Introduction Lesson Flashcards
What is the locomotor system and what are its components?
=musculoskeletal system that allows a wide range of animal movement
Components:
- BONE (osteology)- act as rigid support
- joints (arthrology)- allow movement between bones
- muscles(myology)-produces movement between bones
What are cursors?
They are vertebrates that run on the ground and are structurally modified to enhance speed or endurance
They are either predators or medium to large sized herbivores
What are the cursorial adaptations of the locomotor system?
- REDUCED PECTORAL SKELETON- allows more cranial/caudal movement
- ELONGATION AT THE PROXIMAL END OF THE LIMB- scapula lies laterally
- ELONGATION AT THE DISTAL END OF THE LIMB- long metacarpals, walk on toes or hooves
How is a reduced pectoral skeleton a cursorial adaptation of the locomotor system?
The clavicle is the only bony connection between the forelimb and the axial skeleton
The clavicle is usually absent or vestigial (would be held in place by the acromioclavicular (AC) joint
When the clavicle is absent or reduced, there’s no bony component attaching the forelimb to the trunk
THIS TYPE OF JOINT IS PURELY MUSCULAR AND IS CALLED A SYNSARCOSIS
THIS PARTICULAR JOINT IS CALLED THE OMOTHORACIC JUNCTION
How is the elongation at the proximal end of the limb a adaptation of the locomotor system?
Increasing the leg length= increased stride length
At the proximal end of the forelimb, the scapula (shoulder blade) moves from lying flat against the the back of the broad chest (hanging beneath) to lying flat at the sides of a deep narrow chest (tucked in)
How does elongation of the distal limb lead to cursorial adaptation of the locomotor system?
Increased limb length= increased stride length= a more energy efficient way to cover the ground more quickly
Define the term flexion (INTERACTION BETWEEN LIMBS AND TRUNK)
Folding limb
Define the term protraction (INTERACTION BETWEEN LIMBS AND TRUNK)
Moving the limb forward
Define the term extension (INTERACTION BETWEEN LIMBS AND TRUNK)
Stretching limb
Define the term retraction (INTERACTION BETWEEN LIMBS AND TRUNK)
Moving the limb backwards OR fixing limb and moving the trunk (torso) forwards relative to the limb
What are locomotion and diet linked in and give examples of this in herbivores
Linked in evolution
HORSES: -relatively rigid vertebral column -most of propulsion/stride length results from limbs -fixed suspension phase LESS FLEXIBLE TRUNKS
Define the the term locomotion
A variety of methods that animals use to move from one place to another
Describe the locomotion in cats
-flexible vertebral column allows limbs to swing more
-acts like a bow to increase propulsion/ stride length from limbs
-flexed and extended stride lengths
LESS ABDOMINAL VOLUME
What’s a gait
Sequence of limb movements
What are the 4 different types of gait?
Walk- 4 beat gait (each limb moves forward individually, sequentially and hit the ground separately
Trot(diagonal gait)- 2 beat gate(two limb hit he ground simultaneously. Foot fall sequence is LF+RH and RF+LH)
Canter-3 beat
If left leads (foot fall sequence is RH then LH+RF then LF
If the right leads (foot fall sequence is LH then RH+LF and RF)
Gallop-4 beats
If left leads( foot fall sequence RH then LH then RF then LF)
If right leads (foot fall sequence is LH then RH then LF when RF)
Define the term domestic species
Vertebrates =have a axial skeleton, and a appendicular skeleton (forelimb and hindlimb bones)
SEE INTRODUCTION LECTURE IF CONFUSED
What are the 4 different bone types and how are they different from each other
FLAT(SCAPULA/PELVIS):
- large surface area for muscle attachment
- protection of underlying structures
LONG(HUMERUS/FEMUR):
-support and leverage in limbs
SHORT(CARPUS/FEMUR):
- large range of movement
- anti-concussive
SESAMOID BONES:
-embedded in tendons
-change the angle over bony surface
(Redirect forces, reduce friction so prevent damage)
What are the general features of bones? And identify these on a humerus bone
SMOOTH SURFACE AREAS:
- passage of structures/tendons
- articular surfaces (hyaline cartilage at weight bearing surfaces, resistant to deformation, no blood vessels and no nerves, NO PERIOSTEUM). WILL HAVE PERICHONDRIUM INSTEAD
SPECIFIC BONY CONTOURS:
- Tuberosities/tubers/tubercles/processes
- provide a site for attachment of important structures
ROUGH SURFACE AREAS:
-general muscle attachment
What is the periosteum and what does it contain. Why is it important?
