Rat Dissection Lecture Notes

Introduction to Dissection

• Specimens: Two rats (one male, one female) will be dissected.
• Viewer Discretion: Expectation of viewing internal organs.

Educational Purpose and Respect

• Rats sourced from biological supply companies for educational dissection.
• Respect: Importance of respectful behavior towards specimens in language and actions.

Specimen Preparation

• Preservation: Blood drained; dyes used to highlight circulatory vessels (not natural in live rats).

External Features and Characteristics

General Characteristics

• Mammals: Rats are mammals, exhibit mammalian characteristics:
  • Hair
  • Mammary glands: Milk production in females.

Rodent Characteristics

• Continuous Incisors: Continuously growing front teeth, requiring gnawing to manage.

Biological Sex Differences

Female Rats

• Mammary glands: Pronounced, possibly indicating maturity or pregnancy.
• External Openings: Urogenital opening, vaginal opening, rectum.

Male Rats

• Urogenital Opening: Penis lies beneath the skin; extends for reproduction.
• Scrotum: Contains testes, maintains optimal temperature for sperm production.

Anatomical Directions

• Anterior and Posterior:

  • Anterior: Towards the head
  • Posterior: Towards the tail

• Ventral and Dorsal:

  • Ventral: Towards the stomach (underside)
  • Dorsal: Towards the back

• Proximal and Distal:

  • Proximal: Closer to a focal point
  • Distal: Further from a focal point

• Right and Left:

  • Refers to the specimen's left and right, not viewer's.
  • Important during dissection with the specimen on its back.

Next Steps

• Begin dissection by exploring external anatomy.
• Proceed to open female rat to observe internal structures.