PSY 1001 Lecture Notes - Lecture 4: Peripheral Nervous System, Autonomic Nervous System, Central Nervous System

• School: University of Iowa
• Department: Psychology
• Course: PSY 1001
• Professor: Robert Thunhurst

Document Summary

We all are girls if it wasn"t for the presence of testosterone in womb. Motor output: smooth muscle and to endocrine glands (involuntary) Human brain: 80 100 billion neurons metabolism. Brain is only 2% of body weight, yet accounted for 20% of body. Hodgkins and huxley studied squids and (cid:498)giant axons(cid:499) because it was actually visible and easy to manipulate. Inside of cell is electrically negative, relative to (1) outside. Difference in charge is the (cid:498)potential(cid:499) and is (2) measured across the cell membrane it is called (cid:498)membrane potential(cid:499) When nerve (cid:498)fires(cid:499) it is called action potential (1) Ions movement is driven by 2 things (1) Electrostatic forces (like charges repel, opposite (2) attracts) All or none law: action potential travels length of axon at full strength. Rate law: rate of firing conveys information, not individual action potentials (1) weak stimulus= low rate (2) Otto loewi discovered chemical nature of neurons by using frog heart.