In order for an animal to survive, it must be able to respond instantly to changes in its external and internal environments. This program compares and contrasts animal nervous and endocrine systems, explains stimulus feedback mechanisms, and places coordination and control in a cellular context with explanations of what happens in signal transduction pathways. Narration is supported by animations and footage of animals in action. A powerful tool for enhancing student understanding of complex biological processes. Viewable/printable educational resources are available online. Original title: Coordination and Control One: Animals. (23 minutes)

Living organisms must be able to process environmental changes through receptors, a processors, and effectors. The forms of conduction pf these processes are either neural or hormonal.

Nerves are bundles of many neurons. A neuron consists of dendrite, cell body, and axon. Neurons are of two types: sensory or motor. Sodium and potassium ions facilitate movement of electrical impulses along axons.

An impulse from sensory neurons travels to the brain. The brain processes the impulse and sends a signal back along a motor neuron, stimulating muscles to contract or relax. Reflexes are automatic responses to a stimulus (reflex arc).

Vertebrate nervous systems consist of the central nervous system and the peripheral nervous system. The somatic and autonomic systems operate within these systems.

Hormones are chemical messengers secreted by organism cells response to specific stimuli. Plants and animals need hormones to coordinate growth and development. Vocabulary: neurotransmitter, endocrine, exocrine, and pheromone.

Endocrine hormones are under feedback control. Hormone secreting glands include hypothalamus, pituitary, parathyroid, and thyroid. Hormones include oxytocin, thyroxin, calcitonin, and more.

Estrogen contributes to calcium removal from bones. Adrenal hormones influence carbohydrate metabolism, and sodium and potassium balance. The pancreas has both endocrine and exocrine functions. Gonads contain hormone-producing cells.