Animal Anatomy and Physiology

1. SKELETAL SYSTEMS

2. Two Major Sections of the Skeleton
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 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

3. Variations of Bones
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 Total number of bones vary by species and
even within a species
 Example:
 Horse – 205 bones
 Dog – average - 320 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

4. Bones of the Axial Skeleton
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 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

5. Bones of the Axial Skeleton
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 The Vertebral Column
 Extends the length of the body from the skull
 Protects the spinal cord and allows for
movement
 Anatomy of the Vertebral Disk
 Covered with bony arch - protects spinal cord
 Intervertebral disks can be found between
vertebrae. add cushion between the disks (not
found between C1 and C2)

6. Bones of the Axial Skeleton
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 The Vertebral Column
 Broken down into anatomical divisions
 Cervical(7)
 Thoratic (13)
 Lumbar (7)
 Sacrum (3)
 Coccygeal (14-23)

7. Bones of the Axial Skeleton
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 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

8. Bones of the Axial Skeleton
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 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

9. Bones of the Axial Skeleton
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 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!

10. Bones of the Axial Skeleton
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10/13/10

11. Create it!
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 Congrats…you have graduated from the
school of vertebral engineering! Lets put
that education to good use!

12. Bone of the Axial Skeleton
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 Cranial – PECTORAL LIMBS
 Scapula
 Humerus
 Radius
 Ulna
 Carpus
 Metacarpal
 Phlanges

13. Bones of the Appendicular
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 Scapula
 Joins the humerus through a shallow ball and
socket joint.
 Flat bone with a spine to attach tendons and
ligaments

14. Bones of the Appendicular
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 Humerus
 Upperbone of the forelimb.
 Connects scapula to the elbow

15. Bones of the Appendicular
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 Radius and Ulna - Forearm
 Ulna runs to the point of the elbow and
accepts the end of the humerus.
 Radius 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.

16. Bones of the Appendicular
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 Carpus - Wrist
 Radiusand 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

17. Bones of the Appendicular
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 Metacarpus - Hand
 Long Bones
 Lots of 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.

18. Bones of the Appendicular
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 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.

19. Bones of the Appendicular
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 Caudal End – PELVIC LIMBS:
 Pelvis
 Femur
 Tibia
 Fibula
 Tarsus
 Metatarsus
 Phalanges

20. Bones of the Appendicular
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 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.

21. Pelvis
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10/13/10

22. Bones of the Appendicular
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 Femur – Leg Bone
 Ball
and socket joint to the pelvis.
 Goes to the knee.

23. Bones of the Appendicular
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 Patella – Knee Cap

24. Bones of the Appendicular
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 Tibia and Fibula
 Similar to Ulna and Radius in forearm

25. Bones of the Appendicular
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 Tarsus - Ankle

26. Bones of the Appendicular
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 Metatarsus – Top of foot

27. Bones of the Appendicular
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 Phalanges - Toes