MAMMALIAN SKELETON
MAMMALOGY LAB, WEEK 2
WHAT DOES A SKELETON DO?
•  Provides scaffolding and attachment sites for muscles and
other tissues
•  Protects internal organs
•  Site of blood cell production
•  What is unique about mammalian red blood cells?
•  Plays a role in endocrine regulation to control blood sugar
•  Acts as a reserve of calcium and phosphorus
GENERAL REGIONS OF SKELETON
•  Axial: runs down the center
•  Skull, vertebrae, ribs
•  Appendicular: limbs and pelvis
TYPES OF BONES
•  Long bones
•  Femur, humerus, metacarpals, phalanges
TYPES OF BONES
•  Cuboidal bones:
•  Carpus, tarsus
TYPES OF BONES
•  Plate-like bones:
•  Scapula, pelvis, scapula, cranium
TYPES OF BONES
•  Sesamoids:
•  Patella, knuckle
REGIONS OF A LONG BONE
•  Diaphysis: shaft of long bone
•  Epiphysis: ends of bone, above growth plate
•  Metaphysis: transition between diaphysis and
epiphysis, right below growth plate
VERTEBRAL COLUMN
FIVE TYPES OF VERTEBRAE:
•  Cervical
•  Thoracic
•  Lumbar
•  Sacral
•  Caudal
VERTEBRAL COLUMN
FIVE TYPES OF VERTEBRAE:
•  Cervical
•  Neck region
•  Almost all mammals have exactly 7 cervicals
•  Very top cervical vertebrae are the atlas and axis,
which articulate with the skull at the occipital condyles
ATLAS AND AXIS
VERTEBRAL COLUMN
FIVE TYPES OF VERTEBRAE:
•  Thoracic
•  Connect to ribs
•  Often have large dorsal spines
•  Mammals have 12-15
VERTEBRAL COLUMN
FIVE TYPES OF VERTEBRAE:
• Lumbar
•  “Lower back” region, links to pelvis
•  Most mammals have 6-7, toothed whales
(Odontoceti) have up to 20
•  Often have many spines and processes
VERTEBRAL COLUMN
FIVE TYPES OF VERTEBRAE:
•  Sacral
•  Support the pelvic girdle
•  Often fused together
•  Usually 3-5, up to 10 in Edentata
VERTEBRAL COLUMN
FIVE TYPES OF VERTEBRAE:
• Caudal
•  “Tail bones”
•  Smaller, simpler than other vertebrae
•  Do not contain spinal column, although do have nerves
and blood vessels
•  In humans and apes, bones are fused to form the coccyx
LINKING THE LIMBS TO THE BODY
TWO SETS OF STRUCTURES LINK THE LIMBS TO THE AXIAL
SKELETON:
•  PECTORAL GIRDLE: LINKS FORELIMBS
•  PELVIC GIRDLE: LINKS HINDLIMBS
LINKING THE LIMBS TO THE BODY
TWO SETS OF STRUCTURES LINK THE LIMBS TO THE AXIAL
SKELETON:
•  PECTORAL GIRDLE:
•  CLAVICAL (COLLAR BONE)
•  SCAPULA (SHOULDER BLADE)
LINKING THE LIMBS TO THE BODY
TWO SETS OF STRUCTURES LINK THE LIMBS TO THE AXIAL
SKELETON:
•  PELVIC GIRDLE:
•  ILIUM
•  ISCHIUM
•  PUBIS
REVIEW OF THINGS TO KNOW
•  What does the skeleton do?
•  Regions of skeleton
•  Types of bones
•  Types of vertebrae
•  How do axial and appendicular skeletons connect?
•  How does the vertebral column articulate with the skull?