Male Anatomy

Male anatomy - sagittal view

1

2

3

1. Testis: Produce and store millions of sperm cells. Makes testosterone2. Epididymis: Coiled tubes that hold sperm for 2-3 months until they mature.3. Vas deferens: Tube that passes mature sperm from epididymis to penis.

4

4. Prostate gland: Provides 30-35% of the seminal fluid.

5

5. Seminal vesicles: Sac-like structures attached to the vas deferens that produce 60% of seminal fluid.

Cowper’s gland (also called the bulbourethral gland) produces the fluid that is released from the penis before ejaculation. This fluid “flushes out” the urethra before the arrival of semen.

6

7

8

9

10

6. Scrotum: Pouch-like structure outside the body that maintain the testicles at a certain temperature.

7. Bladder: Organ that collects/stores urine.

8. Urethra: Channel that carries semen and urine out of the body

9. Penis: Made up of spongy tissue that can expand and contract.

10. Anus: Opening from which feces leaves the body.

Semen Production & Ejaculation

2. Sperm mature in epididymi

s

3. Sperm leave

through vas deferens

4. Seminal vesicle and

prostate gland add fluid to make semen

5. Semen leaves

through urethra

1. Sperm are made

in the testicles

Beginning at puberty, the

pituitary gland stimulates the

testicles to start producing

testosterone, the male sex hormone

Sperm production

Testosterone initiates sperm production

Sperm production

starts in seminiferous tubules, organized

into lobules

Cross section of seminiferous tubules

Leydig cells

produce testostero

ne

Germ cells are any cells that give rise to gametes (sex cells)

Male germ cells are called spermatogonia (spermatogonium is

singular)

Every day, about 25 million spermatogonia begin the process to become mature sperm

Spermatogonia enter meiosis (begin to mature and divide) to become primary spermatocytes

Primary spermatocyte

s split into two cells

called secondary

spermatocytesNow the two

secondary spermatocytes each split to become

four spermatids

cells

Spermatogonia

primary spermatocytes

2 secondary spermatocytes

4 spermatids

If 25 millions spermtogonia begin the meiosis process

every day… that means 100 million

sperm are made every day!

Anatomy of sperm The nucleus contains

all the genetic information from the

male bodyThe acrosome

covers the nucleus. The job of the acrosome is to penetrate the

protective layer of the ovum The flagellum

whips back and forth to

move the sperm towards

the ovum

Once mobile, the sperm travel from the seminiferous tubules into the rete testis

From the rete testis, the sperm enter the

epididymis where they are stored until they

finish maturing and are

ejaculated

Cross section of the penisThe corpora

cavernosa and corpus

spongiosum are erectile tissue.

Inside these chambers have a

lot of blood vessels. When a

person is aroused the vessels fill with blood and expand

causing an erection.

Base or root of penis

Shaft of penis

Head or glans of penis

CircumcisionWhether a person is

circumcised depends on their family,

culture,religion, and

personal preferences.