Biological Basis of Behavior- Nervous System

Biological Basis of Behavior: Nervous System 1. 2. 1. 1. - 1. 2. Overview of Functions of the Cerebral Cortex: Frontal lobe is comprised of two main regions: The motor cortex (strip) is responsible for body movements/motor function The prefrontal cortex is responsible for executive functions (thinking, problem solving, etc.) and helps to supervise and direct all other areas of the brain Broca’s area is a part of the frontal lobe (typically on the right frontal lobe) that is responsible for speech production The Parietal lobe is responsible for spatial relation and feeling has a couple different regions: The somatosensory cortex is associated with feeling (not emotions but touch, pressure, temperature, pain, etc.) The sensorimotor cortex includes the motor cortex and somatosensory cortex The occipital lobe is also known as the “striated cortex” which refers to the fact that it appears striated when looked at under a microscope The temporal lobe is the part of the brain that is responsible for auditory processing Wernicke’s area is found in the temporal lobe (important for processing language, aphasia here can lead to “word salad”) Hemispheric Differences & Hemispheric Dominance: Even though the two hemispheres look identical to one another, for most people they often do different things Contralateral control refers to the fact that the left side of the brain controls right side of the body and same goes for the right side (true for almost all senses except for smell) The dominant hemisphere is typically (NOT ALWAYS) opposite of the hand that we write with (so much people are left hemisphere dominant) and has functions such as: Language (Broca’s and wernicke’s are located in the dominant hemisphere) Analytical skills (such as logic and mathematical reasoning) The nondominant hemisphere has functions such as: Understanding the emotional tone of language Creativity, music, and spatial processing Some evidence shows that it helps us put together big picture concepts We use BOTH though, it's not like you don’t use one over the other The two hemispheres communicate through a large band of fibers known as the corpus callosum The Old Brain: As you get more evolutionarily complex, species tend to build on top of older structures, suggesting that the deeper one goes into the brain, the simpler the structures (such as sleeping and breathing) become (also the more shared they are to older species) Brain stem controls basic functions such as heartbeat/breathing and serves as a crossover point for our nerves; it is split up into two parts: Medulla and Pons There is also a structure known as the reticular formation (extends from the brainstem into other areas of the brain as well) and is responsible for filtration of information from the spinal cord and extends specifically to the thalamus, where it is sent to specific areas of the brain (also important for arousal, such as sleep/waken) → if the RF fails, it causes the person to go into a coma The thalamus acts as the relay station for all information in both directions (one exception to this is the sense of smell) The cerebellum is important a number of tasks, such as coordination of voluntary movement (i.e. run and kick a soccer ball at the same time) and if damaged, movements can be pretty jerky/awkward, such as when you drink alcohol Endocrine System & Influence on Behavior: The catecholamines (made in the adrenal medulla) are tyrosine derivatives (tyrosine derivatives also include the thyroid hormones) Autocrine signaling occurs at the cell that secretes them Paracrine signaling occurs at a nearby location (such as hypothalamus acting on the pituitary gland) The pancreas isn’t stimulated by the pituitary gland directly, but does secrete important hormones such as insulin and glucagon Extra Notes: Ghrelin is known as the “hunger hormone” Leptin is associated with “satiety”, or feeling of fullness Neuropeptide Y is one the most potent orexigenic peptides found in the brain. It stimulates food intake with a preferential effect on carbohydrate intake. It decreases latency to eat, increases motivation to eat and delays satiety by augmenting meal size Estrogen has a major role in fluid balance and could be linked to bloating and water retention during the menstrual cycle