Biological Psychology Key Point for this Unit: Everything psychological is simultaneously biological!!

NEURON Dendrites Dendrites – receive messages from other cells and conduct impulses toward the cell body

Cell Body – the cell’s life-support center NEURON Dendrites Cell Body Cell Body – the cell’s life-support center

NEURON Dendrites Cell Body Axon Axon – the extension of a neuron through which messages are sent to other neurons or to muscles or glands

NEURON Dendrites Cell Body Axon Myelin Sheath Myelin Sheath – a layer of fatty cells covering the axon, helps speed neural impulses

Terminal branches of axon – form junctions with other cells NEURON Dendrites Terminal branches of axon Cell Body Axon Myelin Sheath Terminal branches of axon – form junctions with other cells

Biological Psychology It is all about the body!!!! Concerned with the links between biology and behavior (also called Neuroscience)

The Nervous System It starts with a NEURON: an individual nerve cell; the basic building block of the nervous system

How does a Neuron fire? Resting Potential: slightly negative charge. Reach the threshold when enough neurotransmitters reach dendrites. Threshold: level of stimulation required to trigger a neural impulse; excitatory signals minus inhibitory signals must equal a minimum intensity Go into Action Potential; a neural impulse (brief electrical charge) that travels down an axon. All-or-none response.

TYPES OF NEUROTRANSMITTERS Chemical messengers that that traverse the synaptic gap between neurons REVIEW… remember agonists and antagonists??? Agonist – mimic neurotransmitters **Example: Morphine mimics endorphins Antagonist – block neurotransmitters **Example: Poison blocks muscle movement Did you know? Botox is an antagonist that paralyzes facial muscles!

Acetylcholine (ACH) Involved with voluntary muscle movement, learning and memory Lack of ACH has been linked to Alzheimer’s disease.

Dopamine Deals with motor movement and alertness. Lack of dopamine has been linked to Parkinson’s disease. Too much has been linked to schizophrenia.

Serotonin Involved in mood control. Lack of serotonin has been linked to clinical depression.

Endorphins Involved in pain control. Did you know? The word “endorphin” literally means “morphine within”! Endorphins Involved in pain control. Many of our most addictive drugs deal with endorphins. “Runner’s High” occurs when your brain signals the release of endorphins to reduce pain!

The Nervous System The Nervous System - body’s speedy, electrochemical communication network consisting of nerve cells

Central Nervous System (CNS) The Brain and spinal cord Neural networks – interconnected neural cells; more connections made as experience gained

Peripheral Nervous System (PNS) All nerves that are not encased in bone. Sensory and motor neurons that connect the CNS to the rest of the body Is divided into two categories….somatic and autonomic.

Somatic Nervous System Controls voluntary muscle movement. Uses motor neurons.

Autonomic Nervous System Controls the automatic functions of the body. Divided into two categories…the sympathetic and the parasympathetic

Sympathetic Nervous System Arouses the body Fight or Flight Response. Automatically accelerates heart rate and breathing, dilates pupils

Parasympathetic Nervous System Calms the body Automatically slows the body down after a stressful event. Heart rate and breathing slow down, pupils constrict

Sympathetic and Parasympathetic

Types of Neurons Sensory Neurons – sends receptors to CNS Interneurons – internal communication neurons Motor Neurons – CNS to muscle and glands

Reflexes Normally, sensory neurons take info up through spine to the brain. With reflexes though, some reactions occur when sensory neurons reach just the spinal cord. Automatic response to sensory stimulus; interneurons react to sensory neurons w/o going to brain