Chapter 32

3. - signaling molecules sent out by the endocrine system
4. - tissue that binds to and supports other tissues
6. - the widening of the diameter of blood vessels; promotes heat loss
10. - animal that allows its internal condition to change with external changes
12. - two proteins that enable muscles to contract
13. - different types of tissues organized into functional units
14. - the study of the biology functions an organism performs
17. - multiple tiers of cells
19. - the narrowing of the diameter of superficial blood vessels; reduces heat loss
20. - process by which animals maintain internal temperature within a normal range
23. - the transfer of heat by the movement of air or liquid past a surface
24. - a single layer of cells of varying length
26. - organisms use ___ to maintain a steady state or internal balance regardless of external environment

1. - single cell layer
2. - involuntary and non-striated
5. - removal of heat from the surface of a liquid that loses some of its molecules as gas
7. - the transfer of heat between molecules of objects in contact with each other
8. - endocrine cells are grouped in ductless organs called endocrine ___
9. - animal that uses internal mechanisms to control internal change despite external fluctuation
11. - the emission of electromagnetic waves by all objects warmer than absolute zero
15. - involuntary and striated
16. - the study of the biological form of an organism
18. - animals gain heat from external sources
21. - animals generate heat by metabolism
22. - groups of cells with similar appearance and common function
25. - type of muscle that is voluntary and striated