Week 1 Goodnotes

Nervous System Overview

• Divided into two main subdivisions:

  • Central Nervous System (CNS)

    • Comprised of the brain and spinal cord.

    • Responsible for processing information and controlling bodily functions.

  • Peripheral Nervous System (PNS)

    • Connects the CNS to the rest of the body.

    • Composed of thick bundles of axons, called nerves.

    • Carries messages to and from the CNS

    • Has two major subdivisions: Somatic Nervous System (SNS) and Autonomic Nervous System (ANS).

Communication in the Nervous System

• Synapses

  • Tiny spaces between neurons where chemical transmitters are released.

  • Allow communication both electrically and chemically.

  • Types of Communication:

    1. Signal Transmission: Enables transmission of signals from one neuron to another.

    2. Information Processing: Plays a crucial role in how information is processed in the CNS.

    3. Plasticity: Synapses can adapt and change, which is important for learning and memory.

Central vs. Peripheral Nervous System

• CNS vs PNS

  • CNS is the brain and spinal cord; PNS consists of nerves and connects the CNS to the body.

  • PNS has two divisions: Sensory (afferent) and Motor (efferent) fibers.

Somatic and Autonomic Nervous Systems

• Somatic Nervous System (SNS)

  • Controls voluntary or conscious activities.

  • Involves sensory perception and motor control.

• Autonomic Nervous System (ANS)

  • Controls involuntary functions, such as internal organ regulation.

  • Divided into:

    • Sympathetic Division: Prepares the body for stress-related activities (fight or flight).

    • Parasympathetic Division: Calms the body and helps maintain routine operations.

• Homeostasis: The body's state of equilibrium in which biological conditions are maintained at optimal levels.

Spinal Cord and Reflexes

• Routes messages to and from the brain and contains reflexes that operate independently of the brain.

• Organized into segmented sections, each connected to specific body parts through the PNS.

• Reflex Action: Rapid response to stimuli, managed by spinal cord.

Neuroplasticity

• Refers to the ability of the nervous system to change and adapt.

• Involves:

  • Creation of new synapses.

  • Pruning unnecessary synapses.

• Important for learning and memory retention.

Brain Structure

• Cerebral Hemispheres: Divided into two halves by the longitudinal fissure; each hemisphere controls opposite sides of the body.

• Brain Regions:

  • Cerebral cortex with folded structures (gyri and sulci) for various functions.

• Function Processes: Including consciousness, thought, emotion, reasoning, language, and memory.

Lobes of the Brain

• Frontal Lobe: Involved in reasoning, motor control, emotion, language. Contains Broca's area for language production.

• Parietal Lobe: Processes sensory information and spatial awareness.

• Temporal Lobe: Associated with hearing, memory, and emotional responses. Contains Wernicke’s area for language comprehension.

• Occipital Lobe: Main area for processing visual information.

Internal Features of the Brain

• Thalamus: Sensory relay center for all senses except smell.

• Hippocampus: Critical for learning and memory.

• Amygdala: Involved in emotions and memory processing.

• Hypothalamus: Regulates homeostasis and links nervous and endocrine systems.

Brain Imaging Techniques

• CT Scan: Uses X-rays to create images of brain structures.

• PET Scan: Monitors brain activity using a radioactive tracer.

• MRI/fMRI: Generates images of internal structures and tracks blood flow and oxygen levels for functional imaging.

Endocrine System Overview

• Composed of glands that produce hormones, acting as chemical messengers in the bloodstream.

• Hormones regulate bodily functions:

  • Pituitary Gland: Master gland controlling other glands.

  • Thyroid Hormones: Regulate metabolism and energy.

  • Adrenal Glands: Secret hormones for stress response (adrenaline).

  • Pancreas: Regulates blood sugar levels through insulin and glucagon.

  • Gonads: Produce sex hormones impacting reproduction and sexual behavior.

Dysregulation of Hormones

• Can lead to disorders:

  • Hyperthyroidism: Excess thyroxine leads to agitation and weight loss.

  • Diabetes: Insufficient insulin production leads to high blood sugar.