Reproductive Systems and Hormonal Regulation

Flashcards covering the male and female reproductive systems, gametes, accessory organs, hormonal control, and cycle phases grounded verbatim in the lecture source.

What are gametes and how do their chromosome counts compare to other body cells?

Gametes are specialized cells designed for reproducing that have only 1/2 of the chromosomes found in other body cells (Spermatozoa in males and Ova in females).

What are the primary organs (gonads) of the male and female reproductive systems and their main functions?

The male primary organs are the testes and the female primary organs are the ovaries. Their functions are to produce gametes and make hormones.

What is the function of accessory organs in the reproductive system?

Accessory organs, ducts, and exocrine glands are involved in the transportation of gametes.

What are the primary functions of the male reproductive structures?

To manufacture spermatozoa and deliver spermatozoa to the female reproductive tract.

What is the epididymis and what occurs within it?

The epididymis is a greatly coiled tube where the testes deliver sperm cells to mature; it extends upward into the ductus deferens (vas deferens).

What is semen and what functions does it perform?

Semen is an alkalotic mixture containing sperm cells and other secretions. It functions to nourish and transport spermatozoa, neutralize acidity in the male urethra, provide lubrication, and prevent infection using antibacterial enzymes.

What fluid is secreted by the seminal vesicles and what is its role?

The seminal vesicles secrete a thick, yellow, alkaline fluid containing a large number of simple sugars and other substances for sperm nourishment, making up a lot of the volume of semen.

What are the characteristics and functions of the prostate gland's secretion?

The prostate gland produces a thin alkaline secretion that neutralizes acidity and enhances sperm motility. Its muscle tissue contracts to help expel semen.

What are the bulbourethral glands (Cowper glands) and where do they empty?

They are a pair of glands located below the prostate that secrete mucus for lubrication and empty into the urethra.

What are the dual functions of the male urethra?

The male urethra conveys urine from the bladder and semen from the ejaculatory duct to the outside of the body.

What are the three segments of spongy tissue in the penis that fill with blood?

The Corpus (body), Corpus spongiosum, and Corpus cavernosum.

Where are the testes located and when do they descend?

The testes are a pair of organs suspended outside the body inside the scrotum that descend 1-2 months after birth.

What are sustentacular cells and where are they located?

Sustentacular cells are located in the walls of the seminiferous tubules where they nourish and protect developing sperm cells.

What cells are located between seminiferous tubules and what do they produce?

Interstitial cells, which secrete testosterone.

When does spermatozoa production begin and what are the main features of a sperm cell?

Spermatozoa production starts at puberty in the seminiferous tubules. A sperm cell is a tiny individual cell with an oval head that is mostly a nucleus containing chromosomes.

Which two gonadotropin hormones from the anterior pituitary control the testes?

Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH).

What is the function of FSH in the male reproductive system?

FSH promotes the formation of spermatozoa and tells the testes to form sperm.

What is the function of LH in the male reproductive system?

LH stimulates interstitial cells to produce testosterone, which tells the cells to make testosterone to develop sperm.

What age-related changes occur regarding sperm and male reproductive structures?

Decreased sperm motility and quality, BPM (Benign Prostatic Hyperplasia - nonmalignant enlargement of the prostate), and ED (erectile dysfunction).

What is the uterus and what are its structural regions?

The uterus is a pear-shaped muscular organ where a fetus develops. Its regions include the Body (wide upper region) and Fundus (small rounded area above the body and tube entrance).

What are the three layers of the uterus?

Perimetrium (outer layer), Myometrium (muscle layer), and Endometrium (inner layer and lining).

What are fimbriae and what is their function?

Fimbriae are small fringe-like extensions at the opening of the uterine tubes that sweep the ovum into the tube.

What type of epithelium lines the surface of the vagina?

Stratified squamous epithelium on a mucus membrane lining.

What structures comprise the vulva?

The vulva consists of a pair of labia majora and minora, clitoris, vaginal opening, urethra, and mons pubis.

What is the perineum?

The area between the vagina and the anus.

What is the function of the greater vestibular glands?

They are paired glands that produce mucus and provide lubrication.

What is an ovarian follicle?

An ovarian follicle is a small cluster of cells beneath the outer single layer epithelium of the ovary that surrounds a developing oocyte, protects the ovum, and produces hormones.

When are female gametes produced?

Females are born with all the gametes they will ever produce.

What marks the first day of the female reproductive cycle?

The 1st day of menstrual flow.

What is ovulation and how does it divide the reproductive cycle?

Ovulation is the release of a gamete from the ovary. It separates the cycle into the preovulatory (follicular) phase and the postovulatory (luteal) phase.

What occurs during the follicular phase under the influence of FSH?

FSH stimulates follicles to mature. As the follicle enlarges and accumulates fluid, it secretes increasing amounts of estrogen to stimulate further follicle growth until usually only 1 follicle survives to release an ovum.

How does estrogen prepare the endometrium and trigger ovulation?

Estrogen prepares and thickens the endometrium for pregnancy; as estrogen levels increase, it stimulates an LH surge.

When does ovulation occur relative to the LH surge, and what happens to the follicle?

Ovulation usually occurs 1 day after the LH surge, causing the ovarian follicle to rupture and release the ovum into the peritoneum.

What transformation does LH cause after ovulation?

LH transforms the ruptured ovarian follicle into the corpus luteum.

What hormones does the corpus luteum secrete, and what are their functions?

It secretes estrogen and progesterone. Progesterone promotes survival of a fertilized ovum and embryo. Together, estrogen and progesterone cause the endometrium to continue to thicken and inhibit FSH and LH release via a negative feedback system.

What happens to the ovum and corpus luteum if fertilization does not occur?

If not fertilized, the ovum dies within 2-3 days and degenerates 11 days post-ovulation. The corpus luteum degenerates and the endometrium lining is shed during menstruation.

What happens if the ovum is fertilized?

It will begin to secrete hormones that maintain the corpus luteum for a few months.

What is menopause and what are its typical features?

Menopause is the cessation of menstruation, often occurring around 45-55 years of age. It involves a normal decrease in ovarian function and decreased estrogen levels, which can cause unpleasant symptoms that hormone therapy is designed to treat.