Sexual anatomy (male)

Question 1

Sexual health is important for quality of life

Answer 1

1. Sex is healthy, much can go wrong
2. Sexual problems give rise to psychological problems and relational problems
3. And, of course, vice versa!

Question 2

External genitalia male

Answer 2

• Gonades: testes
• scrotum
• Penis

Question 3

Scrotum

Answer 3

Sac of skin superficial fascia hanging outside the abdominopelvic cavity
- contains paired testicles separated by a midline scrotum
- its external position keeps the testes 3 degrees lower than core body temperature

Question 4

Wall of the scrotum

Answer 4

• Dartos muscle: wrinkles scrotum skin for temperature
• Cremaster muscle: lowers and raises the testes keeping them on temperature

Question 5

Testis

Answer 5

250 lobules in each testes
–> each contains 1-4 seminiferous tubules that converge to form a single straight tubule, which leads into the rete testis in which semen is produced
- Leydig cells: produce male sex hormones (testosterone), located between the seminiferous tubules

Question 6

Epididymis

Answer 6

Storage nd maturation are for sperm (a long tube - 6 meter)
- the ducts absorb testicular fluid and pass nutrients to the sperm
- nonmotile sperm enter, pass through its tubes and become motile
- upon ejaculation the epididymis contracts, explenning sperm into the ductus deferens

Question 7

Penis

Answer 7

Glans is the head of the penis
- Meatus or urethrak opening: pass for semen and urine
- Body or shaft
- Corona: raised ridge separating the glans from the body of the penis
- Foreskiin or prepuce: layer covering the glans. Absent in circumcised penises

Question 8

Penis on the inside

Answer 8

• Cylindrical pendant organ located anteripor to the scrotum and functions to transfer sperm to the vagina
• consist of three columns of erectile tissue that are wrapped in connective tissue and covered with skin
• two dorsal columns: corpora cavernosa
• midline ventral column surrounding the urethra: corpus spongiosum

Question 9

Spermatogenesis

Answer 9

• Sperm production begins at puberty and continues throughout males’ life
• entire process, beginning with a primary spermatocyte, takes about 74 days
• after ejaculation, the sperm can live for about 48 hours in the female reproductive tract

Question 10

Spermatogenesis in the body

Answer 10

Sperm are produced within the seminiferous tubulus
- interspersed within the tubules are large cells which are the sustentacular cells which support and nourish the other cells (Sertoli’s cells)

Question 11

Sperm

Answer 11

Head: contains DNA + helmetlike acrosome containing hydrolyc enzymes allowing the sperm to penetrate and enter the egg
Midpiece: contains mitochondria for energy
Tail: flagellum for swimming

Question 12

Summary of the sperm

Answer 12

Produced: seminiferous tubules
Stored: epididyms
Transported: through epididymis by rhythmic peristaltic contracions as they mature

Question 13

Seminal vesicels

Answer 13

On the posterior bladder wall, secrete 60-75% of seminal volume
- fructose: energy for the sperm
- fibrinogen: helps turn sperm into a bolus that can be readily propelled
- prostaglandins: decrease cervical mucus viscosity and stimulate reverse peristalsis of the uterus

Question 14

Prostate

Answer 14

Firm, dense structure size of a walnut, located inferior to urinary bladder
- produces 25-30% seminal fluid
- this fluid is milky: different enzymes, incl. prostate-specific antigen (PSA)

Question 15

Bulbourethral or Cowper’s gland

Answer 15

Pea-sized glands located below the prostate
- produce clear alkaline mucus before ejaculation, neutralizes traces of acidic urine in the urethra, lubricates urethra and head of penis

Question 16

Seminal fluids

Answer 16

olume 2.5- 5.o ml: sperm count of 50-150 million sperm (under 20 million sperm is considered infertile
- pH 7.2-7.7
- testes: source of sperm (2-5% vol)
- Seminal tvesicles - provide fructose and nutrients (60-75% vol)
- prostate gland - provides enzyme, acid phosphatase, citric acid, zinc, and proteolyctic enzyme. (25-30% vol) + suppress poossible immune response woman
- bulbpurethral glands: thicl alkaline mucouslike fluid that neutralizes acids (5% vol)