Chapter 42: Circulation And Gas Exchange Flashcards
Small molecules can move between cells and their surroundings by
Diffusion
Random thermal motion
Diffusion
Diffusion is only efficient over ________ distances
Small
In most animals, the circulatory system is functionally linked to the ___________ ___ ______ with the environment and with body cells
Exchange of gases
Some animals lack a ___________ system
Circulatory
Cnidarians have elaborate _____________ __________
Gastrovascular cavities
Gastrovascular cavities function in _________ and __________ of substances throughout the body
Digestion; distribution
The body wall that encloses the gastrovascular cavity is only ___ cells thick
2
What specimen have a gastrovascular cavity?
Flatworms
What 2 things do Flatworms have that minimize diffusion distances
Flat bodies; gastrovascular cavity
What 3 things do circulatory systems have?
Circulatory fluid
Set of interconnecting vessels
Muscular pump, the heart
The circulatory system connects the ________ that surrounds cells with ________ that exchange gases, absorbs nutrients, and dispose of wastes
Fluid; organs
Circulatory systems can be _______ or _________
Open; closed
In _________, other arthropods, and some molluscs, have circulatory fluid called __________
Insects; Hemolymph
Bathes the organs directly in an open circulatory system
Hemolymph
Hemolymph is a part of a ______ circulatory system
Open
Blood is a part of a ________ circulatory system
Closed
Is confined to vessels and is distinct from the interstitial fluid
Blood