Body Systems Overview and Body Systems Overview and RegulationRegulation

AP BiologyUnit 6

Body Systems Overview

• How can we link major body systems together through the theme of energy?– Digestive– Circulatory– Respiratory– Excretory

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Body Systems: Energy

• Digestive– Obtain and break down food

into nutrients needed for energy

• Circulatory– Transport nutrients to

appropriate locations

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Body Systems: Energy

• Respiratory – Obtain O2 and get rid of CO2

(involved in energy producing reactions)

• Excretory– Filter out wastes created from

cells during energy creating/breakdown processes

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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

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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 amplifiedSlide 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

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Feedback and Regulation

• More complex organisms usually require more regulation in order to maintain homeostasis

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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

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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

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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