Covers the outer surface of bone (except articular surfaces)
Contains blood vessels and nerves
IMPORTANT FOR FRACTURE HEALING, ENTERS MEDULLARY CAVITY VIA NUTRIENT FORAMEN
What can you see on a x-ray/radiograph of a long bone?
- diaphysis
- medullary cavity=hollow centre
- epiphysis= end, incorporates articular surfaces
- metaphysis=transition zone
What are limb bones formed from?
They are formed from centres of ossification
How many centres of ossification do short, sesmoid, flat and long bones have?
Short and sesmoid= usually one centre per bone
Flat and long=usually more than one per bone
ATTACHMENT SITES FOR IMPORTANT STRUCTURES MAY HAVE A SEPARATE CENTRE
How do growth plates/physis appear on radiographs?
Cartilage between centres appears black on radiographs
How do radiographs allow you to determine the age of a animal?
YOUNG ANIMAL: open phases/ growth plates, produces increase in bone length
MATURE ANIMAL:closed growth plates appear as PHYSEAL SCARS
Where is the weakest point of adult and young bones?
Adult=shaft (can lead to fractures)
Young=growth plate (can lead to damage/separation)
Define the term cranial and caudal? When does something become distal, plantar and palmar and identify these on a picture (ON THE POWERPOINT)
Cranial=towards the head (becomes dorsal below the carpus/tarsus)
Caudal=towards the tail (becomes palmar below carpus (FL) and becomes plantar below tarsus (HL))
Define the terms proximal, distal, medial and lateral in relation to limbs
Proximal=top of limb
Distal= bottom of limb
Medial=towards the medial plane
Lateral= away from the medial plane
Where does the origin and insertion of skeletal muscle usually occur?
Origin- usually proximal
Insertion-usually distal
Describe the details of skeletal muscle attachments
-directly to bone
Describe the structure of tendon attachments of bones
- condensation of deep fascia into cords
- less bulky across joints
- small area of attachment
- may have separate centre of ossification
Describe the structure of aponeurosis attachments
LIMITED ACCESS OF BONE
- fibrous tissue arranged as a thin sheet of tissue
- condensation of deep fascia into sheets
- Long area of attachment
What is the aponeurosis across the vertebrae called and what is the last type of attachment which hasn’t been mentioned yet?
CERVICO-THORACO-LUMBAR FASCIA
HAVEN’T MENTIONED THE SUPERFICIAL FASCIA (INCLUDES SUBCUTANEOUS, LOOSE CONNECTIVE TISSUE AND FAT)
Allows attachment of skin with underlying tissues
Define the term flexion and extension in muscle action
Decreased angle=flexion
Increased angle= extension
What does muscle action depend on?
- which joint is crossed
- aspect of joint crossed
What are antagonistic pairs of muscles?
A pair of muscles with opposite actions
What are intrinsic muscles
- origin and insertion within appendicular skeleton
- movement of limb joints
- flexion and extension
What are extrinsic muscles?
- origin at axial skeleton
- insertion in appendicular skeleton
- movement of limb relative to trunk
- protraction and refraction of limb (protraction=forward movement of limb, refraction=backwards movement of the limb)
Describe the attachment between the trunk and forelimb in animals
In domestic species, no joint is present between forelimb and trunk
There is only muscular attachments
The scapula glides over the thorax (pivotal point is midway down the scapula)
