What is located near the tail of a hairless rat? - briefly
The anal opening (vent) lies directly adjacent to the base of the tail in a hairless rat.
What is located near the tail of a hairless rat? - in detail
The area directly adjacent to the caudal extremity of a hairless laboratory rat contains several distinct anatomical features.
- Anus – positioned just ventral to the tail base, it opens into the cloacal region and is surrounded by a ring of sphincter muscle that regulates fecal expulsion.
- Genital papilla – located anterior to the anus; in males it overlies the penile shaft, while in females it covers the vaginal opening. The papilla is supplied by the pudendal nerve and is rich in vascular plexuses.
- Perianal skin – thin, hair‑free epithelium that lacks the protective fur of the rest of the body. The epidermis is keratinized and contains numerous mechanoreceptors that detect tactile stimuli near the tail tip.
- Subcutaneous fat layer – a thin sheet of adipose tissue beneath the skin, providing insulation and serving as an energy reserve. In hairless strains this layer is more exposed, making the region prone to temperature fluctuations.
- Caudal musculature – the musculus caudofemoralis and associated tail‑base muscles attach to the sacral vertebrae, enabling tail movement and assisting in locomotion.
- Vascular supply – the caudal artery runs along the ventral midline of the tail, branching near the tail base to supply the perianal region. Complementary veins drain into the caudal venous plexus.
- Nervous structures – the caudal spinal nerve exits the vertebral column at the sacral level, providing sensory and motor innervation to the tail and adjacent perineal skin.
These components together form the peritail zone, a functional hub for excretory, reproductive, and locomotor activities in the hairless rat model.