Fingers:
– 3 phalange bones • proximal, middle, distal
APPENDICULAR SKELETON PART III: PELVIC GIRDLE
Inferior Appendicular Skeleton
• Ossa Coxae – Ischium – Ilium – Pubis
• Lower Extremity – Femur – Tibia – Fibula – Ankle and Foot
Ossa Coxa
• Look for the flared fan part – That part is superior
• Find the ‘hip socket’ – That part is lateral
• On the back side of the ‘fan’, find the rough part – That part is posterior
• Find the pointy part by the ‘big hole’ – That part is anterior
Features of the Ilium
– Iliac crest – Anterior superior iliac spine – Anterior inferior iliac spine – Posterior superior iliac spine
– Posterior inferior iliac spine – Greater sciatic notch – Iliac fossa
Features of the Ischium
– Ischial spine – Lesser sciatic notch – Ischial tuberosity – Ischial ramus
Features of the Pubis – Superior ramus – Inferior ramus
Features of the Pelvic Girdle
• Acetabulum: – meeting point of the ilium, ischium, and pubis – articulates with head of the femur
• Obturator foramen: – formed by ischial and pubic rami
• Symphysis Pubis
Comparing the Male and Female Pelvis
• Female pelvis: – Smoother ,lighter – Less prominent muscle and ligament attachments – Broad pubic angle (> 100°) – Less curvature of sacrum and coccyx – Enlarged pelvic outlet, wide inlet, ilia project laterally, not upwards
APPENDICULAR SKELETON
PART IV: LOWER LIMBS
What are the bones and features of the lower limbs?
The Lower Limbs • Thigh
– femur • Knee cap
– patella • Leg
– tibia – fibula
• Ankle – tarsal bones
• Foot – metatarsals – phalanges
Femur
(thigh bone) • Look for the rounded ‘head’
– That part is proximal • Look at the distal end with the two smooth surfaces
– That part is distal • Find the large notch between the smooth surfaces
– That faces posteriorly
Features of the Femur – Head – Neck – Greater trochanter – Lesser trochanter – Gluteal tuberosity – Medial epicondyle – Medial condyle – Lateral epicondyle – Lateral condyle – Intercondylar fossa
The Patella
• Base attaches quadriceps femoris tendon • Apex attaches patellar ligament
Tibia (shin bone) • Look for the wide, flat surface with a bump in the middle
– That part is proximal • Look at the distal end with one side extending down medially
– That part is medial
Features of the Tibia – Intercondylar eminence – Tibial tuberosity – Medial malleolus
Fibula
• Look for the more ‘globular’ or rounded head – That part is proximal
• Look at the tapered, pointy end – That part is distal
• On the distal end, find the side that has more articulating surfaces – That faces medial
Features of the Fibula
– Head – Lateral malleolus
Tarsal Bones
– Talus – Calcaneus – Cuboid – Navicular
– Medial cuneiform – Intermediate cuneiform – Lateral cuneiform
Metatarsal Bones
• The 5 long bones of the foot – Numbered I–V from medial (big toe) to lateral – Articulate with proximal phalanges
Phalanges of the Feet
• Hallux: – big toe, 2 phalanges
• distal, proximal • Other 4 toes:
– 3 phalanges • distal, medial, proximal