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