Introduction to Locomotor Anatomy Flashcards
what makes up the axial skeleton
skull
vertebral column
what makes up the appendicular skeleton
forelimb and hindlimb
what are the movements of the limb relative to the trunk
- moving limb cranially = protraction
- moving limb caudally = retraction (propulsion)
- moving limb medially = adduction (towards from body midline)
- moving limb laterally = abduction (away from midline)
what are the movements within the limb
- folding/shortening = flexion
- stretching/lengthening = extension
- rotation = supination/pronation (humans have more)
what is the interaction between limbs (appendicular skeleton) & trunk (axial skeleton)
forward propulsion (hindlimbs play greatest contribution)
- folding limb = flexion
- moving limb forwards = protraction
- stretching limb = extension
- moving limb backwards
or fixing limb and moving trunk forwards relative to limb = retraction
what is the difference in the contribution from axial skeleton/trunk in horses
relatively rigid vertebral column (weight of gut)
most of propulsion/stride length results from limb movement
what are the features of cat locomotion
flexible vertebral column
acts like bow to increase propulsion/stride length from limbs
what other structures besides bones contribute to movement
- bones
- joints: allow movement between bones
- ligaments: hold bones together
- muscles: produces movement between bones across joints
- tendons: attach muscle to bone across joints
- nerve supply: control of movement
- blood supply: metabolic support
what are the classifications of bone
- long
- flat
- short
- sesamoid
- irregular
what are the features of long bones
humerus and femus
majority of limb bones
support and leverage in limbs
what are the features of flat bones
scapula, pelvis, skull
large surface area for muscle attachment
protection of underlying structures
what are the features of short bones
carpal, tarsal bones
large range of movement between bones
anti-concussive/shock absorbing
what are the features of sesamoid bones
patella
embedded in tendons
redirect forces where change in angle
reduces friction so prevents damage
what are the features of irregular bones
vertebrae
midline/axial location
unique
what are the surface features of bones
- rough areas on bone surfaces
- bony bumps
- smooth areas on surface of bone
what are rough surfaces on bone covered by
covered by periosteum
areas for general muscle attachment
what are bony bumps
tuberosity/tuber/tubercle/trochanter/process, etc
provide specific sites for attachment of important structures
what are the smooth areas on the surface of bone and what are they covered in
articular/joint surfaces
covered in hyaline cartilage
subchondral bone
osteochondral junction
what are the visible features of long bones on radiographs
- diaphysis = shaft
- cortex = wall
- medullary cavity = hollow centre
- epiphysis = proximal or distal end (articular surfaces located here)
- metaphysis = transition zone (between epiphysis & diaphysis)
how do limb bones develop
endochondral ossification –> requires blood supply
how does endochondral ossification occur (6)
- cartilage precursor
- mineralizes in sections = centres of ossification
- cartilage between centres of ossification = physis/growth plate
- produce increase in length of bone
- growth stops at specific time –> reflects contribution of that physis to overall length
- physis mineralizes/growth plate “closes”
what are physes
appear black on radiographs –> don’t mistake for joint spaces or fractures
physical scar left in adult
how many centres of ossification do short, sesamoid bones, flat, long and irregular bones contain
short and sesamoid bones –> usually 1 per bone
flat, long and irregular bones –> usually more than 1 per bone
what is the weakest part in adult bones
shaft of bone
where are the weakest part of the bone in young animals
physes weakest –> damage/separation
development of subsequent problems
what are the 3 main types of joint
- fibrous
- cartilagenous
- synovial
what are the features of fibrous joints
little movement
held together by ligaments
skull sutures, radius & ulna/equine metacarpal bones (syndesmosis)
what are the features of cartilagenous joints
little movement
synchondrosis/synarthrosis
pelvic/mandibular symphysis
what are the features of synovial joints
most limb joints
allow range of motion between bones
what are the 5 typicall components of synovial joints
- hyaline cartilage
- synovial fluid
- synovial membrane
- joint capsule
- collateral ligaments
what is hyaline cartilage
covers articular/joint surfaces (subchondral areas of bone are smooth)
what are the functions of hyaline cartilage
- reduces friction
- flexible for shock absorption
- no blood vessels
- no nerve endings
what is synovial fluid
viscus
nourishes cartilage
lubricates
what is the function of synovial membrane
produces synovial fluid
physical barrier to contain fluid
what is the joint capsule
fibrous layer outside synovial membrane
attaches round osteochondral junction
what are collateral ligaments
formed from joint capsule
located medially and laterally
fibrous structure running from bone - bone
what are the functions of ligaments
- hold bones together
- reduce movement in unwanted directions
