Couldn't find what you looking for?

TRY OUR SEARCH!

When it comes to the male genitals, there's a whole lot more there than meets the eye. Sure, you know where your penis is. But what about the rest of it? This simple guide walks you through the external and internal male reproductive and urinary anatomy.

When looking at the penis, most people know the basic and most general information, but there is more to consider when thinking of the organ as a whole. What is a penis? How does it work? What does it do? How long is the average penis? How big can a penis be?  These are all interesting questions and ones which will be addressed.  In the following article, we will attempt to dissect the urinary and reproductive system of the penis and talk about the myths and truths, in order to better educate everyone about one of the most interesting organs of the male body.

What is a Penis?

The penis is the male sex organ which consists of many different parts, both internal and external.  Both vertebrate and invertebrate male organisms have a penis, and the organ can be found in reptiles and mammals as well.  The penis is responsible for delivering sperm during sexual intercourse and removes waste from the body through the act of urination.

The External and Internal Anatomy of the Penis

The tip or head of the male penis is referred to as the glans, which is covered with foreskin, which can be retracted to expose the tip of the organ. There are three columns of tissue which compose the penis, two corpora cavernosa which lie next to one another on the back side of the organ, and one corpus spongiosum which is in between the corpora cavernosa layers.  Underneath the penis, the foreskin is attacked to the frenulum, which is a small fold of tissue which restricts the motion of the penis.

On the tip of the penis is the urethral opening which is responsible for the passage of urine and during sexual intercourse, the tube releases sperm.  Sperm are manufactured in the testes and stored in the testicles.  During the process of ejaculation, sperms are thrust upward through the vas deferens glands, which are located behind the bladder.  Ejaculatory fluids are added to the sperm from the seminal vesicles and the vas deferens become ejaculatory ducts, which join with the urethra inside the prostate gland and during sexual intercourse and climax, seminal fluid is released through the tip of the penis out of the urethral tube.

The human penis is very different than the penis in other mammals, it lacks an erectile bone.  The human penis relies on blood engorgement during sexual excitement to achieve an erect state.  The human penis does not withdraw into the abdomen and is bigger than that of other mammals, and is directly in proportion to body mass.   The penis of a male human starts growing during puberty, which can occur in some males at approximately 10 years old or later, the penis is usually done growing by the time a male reaches 18-21 years of age.  Penis size has nothing to do with race, hand or shoe size or size of the nose, the size of each male is unique to that person, with the average length being 5.1-5.9 inches and the average circumference of 4.972 inches, when fully erect.

The Reproductive Function of the Penis

The male reproductive system consists of the following; the penis, testicles, epididymes, vas deferens, prostate and seminal vesicles.  The inside of the penis contains two cylindrical tissues, two main arteries, many veins and nerve tissues.  The testicles produce sperm and testosterone and are located behind the penis; each testicle connects to a small tube called the epididymes, which is the organ responsible for storing sperm.  The epididymes connects to the prostate through a pair of tubes called the vas deferens, which are part of the spermatic cord.

The prostate gland is located under the bladder and in front of the rectum and is protected by the prostate capsule.  The urethra passes through the prostate and into the neck of the bladder and produces prostate specific antigen and prostatic acid phosphatase which are mixed with seminal fluid and forms seminal fluid.  The seminal vesicles are located in close proximity to the prostate and release a thick fluid that combines with seminal fluid and sperm to form semen.

The entire male reproductive system relies on and is dependent on hormones, which are chemical stimulants which control the activity of the penis.  The primary hormones involved in the reproductive functions of the penis are luteinizing hormone (LH), testosterone and follicle-stimulating hormone (FSH).

LH and FSH are manufactured by the pituitary gland which is found at the base of the human brain.  FSH is needed for the male body to be able to manufacture sperm and LH stimulates the production of testosterone, which is needed in order for the body to keep making sperm.  Testosterone is the hormone responsible for the development of male characteristics, which includes strength, bone mass, distribution of fat, muscle mass and sexual drive.

The Urinary Function of the Penis

The urinary tract of the human body consists of the kidneys, ureters, bladder and the urethral tube.  The kidneys remove waste from the blood and body and into the ureter.  Once in the ureters the urine goes from the renal pelvis and into the bladder.  The bladder is a hollow organ which stores urine and is found behind the pubic bone.  Muscles in the bladder tighten around the urethral opening and prevent urine from being leaked. When the volume of urine reaches a certain capacity, the brain responds by sending a signal to the sphincter, which causes relaxation and allows urine to be expelled from the body. 

When the bladder contracts, urine is expelled from the body through the urethra, which is a tube composed of smooth muscle fibers, elastic tissues, and sphincter muscle and collagen tissue.  In males, the urethra is approximately 8-9 inches long and extends from the neck of the bladder to the end of the penis.  Through muscle contraction in the male penis, urine moves through the various tubes and is expelled from the end of the organ, which is how urine is released from the male body.

Overview

With the information contained in this article, men and women should have a better understanding of the anatomy and physiology of the male penis.  The penis is much more than just an extension of the male body and is necessary for human reproduction and waste removal purposes, and more than just a simple sexual or pleasure organ. 

  • www.ifsha.org/glossary.htm#p
  • en.wikipedia.org/wiki/Penis#Structure
  • www.cirp.org/pages/anat/
  • en.wikipedia.org/wiki/Human_penis_size
  • www.webmd.com/sex-relationships/guide/male-reproductive-system
  • www.urologyhealth.org/print/index.cfm?topic=112
  • www.umm.edu/ency/article/001278.htm