It attaches to prey (usually fish) using a circular muscle.
Uses horned teeth to drill holes and suck blood from prey, making it parasitic.
Anatomical Locations
Anterior Aspect: Mouth region.
Posterior Aspect: Opposite mouth, where fins are.
Dorsal Aspect: Back, location of dorsal fins.
Ventral Aspect: Belly side.
Headward Region Anatomy
Eyes: Appear cloudy due to preservative.
External Nostril: Tiny hole leading to olfactory bulb for smell processing.
Lateral Line System: Detects water vibrations, similar to tympanic membrane in humans.
Gills
External Gills: Series of holes for water entry and gas exchange.
Internal Gill Slit: Connects external gills to internal structures.
Fins and Movement
Single Dorsal Fin: Lacks paired fins, moves snake-like in water.
Anterior Dorsal Fin
Posterior Dorsal Fin
Caudal Fin: Used for propulsion.
Cloaca and Anus
Anus: End of digestive tract.
Cloaca: Common opening for reproductive and urinary tracts.
Dissection Process
Cut midline through the lamprey using a scalpel.
Ensure a firm grip and careful cutting.
Internal Anatomy
Buccal Cavity: Contains horned teeth, used for gripping.
Buccal Papillae: Sensory structures around the mouth.
Pharynx: Leads to dorsal and ventral branches.
Dorsal Branch: Forms esophagus and intestine.
Ventral Branch: Becomes respiratory tube with gills.
Internal Organs
Esophagus and Intestine: Part of digestive tract.
Liver: Green organ near intestine.
Gonads: Reproductive organs.
Heart: Muscular structure posterior to gills.
Nervous System
Olfactory Bulb: Processes smell from external nostril.
Brain: Located near olfactory bulb.
Spinal Cord: Continuation of the brain.
Notochord: Provides flexible support, characteristic of chordates.
Cartilage
Provides additional support to the lamprey.
Conclusion
The lecture covered the external and internal anatomy of the lamprey, highlighting its adaptation as a parasitic organism and the evolutionary features of chordates.