1. Skeletal Systems

2. Two Major Sections of the Skeleton
Axial Skeleton
Used to protect fragile tissue that is held underneath
Vertebrae, ribs, skull sternum
Appendicular Skeleton
These bones allow for movement
Bones of the limbs
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3. Variations of Bones
Total number of bones vary by species and even within a species
Example:
Horse – 205 bones
Dog – average bones
Some dogs are born with short tails and others have long tails which change the number of vertebrate present
Dewclaws  some are born with some are born without changing the number of digits present
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4. Bones of the Axial Skeleton
Cranium
Made mostly of flat bones (50 bones in a dog)
Shape varies between species and breed
Used for protection of the brain and other sense organs (taste, smell, hearing, sight,)
Lower jaw – mandible, is moveable allowing an animal to obtain and chew food
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5. Bones of the Axial Skeleton
The Vertebral Column
Extends the length of the body from the skull
Protects the spinal cord and allow for movement
Anatomy of the Vertebral Disk
Covered with bony arch - protects spinal cord
Spinous and transverse process are sites of tendon and ligament attachment
Intervertebral disks can be found between vertebrae add cushion between the disks (not found between C1 and C2)
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6. Bones of the Axial Skeleton
The Vertebral Column
Broken down into anatomical divisions
Cervical (7)
Thoratic (13)
Lumbar (7)
Sacrum (3)
Coccygeal (14-23)
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7. Bones of the Axial Skeleton
The Vertebral Column
Cervical Vertebrae – neck
Mammals have 7 Cervical Vertebrae
C1 – Atlas – allows for up and down movement of head
C2 – Axis – allows for side to side movement
Thoracic Vertebrae – have attached ribs
Help to protect the heart and lungs, allow for respiration
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8. Bones of the Axial Skeleton
The Vertebral Column
Lumbar Vertebrae – lower back between thoracic vertebra and pelvis
Flexes and extends as an animal moves
Provide support for organs in the abdomen
Sacrum Vertebrae
Fuse with the pelvis allowing support of the hind end of the animal
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9. Bones of the Axial Skeleton
The Vertebral Column
Coccygeal Vertebrae – Tail
Vary by species and within the species
Dogs typically have 20 Coccygeal vertebrae but can range from 6-23!
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10. Bones of the Axial Skeleton
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11. Create it!
Congrats…you have graduated from the school of vertebral engineering! Lets put that education to good use!
See Handout!
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12. Bone of the Axial Skeleton Activity
Cranial most part first – PECTORAL LIMBS
Scapula
Humerus
Radius
Ulna
Carpus
Metacarpal
Phlanges
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13. Bones of the Appendicular Skeleton
Scapula
Joins the humerus through a shallow ball and socket joint.
Flat bone with a spine to attach tendons and ligaments
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14. Bones of the Appendicular Skeleton
Humerus
Upper bone of the forelimb.
Connects scapula to the elbow
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15. Bones of the Appendicular Skeleton
Radius and Ulna - Forearm
Ulna runs to the point of the elbow and accepts the end of the humerus.
Radius (cranial) closely connects to the ulna and forms the remainder of the elbow joint.
The elbow joint is a hinge joint and the reason that we can twist our forearm is because of the movement between the radius and ulna, not the elbow joint.
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16. Bones of the Appendicular Skeleton
Carpus - Wrist
Radius and ulna continue to the carpus.
Group of bones arranged in two rows.
Number of bones vary among species.
Dog – 7
Ruminants – 6
Horse – 7 or 8
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17. Bones of the Appendicular Skeleton
Metacarpus - Hand
Long Bones
Lots differences in species.
Dogs and cats have four long and one much smaller one (dewclaw)
Horses have only one major bone, corresponds to the third one in other species, but has two smaller ones as well.
Ruminants only have one very large metacarpal bone. As the ruminant embryo develops, the third and fourth one fuse together.
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18. Bones of the Appendicular Skeleton
Phalanges – fingers and toes
Number of toes corresponds to the number of metacarpal bones.
Singular form is phalanx.
The last phalanx is covered by the nail or hoof.
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19. Bones of the Appendicular Skeleton
Review the order…
Scapula
Humerus
Radius
Ulna
Carpus
Metacarpal
Phlanges
Create an acronym… S H R U C M P
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20. Bones of the Appendicular Skeleton
Caudal End – PELVIC LIMBS:
Pelvis
Femur
Tibia
Fibula
Tarsus
Metatarsus
Phalanges
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21. Bones of the Appendicular Skeleton
Pelvis
3 fused bones.
Pubis
Ischium
Ilium
Sacrum supports the pelvis.
Connection can be damaged, and may split away.
Pelvis is made of two halves.
Each half divides into regions: ilium, ischium, pubis.
Ilium joins to the sacrum.
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22. Pelvis
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23. Bones of the Appendicular Skeleton
Femur – Leg Bone
Ball and socket joint to the pelvis.
Goes to the knee.
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24. Bones of the Appendicular Skeleton
Patella – Knee Cap
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25. Bones of the Appendicular Skeleton
Tibula and Fibula
Similar to Ulna and Radius in forearm
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26. Bones of the Appendicular Skeleton
Tarsus - Ankle
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27. Bones of the Appendicular Skeleton
Metatarsus – Top of foot
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28. Bones of the Appendicular Skeleton
Phalanges - Toes
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29. Bones of the Appendicular Skeleton
Review the order…
Pelvis
Femur
Patella
Tibula
Fibula
Tarsus
Phalanges
Create an acronym… P F T
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