Recording-2025-02-04T16_34_03.506Z

Announcements and Reminders

• Homework Discussion 2 on Packback

  • Now available for access and submission

  • Open until Sunday at 11:59 PM

  • Full credit: Post a question and 2 responses

  • Software evaluates submissions; discrepancies may occur post-deadline

• Next Tuesday's Class

  • No class on the 11th due to a doctor's appointment

  • Lecture will be posted as a video on Canvas

  • Students expected to review the lecture independently

Neuroanatomy Introduction

• Focus on biological and physiological aspects of biopsychology

• Importance of the brain: weighs approximately 3 pounds

• Brain composition: 60% fat

• High density of neurons and synapses:

  • ~100,000 neurons and 1,000,000,000 synapses in a grain of tissue

• Estimated storage capacity: 2.5 million terabytes

• Communication speed: up to 268 mph

• Misconception: We use only 10% of our brain; majority is active even subconsciously

• Brain produces 23 watts of electrical power, sufficient to light a small bulb

• Brain remains active during sleep, particularly during REM sleep

Brain Activity and Coordination

• Neuronal firing can become uncoordinated, leading to seizures

• Damage to the brain affects behavior, mood, and personality

• Neuroscience methods help illustrate the connection between brain activity and behavior

• Case studies: e.g., Phineas Gage

• Different types of studies:

  • In vivo: Living organisms active during experiments

  • Ex vivo: Tissues removed from organisms for study

  • In vitro: Isolated cells studied outside their biological context

Neurons and Their Functions

• Neurons as unique cells; communicate via electrical and chemical processes

• Neurons do not reproduce through mitosis but can repair to some extent

• Neuron structure includes:

  • Cell membrane with selective ion channels and neurotransmitter receptors

  • Axons and dendrites for communication

• Communication is electrochemical:

  • Action potentials represent electrical impulses

  • Neurotransmitter release enables chemical communication between neurons

• Sensory information transmitted from the periphery to the brain, creating comprehensive understanding

  • E.g., touching something hot results in pain perception and a response to pull away

Nervous System Overview

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

• Peripheral Nervous System (PNS): All nervous system parts outside the CNS

• Somatic Nervous System: Communicates sensory information and controls voluntary muscles

  • Afferent fibers: carry sensory info to the CNS

  • Efferent fibers: transmit commands from the CNS to the body

• Autonomic Nervous System: Regulates internal processes; divided into:

  • Sympathetic System: Activates fight-or-flight responses (e.g., increased heart rate)

  • Parasympathetic System: Promotes rest-and-digest functions (e.g., increased digestion)

Key Terms in Nervous System Communication

• Afferent neurons: Carry information from the body to the CNS

• Efferent neurons: Transmit instructions from the CNS to peripheral effectors

Processing Information

• Communication between peripheral sensory neurons and the CNS

• Example of bee sting:

  • Afferent neurons transmit pain sensation to the brain while the brain sends an efferent response to pull away

Summary of Nervous System Structure

• Flow of information:

  • Receptors ➜ Afferent neurons ➜ CNS ➜ Efferent neurons ➜ Effectors

• Breakdown of PNS:

  • Somatic system: sensory (afferent) and motor (efferent) functions

  • Autonomic system: involuntary functions, further divided into sympathetic and parasympathetic responses

Sympathetic and Parasympathetic Activation

• Sympathetic: Prepares body for action (increase heart rate, slow digestion)

• Parasympathetic: Supports recovery and energy storage (decrease heart rate, increase digestion)

Research Considerations

• Importance of understanding neuron function and synaptic connections in psychology

• Pruning process during development reduces connections in adulthood based on experiences

  • Possible implications in conditions like autism and ADHD regarding synaptic pruning dynamics.