Body Systems Overview and Regulation AP Biology Unit 6

Body Systems Overview How can we link major body systems together through the theme of energy? –Digestive –Circulatory –Respiratory –Excretory Slide 2 of 11

Body Systems: Energy Digestive –Obtain and break down food into nutrients needed for energy Circulatory –Transport nutrients to appropriate locations Slide 3 of 11

Body Systems: Energy Respiratory –Obtain O 2 and get rid of CO 2 (involved in energy producing reactions) Excretory –Filter out wastes created from cells during energy creating/breakdown processes Slide 4 of 11

Bioenergetics Tracing the energy flow through an animal What happens to the energy? Used for –Cellular Respiration –Building –Storage * Some energy is also lost as heat Slide 5 of 11

Feedback and Regulation Feedback and regulation is important for maintaining homeostasis Homeostasis = internal balance (temperature, levels of hormones, etc.) Feedback can be either positive or negative –Negative = triggers something to stop –Positive = triggers something to be amplified Slide 6 of 11

Feedback and Regulation Cells must be kept in an aqueous environment (prevents cells from drying out) Interstitial fluid = fluid between cells that allows nutrients and wastes to be transferred in and out Slide 7 of 11

Feedback and Regulation More complex organisms usually require more regulation in order to maintain homeostasis Slide 8 of 11

Regulation When environmental conditions change, animals react to these changes in a variety of ways –Regulator = animal who uses internal processes to maintain internal conditions Ex. humans –Conformer = animal who will adjust to the environment Ex. Spider crabs Slide 9 of 11

Temperature regulation Ectotherm –Gains heat from environment –Can’t internally regulate their own body temperature Endotherm –Internal processes generate enough heat to regulate body temperature Slide 10 of 11

Temperature Regulation in Humans Controlled by the hypothalamus in the brain Several different mechanisms can be used to regulate body temperature –Dilation and constriction of blood vessels –Sweating (Evaporative cooling) –Muscle contractions (ex. shivering) Slide 11 of 11