SCAPA2 Week 4

Eduvos Overview

• Eduvos Mission: Focus on student education and future opportunities through a comprehensive approach to learning.

• Course: Anatomy and Physiology I (SCAPA2)

Course Structure and Resources

Disclaimer

• Content on myLMS may slightly differ from live sessions but comprises essential material for assessments.

Flipped Classroom Model

• Lectures may recommend revision of concepts to prepare for self-study.

• Self-study is imperative for engaging in active learning during lecturer-led sessions, promoting higher-order thinking activities.

• Students are encouraged to complete practice activities and prepare questions to discuss during lectures.

Week 4 Learning Objectives

1. Receptors for Somatic and Special Senses: Understand types and functions.

2. Transduction Process: Grasp how receptors convert physical stimuli into electrical signals, focusing on:

   • Transduction

   • Threshold

   • Adequate Stimulus

   • Receptive Field

   • Receptor Potential

3. CNS Processing: Explain how the CNS determines modality, location, intensity, and duration of stimuli.

4. Pathway Tracing: Trace somatic sensation pathways from receptors to the somatosensory cortex.

5. Types of Somatosensory Receptors: Describe functions and differences.

6. Pain and Itch Sensation: Mediated by nociceptors and their neural pathways.

Today's Lesson Overview

• Topics Covered: General properties of sensory systems, focus on somatic sensation.

Somatic Nervous System

• Function: Controls voluntary muscles and transmits sensory information to the CNS.

Activity: Sensory Receptors

• Discussion Topics:

  • Definitions and examples of:

    • Chemoreceptors

    • Mechanoreceptors

    • Thermoreceptors

    • Photoreceptors

    • Proprioceptors

    • Baroreceptors

    • Osmoreceptors

    • Nociceptors

• Discuss "non-neural accessory structures" in sensory systems.

Sensory Transduction

Process Steps

1. Detection of Stimulus: Receptors respond to specific stimuli within their receptive fields.

2. Transduction: Stimulus interaction generates a receptor potential affecting membrane potential based on stimulus strength.

3. Reaching the Threshold: Strong receptor potential triggers action potential in sensory neurons; if threshold not reached, no signal is sent.

4. Transmission: Action potentials travel along sensory neurons to the CNS, where the brain interprets them as sensations (e.g., touch, pain).

Integration of Sensory Information

• Spinal Cord Processing: Sensory info travels to the brain via ascending pathways; the thalamus acts as a relay station.

• Olfactory Information Exception: Processes directly to olfactory cortex instead of the thalamus.

• Perceptual Threshold: Minimum stimulus intensity required for awareness.

• Habituation: Decreased sensitivity due to sustained stimulation, aided by inhibitory modulation.

Properties of Stimulus Differentiation

• Modality: Identified by the activated sensory neurons.

• Location: Determined by the activated receptor fields; exceptions exist (aural stimuli).

• Duration: Coded by action potential duration; receptor adaptation occurs.

• Intensity: Coded by the number and frequency of action potentials.

Pathways of Somatic Perception

• Involves:

  1. Receptor Activation

  2. Action Potential in Primary Sensory Neuron

  3. Synapse in CNS

  4. Secondary Sensory Neuron

  5. Tertiary Sensory Neuron Synapse in Thalamus

  6. Projection to Somatosensory Cortex

Types of Sensory Pathways

• Fine Touch, Proprioception, Vibration

  • Synapse in medulla.

• Pain, Coarse Touch, Temperature

  • Synapse in spinal cord.

Pain Perception

Types of Pain

• Acute, Chronic, Neuropathic, Ischemic, Referred Pain

• Nociceptor: responds to harmful stimuli and conveys signals indicating potential threats.

Case Study: Nociceptive Pain

• Scenario: Acute pain from injury; symptoms include sharp pain, swelling, and increased pain with movement.

• Diagnosis: Nociceptive pain during tissue injury; managed by understanding nociceptive pathways.

Week 4: Lesson 2 Objectives

• Overview of gustation, olfaction, hearing, and vision, plus corresponding neural pathways and processing.

Activities and Quizzes

• Engage in drawing anatomical structures related to sensory systems, conducting activities that reinforce understanding of concepts, and quizzes to assess comprehension of sensory physiology.

Case Study: Pupil Response

• Use case studies to analyze sympathetic nervous system functions concerning pupil dilation in response to varying stimuli.

Review and Prepare

• Prepare for upcoming assessments by revising content available on myLMS, engaging with practice activities, and utilizing resources for studying.