Human Anatomy and Physiology Lecture

Introduction

• Instructor: Professor Pablo
• Course: Human Anatomy and Physiology Part 2
• Topic: Sensory Physiology Series - Focus on Taste and Introduction to Eye Physiology
• Context: Lecture delivered online due to COVID-19; recorded using a cell phone.

Sensation of Taste

Gustatory Receptors

• Located on the papillae on the tongue.
• Types of papillae:
  • Filiform Papillae: Hair-like, not primarily involved in taste.
  • Foliate Papillae: Fold-like structures.
  • Fungiform Papillae: Mushroom-shaped, contain many taste buds.
  • Circumvallate Papillae: Have the most taste buds, located near the back of the tongue.
• Taste buds contain gustatory receptor cells, which are similar to olfactory receptor cells.

Primary Taste Sensations

• Sweet: Highest concentration at the tip of the tongue.
• Salty: Concentrated on the sides near the front.
• Sour: Located further back on the tongue.
• Bitter: Found at the very back of the tongue.

Additional Taste Sensations

• Umami: Detects protein, particularly the amino acid glutamate.
• Possible receptors for water and peppery flavors.

Tongue Anatomy and Taste Detection

• Geographic Tongue: Some people have retracting papillae, causing flat spots.
• Nerve Involvement:
  • Cranial Nerve 7 (Facial Nerve): Monitors the anterior two-thirds of the tongue.
  • Cranial Nerve 9 (Glossopharyngeal Nerve): Monitors the back of the tongue.

Anatomy of a Taste Bud

• Structure:
  • Contains a taste pore where gustatory cells extend their cilia.
  • Cells:
    • Gustatory Receptor Cells: Long narrow cells with cilia for taste molecule binding.
    • Support Cells: Develop into new gustatory receptors as they die.
    • Basal Cells: Mitotic cells that replace gustatory receptor cells.
• Gustatory receptors are one of two types of neuronal replacement in adults, along with olfactory receptors.

Relationship Between Taste and Smell

• Taste and smell are closely linked.
• Pinching the nose can decrease the ability to taste.
• Aging affects gustatory receptor replacement, decreasing taste sensitivity.

Conclusion

• This lecture covered the anatomy and physiology of taste.
• The next video will focus on the anatomy and physiology of the eye.

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• Note: Understanding these concepts is crucial for comprehending the sensory physiology and its implications on human health.