1) Subdivisions of the nervous system (1)

Subdivisions of the Nervous System

  • Central Nervous System (CNS)

    • Comprises the brain and spinal cord.

    • Functions to process and coordinate sensory information, and activate responses.

    • A key role in both conscious and unconscious reactions, including reflexes.

  • Peripheral Nervous System (PNS)

    • Encompasses all nerves outside the CNS.

    • Responsible for transmitting information to and from the CNS.

    • Divided into two main branches: the somatic nervous system and the autonomic nervous system.

Learning Intentions and Success Criteria

  • Learning Intention: Identify the roles of different subdivisions of the nervous system in response to sensory stimuli.

  • Success Criteria: Ability to recognize relevant divisions in scenarios of conscious and unconscious responses.

Activities Overview

  • Lesson One: Notes from slides, brain jigsaw group task, and human nervous system activity.

  • Lesson Two: Focus on divisions of the autonomic nervous system, including notes, handouts (Nelson worksheets), and conscious vs unconscious responses exercises.

Central vs. Peripheral Nervous System

  • CNS: Brain and spinal cord; processes information and triggers responses.

  • PNS: Comprises nerves outside of CNS; facilitates communication between CNS and body.

Central Nervous System

  • Main functions include:

    • Processing information from sensory organs.

    • Activating appropriate responses through the body.

Brain Structure and Functions

  • Cerebral Cortex: Thin outer layer for processing complex information and coordinating body actions.

  • Forebrain: Higher-level functions including emotion, cognition.

  • Midbrain: Involves sensory information processing.

  • Hindbrain: Controls basic life-support functions (e.g., breathing).

  • Lobes of the Brain:

    • Frontal, Parietal, Temporal, Occipital—each responsible for different functions.

Spinal Cord Functions

  • Links the brain with the body through the PNS.

  • Main functions include:

    • Receiving sensory information and sending it to the brain.

    • Receiving motor information from the brain and directing it to the body.

Peripheral Nervous System Types

  • Somatic Nervous System:

    • Connects CNS to sensory organs and skeletal muscles.

    • Controls voluntary muscle movements and sensory input from the body (e.g., touch).

  • Autonomic Nervous System:

    • Controls involuntary functions (heart rate, digestion) and responses to stress (fight or flight).

    • Divided into sympathetic (activating during stress) and parasympathetic (restoring calm).

Autonomic Nervous System Responses

  • Sympathetic Nervous System:

    • Activation during stress; increases heart rate, dilates pupils, enhances metabolic functions.

  • Parasympathetic Nervous System:

    • Restores body functions to calm; decreases heart rate, directs digestion.

Conscious vs Unconscious Responses

  • Conscious Responses:

    • Involve awareness, deliberate actions, and control (e.g., deciding to wear sunglasses).

  • Unconscious Responses:

    • Occur automatically and do not require conscious thought (e.g., heart rate regulation).

Spinal Reflexes

  • Definition: An unconscious response to stimuli that bypasses the brain, controlled by the spinal cord.

  • Example: Touching a hot object leading to an automatic withdrawal of the hand.

Summary of Learning Outcomes

  • Understanding the function and interaction of CNS and PNS.

  • Ability to distinguish between conscious and unconscious responses to stimuli.

  • Familiarity with structure and roles of the nervous system divisions and their physiological implications.