Biological Basis of Behavior PDF

Biological Basis of Behavior General Psychology Dr. Lakshmi Bandlamudi. Genes and Behavior: Human Body contains more than 100 Trillion Cells \| Each Cell except the Red Blood Cell contains the Nucleus. \| Each Nucleus contains 46 Chromosomes -- 23 from Father and 23 from Mother. \| Some Ge...

Biological Basis of Behavior General Psychology Dr. Lakshmi Bandlamudi. Genes and Behavior: Human Body contains more than 100 Trillion Cells \| Each Cell except the Red Blood Cell contains the Nucleus. \| Each Nucleus contains 46 Chromosomes -- 23 from Father and 23 from Mother. \| Some Genes in the body are Dominant Genes (express themselves, while others are Recessive Genes (Dormant and might not express themselves and they make become dominant in the next generation) **Principles of Behavioral Genetics:** 1. The relationship between specific genes and behavior is complex, usually with many genes involved in each trait. 2. Most traits such as height, weight, intelligence and personality, are the result of many dozens or hundreds of genes in your Genome body and this process is called **Polygenic Transmission.** 3. When a single Gene s responsible for a specific condition it is called **Monogenic Transmission. The Neuromuscular** disease called **Huntington's disease** is the only physical condition determined by a single Gene. If this specific gene is present in the Genome, the individual is sure to suffer from Huntington's disease. 4. By studying twins and adoptees, behavioral geneticists study the contributions of hereditary and environmental influences. 5. **The Environment can change Gene Expression.** Genes do not have the final say. Environmental factors and health habits can change Gene Expression and that is called **Epigenetics.** **The Nervous System:** **NERVOUS SYSTEM** **\|** **\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_** **\| \|** **Central Nervous System** (CNS) **Peripheral Nervous System** (PNS) \| \| \| \| **Brain Spinal Cord Somatic Autonomic** **Nervous System Nervous System** **The Cells of the Nervous System:** Without the Nervous System we would have no sensory experiences -- no seeing, hearing, touching, tasting, smelling or feeling. We would have no thoughts, memories or emotions. The Central Nervous System is made of two types of Cells -- Glial Cells and Neurons. 1. **Glial Cells:** - *Glia* is the Greek word for "glue." Hence they serve the primary function of holding CNS together. - They support structural support for holding the Central nervous System together. - They ensure smooth communication between Neurons. - The also clean up the cellular debris. - They produce materials that insulate Neurons (Myelin). - Aid Cell metabolism - Help form Blood-Brain barrier. - Play a key role in breathing and regulate neuronal transmission. - Play a crucial role in neural regeneration repair after a brain injury. 2. **Neurons:** - There are more than 10 Billion neurons in the human brain. - Each Neuron has close to 10,000 connections to other neurons. - Neurons are the building blocks of the Nervous System. All major structures of the brain are composed of Neurons. - Information travels ***within a neuron*** in the form of an **Electric signal.** - Information is transmitted ***between neurons*** through chemical substances called **Neurotransmitters.** **Structure of a Neuron:** Macintosh HD:Users:lakshmibandlamudi:Desktop:172432-1-Structure-of-a-Typical-Neuron.png 1. Soma: The cell body of the neuron. 2. Nucleus: Contains genetic information 3. Axon: Extending from one side of Soma is a long projection called Axon and it transmits information in the form of electrical impulses. 4. Myelin Sheath: fatty substance wrapping parts of Axon. It insulates the Axon enabling electrical impulses to pass smoothly. 5. Dendrites: Finger like projections extending from Soma. Receiving Dendrites receive incoming messages from other neurons. 6. Terminal Button: They are at the end of sending Dendrites where electrical signals are converted into chemical substances called **Neurotransmitters.** 7. The junction between the terminal button of one neuron and the dendrites of the adjacent neuron is called **Synapse.** **The Brain:** Brain is a product of Evolutionary Process.  **Hindbrain:** The oldest brain region is the Hindbrain, and it is directly connected to the **Spinal Cord.** It regulates breathing, heart rate and arousal. Extending directly from the Spinal cord is **Medulla --** that regulates breathing, heart rate and blood pressure. **Pons:** Serves as a bridge between lower brain, midbrain and forebrain. **Cerebellum:** Known as the "little brain" -- responsible for body movement, balance, coordination, finer motor skills and cognitive activities such as learning and language. **Reticular Formation:** The network of nerve fibers that runs through the Hindbrain and Midbrain, crucial for waking up and falling asleep. Midbrain: It is the smallest part of the brain. Controls eye muscles, auditory and visual information and initiate voluntary movement of the body. Loss of neurons in the Midbrain is the main cause of **Parkinson's disease** and hence the individual shakes uncontrollably. **Forebrain:** It is the largest part of the human brain. It consists of the Cerebrum, Thalamus and the Limbic System. **Thalamus:** A Forebrain structure that receives information from the senses and relays it to the cerebral cortex for processing. **Limbic System:** **Hypothalamus:** A structure directly below the Thalamus. It regulates almost all our major drives and motives, including hunger, thirst, temperature and sexual behavior. It controls the Pituitary Gland, which is responsible for producing and controlling the hormones. **Hippocampus:** Wrapped around the Thalamus is Hippocampus, which plays a vital role in learning and memory. **Amygdala:** A small almond shaped structure directly in front of Hippocampus. It plays an important role in processing emotional information, especially related to Fear.