On the vegetative and sensitive innervation of the Retractor clitoridis muscle in some domestic animals.

The study explores the structure and nerve supply (both automatic and sensory) of the muscle that retracts the clitoris in several domestic animals. The researchers observed differences in types and abundance of nerve receptors among different animals.

Study Background and Methods

• This research delves into the innervation of the Retractor clitoridis muscle – the muscle controlling the retraction of the clitoris – in various domestic animals. The species examined included cows, ewes, goats, mares, and sows.
• Primarily, the scholars have focused on the origins and terminations of this muscle, as well as its automatic and sensory innervation, represented by varying types of receptors.

Study Findings

• In terms of origins, in cows, ewes, goats, and mares, the muscle originates from the coccygeal vertebrae. However, in sows, the muscle starts from the anal musculature.
• Regardless of the origin, the termination point is consistent – at the base of the clitoris.
• All studied species presented that the muscle has an automatic nerve supply. This type of innervation involves involuntary body functions and it was represented by either isolated or group of ganglion cells.
• Moreover, a sensory nerve supply was detected as well, represented by different types of nerve endings or ‘receptors’. These included Pacinian corpuscles, Pacinian-like corpuscles, Golgi-Mazzoni’s corpuscles, and Krause’s end bulbs, which are responsible for sensations like pressure and vibration.

Differences Amongst Species

• Significant variability was noted between the animals in terms of the types and abundance of these sensory receptors. For instance, the sow, ewe and goat had all mentioned receptor types and they appeared in high response. However, in cows and mares, the researchers found only Pacinian and Pacinian-like corpuscles, which were present in smaller numbers.
• The researchers also provided a description of the morphology of these sensory nerve receptors and proposed speculations about their possible functional roles in different animals.