LOCOMOTION Flashcards
Proximal limb bones are called what?
Humerus
Distal limb bones are the what in:
a) forelimbs?
b) hind limbs?
a) radius
b) tibia
The ulna is found in (a) limbs and the fibula is found in (b) limbs.
a) fore
b) hind
What are the metacarpels and metatarsels?
bones prior to the phalanges, carpels are in forelimbs and tarsels in hind
a) Digits contain what bones?.
b) 4 have how many and 1 has?
a) phalanges
b) 4 have 3 and 1 has 2
a) What did the basic amniote pectoral girdle look like?
b) Contrast this to the ancestral pectoral girdle in mammals?
c) What did this allow?
d) Is the pectoral girdle fused to spine? What does this allow?
a) very basic
b) shows reduction in ventral portion, leaving clavicle and dorsal portion extended to form scapula
c) greater musculature
d) NO, allows greater mobility and shock absorption
- allows for a muscular sling
How did the pelvic girdle change?
What did this mean?
the illium (upper portion) rotated and extended whereas the lower portions (ischium and pubis) were rotated backwards -extends forward of joint and allows greater musculature
Name the 3 processes?
- elbow (olecranon)
- hip (throchanter)
- ankle or heel (calcaneus)
Bones are the (a) and (b) are the fulcrums.
- levers
- joints
What provides in forces?
What provides out forces?
Distance to in lever from fulcrum to in force?
Distance to out lever from fulcrum to out force?
- pulling of tendons
- teeth, claws, feet etc.
- In-lever arm
- Out- lever arm
a) A low in lever but high out lever ratio means what?
b) A high in lever but low out lever ratio means what?
a) lots of power, but little speed
b) little power, but lots of speed
Specialisation for cursorial locomotion
- distal segments greater than proximal
- clavicle reduction or loss to aid free scapula movement
- shift from plantigrade to digitigrade to unduligrade stance
- flexion and extension of spine
- incorporating suspension
- moving muscle attachment to have greater limb control, closer to pivot joint
- reposition scapula as a shoulder girdle so that limbs are underneath
How are stride rates increased?
- reduced muscle mass in limbs, use long distal tendons
- lose muscles required for side to side movement
- lose bone mass, fibula is greatly reduced
- fusion of metacarpels
- joints act as hinges to avoid dislocation
Why would an organism operate fossorial locomotion?
- digging to establish safer habitat
- secure food items
- escape predators
3 forms of digging
- chisel tooth digging
- scratch digging
- rotational thrust digging
Key adaptations for fossorial locomotion?
basically OPPOSITE TO CURSORIAL
- retaining the clavicle
- short broad limbs that retain 5 digits to attach to claws
- posterior extension of the scapula
- muscles insert far from pivot
- enlarged processes for muscle attachment
What is natatorial locomotion?
swimming
Part time swimmers are known as being ‘(a)’ and have adaptations similar to those in fossorial locomotion. Describe these.
a) paraxial
- large in lever arms
- huge areas for muscle attachment
- proximal limb shortening
- manus elongation
Full time swimmers are known as being ‘(a)’ and have what kind of adaptations? (b)
a) axial
b) - greatly reduced proximal bones
- hyperphalangy
- fin like limbs
- distal bones part of paddle
What kind of undulations to axial swimmers use?
- dorso ventral NOT LATERAL
What structure in axial swimmers is supported by connective tissue?
What kind of shape are axial swimmers?
- long robust tail
- fusiform
What is scansorial locomotion?
- adapted for climbing
How do scansorial animals add friction and overcome the steeper shearing force pushing them down?
- bind with surface eg. sucker footed bat
- interlock with surface eg. koala
- prehensile tail
- globular digits
How do scansorial animals avoid toppling?
- grasping extremities to exert on opposing torque
- hang under surface
- lower your centre of gravity
- become smaller
- use a tail
