29. Locomotion Flashcards
what are the two forces to keep animas stationary? how do animals get over this barrier?
friction and gravity!
energy expenditure helps get animas over these barriers - depends on animals anatomy
what are the are the major force to overcome in water? give three
- less gravity (buoynacy)
- water is denser - viscous
- more drag - friction
what do aquatic mammals do to overcome the forces in the water?
- they have a fusiform shape (oval)
- the movement is streamline
- there are undulations movements - think going side to side
what are the major forces to overcome locomotion in the air? (1)
gravity
how do mammals that fly overcome the forces in the air? 3 points
- very light bodies - low fat mass
- fusiform shape (oval)
- wings shaped like hydrofoil to create lift
what are the major forces to overcome locomotion on land? 3 pooints
the effect of gravity
balance
air resistance
how do mammals overcome the forces on land? (2)
they have minimal air resisitance by differing shapes
feet in varying shapes - depending on environment, to stabilise
what are the four different types of legged locomotion
- stance
- number of legs
- foot shape
- gait
what are the 3 types of stances and what is in common for stances for all mammals?
the sprawling stance - legs used to drag body ver land (amphiban/reptile)
the semi erect stance - legs to side but body off floor - reptiles
the fully erect stance - upright and legs underneath - mammals and birds
all mammals have a fully erect stance
what are the three variation in the number of legs?
bipedal - hopping or alternating gait (walking)
tripedal - using a tail as a thrid leg
quadrupedal - all fours
what are the four variations of foot shape?
plantigrade
digitgrade
unguligrade
knuckle walking
what is plantigrade food shape and what is an advantage and disadvantage?
plantigrade is when the hole foot is flat on the ground
advatages: good stability platform
disadavantage: slower because heavier to move
what is digitgrade and what are the advantages (3) and disavantages?
mammals walking on their toes.
advantages: greater stride for speed, quiet (good for stalking) energy effiecet for moving fast
disadvantages: less balance
what is unguligrade and what is the advantages (3) and disadvantages?
walking on the tips of toes - ie nail.
advantages: even greater potential for speed and stride lenghth
disadvantage: walking in varying weather conditions due to the small weight dispersal - fall through mud and snow
what is knuckle walking and what is the advantages and disadvantages?
knuckle walking is quadrupedal locomotion
advantage - feet used for food gathering and climbing
disadvantage - much slower
what is gait?
the way the a mammal walks and steps
why could running be more effiencent than walking for a land based bipdeal?
because walking requires one foot on the ground at a time, therefore when walking at higher speeds it could be easier to run due to the flight phase which allows for more effiencentcy at higher speeds
how can the stride frequency (how fast feet can touch the ground) be increased?
reducing body size
reduce limb length
there will be less weight to move!
how can a mammals on land increase stride lenghth?
increase body size
increase spine flexibiility
increase leg lenghth
