Emotions and Physiology

• Emotional reactions such as excitement and fear can trigger physiological responses.
• Goosebumps as a physical response indicating emotional arousal.
• Fight or Flight Response:
  • Triggered by hormones like norepinephrine and epinephrine.
  • Inhibit intestinal motility; not a priority during stress responses.

Hormonal Effects on Organs

• Norepinephrine and Epinephrine Impact:
  • Effects on Bronchioles:
  • Dilate Bronchioles: Facilitates airflow into the lungs during stress.
  • Contrasting Effects in the Heart: Increases heart rate during fight or flight.
  • Beta Adrenergic Receptors:
  • Generally inhibited affecting these responses.

Drug Interactions and Pharmacology

• Pharmaceutical Drugs:
  • Designed to mimic or block acetylcholine or norepinephrine and epinephrine effects to manage bodily functions.
  • Receptor Binding Patterns:
  • Epinephrine: Given primarily to beta receptors.
  • Norepinephrine: Typically binds to alpha receptors.

Clinical Applications of Epinephrine

• Common Usage: EpiPen for allergic reactions (e.g., anaphylaxis).
  • Mechanism:
  • Inhibits bronchial constriction, promoting dilation for better breathing.
  • Other Uses:
  • Cardiac arrest treatment to stimulate heartbeats.
  • Used in severe asthma attacks to alleviate respiratory distress.
  • Helps manage anaphylaxis by counteracting severe allergic responses and lowering inflammation.

Clinical Applications of Norepinephrine

• Used in Septic Shock:
  • Impact: Raises dangerously low blood pressure caused by vasodilation due to infection.
  • Administered to counteract effects of septicemia or severe infections.

Sympathomimetics and Sympatholytics

• Sympathomimetics: Drugs that enhance sympathetic nervous system responses, mimicking natural stimulants (e.g., epinephrine).
  • Example: Phenylephrine - used in decongestants to reduce nasal swelling.
• Sympatholytics: Drugs that inhibit sympathetic nervous system activity (e.g., Beta blockers).
  • Indicated for patients with high blood pressure or heart conditions to reduce heart rate.

Parasympathetic Pharmacology

• Parasympathetic Mimetic: Enhances actions of the parasympathetic nervous system.
  • Example: Pilocarpine for glaucoma treatment, alleviating intraocular pressure.
• Parasympathetic Lytic: Inhibits actions of the parasympathetic nervous system.
  • Example: Atropine used to dilate pupils and manage specific medical scenarios.

Sensory Receptors and Pain

• Types of Receptors:
  • Thermoreceptors: Detect temperature changes.
  • Photoreceptors: Respond to light and facilitate vision.
  • Nociceptors: Specialized for pain detection, indicative of potential tissue or bodily damage.
  • Mechanoreceptors: Respond to physical deformation; crucial for hearing and balance.
• Proprioceptors: Provide body position and movement feedback to the brain.

Case Study: Pain Perception

• Example of Pain Sensitivity: Ashlyn Blocker, child with congenital insensitivity to pain.
  • Interesting case detailing severe implications of lacking pain perception.
  • Had multiple instances of injury ranging from burns to more serious trauma, emphasizing the protective role of pain.

Understanding Pain Mechanisms

• Pain Types:
  • Somatic Pain: Felt in skin, muscles, and joints, subclassified into superficial and deep pain types.
  • Superficial pain: Sharp or prickling sensations.
  • Deep pain: Aching or throbbing sensations.
  • Visceral Pain: Originates from internal organs, often poorly localized but intensely felt.

Pain Response and Reflexes

• Nociceptors: Free nerve endings responsible for pain signaling, activated during injury to alert brain systems.
  • Substance P: Neurotransmitter involved in transmitting pain signals to the brain; crucial for understanding pain pathways.
• Pain Pathways:
  • Signals relay from nociceptors to spinal cord and relevant brain regions to process and interpret pain.

The Future of Pain Management

• Chronic Pain Recognition: Not just a symptom; can become its own disease.
  • Understanding the change in pain perception pathways to develop more effective treatments.
• Research Directions:
  • Development of drugs targeting underlying pain mechanisms to alter synaptic processes engaged in chronic pain conditions.