1. Bone: Skeletal anatomy Flashcards
What is the functions of bone?
- Gives support and rigidity
- Act as levers for the muscles, providing locomotion & movement
- Protects internal organs
- Stores Ca, P & Mg
What are the 4 shapes of Bones?
- Flat bones
- Short or cuboidal bones
- Irregular bones
- Long bones
What is the purpose of the flat bones? What is an example?
- Acts as protection
- Skull
What do short or cuboidal bones do? What are some examples?
- Acts as shock absorbers
- Carpal bones, tarsal bones, phalanges
What are the purpose of irregular bones? What are some examples?
- Perform specialized functions (protect spinal cord, control tension of a tendon like a pulley)
- Vertebrae, sesamoids, patella
What do Long Bones do? What are some examples?
- Act as supporting columns and levers
- femur, humerus, radius, tibia, metacarpal
When it comes to the axial skeleton what is contained in the skull?
34 of the 206 bones in the horse’s body are in the skull
What is the function of the Vertebral column (spine)?
- Provides support to suspend the enormous weight of the gut
- Houses and protects the spinal cord
- Provides rigidity that enables transfer of movement from rear to front
What are the 5 regions of the spine?
- Cervical
- Thoracic
- Lumbar
- Sacrum
- Caudal (coccygeal)
What is contained in the cervical region of the spine?
- 7 Vertebrae
- Atlas (1st)- nodding of the head
- Axis (2nd)- Twisting movement of the head
- Arranged in an “s” does not follow the crest of the neck
What is contained in the Thoracic region of the spine?
- Most horses have 18 vertebrae
- Large dorasl spinous process
- The horse’s withers = T3-T10
- Each thoracic vertebrae attaches to a pair of ribs
What is in the Lumbar region of the spine?
- 6 vertebrae ( having 5 makes it shorter, stronger lion/coupling)
- Large transverse processes
- Lumbosacral joint = where lumbar join the sacrum ( portion of spine capable of flexion)
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What is in the Sacrum region of the spine?
- 5 vertebrae
- Fused together
- Attached to pelvis; forms the sacroiliac joint
What is in the Caudal (coccygeal) region of the spine?
15-20 vertebrae forming the tail
How is the range of motion in the spine work?
- The horse’s back is relatively inflexible from the withers to the tail
- Neck,tail, and lumbosacral joints are the most flexible regions of the horse’s spine.
How do the ribs work within the body of the horse?
- Each thoracic vertebrae attaches to a apir of ribs (18 pairs of ribs)
- Sternal ribs = first 9 pairs of ribs attached to the sternum and vertebrae
- False ribs = last 9 pairs of ribs attached to vertebrae but not directly attached to sternum
How are sternum and false ribs attached? What is its purpose?
- They are linked together at the bottom by bands of carilage which form the costal arch
- Allows greater movement for expansion of lungs
- Last pair of ribs are not attached to adjacent ribs = “floating ribs”
For the appendicular skeleton the portion of the forelimb (thoracic limb) what does it contain?
- Due to lack of a collar bone, the forelimb is attached to the body by muscles and ligaments
- The horse’s forelimbs are primarily designed to support the weight of the horse’s body and absorb concussion
- Forelimb does not propel the horse forward, but instead pull body forward.
- Allows greater freedom of movement and compensates for lack of flexibility in the spine
What consists of the 7 carpal bones?
- Proximal row: radial, intermediate, ulnar carpals
- Distal row: (1st), 2nd, 3rd, 4th carpals
- Palmar (back) of knee: accessory carpal
What is the reason for the arrangment of carpal bones?
It is designed to absorb shock
What make up the 3 metacarpal bones?
- 3rd metacarpal
- 2nd (medial) and 4th (lateral) metacarpals
What make up the phalanges?
- 1st Phalanx
- 2nd Phalanx
- 3rd Phalanx
What are the 3 sesamoid bones?
- Proximal medial
- Lateral sesamoids
- Distal sesamoids
What is the function of the sesamoid bones?
Their functions is to act as pulleys , they enable tendons to exert pull on the phalanges (with less force)
