Reproductive System: Male

Question 1

The common purpose of the male and female reproductive systems is

Answer 1

To produce offspring

Question 2

Four tasks of reproduction are:

Answer 2

◦ Form gametes – sperm (♂) & ova (♀)
◦ Bring gametes together via sexual intercourse (♀♂)
◦ Combine genetic information via fertilization to form a zygote (♀)
◦ Support fetal development (gestation) & birth of baby (parturition)(♀)

Question 3

Ovaries & testes are

Answer 3

The primary sex organs (gonads)
◦ Produce gametes (sex cells: ova & sperm)
◦ Secrete steroid sex hormones (development of secondary sex characteristics: androgens/testosterone and estrogens/progesterone

Question 4

Accessory reproductive organs are

Answer 4

Ducts, glands
& external genitalia

Question 5

Gonadotropin releasing hormone (GnRH) from hypothalamus stimulates
release of gonadotropin from

Answer 5

The anterior pituitary

Question 6

Gonadotropins that stimulate gamete production & sex
hormone secretion

Answer 6

◦ luteinizing hormone (LH)
◦ follicle-stimulating hormone (FSH)

Question 7

Target tissue effects & negative feedback control of sex hormones is regulated by

Answer 7

Hypothalamus & anterior pituitary
◦ ♂: testosterone;
◦ ♀: estrogen & progesterone

Question 8

Males produce

Answer 8

4 sperm

Question 9

Nuclear division in the gonads that forms gametes:

Answer 9

Meiosis: haploid cells introduce genetic variation

Question 10

Females produce

Answer 10

1 ovum (+ 3 polar bodies; allows conservation of other cell components)

Question 11

Accessory ducts of male reproductive system are:

Answer 11

epididymis, ductus (vas) deferens, ejaculatory duct, urethra

Question 12

Accessory glands of male reproductive system are:

Answer 12

seminal vesicles, prostate gland, bulbourethral glands

Question 13

Testes are housed by the

Answer 13

Scrotum: a sac of skin & superficial fascia that hangs outside the abdominopelvic cavity at root of penis –
◦ Provides an environment 3°C below body temp for sperm production
◦ Responds to temperature changes (shorter & wrinkled when too cold; flaccid & loose when too hot to increase heat loss)

Question 14

Testes are each divided into

Answer 14

~ 250 lobules containing 1–4 seminiferous tubules
◦ Converge into a tubule that conveys sperm into
the rete testis

Question 15

In seminiferous tubules: cells that give rise to sperm are

Answer 15

Spermatogenic cells

Question 16

In seminiferous tubules
cells that support cells that nourish & protect spermatogenic cells are

Answer 16

Sertoli cells (sustentocytes; nurse cells)
◦ Promote sperm production by germ cells
◦ Form blood-testis barrier to protect sperm cells

Question 17

Seminiferous tubules are surrounded by 3-5 layers of

Answer 17

Smooth muscle-like myoid cells smooth
◦ May help move sperm & fluids out of the testes

Question 18

◦ Within connective tissue
surrounding the seminiferous tubules
◦ Produce androgens (testosterone)

Answer 18

Interstitial endocrine (Leydig) cells

Question 19

Absorbs heat from the testicular artery to maintain temperature homeostasis around testes

Answer 19

Pampiniform venous plexus
◦ testicular veins surrounding the testicular artery
◦ Blood sitting outside of main body structures: cool down before it reaches the testes
◦ Exchange in temp as flows into the testes

Question 20

Contains autonomic nerve fibres, blood vessels, & lymphatics; passes through the inguinal canal to each testis

Answer 20

Spermatic cord

Question 21

In males luteinizing hormone (LH) stimulates

Answer 21

Testosterone synthesis by interstitial endocrine (Leydig) cells

Question 22

In males follicle-stimulating hormone (FSH) indirectly stimulates spermatogenesis by

Answer 22

Stimulating Sertoli cells to release androgen-binding
protein to keep testosterone levels high around spermatogenic cells

Question 23

The final trigger for spermatogenesis is

Answer 23

Testosterone

Question 24

High blood testosterone inhibits

Answer 24

Hypothalamic release of GnRH & resulting anterior pituitary release of gonadotropins (FSH & LH)
◦ Negative feedback control

Question 25

The FSH-inhibiting protein released by Sertoli cells when sperm count is high

Answer 25

Inhibin

Question 26

Testosterone is a steroid hormone synthesized from

Answer 26

Cholesterol

Question 27

Testosterone must be converted to

Answer 27

Other hormones in some cells: ◦ Dihydrotestosterone (DHT) in prostate ◦ Estradiol (a form of estrogen) in some neurons

Question 28

Other function of testosterone:

Answer 28

Targets accessory organs (ducts, glands, & penis) causing them to grow to adult size & function (secondary sex characteristics)

Question 29

Testosterone level of male infants before birth:

Answer 29

two-thirds that of an adult ◦ for reproductive system development ◦ levels recede after birth & remain low until puberty

Question 30

Male secondary sex characteristics induced by testosterone:

Answer 30

◦ Pubic, axillary, & facial hair ◦ Deepening of the voice, thickening of the skin & increase in oil production ◦ Increase in bone/skeletal muscle size & mass ◦ ↑ basal metabolic rate

Question 31

◦ Coiled tube that provides place for immature sperm to develop until ejaculation (gain ability to swim) ◦ 1 connected to each testis ◦ 6 m long (longer than a bus)

Answer 31

Epididymis

Question 32

Immature sperm take how long to pass through the epididymis

Answer 32

2-6 days

Question 33

Extends as part of the spermatic cord from epididymis, through the inguinal canal, into the pelvic cavity, over the bladder, into the ejaculatory duct, and through the prostate gland to join the urethra

Answer 33

Ductus deferens (vas deferens)

Question 34

◦ Terminal portion of the testis-associated duct system ◦ Carries both urine & sperm to exterior

Answer 34

Urethra

Question 35

Semen is

Answer 35

◦ A milky white, sticky mixture of sperm & accessory gland secretions ◦ The transport medium for sperm; supports & protects

Question 36

Seminal glands produce

Answer 36

Seminal fluid ◦ 60% of semen ◦ Alkaline: ↑ sperm motility & fertilization ability (coagulating enzyme)

Question 37

Function of the prostate gland

Answer 37

◦ 25% of semen ◦ Role in sperm activation

Question 38

Bulbo-urethral glands produce

Answer 38

A thick, clear mucus prior to ejaculation to neutralize acidic urine left over in urethra

Question 39

3 erectile tissue bodies (connective tissue & smooth muscle riddled with vascular spaces) of the penis:

Answer 39

◦ 1 corpus spongiosum surrounding the urethra ◦ 2 corpora cavernosa making up most of the penis

Question 40

An erection is

Answer 40

The engorgement of erectile tissues when blood fills vascular spaces during sexual arousal

Question 41

During arousal, parasympathetic activity promotes

Answer 41

Release of nitric oxide (vasodilator), causing dilation of penile arterioles ◦ Engorgement of corpora cavernosa compresses penile veins, ↓ blood flow out of penis to maintain erection

Question 42

Ejaculation of semen is triggered by the

Answer 42

Sympathetic nervous system