Chapter 3: Biopsychology

Page 1: Introduction to Biopsychology

• Evolution and Sickle-Cell Anemia

  • Normal blood cells vs. sickle-shaped cells

  • Sickle-cell anemia can cause blockages in blood flow.

  • Explanation of how sickle-cell anemia has survived through natural selection despite its detrimental effects in certain environments (refer to pages 74-74).

  • Certain environmental conditions can favor genes which are otherwise harmful.

Page 2: Cells of the Nervous System: Neurons

• Neurons Overview

  • Neurons are specialized nerve cells responsible for transmitting information.

  • Parts of a Neuron:

    • Dendrites: Receive messages (like roots of a tree).

    • Soma (Cell Body): Contains nucleus and organelles.

    • Axon: Long projection that transmits impulses.

    • Terminals: Release signals to other neurons.

    • Myelin: Insulating cover for some axons, speeds up transmission of signals.

• Glial Cells: Supportive cells which nourish neurons, eliminate waste, and direct growth.

Page 3: Synaptic Transmission

• Synapse: The gap between terminal buttons of one neuron and dendrites of another.

• Firing Process:

  • Impulse travels down axon (action potential).

  • Release of neurotransmitters at the terminal end to communicate with the next neuron.

Page 4: Neural Firing and Neurotransmitters

• All-or-None Principle:

  • Neurons transmit impulses of uniform strength.

  • Stronger stimuli lead to more frequent firings.

• Refractory Period:

  • Time post-firing when a neuron recovers before firing again.

• Neurotransmitters:

  • Chemical messengers that cross synapses to facilitate neuron communication.

  • Receptor Sites: Located on receiving neurons’ dendrites.

  • Reuptake Process: Some neurotransmitters are reabsorbed by the releasing neuron after synaptic transmission.

Page 5: Reuptake and Nervous System Overview

• Reuptake Mechanism:

  • Neurotransmitters reabsorb into the sending terminal for recycling.

• Nervous System Structure:

  • Divided into two major parts:

    • Central Nervous System (CNS)

    • Peripheral Nervous System (PNS)

Page 6: Parts of the Peripheral Nervous System

• Somatic Nervous System:

  • Controls voluntary movements; carries information to and from the brain via sensory and motor neurons.

• Autonomic Nervous System:

  • Regulates involuntary functions; divided into:

    • Sympathetic Division: Activates during stress, uses energy.

    • Parasympathetic Division: Calms the body, replenishes energy.

Page 7: Autonomic Nervous System Divisions

• Opposite Effects of Divisions:

  • Sympathetic and parasympathetic systems have contrasting experiences impacting heart rate, digestion, etc.

• Spinal Cord:

  • Connects brain to body; relay center for reflexes and bodily functions. Contains gray and white matter.

Page 8: Spinal Cord and Reflexes

• Reflex Arc:

  • Quick, unlearned responses to stimuli, involving gray and white matter.

  • Gray matter signals muscles quickly, while white matter sends messages to the brain, justifying the delay in perception of movement.

• Corpus Callosum:

  • Connects hemispheres of the brain for communication.

Page 9: Brain Structure

• Brain Divisions:

  • Forebrain, Midbrain, and Hindbrain; each with specialized functions.

• Cerebral Cortex: Divided into left and right hemispheres.

Page 10: Functions of the Forebrain Lobes

• Lobes of the Cortex:

  • Occipital Lobe: Vision.

  • Temporal Lobe: Hearing and language functions.

  • Parietal Lobe: Somatosensory input.

  • Frontal Lobe: Executive functions (planning, decision-making) and motor cortex (controls movement).

Page 11: Somatosensory Cortex and Language

• Somatosensory Cortex:

  • Processes sensory information with spatial relationships mirrored in its organization.

• Language Areas:

  • Broca's Area: Speech production.

  • Wernicke's Area: Speech comprehension; damage leads to distinct language deficits.

Page 12: The Limbic System

• Key Components:

  • Hippocampus: Involved in memory.

  • Amygdala: Emotional responses; associates memories with emotions.

  • Hypothalamus: Regulates body temperature, appetite, blood pressure.

Page 13: The Midbrain and Attention

• Reticular Formation:

  • Regulates attention, sleep, and alertness; sends signals from lower brain to cortex.

  • Plays a role in filtering sensory information.

Page 14: The Hindbrain Structure

• Hindbrain Components:

  • Medulla: Manages autonomic functions (heart rate, blood pressure).

  • Pons: Bridges communication from lower brain to higher functions.

  • Cerebellum: Coordinates movements and balance.

Page 15: Researching the Brain

• Research Methods:

  • Case studies, animal research, and various brain imaging techniques (EEG, CT, PET, MRI, fMRI).

Page 16: Brain Imaging Techniques

• Overview of imaging methods:

  • CAT/CT Scan: X-ray imaging for brain structures.

  • MRI: Uses magnetic fields for detailed images.

  • fMRI: Monitors real-time brain activity.

Page 17: The Endocrine System

• General Overview:

  • Ductless glands release hormones into the bloodstream; major glands include the hypothalamus and pituitary gland.

Page 18: Major Glands of the Endocrine System

• Pituitary Gland:

  • The master gland that secretes hormones influencing other glands.

  • Growth hormone; parenting behavior hormones.

• Pineal Gland: Secretes melatonin, regulating sleep.

Page 19: Adrenal Glands and Stress Response

• Function: Secretes epinephrine (adrenaline) and cortisol to manage stress responses.

• Pancreas: Regulates blood sugar levels; issues lead to diabetes.

Page 20: Gonads and Hormonal Regulation

• Gonadal Functions:

  • Testes: Secrete testosterone, influencing male characteristics and aggression.

  • Ovaries: Secrete estrogen and progesterone, regulating female features and menstrual cycle.