Americas Pavilion: Respiratory and Circulatory Systems

VOCABULARY flashcards covering the comparative anatomy of respiratory and circulatory systems in various animals including fish, mammals, insects, and invertebrates.

Single circulation system

A system found in fish where blood is pumped through only one circuit: from the heart, to the gills, to the body, and back to the heart.

Double circulatory system

A system in mammals and land vertebrates where blood flows from the heart to the lungs and back, then from the heart to the body and back, passing through the heart twice.

Diving reflex

A physiological response triggered by nerve endings in the mouth and nose that helps conserve oxygen by rushing blood to vital organs like the brain and heart.

Vasoconstriction

The narrowing of blood vessels to slow circulation to the extremities, used by animals like the North American River Otter during dives.

Bradycardia

A slowing down of the heart rate used to save oxygen during a dive.

Tracheae

A system of internal tubes in insects, such as the Florida lubber, that delivers oxygen directly to the body tissues.

Spiracles

Holes along the body of an insect through which oxygen and carbon dioxide are exchanged.

Hemolymph

The body fluid found in animals with open circulatory systems, such as insects and lobsters.

Open circulatory system

A system where blood is not contained in veins and arteries but returns to the heart through interconnecting spaces called venous sinuses.

Hemocyanin

A copper-containing molecule in the blood of some invertebrates that turns light blue when oxygenated and is about a quarter as effective as hemoglobin.

Hemoglobin

An iron-rich blood pigment found in vertebrates that makes blood red and is more efficient at carrying oxygen than hemocyanin.

External gills

Respiratory organs that allow the Axolotl to efficiently extract oxygen while remaining under water.

Vestigial lung

A smaller, unused lung found in most snakes alongside their one working lung.

Hypotensive shock

A failure of circulation resulting from a drop in blood pressure when too many blood vessels open, which can be induced by some snake venoms.

Water vascular system

A complex system used by sea stars that utilizes seawater instead of blood to keep things moving throughout the body.

Papulae

Also known as skin gills, these are small projections near the base of spines on sea stars used for oxygen uptake through diffusion.

Cutaneous respiration

A form of respiration where gas exchange occurs through the skin, used by amphibians like the blue poison dart frog.

Faveoli

Honeycomb-shaped structures that line the walls of lizard lungs to increase respiratory surface area for gas exchange.

Gill hearts

Two hearts in an octopus that pump blood to the gills to dump waste and load oxygen.

Systemic heart

The heart in an octopus that pumps oxygen-rich blood through the rest of the body.

Closed circulatory system (Octopus)

A system where blood travels exclusively through blood vessels, representing about $5\%$ of the octopus's body volume.