The Reproductive System

Flashcards about the reproductive system to help students review lecture notes and prepare for exams.

What is the role of luteinizing hormone (LH) in ovulation?

A surge of LH triggers the release of an oocyte (immature egg cell) into the uterine tube, where it is available to be fertilized by sperm.

What is the male gamete called and what is its function?

The male gamete is called a sperm (or spermatozoon), and its function is to combine with the chromosomes in an oocyte (egg) during fertilization.

What is the main function of the male reproductive system?

To produce sperm and transfer them to the female reproductive tract.

What two crucial components do the paired testes produce?

Sperm and androgens, the hormones that support male reproductive physiology.

What is the scrotum and its primary function?

The scrotum is a skin-covered, highly pigmented, muscular sack that houses the testes and regulates their temperature for efficient sperm production.

What is the clinical term used when one or both of the testes fail to descend into the scrotum prior to birth?

Cryptorchidism.

What do Sertoli cells secrete, and what is the function of the blood-testis barrier?

Sertoli cells secrete signaling molecules that promote sperm production. The blood-testis barrier keeps bloodborne substances from reaching the germ cells and prevents autoimmune responses.

What is spermatogenesis, and where does it occur?

Spermatogenesis is the process of sperm production, and it occurs in the seminiferous tubules of the testes.

What is the function of the acrosome in a sperm cell?

The acrosome covers most of the head of the sperm cell as a cap that is filled with lysosomal enzymes important for preparing sperm to participate in fertilization.

What is the role of the epididymis in sperm maturation?

The epididymis is where newly formed sperm continue to mature and acquire the ability to move under their own power.

What is semen composed of, and which glands contribute to its production?

Semen is the thick, milky fluid ejaculated by males and is composed of sperm and fluids from the seminal vesicles, prostate gland, and bulbourethral glands.

What is the function of the fluid released by the bulbourethral glands?

The fluid lubricates the end of the urethra and the vagina, and helps to clean urine residues from the penile urethra.

What causes the stiffness of the penis during an erection?

A penile erection results from vasocongestion, or engorgement of the tissues because of more arterial blood flowing into the penis than is leaving in the veins.

What is Erectile dysfunction (ED) and its causes?

Erectile dysfunction (ED) is a condition in which a man has difficulty either initiating or maintaining an erection. In addition to aging, ED is associated with diabetes, vascular disease, psychiatric disorders, prostate disorders, the use of some drugs such as certain antidepressants, and problems with the testes resulting in low testosterone concentrations.

What is the role of testosterone? What cells produce it?

Testosterone promotes spermatogenesis, muscle development, bone growth, the development of secondary sex characteristics, and maintaining libido. It is released by Leydig cells.

What is the function of gonadotropin-releasing hormone (GnRH)?

Pulsatile release of GnRH from the hypothalamus stimulates the endocrine release of hormones from the pituitary gland.

What hormones do the hypothalamus and pituitary gland produce that are critical for male reproductive function?

The hypothalamus produces gonadotropin-releasing hormone (GnRH), and the pituitary gland produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

What are the symptoms of andropause in men?

Symptoms of andropause include fatigue, reduced muscle mass, depression, anxiety, irritability, loss of libido, and insomnia. A reduction in spermatogenesis resulting in lowered fertility is also reported, and sexual dysfunction can also be associated with andropausal symptoms.

Name the external female reproductive structures.

The external female reproductive structures are referred to collectively as the vulva (Figure 27.10). The mons pubis, the labia majora, the labia minora, clitoris, the hymen and the vaginal opening.

What is the function of the vagina?

The vagina serves as the entrance to the reproductive tract and also serves as the exit from the uterus during menses and childbirth.

What function does the normal population of microorganisms in the vagina perform?

They help to protect against infection by pathogenic bacteria, yeast, or other organisms that can enter the vagina by maintaining an acidic pH.

What are the female gonads and their function?

The ovaries are the female gonads, and they produce oocytes.

What is the ovarian cycle?

The ovarian cycle is a set of predictable changes in a female’s oocytes and ovarian follicles.

Describe Oogenesis

The process begins with the ovarian stem cells, or oogonia. Oogonia are formed during fetal development, and divide via mitosis

How does the diploid secondary oocyte become an ovum—the haploid female gamete?

