LT Animal Flashcards
fish: number of ventricle, atria, circuits, blood mixing?
1 ventricle, 1 atrium, 1 ciruit, no blood mixing
amphibians: number of ventricle, atria, circuits, blood mixing?
1 ventricle, 2 atria, 2 circuits, blood mixing
reptiles (except crocodilians): number of ventricle, atria, circuits, blood mixing?
1 ventricle, 2 atria, 2 circuits, blood mixing (& partial septum)
birds and mammals: number of ventricle, atria, circuits, blood mixing?
2 ventricles, 2 atria, 2 circuits, no blood mixing (complete septum)
What are vertebrates?
Animals with heads and spinal cords protected by a backbone.
What is a closed circulatory system?
Blood pumped through vessels in a unidirectional flow (heart → arteries → capillaries → veins → heart).
Valves prevent backflow.
What is an open circulatory system?
Hemolymph pumped into a cavity where it surrounds cells before returning to the heart.
(not always enclosed in vessels)
Functions of the respiratory system?
Oxygen diffusion into the blood.
Carbon dioxide diffusion out of blood into the air.
Characteristics of respiratory systems?
Extensive capillary networks.
Large, thin surface area.
Must remain moist for gas exchange.
Respiratory structures in tetrapods vs. aquatic organisms?
Gills in water.
Lungs in terrestrial environments.
Amphibians: Use lungs, mouth lining, and skin for respiration.
What are systemic and respiratory capillary beds?
Systemic: Oxygen delivered to cells.
Respiratory: CO₂ removed from blood and expelled.
Fish circulatory and respiratory systems?
Respiration:
Gills specialized for water.
Breathing: Water enters mouth → forced through gill slits → oxygen diffuses across filaments.
Circulation:
Single loop.
Low blood pressure (muscle movement aids return flow).
Amphibians’ respiratory system?
Simple lungs.
Mouth lining for gas exchange (at rest on land).
Skin for underwater respiration.
Amphibians’ circulatory system?
3 chambers: 1 ventricle, 2 atria.
2 loops: Pulmocutaneous and systemic circuits.
Blood mixing reduced by:
Ventricular ridge.
Timed contractions.
Reptiles’ respiratory system?
Lungs with alveoli for efficient gas exchange
Reptiles’ circulatory system?
Non-crocodilian:
3 chambers.
2 circuits.
Partial septum reduces blood mixing.
Crocodilian:
4 chambers.
2 circuits.
Blood mixing via foramen of Panizza (hole between two aortae).
Aortae:
Main: Carries oxygenated blood.
Bypass: Active during apnea (carries deoxygenated blood).
Birds and mammals’ respiratory system?
Highly branched lungs with alveoli for gas exchange.
Efficient for oxygen uptake (endotherms, high activity levels).
Birds and mammals’ circulatory system?
4 chambers: Fully separate systemic and pulmonary circuits.
No blood mixing (convergent evolution).
What did all tetrapods evolve from
fish-like ancestors
What are characteristics of animals with high metabolic demands?
Extensive use of muscles for activities like flying (birds) or running (mammals).
Endothermy: Internal mechanisms to regulate body temperature.
Require efficient respiratory and circulatory systems to supply oxygen and remove CO₂.
Why do birds and mammals have high metabolic needs?
Endothermy demands a continuous supply of energy to maintain body temperature.
High muscle activity levels (e.g., flying or running) require rapid oxygen delivery.
What adaptations support high metabolism in birds and mammals?
Highly efficient lungs with extensive branching and alveoli for gas exchange.
What are characteristics of animals with low metabolic demands?
Ectothermy: Dependence on the environment for temperature regulation.
Lower muscle activity (e.g., “sit-and-wait” predators like reptiles).
Tissues require less oxygen, and CO₂ buildup is slower.
Why do reptiles have low metabolic needs?
They are ectotherms and don’t expend energy on temperature regulation.
They engage in less frequent, intense physical activity compared to endotherms.
