The Skeletal System Flashcards
1/3 organic, 2/3 inorganic material
Average total number: 319 bones
Bones
this does not include the bones of the __ __ since many dogs do not have this
dew claw
3 Major Groups of the Skel. Syst.
- Axial
▫ Skull, vertebral column, ribs & sternum - Appendicular
▫ Thoracic & pelvic limbs - Visceral
▫ Baculum = os penis (dogs)
Hard, tough connective tissue with living cells arranged in rings
Bone
Living cells, ____, for growth & repair
Osteocytes
Matrix secreted made mostly of minerals, _____, for rigid structure in bone
Calcium
Phosphate
Bone Contains protein, ___, that gives strength and flexibility= less brittle and prone to breakage in bones
Collagen
Importance: For body structure, protection of organs and produces blood cells
Bone
Flexible connective tissue with living cells arranged in pairs/bundles.
Cartilage
*cartilage
Matrix contains more ___ and less ___ than bone
- Softer and more elastic than bone
Collagen
Minerals
*cartilage
Found at the ends of bones, in the __ __ ___.
- Importance: Prevents friction and withstands shock.
Nose, ears and trachea
Thick strand attaching muscle to a bone.
Tendons
Tendons are Made of strong _____
- Tough and does not stretch
- Capable of withstanding tension
- Importance: Enables movement of bones
Fibrous collagen
A flexible band attaching a bone to another bone.
Ligaments
Ligaments are Made of tough _____
- Elastic, can stretch and “snap-back”
- Importance: Keeps bones stable and prevents dislocation
elastin fibres
Functions of Bone (4)
- Supports and protects soft organs of the body
- Acts as levers for muscular action
- Stores calcium and phosphorus
- Encloses the blood forming elements (RBC, WBC, Hb, platelets) and in the adult, the bone also stores fat.
Classification of bones acc. to shape (6)
long bones
short bones
irregular bones
flat bones
sesamoid bones
sutural bones
▫ Found mainly in the limbs/extremities
▫ Has a body/shaft called diaphysis and two ends called the epiphyses
▫ this form levers and possess great tensile strength
Long bones (ossa longa)
▫ End of long bones are covered by ______ as they enter the formation of joints
hyaline cartilage
Enlargement of each extremity of a long bone serves a dual purpose:
Decreases the risk of dislocation
Provides a large bearing surface for articulation
▫ Carpal (wrist), tarsal (ankle) – contains 7 bones
▫ Associated with the spread of pressure exerted in these regions
Short bones (ossa brevis)
▫ To alter the course of tendons at the places where greatest friction is developed.
Sesamoid bones (ossa sesamoidea)
▫ Found in the thoracic and pelvic girdles and in the head and thorax
▫ For PROTECTION
▫ Weigh less
Flat bones (ossa plana)
Cranium = outer and inner tables of compact bones and an intermediate uniting spongy bone called __
diploe
bones which contain air cavities
Pneumatic bones (ossa pneumatica)
- Vertebral column, bones of the skull that are not flat, 3 parts of the hip bone (os coxae)
- Jutting processes are the characteristic features
- For muscular and ligamentous attachment; some for articulation
Irregular bones (ossa iregulata)
▫ bones arising from cartilages
Endochondral/replacement/cartilage bones
▫ bones that develop from connective tissue sheets or membranes (roof of the cranium)
▫ Ex. skull, jaws, gill covers, and the shell (of tortoises and turtles).
Membrane/dermal bones
▫ The spongy bone of the skull is known as diploe.
Cancellous or spongy bone (substancia spongiosa)
Compact bone (other term)
(substancia compacta/corticalis)
- Diaphysis and epiphyses are seperated by this cartilage (in young, ______)
epiphyseal plate
(marrow cavity) is a space occupying the hollow portion of the bone surrounded by the cortex of the long bone.
Medullary cavity
Bone marrow color;
- Young – red marrow
- Adult – red and yellow marrow (fat)
compact bone surrounding the shaft of the long bone
Cortex
*bone covering layers
layer of specialized connective tissue covering the nonarticular surface of the bone
Periosteum
*bone covering layers
connective tissue covering the cartilage of articular surface
Perichondrium
*bone covering layers
thin fibrous membrane that lines the medullary cavity and osteonal (Haversian) canals of a bone
Endosteum
*bone covering layers
▫ Name given to the covering of the bones which participate in forming boundaries of the respiratory or digestive system.
▫ Lines all of the paranasal sinuses and contains mucous cells
Mucoperiosteum
- Nutrient artery and vein (nutrient foramen)
- Anastomosing vessel of the epiphyseal plate and the periosteum
Vessels
Sensory nerves
Nerves
Types of bones in the skull (2) according to shape
Flat bones
Irregular bones
*type of bone in the skull
comprise most of the bones of the skull and are formed in membrane such as the dorsum of the skull or calvaria.
Flat bones
*type of bone in the skull
like the bones of the ventral part of the cranium are preformed in cartilage
Irregular bones
Two forms of bones are recognized based on structure: (2)
Cancellous or spongy bone
Compact bone
is numerous in the extremities of long bones and forms the internal substance of short and irregular bones
Cancellous bone
appears as a solid mass. It is thicker in the shaft of long bones than in their extremity
Compact bone
is located at the caudal part of the cranium in which it forms the caudal wall and part of the ventral wall or base of the skull.
occipital bone
a large oval opening in the posteroventral portion of the skull thru which the spinal cord and its associated structures pass.
foramen magnum
Bone is highly vascular as compared to _______ which is devoid of blood supply.
Cartilage
