Medicine first year Anatomy Notes

Introduction to The Skeleton

Role of the skeleton:
Locomotion/support

 Two fundamental divisions of skeleton
 Skeleton
o Axial skeleton
 Support and protection
 E.g. skull protects brain
 vertical column protects spinal cord
 rib cage protects heart + lung + kidneys
 80 bones along the longitudinal axis
o Appendicular skeleton
 Locomotion
 arms and legs
 Added on to main body: for walking etc
 Joints between bones
o different types of joints, depending on types of connective tissue
 Muscles move bones by acting on joints
o muscles have to cross joints to be able to work, cannot just cross bone alone
o muscles motivated by nerves: sense movement
 Nerves make muscles move
o Afferent nerves:
 sensory neurons that carry nerve impulses from sensory stimuli towards the
central nervous system and brain
o efferent nerves
 motor neurons that carry neural impulses away from the central nervous
system and towards muscles to cause movement




Axial skeleton
 Skull

,  Ribs, sternum
 vertebrae
 More in children, some bones fuse (in joints)
 Cage extends to protect liver and kidneys




 Know main bones, and sutures: frontal bones, coronal suture,
 Many bones inside skull as well




 Brain floats in small amount of cerebral spinal fluid
 Sections of brain:
o Frontal
o middle
o posterior