The bundles of muscles in the penis are:
1. Corpus cavernosa: This is a pair of erectile tissues that run along the length of the penis. It is responsible for the majority of the penis's rigidity during an erection. The corpus cavernosa contains smooth muscle fibers and is surrounded by tough fibrous tissue.
2. Corpus spongiosum: This is another erectile tissue that surrounds the urethra, which is the tube that carries urine and semen out of the body. The corpus spongiosum helps to maintain the shape and structure of the penis during an erection. It also contains smooth muscle fibers.
Explanation:
- The penis is composed of several structures, including erectile tissues and muscles.
- The erectile tissues, known as corpus cavernosa and corpus spongiosum, play a crucial role in achieving and maintaining an erection.
- The corpus cavernosa is located on the top side of the penis, while the corpus spongiosum surrounds the urethra and is located on the underside of the penis.
- Both the corpus cavernosa and corpus spongiosum contain smooth muscle fibers, which allow them to expand and fill with blood during an erection.
- The contraction and relaxation of these smooth muscle fibers are controlled by the autonomic nervous system.
- When the penis is not erect, the smooth muscle fibers are contracted, restricting blood flow to the erectile tissues.
- During sexual arousal, signals from the brain trigger the relaxation of the smooth muscles, allowing blood to flow into the corpus cavernosa and corpus spongiosum.
- This increased blood flow causes the erectile tissues to expand and become rigid, resulting in an erection.
- The bundles of muscles in the penis work together to facilitate sexual function and allow for a healthy erection.