Lesson 7.2: The Science behind Sleep | Crossword


Across

3.physical, behavioral, and mental changes in the body that occur naturally and typically follow the 24-hour cycle of the sun

Down

1.a hormone released by the pineal gland that increases feelings of relaxation and tiredness
2.the fatigue that people experience after changing time zones during travel
4.a type of cell that makes up the body’s nerve tissues

G-W Learning