THE SKELETAL SYSTEM

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THE SKELETAL SYSTEM

• CH. 6
• INTRODUCTION TO CHAPTER

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ROOTS

• arthr/o joint
• cervic/o neck
• chondr/i, chondr/o, chondr/io cartilage
• cost/o rib
• myel/o bone marrow
• occipit/o back of head
• oss/eo, oss/i, ost/e, ost/eo bone
• sacr/o sacrum
• spondyl/o vertebra
• stern/o sternum

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WHY DO WE NEED A SKELETON?

• It provides a framework for the body and gives it
  ___________.
• It supports organs and ____________ them from
  injury.
• It provides a place for muscles, ligaments, and
  tendons of the body to ____________ to.
• It helps to make ________________ possible.
• It stores ______________.
• It provides a place for __________________.

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WHAT IS BONE AND WHAT IS IT MADE OF?

• Bone is one of the types of ______________ tissue
  in the body.
• It is also called _____________ tissue.
• It is made up of water and mineral salts.
• ________________ is the formation of or
  conversion into bone or a bony substance
  (calcification is the deposition of calcium in a
  tissue).

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WHAT IS BONE MADE OF?

• The outer surface is called _____________ BONE
  and is very dense.
• It is the thickest in the midshaft of a long bone
  to provide strength and prevent bending of the
  bone
• The inner layer is called ________________ BONE
  and is spongy and latticelike and is less dense
  than compact bone

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WHAT IS BONE MADE OF?

• The SHAFT (____________) of the bone contains the
  _____________ CAVITY
• It is filled with YELLOW MARROW (fat storage) and
  RED MARROW (hematopoietic tissue)
• Yellow marrow replaces red marrow as an animal
  ages.

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WHAT IS BONE MADE OF?

• ________________ covers the surface of bone and
  is a tough, vascular membrane. It is where
  tendons, ligaments, and muscles attach to the
  body. It has a nerve and blood supply.
• The inner layer of the periosteum contains
  ___________________ which are cells responsible
  for bone growth and repair.

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WHAT IS BONE MADE OF ?

• The medullary cavity of bone has arteries and
  veins that enter and exit the cavity via the
  ___________ ____________ which are openings in
  the bone

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HOW DO BONES GROW?

• They grow in LENGTH at the junction of the
  EPIPHYSIS and the DIAPHYSIS at the _____________
  _________ (growth plate). It is also called the
  ___________.
• They grow in THICKNESS in the layers of the
  periosteum.

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HOW DO BONES GROW?

• Bones are stimulated to grow via ___________
  HORMONE (GH) which is produced by the
  ____________ gland.
• There is a teamwork between ______________
  producing bony tissue and _______________ eating
  away bony tissue to prevent the bone from
  becoming too thick. This process slows as an
  animal ages.

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SHAPES OF BONE

• ________ (femur, humerus)
• ________ (carpal bones)
• ________ (sternum, scapula)
• ____________ (vertebrae)

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AXIAL APPENDICULAR SKELETON

• AXIAL SKELETON SKULL, HYOID BONE,VERTEBRAL
  COLUMN, RIBS, STERNUM
• APPENDICULAR SKELETON BONES OF THE LIMBS

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SKULL

• 2 major segments
• Bones of the Cranium and Facial Bones
• PURPOSE protects the brain and the sensory
  organs.
• The ONLY mobile bone is the ______________________
  (lower jaw)
• The skull bones unite at the ____________.

