Vitamins

•Organic molecules

Minerals

• Inorganic

• Trace minerals needed in very small amounts

Nervous System

• Function: collects information about the body’s internal and external environment, processes that information and responds to it

Impulses

• Name given to the messages carried by the NS which are actually electrical signals

• Cells that transmit impulses are Neurons

The Nerve Impulse

• Electric potential

Resting Potential

• -70 mV(millivolts)

Action Potential

• Threshold: The minimum level of a stimulus that will cause an impulse

What happens when impulse reaches end of neuron?!

• Synapse: space between neurons

• Neurotransmitter: chemicals that carry impulse across the synapse

Reflex Arc

Reflex: quick, automatic response to a stimulus

• Sensory Neuron: type of nerve cell that receives information from sense receptors and carries it to CNS

– Sensory Receptor: transmit information about internal and external changes in the environment (types….p. 906)

• Interneuron: type of nerve cell found in the spinal cord; processes information for a reflex

• Motor neuron: type of nerve cell that carries directions from interneurons to muscles or glands

Effector: muscle or gland stimulated by the motor neuron

CNS…spinal cord and BRAIN!!

• Contains billions of neurons and other supporting tissue

• Must process, relay and form responses to huge amounts of information and stimuli

• Largest region: Cerebrum

Cerebrum

• Responsible for voluntary or conscious activities• Site of intelligence, learning and judgement• Deep groove divides cerebrum into right and left

hemispheres• Hemispheres connected by the corpus callosum• Each hemisphere divided into lobes!

• Outer layer of cerebrum= CEREBRAL CORTEX– Consists of grey matter– Where actual processing occurs– Thoughts, planning, learning– Folds and grooves…increase surface area!

• White Matter– Inner layer of cerebrum– Actually bundles of axons and myelin sheaths– This layer still a bit of a mystery…..

• Cerebellum: coordination and balance

• Medulla: controls involuntary processes

– Ex: regulation of blood pressure, beating of your heart, breathing, peristalsis

– Part of the brain stem

• Thalamus: receives info from sensory receptors and sends it to correct part of cerebrum to be processed

• Hypothalamus: control center for recognition and analysis of hunger, thirst, fatigue, anger and body temperature

• Limbic system: emotion, behavior and memory– Area under heavy research!!– Amygdala: long term memory and emotional learning