Intro To Muscoskeletal System Flashcards
LO: Know adaptations of locomotor system in cursors
- Reduced pectoral skeleton:
-allows more cranial/caudal movement
- clavicle is usually absent or vestigial
- no skeletal component attaching the forelimb to the trunk
- instead there is omothoracic junction - purely muscular (synsarcosis) - Elongation at proximal end of limb:
- scapula lies laterally
- increases leg length, therefore increasing stride length - Elongation at distal end of limb:
-long metacarpals, walk on toes or hooves
-increases leg/stride length
LO: Describe various movements of the limbs relative to the trunk
Interaction between limbs and trunk:
Flexion, protraction, extension and retraction = forward movement of animal
LO: Recognise various types of bones
- Flat (scapula/pelvis):
- large surface area for muscle attachment
- protection of underlying structures - Long (humerus/femur):
- support and leverage in limbs - Short (carpus/tarsus):
- large range of movement
- anti-concussive
-> allows for wide range of movement - Sesamoid bones:
- embedded in tendons
- change in angle over bony surface
-> redirect forces
-> reduce frictions to prevent damages
LO: Describe the anatomy of a long bone, relations various structures to the function
- Smooth surface areas:
-> passage of structures/tendons
->articular surfaces- hyaline cartilage at weight bearing surfaces
- resistant to deformation
- no blood vessels or nerves
- no periosteum
- Specific bony contours
-> tuberosities/tubers/tubercles/processes
-> provide site for attachment to important structures - Rough surface areas
-> general muscle attachment
*Periosteum: covers outer surface of bone (except articular surfaces)
- contains blood vessels & nerves
-important for fracture healing
- enters medullary cavity via nutrient foramen
LO: Describe how bones of the limb are formed from centres of ossification
LO: Explain the bone growth
LO: Recognise the growth plates on a radiograph
- Distinguish between the radiograph of a young and mature animal
Cartilage between centres appears black on radiographs = physics/growth plates
Young animal: open growth plates (visible on radiograph)
-continues to produce increase in bone length
Mature animal: closed growth plates = physeal scars
- time of closure depends on contribution of specific physical to limb length
-can estimate age from growth plate closure time
LO: Describe gross features of skeletal muscle
Gross features:
- made up of individual muscle fibres;
Arranged in parallel lines;
Collected into bundles;
Covered by fibrous tissue (deep fascia)
Attached to rigid structures - usually bone
Origin - usually proximal
Insertion - usually distal
Various types - circular, sphincter
- two bellied, two headed, single headed, multipennate, bipennate
What is the locomotor system?
What does it consist of?
Locomotor system = muscoskeletal system that allows for wide range of animal movement
Components:
Bones (osteology) - acts as a rigid support
Joints (arthrology) - allows movement between bones
Muscles (myology) - produces movement between bones
Contribution from trunk:
- dependent on species
Herbivores: roughage diets and bulky abdominal viscera
- less flexible trunks, rely more on limbs elongation
E.g. Horse - relatively rigid vertebral column
- Most of propulsion/stride length results from limbs
- Flexed suspension phase
Carnivores: small volume, consuming meat diet
- run fast
- flexible trunks, multipurpose limbs
E.g. Cat - flexible vertebral column allowing limbs to swing more
- bow-like, increase propulsion/stride length from limbs
- flexed & extended suspension phases
How is skeletal muscle attached?
(Origin or insertion)
-> Attached directly to bone (rough surface or bony tuber)
-area of attachment depends on muscle
->Via tendons
- condensations of deep fascia into cords
- less bulky across joints
- small area of attachment
- may have separate centre of ossification
-> Via aponeurosis (limited access to bone)
- fibrous tissue arranged as a thin sheet of tissue
- condensations of deep fascia into sheets
- long area of attachment
What are intrinsic muscles?
Intrinsic skeletal muscle:
- origin and insertion within appendicular skeleton
- responsible for movement of limb joints
- flexion and extension
What are extrinsic muscles?
Extrinsic skeletal muscles:
- origin on axial skeleton
- insertion in appendicular skeleton
- responsible for movement of limb relative to trunk
- protraction and retraction of limb