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• SINUSES are located within the skull and are
  _______- filled cavities
• Sinuses are usually named for the skull bone
  that contains the sinus

The nares open into 2 major air passages that end
in the pharynx. The nasal passages are filled
with very fine scrolls of bone called
___________________. These are covered in pink
mucosa. Air is warmed, moistened, and filtered as
it passes through the turbinates in the nose on
the way to the lungs. 
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• CRANIAL BONES
• FRONTAL BONES form the forehead
• Horns are an extension of the frontal bone
• PARIETAL BONES form upper part of each side of
  the skull
• TEMPORAL BONES form the lower part of the
  sides of the skull.
• OCCIPITAL BONE forms the back of the skull
• foramen magnum opening at the base of the
  occipital bone that allows the spinal cord to
  pass from the skull to the spine

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• FACIAL BONES
• MAXILLA bone that forms the upper jaw
• MANDIBLE forms the lower jaw. Only movable bone
  in the skull

maxilla
mandible
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• HYOID APPARATUS U shaped structure made up of
  both bone and cartilage. Suspends the tongue,
  larynx, and floor of the mouth

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VERTEBRAL COLUMN (backbone)

• There are 5 types of vertebrae ____________(C),
  ____________ (T), ______________ (L),
  ____________ (S), _______________ (Cy)

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• Each vertebrae has a body and an arch.
• Body bears the weight
• Arch forms the canal that houses the spinal cord

• Intervertebral discs are between the bodies
• -Made of cartilage and serve as shock absorbers

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CERVICAL VERTEBRAE

• 1st vertebrae _______ supports the skull
• 2nd vertebrae _____
• what the atlas rotates on

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THORACIC VERTEBRAE

• Attach to ribs
• Thoracic Cage composed of the thoracic
  vertebrae, ribs, costal cartilages, and sternum
• protects the vital organs of the chest and allows
  the lungs to expand and contract during
  respiration

22
RIBS

• PURPOSE form the thoracic wall and protect the
  heart and lungs
• Flat, curved
• Each rib has bony and cartilagenous components
• The cartilagenous component is located ventrally
• They unite at the ___________________ junction

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STERNUM

• BREASTBONE
• Located on ventral midline of chest
• Flat bones called STERNEBRAE that connect to each
  other via cartilage
• Most cranial bone is the __________________
• Most caudal bone is the __________________

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LUMBAR VERTEBRAE

• Support the abdomen
• One bone that results from the fusion of 3-5
  vertebrae
• Attaches to pelvis

SACRAL VERTEBRAE
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COCCYGEAL VERTEBRAE

• Also called caudal or tail vertebrae
• Can be docked- spinal cord ends near the
  lumbosacral junction

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AXIAL APPENDICULAR SKELETON

• AXIAL SKELETON SKULL, HYOID BONE,VERTEBRAL
  COLUMN, RIBS, STERNUM
• APPENDICULAR SKELETON BONES OF THE LIMBS

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• SCAPULA (shoulder blade)
• Large triangular bone on the side of the thorax
• HUMERUS (upper arm)
• ULNA and RADIUS (forearm)
• Ulna forms the elbow
• CARPUS (wrist)
• Numerous short/irregular bones arranged in 2 rows

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• METACARPALS (palm)
• Vary in number between species (Ex dog 5,
  horse 3)
• Numbered from medial to lateral
• DIGITS (toes)
• Numbered from medial to lateral
• PHALANGES are located within the digits
• Usually 3 phalanges in one digit (P1, P2, P3)

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• PELVIS (hip)
• 3 pairs of bones that fuse to become one
• IIium the largest bone
• Flares out to the side
• Ischium strongest, most caudal
• Pubis Most ventral
• FEMUR (thigh)
• Longest bone in the body
• Forms part of the STIFLE (knee)

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• PATELLA (kneecap)
• TIBIA (shin) AND FIBULA
• Tibia is larger than fibula, and bears more
  weight

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• TARSUS (ankle)
• Called HOCK in animals
• Composed of numerous irregularly shaped bones
  arranged in rows
• METATARSALS (foot)
• Very similar to metacarpals
• Vary in number between species
• Numbered medial to lateral
• DIGITS (toes)
• Same as forelimb

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JOINTS-an articulation between bones and
cartilage that is held in place by ligaments

• SYNARTHROSES (Fibrous joints)
• no movement
• Ex Skull
• AMPHIARTHROSES (Cartilaginous joints)
• slight movement
• Ex Pelvis at pubic symphysis, vertebral column
• DIARTHROSES (Synovial joints)
• freely movable
• Most numerous in the body
• Ex Hip joint, shoulder joint