psychology-10.24 Chapter 3 Biopsychology

Chapter 3: Biopsychology

3.1 Human Genetics

• Learning Objectives:

  • Explain evolution by natural selection principles.

  • Describe genotype vs phenotype.

  • Discuss the impact of gene-environment interactions on behavior.

• Genetics in Psychology:

  • Psychologists study genetics to understand biological influences on behavior.

  • Genetic variations lead to different behavioral outcomes even in individuals with similar biological mechanisms.

• Sickle-Cell Anemia Case Study:

  • A genetic condition causing red blood cells to adopt a crescent shape.

  • Impacts the cells' functionality and can lead to severe health symptoms.

  • Carriers of the sickle-cell gene are resistant to malaria, providing a genetic advantage in endemic areas.

  • Illustrates the evolutionary concept of "survival of the fittest" in context.

3.2 Cells of the Nervous System

• Learning Objectives:

  • Identify neuron parts.

  • Describe neuron communication.

  • Explain drug interactions with neurotransmitter systems.

• Neurons and Glial Cells:

  • Neurons: Information processors; main functional unit of the nervous system.

  • Glial Cells: Support neurons; provide structure, nutrition, and protection.

• Neuron Structure:

  • Soma: Cell body containing the nucleus.

  • Dendrites: Receive signals from other neurons.

  • Axon: Transmits electrical impulses; covered by myelin sheath.

  • Synaptic Vesicles: Release neurotransmitters into synapse.

• Neuronal Communication:

  • Neurons communicate via electrical and chemical signals.

  • Resting potential; action potential induced when threshold is met.

  • Neurotransmitter binding has lock-and-key specificity.

3.3 Parts of the Nervous System

• Learning Objectives:

  • Differentiate between CNS and PNS.

  • Explain somatic vs autonomic nervous systems.

  • Distinguish between sympathetic and parasympathetic divisions.

• Nervous System Divisions:

  • Central Nervous System (CNS): Brain and spinal cord.

  • Peripheral Nervous System (PNS): Connects CNS to the body.

    • Somatic Nervous System: Controls voluntary movements.

    • Autonomic Nervous System: Controls involuntary actions; consists of:

      • Sympathetic Division: Prepares body for stress (fight or flight).

      • Parasympathetic Division: Calms body post-stress.

3.4 The Brain and Spinal Cord

• Learning Objectives:

  • Explain spinal cord functions.

  • Identify brain hemispheres and lobes.

  • Describe brain imaging techniques.

• Spinal Cord Functions:

  • Connects brain to the body; facilitates reflex actions independent of the brain.

• Brain Structures:

  • Cerebral Cortex: Covers the brain, involved in higher functions.

  • Lobes of the Brain:

    • Frontal Lobe: Reasoning, planning, impulse control.

    • Parietal Lobe: Processes sensory information.

    • Temporal Lobe: Associated with hearing and memory.

    • Occipital Lobe: Responsible for visual processing.

• Imaging Techniques:

  • CT Scan: Uses x-rays to create detailed images.

  • PET Scan: Monitors blood flow and brain activity via a radioactive tracer.

  • MRI: Uses magnetic fields for detailed images of brain structures.

  • fMRI: Measures brain activity over time via blood flow changes.

  • EEG: Records electrical activity in the brain to assess overall brain function.

3.5 The Endocrine System

• Learning Objectives:

  • Identify major glands of the endocrine system.

  • Describe hormones secreted by each gland.

  • Explain the role of hormones in regulating bodily functions.

• Endocrine System Overview:

  • Glands release hormones into the bloodstream; slower response, longer-lasting effects than neurotransmitters.

• Major Glands and Hormones:

  • Pituitary Gland: Master gland; controls other glands; secretes growth hormone, endorphins.

  • Thyroid Gland: Regulates metabolism, growth (thyroxine).

  • Adrenal Glands: Release hormones for stress responses (epinephrine, norepinephrine).

  • Pancreas: Regulates blood sugar (insulin, glucagon).

  • Gonads: Secrete sexual hormones (estrogens, androgens) impacting sexual behavior and motivation.

Key Terms

• Action Potential: Electrical signal moving along the axon.

• Neurotransmitter: Chemical substance transmitting signals across a synapse.

• Genotype and Phenotype: Genetic makeup vs. observable traits.

• Agonist and Antagonist: Drugs that either enhance or inhibit neurotransmitter effects.

• Sympathetic vs Parasympathetic: Systems controlling fight or flight versus rest and digest functions.