Bones Flashcards
components of locomotor system
- bones
- joints
- muscles (skeletal)
- nerves and blood vessels
types of bones
- long bones; columns and levers for movement
- flat bones; protection and muscle attachment
- short bones; diffuse concussion, reduce friction (sesamoid)
- irregular bones
functions of bones
support, protections, movement (muscle attachment), mineral homeostasis, production of blood cells (haemopoiesis)
epiphysis
ends of bones
what are epiphysis generally covered with
articular cartilage
epiphyseal cartilage
aka growth plate, separates epiphysis from rest of bone, when animal matures this ossifies and turns into bone
diaphysis
shaft of bone
metaphysis
either end of diaphysis
inbetween diaphysis and epiphysis cartilage
compact bone
external dense layer of bone
spongy or cancellous bone
internal, spicules (trabeculae) arranged according to mechanical stresses
periosteum
external membrane, covers bone everywhere except where there is articular cartilage
contains blood vessels that provide nutrition to bone and continuous with tendons where muscles attach to bones, also full of nerves
can actually suture this
endosteum
internal membrane
medullary cavity
hollow centre of bone
red marrow in young animals and yellow marrow in mature animals
nutrient foramen
where major blood vessel goes through to provide blood supply to tissues inside the bone, usually about halfway down the shaft
true or false bone is dynamic living material
true
what influences do bones renew and remodel is response to
mechanical, metabolic (ex lactation) , nutritional, endocrinological
how much blood supply do bones need
about 10-20% of cardiac output
nutrient artery
- major blood supply
- breaks into proximal and distal medullary arteries
- passes through nutrient foramen
metaphyseal artery
- smaller than main nutrient arteries
- enters into metaphysis (proximal and distal)
- anastomose with medullary arteries at capillary level
periosteal arterioles
supply outer cortex of diaphysis in areas of strong fascial attachment
anastomose with medullary artery
epiphyseal arteries
this blood supply is separate to metaphyseal supply in young animals due to epiphyseal plate
one animal matures the growth plate ossifies then blood supply from metaphysis can cross this “barrier” and epiphyseal arteries become less important
membranous bones
develop on layers of collagen fibres (ex flat bones of skull)
cartilaginous bones
develop in pre-existing cartilage (most bones)
sesamoid bones develop in response to
friction in utero
tensile strength
strength not to be pulled apart
provided by collagen fibers in bones
compressional strength
strength not to be pushed together
provided by mineral salts
bones have less ____ strength than ____ strength; which means fractures tend to be on
less tensile strength that compressional strength
fractures tend to be on opposite side to where stress/force was applied
bones need to be
rigid, withstand compressional force or stress, withstand tensile force (stress), light
spongy bone or trabeculae in the epiphyses are aligned in _____ to withstand forces/stress
lamella
pressure lamella and tension lamella
______ is an essential stimulus for proper bone formation
pull of muscle
skeleton is divided into
cranial and post cranial
post cranial further divided into axial (vertebrae, ribs and sternum)
and appendicular (bones of limbs and girdle)
vertebral column
cervical C (7) atlas (wing), axis
thoracic T
lumbar L
sacral S
caudal Ca
ribs
true: sternal ie join to sternum
false; asternal connect to cartilage of rib
one floating rib
pentadactyl limbs order
- humerus/ femur
- radius and ulna/ tibia and fibula
- 2 rows of carpals/ 3 rows of tarsals
- metacarpals/ metatarsals
- proximal phalages
- middle phalanges
- distal phalanges
thoracic girdle
just scapula is most domestic animals
some mammals still have clavicle (collar bones)
proximal and distal carpals
proximal; radial and intermediate, ulnar and accessory
distal carpals 14
metacarpals
1-5, thumb is one
pelvic girdle
2 os coxae= pelvis
ilium (dorsal cranial)
ischium (caudal)
pubis (ventral)
proximal and distal tarsals
talus (main weight bearing)
calcaneus
central
distal 1-4
movement of vertebral column in dogs, horses, ruminants and pigs
- dogs (and other. carnivores); bending at T11 (the anticlinal vertebra)
- horse; column is rigid, all movement in legs
- ruminants; slight bending
- pigs; some bending
sternum and ribs form the
thorax
what is site of attachment for forelimb
thoracic wall
