|
Home > Preview
The flashcards below were created by user
djwon1
on FreezingBlue Flashcards.
-
Amniotic Egg
- Reproduce via internal fertilization
- Fertilized egg is encased in an amniotic egg
- Protects the young from dehydration and injury
-
Different demands on land than in water
- Less viscous
- Less dense
- Higher O2 level
- Gravity has greater effect on land
-
Specific Challenges of Terrestrial Existence: Support
- Increase in bone mass
- Change in overall structure of skeleton – limbs articulate with spine via girdles
-
Bone Structure
- Strong but light
- Amniotes: Concentric layers of bone around blood vessels (Haversian Canal)
-
Joints
- Cancellous bone enclosed in joint capsule
- Synovial fluid (lubrication)
- Cartilage on ends (friction)
-
Zygapophyses
- articulating surfaces that resisttorsion and compression
- Similar to suspension bridge
-
Important changes in Tetrapod
- Snout length
- Mode of reproduction
- Neck, pectoral girdle free from head Respiratory (lungs and trachea)
- Vertebrae differentiation
- Attachment pelvic girdle to column
- Form of limbs
- Epaxial and Hypaxial muscles
- Presence of urinary bladder
-
function of Axial Muscles in fish is side to side bending but in tetrapods:
- Postural support
- Lung ventilation
- Locomotion
-
Important hypaxial muscles in Amniotes:
- Transversus abdominus
- Costal muscles --> inhalation and exhalation
- Rectus abdominus – mostly postural role
-
Vertebrae differentiation
cervical
trunk
sacral
caudal
- cervical - Up/down and side/side movement of neck
- trunk - Thoracic (ribs), lumbar (lost ribs in mammals)
- sacral - Fused with pelvic girdle
- caudal - tail
-
Development of Neck in Tetrapods. Loss of ___ --> ___ not connected to head
- opercular bone
- Pectoral girdle
-
Appendicular Skeleton - Limb and limb girdle
- Pectoral, pelvic fins derived from fishes (ray-like structure)
- Pelvic girdle fused to sacral vertebrae (3 paired bones on each side)
- Pectoral girdle, forelimb forms tripod of support (and girdle free from dermal skull)
-
Energetically more expensive than in water:
___>___>___
walking>flying>swimming
-
Primitive locomotion:
Axial flexion of body -> uses trunk muscles, not limb muscles
-
Isometric Scaling
changes in size do not result in changes in proportion (1:1 ratio)
-
Negative Allometry
smaller as animal gets larger(e.g. metabolic rate, respiration)
-
Positive Allometry
larger as animal gets larger(e.g. skeletal mass)
-
Eating on Land
- jaws and teeth
- Derived tetrapods have palate fused to braincase
- tongue and hyoid apparatus
- Salivary glands for swallowing
-
Breathing on Land
- Less dense, more O2 in air
- Tidal respiration
- Movement of ribs – negative pressure in abdominal cavity
-
Why don't gills work on land?
lose surface area by collapsing
-
Circulatory System
- High blood pressure
- Thick-walled muscular heart
- Valves in veins – resist backflow
- Separation of oxygenated (arterial) and deoxygenated (venous )blood (Double Circulatory System) – permanent ventricular septum
-
Further Adaptations of circulatory system
- Changes in aortic arches
- Three arches retained (Carotid, systemic, pulmonary - brain body lungs)
- Coronary arteries –feed heart
-
Vision
- focuses light on retina
- Flatter lenses than fishes, change shape to focus
-
Derived features of vision
- Eyelids
- Glands that lubricate eye
- Nasolacrimal duct, moist
-
Hearing
- Sound channeled through inner ear
- Transmission of sound waves through chain of bones in middle ear (sound amplifier)
- Organ of Corti – has hair cells that transmit sound info.to CNS
- Amphibians – independent evolution of hearing
-
Pathways for water loss
- 1. Body surface
- 2. Respiratory system
- 3. Kidneys
-
Water Conservation adaptations
- Tetrapod ancestors = dermal scales
- Outer layer composed of keratinized epidermal cells (keratin = insoluble protein + lipids to reduce water loss)
-
Urogenital Ducts in Tetrapods
Derived tetrapod feature =
bladder
-
Urogenital Ducts in Tetrapods
Derived amniote character =
ureter (duct that drains kidney)
-
Most Verts. = common openingfor urinary, digestive, andreproductive tracts, ___
cloaca
-
Only marsupials and placentals:
Separate urogenital and digestive system openings;replaced cloaca
-
Thermoregulation
- Ectotherm “outside heat” – reptiles, amphibians vs.
- Endotherm “inside heat” – birds, mammals
-
Mechanisms for Gaining or Losing Heat
- Solar Radiation
- Thermal (infrared)radiation
- Convection
- Conduction
- Evaporation
- Metabolic heat production
-
Ectothermy:
- Eat less
- Live in places where endotherm can’t survive
-
Endothermy:
- Live in cold climates and active at night
- High Energy cost and food requirements
|
|
Get the free mobile app
Take the Quiz
Learn more
Learn more