Lecture 13 Flashcards
Circulation pt. II
What does circulation in fish look like?
For the most part its the same like other animals, however there is no heart in-between the breathing organ and the systemic circulation, also the oxygenated myocardium depends on blood flowing through the limen of the heart.
How does the air breathing organs work in fish in terms of circulation?
Air Breathing Organs (ABO) derived from
structures like the mouth membranes, gut, or
swim bladder
- These organs tend to receive blood the same
way as other systemic organs, from the gills.
So, the oxygenated blood leaving this tissues
moves into veins
What are the 3 main themes that dominate the research of avian and reptile circulatory systems?
- Selective distribution: To what extent is oxygenated blood sent to the tissues and
deoxygenated blood sent to the lungs - Maintenance of different blood pressures in the systemic and pulmonary circuits: Can high
pressures be maintained in the systemic circuit to produce high flow rates while low
pressures are maintained in the pulmonary circuit to prevent damage - Redistribution of cardiac output: To what extent is flow to the lungs adjusted separately from
the rest of the body
Circulation in amphibians and reptiles theme 1 (selective distribution)
Amphibians and reptiles that breathe through lungs have specialized heart structures to manage oxygenated and deoxygenated blood flow, preventing significant mixing until it reaches the ventricle. While amphibians rely on a contractile conus arteriosus for blood distribution, crocodilians have fully separated ventricles and can coordinate blood flow with intermittent breathing.
Circulation in amphibians and reptiles theme 1 and 2
Lung-breathing amphibians and reptiles regulate oxygenated and deoxygenated blood flow with partially divided ventricles, minimizing mixing and allowing pressure control to each artery.
Circulation in amphibians and reptiles theme 3
Lung-breathing amphibians and reptiles manage blood flow to minimize mixing, with crocodilians having fully separated ventricles and adjusting lung blood flow through vascular resistance during breathing and apnea.
What does circulation in invertebrates with closed systems look like?
Invertebrates with closed circulatory systems, like annelids and cephalopods, and molluscs circulate blood through a network of vessels, ensuring efficient delivery of oxygen and nutrients directly to tissues.
What does circulation in invertebrates with open systems look like?
Most invertebrates have open circulatory systems where a central heart pumps hemolymph through arteries and capillary beds before it flows into open spaces called sinuses and lacunae, mixing with extracellular tissue fluid. These spaces are lined with non-vascular cells, distinguishing open systems from closed ones.