General Biology2 Summers

Respiration and oxygen availability Heart and Circulation/Transport Nutrition, Digestion, Metabolism Excretion and Elimination

Chemical Messengers Sexual Reproduction Neuronal Structure & Signals Sensory Reception

text:Biological Science 5th Edition - Freeman ..: Read Chap 46 for this lecture Integration of Neural Function Neuromuscular Action - Behavior syllabus Figures acronyms    end

XVI. Central Neural Integration 	


	A. Central Nervous system


		1. Brain and spinal cord


		2. integrating input from the peripheral nervous system


			a. reflex arc


				i. afferent (sensory) neurons bring signal to spinal cord


				ii. interneurons (association) relay signal to
				     efferent (motor) neurons


					(1) interneurons connect other neurons


				iii. muscle contraction stimulated by efferent innervation


				iv. many voluntary actions (e.g. walking) are reflexes


					(1) brain is not necessary but may add information


		3. Brain


			a. specialized divisions with specialized function


				i. increased development with evolutionarily increased
				   behavioral complexity


					(1) hindbrain (e.g. medulla)- relatively unchanged 


						(a) regulates essential functions like breathing


					(2) midbrain and diencephalon (e.g. hypothalamus)
					     - little changed 


						(a) regulates essential, but slightly variable
						     functions like reproduction, temperature, satiety
						
						
						(b) produces neurotransmitters (DA, NE, 5-HT)
						     and neurohormones (GnRH, TRH)


					(3) forebrain (e.g. cortex)- greatly increased in mass
					     in animals with increasingly complex behaviors


				ii. cortex divided into gyri (ridges) each  loosely
				     associated with specific functions


					(1) e.g. Broca's area - speech


					(2) areas related to sensory information from
					     each area of the body 


						(a) the more sensitive the area
						     the more brain allocated to it


	B. Peripheral Nervous System


		1. Autonomic Nervous System


			a. sympathetic nervous system


				i. secretes NE:
				    fight or flight: ®ñ heart rate, ñ blood pressure and ñ awareness,
				   ¯ digestion, ¯ reproduction


			b. parasympathetic ns


				i. secretes ACh:
				    rest and digest: ¯ HR, ñ digestion


			c. all internal organs and blood vessels are innervated by both
			
			
				i. balanced


		2. Somatic Nervous System


			a. innervates skeletal muscle for voluntary movements
			
			
				i. secretes ACh (acetylcholine)


				ii. many voluntary movements do not require the brain