Module 3
1. Module 3
1.6. Page 4
Module 3—The Male and Female Reproductive Systems
Lesson Summary
In Lesson 1 you investigated the following focusing questions:
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What are the main structures and functions of the male reproductive system?
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How do these structures support continuity of the human species?
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What is the functional unit of the male reproductive system?
The male reproductive system is designed to produce and release large numbers of sperm. The gametes (sperm) are produced within the seminiferous tubules in the gonads (testes), where the temperature for proper sperm development is controlled by the scrotum. There the developing sperm are supported by the Sertoli cells and are transferred to the epididymis to be matured and stored.
During ejaculation, the ductus deferens helps transfer the sperm from the testes to the urethra, picking up the semen and seminal fluids on the way. The seminal fluids help the sperm by providing sugar for energy, alkalinity to neutralize urine and vaginal acids, and a medium for motility. Semen leaves the male body through the penis. The male reproductive system and sperm structure allow for sperm to be deposited into the female and to move through the female reproductive system.
Childhood illnesses, sexually transmitted infections, structural problems, and environmental and societal factors can all interrupt the function of the male reproductive system. The end result of sexual reproduction is the formation of a fertilized egg that contributes to variation and continuation of the human species.
Lesson Glossary
Consult the glossary in the textbook for other definitions that you may need to complete your work.
Cowper’s gland: a gland secreting fluids to form semen
ductus deferens: a smooth muscle tube that carries the semen from the epididymis to the penis
ejaculation: the release of semen from the penis
ejaculatory duct: a tube from the ductus deferens to the penis
epididymis: a cap on each testicle where sperm are matured and stored prior to ejaculation
fertility: the ability to produce gametes and reproduce
gamete: a haploid cell made during meiosis that participates in fertilization to make a zygote
gonads: sex organs that produce gametes (sperm or egg); testes in males and ovaries in females
infertility: the inability to reproduce
penis: the copulatory organ of the male that transfers semen to the female
primary sex characteristics: structures in the male or female that are essential for reproduction
prostate gland: a muscle-like gland secreting alkaline fluid to neutralize the acids in urine
scrotum: a pouch of skin located below the penis that holds the testes
secondary sex characteristics: characteristics that distinguish male from female but are not required for reproduction
semen: the ejaculated liquid that contains sperm plus the secretions of the seminal vesicles, prostate, and Cowper’s gland
seminal vesicles: glands producing a fluid containing fructose, which supplies energy for use by sperm
seminiferous tubules: coiled, hollow tubes in the testes where sperm are produced
Sertoli cells: ‘nurse’ cells in the seminiferous tubules that assist in spermatogenesis and produce the hormone inhibin
sex hormone: a biochemical compound controlling the development, maintenance, and function of the reproductive system and secondary sex characteristics
sperm: the male gamete
In sexual reproduction, the haploid sperm contributes half the chromosomes to the zygote; the egg contributes the other half.
testes: paired male gonads that produce sperm and secrete testosterone
testicles: a pair of male gonads producing sperm and testosterone; also called testes
urethra: the tube leading from the bladder to the penis
The urethra may carry either urine or semen.