Role of nerve regulation for bechaviour

Central & peripheral nervous system The central nervous system includes the brain and the spinal cord. Bundles of neuron axons that carry information in the peripheral nervous system.

Motor Efferent Division Can be divided further: Somatic nervous system VOLUNTARY (generally) Somatic nerve fibers that conduct impulses from the CNS to skeletal muscles Autonomic nervous system INVOLUNTARY (generally) Conducts impulses from the CNS to smooth muscle, cardiac muscle, and glands.

Somatic vs. Autonomic Voluntary Involuntary Skeletal muscle Single efferent neuron Axon terminals release acetylcholine Always excitatory Controlled by the cerebrum Involuntary Smooth, cardiac muscle; glands Multiple efferent neurons Axon terminals release acetylcholine or norepinephrine Can be excitatory or inhibitory Controlled by the homeostatic centers in the brain – pons, hypothalamus, medulla oblongata

Reflex a simple, automatic, inborn response to a sensory stimulus Skin receptors Muscle Sensory neuron (incoming information) Motor neuron (outgoing information) Brain Interneuron Spinal cord

Neural Networks interconnected neural cells with experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results computer simulations of neural networks show analogous learning Inputs Outputs Neurons in the brain connect with one another to form networks The brain learns by modifying certain connections in response to feedback

Sympathetic nervous system - branch of the autonomic nervous system that produces rapid physical arousal in response to perceived emergencies or threats. Parasympathetic nervous system - branch of the autonomic nervous system that maintains normal bodily functions and conserves the body’s physical

Autonomic Nervous System 2 divisions: Sympathetic “Fight or flight” “E” division Exercise, excitement, emergency, and embarrassment Parasympathetic “Rest and digest” “D” division Digestion, defecation, and diuresis

The Central Nervous System The central nervous system includes the brain and the spinal cord. This is the primary internal communication network of the body; divided into the central nervous system and the peripheral nervous system.

The Brain Capturing a Thought

Out In

Specialized Cortical Regions revealed with PET scan

Saparate cell 4th weeks 24 weeks Newborn child As the human fetus develops, brain cells multiply, differentiate, and migrate to their final locations. By the fourth week of prenatal development, new neurons are being generated at the rate of 500,000 per minute. By 24 weeks of prenatal age, the brain has nearly its full complement of neurons. Saparate cell 24 weeks 4th weeks Newborn child

After birth, the neurons grow in size and continue to develop new dendrites. Myelin forms on neuron axons in key areas of the brain, such as those involved in motor control. Axons also grow longer, and the branching at the ends of axons becomes more dense. By adulthood, the fully mature human brain weighs about three pounds.

The ‘Split Brain’ studies Surgery for epilepsy : cut the corpus callosum Roger Sperry, 1960’s Special apparatus picture input to just one side of brain screen blocks objects on table from view Nonverbal right hemisphere Verbal left key words: left hemisphere; right hemisphere; corpus callosum; epilepsy This slide is a schematic of the task shown in the video clip on the previous slide

The ‘Split Brain’ studies Picture to right brain can’t name the object I saw an apple. “What did you see?” Nonverbal right hemisphere Verbal left Nonverbal right hemisphere Verbal left ?? “What did you see?” “Using your left hand, Pick up what you saw.” left hand can identify by touch Picture to left brain can name the object left hand cannot identify by touch