THE BIOLOGY OF MIND - BEHAVIOR BY: JOEY LUNA, BA PSYCH., MSW, ACSW

BIOLOGICAL PSYCHOLOGISTS Study links between our biology and behavior. Every idea, mood, every urge, laugh, cry is a biological happening.

Neurons Neurons are nerve cells: basic building block of the nervous system. -Throughout life, new neurons are formed while unused neurons wither away. Dendrites are bushy branching extensions that receive messages and conduct impulses toward the cell body. Axon the neuron extension that passes messages through its branches to other neurons or muscles or glands. -Some axons are very long and run along several feet through the body. Ex. Axon carrying orders to a leg muscle is as long as a four mile long rope.

Neurons cont.

Neurons cont. Myelin Sheath a fatty tissue layer segmentally encasing the axons of some neurons, enables greater transmission speed as neural impulses hop from one node to the next. -As myelin matures up to age 25, neural efficiency, judgment and self-control grow. -If myelin degenerates, multiple sclerosis results. Communication to muscles slows, with eventual loss to muscle control.

Neurons cont.

Multiple Sclerosis Selma Blair

Neurotransmitters Neurotransmitters chemical messengers that cross synaptic gaps between neurons.

How do Neurotransmitters Influence Us? Researchers have discovered that there are several dozen neurotransmitters that have an impact on our mood, memories and mental abilities.

Acetylcholine (ACh) Plays an important role in learning and memory. Also the messenger in every junction between motor neurons (carrying information from brain and spinal cord to the body’s tissues) and skeletal muscles. When ACh is released to our muscle cell receptors, our muscles contracts. If ACh transmission is blocked- as it happens with anesthesia and poisons like snake venom- we are paralyzed. Malfunctions of ACh include Alzheimer’s disease

Other Neurotransmitters and Functions Dopamine Influences movement, learning, attention, and emotion Oversupply linked to schizophrenia. Undersupply linked to Parkinson's Disease. Serotonin Affects mood, hunger, sleep and arousal. Undersupply linked to depression. Norepinephrine Helps control alertness and arousal Undersupply can depress mood.

How drugs and other chemicals alter neurotransmission Drugs affect our neurotransmitters differently. Either as an agonist or antagonist. -Agonist increase neurotransmitters action. -Antagonist decrease a neurotransmitters action.

The Nervous System Central Nervous System (CNS) -brain and spinal cord Peripheral Nervous System (PNS) -responsible for gathering info and transmitting CNS decisions to other body parts. Sensory Neurons -carry messages from body’s tissues and sensory receptors inward. Motor Neurons -carry instructions from CNS to the body's muscles and glands. Interneurons -messages are processed between sensory and motor neurons.

The Peripheral Nervous System Somatic and autonomic Somatic Nervous System -enables voluntary control of our skeletal muscles. Autonomic Nervous System (ANS) -Controls our glands and our internal organ muscles.

Brain Structures Brainstem Oldest region. Spinal Cord enters the skull. Medulla Controls heartbeat and breathing. Damage to this area often leads to vegetative states Pons Helps coordinates movements and controls sleep. Thalamus Brain’s sensory control center. Receives information from all senses, with the exception of smell and routes that information to brain regions that deal with seeing, hearing, tasting and touching.

The Cerebellum Enables nonverbal learning and skill memory. Allows us to judy time, modulate our emotions and discriminate sounds and textures. Coordinates voluntary movement. Damage is associated with difficulty in walking and balance and coordination. Alcohol affects cerebellum.

The Amygdala Responsible to aggression and fear.

The Hypothalamus Influence and help govern bodily maintenance. Regulates Hunger, regulates thirst, body temperature and sexual behaviors.

The Hippocampus Processes conscious, explicit memories and decreases in size and function as we grow older.

Structure of The Cortex

Structure of The Cortex cont. Frontal Lobes Involved in speaking and muscle movements and in making plans and judgments Parietal Lobes Receives sensory input for touch and body position Occipital Lobes Receives information from the visual fields. Temporal Lobes Auditory areas