Prostate Gland Anatomy and Function

12 Questions

Which of the following is NOT one of the anatomical zones of the prostate?

Posterior zone

What percentage of the prostate volume is represented by the peripheral zone?

70%

What is the approximate weight of the prostate gland by the age of 20?

20g

Which zone of the prostate is most commonly associated with benign prostatic hypertrophy?

Transitional zone

Which of the following cell types is NOT found in the prostate gland?

Adipocytes

Where are inflammatory processes like prostatitis most commonly seen?

Central zone

What is the main factor responsible for the development and growth of the prostate gland?

Dihydrotestosterone (DHT)

Which of the following is NOT a common symptom of Benign Prostatic Hyperplasia (BPH)?

Blood in the urine

Which of the following statements about the 5α-reductase enzyme is correct?

The type 2 isoenzyme is primarily active in the reproductive tissues, including the prostate.

What is the primary role of sex hormone-binding globulin (SHBG) in relation to testosterone?

It binds to and transports testosterone in the bloodstream.

What is the primary mechanism by which DHT contributes to prostate growth in BPH?

DHT binds to the androgen receptor and triggers the production of cellular growth factors.

Which of the following statements about the prostate gland size is correct?

The prostate gland starts to enlarge microscopically around the age of 40.

Study Notes

Prostate Gland

The prostate gland is a walnut-shaped gland that forms part of the male reproductive system and surrounds the urethra.
It secretes semen, which carries sperm, and weighs approximately 20g by the age of 20.
The prostate gland consists of stromal and epithelial elements, including smooth muscle cells, fibroblasts, endothelial cells, secretory cells, basal cells, and neuroendocrine cells.

Prostate Zones

The prostate gland has four anatomical zones: peripheral, central, transitional, and anterior.
The peripheral zone forms 70% of the prostatic volume, and 60-70% of prostate cancers occur in this zone.
The central zone represents 25% of the prostate volume and contains the ejaculatory ducts, and is prone to inflammatory processes.
The transitional zone represents 5% of the total prostatic volume and is where benign prostatic hypertrophy occurs.
The anterior zone is predominantly fibromuscular with no glandular structures.

Benign Prostatic Hyperplasia (BPH)

BPH is a histologic diagnosis that refers to the proliferation of smooth muscle and epithelial cells within the prostatic transition zone.
The size of the prostate gland increases microscopically from the age of 40, and half of all men over 60 develop an enlarged prostate.
By the age of 70 and 80, 80% of men experience urinary symptoms due to BPH.

Endocrine Control of Prostatic Growth

The size of the prostate gland is maintained through a homeostatic balance between cell renewal (proliferation) and cell death (apoptosis), regulated by hormones secreted by the endocrine system.
Androgens, mainly testosterone, are responsible for the maturation of genital organs and development of male secondary sexual characteristics.
Testosterone is produced by Leydig cells of the testis and the adrenal glands, and circulates in the bloodstream bound to sex hormone binding globulin (SHBG).
Dihydrotestosterone (DHT) is produced from testosterone through the 5 alpha-reductase enzyme, and is 2.5 times more potent as a male sex hormone.

Symptoms of BPH

Symptoms of BPH include problems emptying the bladder or problems with bladder storage, such as:
- Difficulty starting a urine stream (hesitancy and straining)
- Decreased strength of the urine stream (weak flow)
- Dribbling after urination
- Feeling that the bladder is not completely empty
- An urge to urinate again soon after urination