NCBI Bookshelf. Molecular Biology of the Cell. New York: Garland Science; In most species, there are just two types of gamete , and they are radically different. The egg is among the largest cells in an organism, while the sperm spermatozoon , plural spermatozoa is often the smallest. The egg and the sperm are optimized in opposite ways for the propagation of the genes they carry.
Nine Things You Never Knew About Sperm (PHOTOS)
Sperm - Molecular Biology of the Cell - NCBI Bookshelf
Semen is the cloudy white bodily fluid that is emitted from the urethra and out of the penis during ejaculation. It consists of mobile sperm cells called spermatozoa and a nutrient-rich fluid called seminal fluid. During ejaculation, a thick-walled duct called the vas deferens carries the sperm cells from the epididymis to the urethra and then outside of the body or into the vagina by means of the penis. These three glands, often referred to as accessory sex glands, are the bulbourethral glands also called Cowper's glands , the prostate gland, and the seminal vesicles. The first portion of seminal fluid about 5 percent consists of secretions from the Cowper's glands. These pea-sized glands produce what is called the pre-ejaculate fluid, the small amount of fluid that is released before ejaculation.
Normal sperm count: Everything you need to know
Every sperm is great. In fact, the average male will produce roughly billion sperm cells over a lifetime and shed at least one billion of them per month. A healthy adult male can release between 40 million and 1. In contrast, women are born with an average 2 million egg follicles, the reproductive structures that give rise to eggs.
Semen , also called seminal fluid , fluid that is emitted from the male reproductive tract and that contains sperm cells, which are capable of fertilizing the female eggs. Semen also contains other liquids, known as seminal plasma , which help to keep the sperm cells viable. In the sexually mature human male, sperm cells are produced by the testes singular, testis ; they constitute only about 2 to 5 percent of the total semen volume.