attached to bone/exoskeleton for locomotion

under voluntary control

surrounds hollow tubes and cavities for propulsion of contents

under involuntary control

found only in the heart

under involuntary control

senses, sends, and stores "information"

information - chemcial, electrical, light, heat, pressure, mechanical, or pain stimuli

initiates and conducts electrical signals from on part of an animal's body to another

electrical signals produced in one nerve cell may stimulate or inhibit other nerve cells to:

initiate new electrical signals

stimulate muscle to contract

stimulate glands to release chemicals

sheets of densely packed cells that:

cover the body or individual organs

line the walls or body cavities

specialized to protect, secrete, and absorb

connect, anchor, and support

includes blood, adipose, bone, cartilage, loose and dense connective tissue

largest diversity of structure and function

form an extracellular matrix around cells:

provides scaffold for attachment

protects and cushions

mechanical strength

transmit information

different organs work together to perform an overall function

maintain same fluid composition as environment

"cheaper"

snakes, lizards, frogs, salamanders

internal composition of fluids different from environment

"expensive"

humans

accelerates a process

reinforces the direction of the change

(birth, urination, sneeze)

animal's body begins preparing for a change in some variable before it occurs

anticipatory

speeds up homeostatic responses and minimizes deviations from the set point