Terrestrial Life Flashcards
What are 6 areas that organisms adapted in for terrestrial life?
Locomotion, gravity and support, respiration, sensory system, circulation, feeding, temp and water loss
What two things does the stability of the vertebrate body rely on?
Strong limb to support the body weight, and a center of gravity that is above or in the polygon formed by the limbs
What does rigidity of the vertebrate body rely on?
Relies on tensions from muscles/ tendons and ligaments, as well as thicker bones and other connective tissues
What is a ligament? What does it act in conjunction with?
Ligament is an elastic structure that prevents bones from moving too much, and the muscles on each side of the limb act with it to stabilize joints
What are the two main components of locomotion?
Posture which is a static stance where the body is usually stable, and gait which is a dynamic sequence of stance, usually transitioning from one stance to another
What are the two major postures?
Sprawling: plesiomorphic, 90 degree elbow joint, large adductor muscles under humerus required for locomotion, typical of squamates and urodelans
Parasagittal: derived, limbs positioned under the trunk of the body, adductor muscles under the humerus are reduced, body is somewhat steady during locomotion, typical of therian mammals and birds
What type of animal switches between sprawling and parasagittal stances?
Crocs
While taking a step, what are the two phases a limb switches between?
Stance phase where the limb contacts the ground and muscles contract to provide forward momentum
Swing phase where the limb is lifted and moves forward
What three situations require additional muscle work?
accelerating rapidly, climbing vertically, as well as individuals with heavier limbs and body weight
What are the three methods of studying gait?
Kinematic simulations, footprints, as well as high speed videos
How do tetrapod usually capture their prey?
They use their muscular tongue or forelimbs to get food into their mouths then process by chewing or inertial feedingW
What are the two ways tetrapods process their food?
Chewing: items are broken down by tossing and repeatedly biting
Inertial feeding: with food idea held in mouth, the predator jerks his head to provide momentum to the prey, then the jaw is loosened then closed again
Describe the two processes involved in respiration of tetrapods
Ventilation which is transporting air into and out of the respiratory organs, as well as gas exchange in a moist membranous structure with rich blood supply
What are the two ways to use lungs for ventilation? Describe them
Buccal pumping: nostrils open and buccal cavity expands for air to be drawn into it, then glottis opens and buccal cavity constricts which forces air into expanded lung, then glottis closes and lungs constrict forcing air out, then both cavities constrict forcing air out the nostril
Costal ventilation: body wall of the trunk expands to allow air into the lungs through the nostril, then the body wall of the trunk constricts/collapses to force air out of it through the nostrils
Circulation in tetrapods
Blood must be pumped uphill, it is working against gravity position of the heart is shifted caudally and vertebrates have higher blood pressure and valves within veins to prevent backflow