Meiosis of a secondary oocyte is completed only if a sperm succeeds in penetrating its barriers.

Why is it important that the female gamete contains a larger amount of cytoplasm?

The larger amount of cytoplasm contained in the female gamete is used to supply the developing zygote with nutrients during the period between fertilization and implantation into the uterus.

What are ovarian follicles?

Ovarian follicles are oocytes and their supporting cells.

What is the zona pellucida?

The thin acellular membrane that the primary oocyte secretes.

What key even does the LH surge induce?

The LH surge leads to ovulation of the dominant follicle.

What is luteinization?

The surge of LH also stimulates a change in the granulosa and theca cells that remain in the follicle after the oocyte has been ovulated.

What is the the corpus luteum, and what is its function?

The corpus luteum is a term meaning “yellowish body”. It is formed from the granulated cells of the dominant follice. The corpus luteum and luteinized granulosa and theca cells produces large amounts of the sex steroid hormone progesterone, a hormone that is critical for the establishment and maintenance of pregnancy.

What is the main function of the uterein tubes?

Serve as the conduit of the oocyte from the ovary to the uterus

What happens when fertilization occurs in the fallopian tubes?

When fertilization does occur, sperm typically meet the egg while it is still moving through the ampulla. If the oocyte is successfully fertilized, the resulting zygote will begin to divide into two cells, then four, and so on, as it makes its way through the uterine tube and into the uterus. There, it will implant and continue to grow.

What part of the uterus is shed during menstruation?

The stratum funtionalis layer of the endometrium.

What is the menses phase?

The menses phase of the menstrual cycle is the phase during which the lining is shed; that is, the days that the woman menstruates.

What is the proliferative phase?

Once menstrual flow ceases, the endometrium begins to proliferate again, marking the beginning of the proliferative phase of the menstrual cycle.

What happens in the secretory phase in preperation of implantation?

In the uterus, progesterone from the corpus luteum begins the secretory phase of the menstrual cycle, in which the endometrial lining prepares for implantation. Over the next 10 to 12 days, the endometrial glands secrete a fluid rich in glycogen. If fertilization has occurred, this fluid will nourish the ball of cells now developing from the zygote. At the same time, the spiral arteries develop to provide blood to the thickened stratum functionalis.

What is the most common cause of cervical cancer, and what is a prevention method?

Research over many years has confirmed that cervical cancer is most often caused by a sexually transmitted infection with human papillomavirus (HPV). A prevention method is regular cervical screening exams called pap smears, which samples cells of the cervix, allowing the detection of abnormal cells.

What happens to breast tissue during the normal hormonal fluctuations in the menstrual cycle?

Breast tissue responds to changing levels of estrogen and progesterone, which can lead to swelling and breast tenderness in some individuals, especially during the secretory phase.

How do birth control pills work?

By providing a constant level of both estrogen and progesterone.Which negatively feeds back onto the hypothalamus and pituitary, thus preventing the release of FSH and LH.

What are the effects on a woman's body during menopause?

During the years leading up to menopause, there is a decrease in the levels of the hormone inhibin, which normally participates in a negative feedback loop to the pituitary to control the production of FSH. The menopausal decrease in inhibin leads to an increase in FSH.

How does the SRY (Sex-determining Region of the Y chromosome) affect sexual development?

Without a functional SRY gene, an individual will be female. With it, the SRY gene actively recruits other genes that begin to develop the testes, and suppresses genes that are important in female development.

What happens if sustentacular cells fail to secrete properly?

Without such sustentacular cell secretion, the Müllerian duct will develop; without testosterone, the Wolffian duct will degrade making the offspring female.

What physical changes occur at puberty through hormones?

A concerted release of hormones from the hypothalamus (GnRH), the anterior pituitary (LH and FSH), and the gonads (either testosterone or estrogen) is responsible for the maturation of the reproductive systems and the development of secondary sex characteristics, which are physical changes that serve auxiliary roles in reproduction.

List some difference of physical changes between male and female signes of puberty:

Male Female::Increased larynx size and deepening of the voice Deposition of fat, predominantly in breasts and hips::Increased muscular development Breast development::Growth of facial, axillary, and pubic hair, and increased growth of body hair::Broadening of the pelvis and growth of axillary and pubic hair