To create new male contraceptive options, we have to understand the male reproductive system. Human males have reproductive organs (also called genitals) that are both inside and outside the pelvis. Altogether, the male genitals include four parts that comprise the male reproductive system.
Chapter 4:
Nuts & Bolts (Male Anatomy)
Key Points/Learning Objectives
- How does the male reproductive system work?
- What does the sperm’s life cycle look like?
Overview
These are the four key parts of the male reproductive system:
- the testicles,
- the duct system, which is made up of the epididymis and the vas deferens,
- the accessory glands, which include the seminal vesicles and prostate gland,
- and the penis.
The male genitals, also called sex organs, work together as a reproductive system to produce and release sperm-containing semen. Sperm in the semen can fertilize an ova or egg to produce a baby (called conception).
Contraception, or birth control, is a method used to prevent conception when a person or couple wants to be sexually active but is not ready to start a family. Female hormonal contraception is based on interruption of the menstrual cycle. Because sperm are produced continuously, there is no similar male reproductive cycle to interrupt.
Historically, methods of male contraception were focused on one part of the male reproductive system, namely, putting a full stop to sperm production. These days, researchers are focusing on affecting sperm function as well as halting sperm production. Examples of functional changes in the male reproductive system include preventing sperm from swimming, and preventing sperm from being able to fertilize an egg.
The Male Reproductive System
External Videos
Anatomy of the Male Reproductive System
By R. Dewaele (Bioscope, Unige), J. Abdulcadir (HUG), C. Brockmann (Bioscope, Unige), O. Fillod, S. Valera-Kummer (DIP), www.unige.ch/ssi – Outils pédagogiques – Teaching tools – Sciences, Sexes, Identités – UNIGE (adapted from the PDFs), CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=80330324
Key Organs & Structures
The Male Reproductive System can be broken up into two major part: the external organs, those located outside of the body cavity, and the internal organs or accessory organs, those underneath the skin.
External organs include the penis, scrotum, testicles, and epididymis.
Videos
Internal organs or accessory organs include the bulbourethral glands, ejaculatory ducts, prostate gland, seminal vesicles, seminiferous tubules, urethra, and vas deferens.
Videos
Study Break!
The Most Important Player: The Sperm
Sperm is the male reproductive cell or gamete, a microscopic cell with a head and tail that looks like a tadpole.
This determined little cell is hyper-focused on one job and one job only. It wants to find an egg and make a baby. This single-cell organism can accomplish its mission through sex or in vitro fertilization.
Sperm vs. Semen: Roles and Responsibilities
Luckily, sperm doesn’t have to travel alone. Thanks to semen, sperm is carried away.
Semen, or seminal fluid, is an organic fluid created to contain and transport sperm, or spermatozoa, from the male reproductive tract into the female reproductive tract. Semen contains all the chemicals that a sperm cell could need. The seminal vesicles in the pelvis and the prostate provide these chemicals.
How is Sperm Made?
Videos
Blog posts
Bird & the Bees
Sperm motility is the ability of sperm to swim through the female reproductive tract in order to fertilize an egg. Ejaculation is the discharge of semen from the male reproductive tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. Sperm then are moved from the epididymis, the vas deferens to the urethra before exiting the body and entering the vaginal canal, cervix, and uterus and swimming up the fallopian tubes. Once the sperm have reached the egg, or oocyte, the process of fertilization, binding to the egg via the acrosome reaction, begins.
Puberty
Puberty is the process in which a human child’s body matures into an adult capable of sexual reproduction. It is initiated by hormonal signals from the brain to the ovaries in females and testes in males, also known as the gonads. In response to these signals, the gonads produce the hormones required for the physiological transformation of the human body, including changes to the sex organs and the stimulation of sexual desire in people (i.e., the libido).
Videos
Blog Posts
What is Puberty?
Video Game: Sperm Invaders
For more information, check out: Intended Podcast: Episode 2: Sperm Science
Episode Two – Sperm Science
