Transcript Anatomy and Physiology of Dogs and Cats

Anatomy and Physiology of Dogs
and Cats
Bones, Joints, Synovial Fluid
Bones
• Cellular structures where the extracellular
fluid environment of the cell is surrounded by
a rigid, calcified frame
Function of the Skeleton
• Gives identifiable form
to body
• Provides protection
• Location of blood
formation
• Mineral source
• Movement
• Accommodates loads
and stresses
Joint
• Moveable union
between two bones
• Enclosed by a joint
capsule filled with
synovial fluid
• Why SF?
Axial Skeleton
• Lie on long axis (midline) of body
• Includes:
– Skull
– Vertebrae
– Ribs
– Sternum
Appendicular Skeleton
• Made up of bones of
the front (pectoral) and
hind (pelvic) limbs and
their respective
pectoral girdle
(shoulder) and pelvic
girdle (pelvis)
A & P of Long Bones
• Contains spongy
(cancellous) and compact
bone
• Spongy bone have
trabeculae which are
mineralized tissue
• Regions between trabeculae
are filled with marrow
A & P of Long Bones
• Rigidity and strength of long bones is caused
by the hardness of compact bone and the
scaffolding arrangement of the trabeculae
(parallel to the lines of maximum stress)
A & P of Long Bones
• The epiphysis refers to
either extremity of a long
bone and the diaphysis is
the cylindrical shaft
between the two epiphyses
• The metaphysis is the flared
part of the bone at the ends
of the diaphysis
A & P of Long Bones
• The diaphysis contains
the marrow (medullary)
cavity that is
surrounded by compact
bone
– Bone marrow is the site
of blood production
A & P of Long Bones
• The epiphyses have spongy
bone surrounded by
compact bone
• The epiphyseal plate is
composed of hyaline
cartilage and represents the
point of growth in a
longitudinal direction
– In mature bones the
cartilage has been
replaced by bone
A & P of Long Bones
• The contact area of the
bone that articulates
with its neighboring
bone at a moveable
joint is covered with
articular cartilage
• All other outer surfaces
are covered with
periosteum