The prostate is a small gland belonging to the male reproductive system, primarily responsible for producing a fluid that constitutes a significant portion of semen. This fluid, which is slightly alkaline, helps to nourish and protect sperm, aiding in their mobility and survival. Understanding the prostate’s physical characteristics and placement is helpful, as its location means any changes in its size can affect the urinary tract.
Physical Description and Dimensions
The prostate gland is often described visually as being similar in size and shape to a walnut. It is a dense, fibromuscular gland enclosed by a thin, fibrous capsule. The gland is relatively small, with typical dimensions measuring approximately 4 centimeters wide, 3 centimeters high, and 2 centimeters thick.
The prostate’s weight generally falls within a range of 20 to 25 grams in a healthy adult. When felt by a doctor during an examination, the gland has a firm yet rubbery texture and a smooth surface. Its internal structure is composed of both glandular tissue and connective tissue.
Anatomical Placement
The prostate is a fixed organ situated deep within the male pelvis, determining its relationship to surrounding structures. It is positioned directly beneath the urinary bladder, where it surrounds the very beginning of the urethra. This section is specifically called the prostatic urethra, which carries urine and semen out of the body.
The shape of the prostate is sometimes compared to an inverted cone, with the base resting against the bladder neck above and the apex pointing downwards. It is situated in front of the rectum, separated by a layer of fascia. This proximity to the rectum allows for its examination through a procedure known as a digital rectal exam.
Changes in Appearance Over a Lifetime
The prostate’s size and shape are not constant throughout a man’s life, undergoing two primary phases of growth. The first growth phase occurs during puberty, where the gland doubles in size as a result of hormonal changes. After this initial growth, the prostate reaches its typical adult size of a walnut, remaining relatively stable until a man reaches his mid-forties.
The second phase of growth often begins around age 25 and continues throughout life, becoming more noticeable in middle age. This non-cancerous enlargement is known as Benign Prostatic Hyperplasia, or BPH. As this growth progresses, the gland can physically expand, sometimes reaching the size of an apricot by age 40, or even the size of a lemon or a golf ball by age 60.
This increase in size often causes the gland to become irregular or nodular in shape as the tissue multiplies. The enlargement typically occurs in the transition zone of the prostate, which is the area surrounding the urethra. While this growth is common with age, the rate and severity of the size change can vary significantly among men.