A&PII: CH 22

What do gonads produce?

Hormones and gametes (sex cells).

What are the male gonads called?

Testes.

What are the female gonads called?

Ovaries.

What type of cells do testes produce?

Sperm cells (spermatozoa).

What type of cells do ovaries produce?

Ova (oocytes, eggs).

How many chromosomes do sex cells have?

23 chromosomes (1 set of genetic instructions).

What restores the genetic information to 46 chromosomes?

The union of sperm and egg at fertilization.

What chromosome do all ova carry?

An X chromosome.

What determines the sex of the embryo?

The sperm; XX results in female, XY results in male.

What type of cell division produces sex cells?

Meiosis.

What are the two divisions in meiosis called?

Meiosis I and Meiosis II.

What happens during Meiosis I?

Homologous pairs of chromosomes are separated, resulting in haploid cells.

What happens during Meiosis II?

Chromatids are separated, resulting in cells that are still haploid.

What is synapsis in Prophase I?

The pairing of homologous chromosomes.

What occurs during crossover in Prophase I?

Exchange of genetic material between homologous chromosomes.

What is the outcome of Telophase I?

Two new haploid daughter cells are formed.

What is the function of the epididymis?

Transport sperm from the rete testis to the ductus deferens.

What do seminal vesicles secrete?

Fructose, prostaglandins, and alkaline fluid.

What is the role of the prostate gland?

Secretes a thin, milky, alkaline fluid that enhances sperm motility.

What do bulbourethral glands secrete?

A mucus-like fluid that lubricates the urethra.

What is the average sperm concentration in semen?

120 million sperm cells per mL.

What is capacitation in sperm?

The process that allows sperm to fertilize an egg, occurring in the female tract.

What is the function of the scrotum?

Houses the testes and maintains a lower temperature for sperm production.

What is the structure of the penis composed of?

Three columns of erectile tissue: two corpora cavernosa and one corpus spongiosum.

What is spermatogenesis?

The formation of sperm cells through meiosis and spermiogenesis.

How many sperm cells are produced from one primary spermatocyte?

Four sperm cells.

What is the role of sustentacular (Sertoli) cells?

Support and nourish developing sperm cells.

What is the sequence of sperm formation?

Spermatogonia → primary spermatocytes → secondary spermatocytes → spermatids → spermatozoa

How many chromosomes does each sperm have?

23 chromosomes

What are Sertoli cells?

Large cells in seminiferous tubules that support and nourish spermatogenic cells.

What are the three distinct parts of a sperm?

Head (contains nucleus and acrosome), middle piece (contains mitochondria), tail (provides motility).

What is the function of the acrosome in sperm?

It contains enzymes that penetrate layers around the oocyte during fertilization.

How long do sperm typically survive in the female reproductive tract?

About 48 hours.

What hormone does GnRH stimulate the anterior pituitary to produce?

Gonadotropic hormones, including FSH and LH.

What is the role of FSH in male reproductive health?

Promotes spermatogenesis.

What does LH stimulate in the testes?

Stimulates androgen (testosterone) production.

What are the primary female sex organs?

The ovaries.

What is the function of the uterine tubes?

Transport ovulated egg cells from the ovary to the uterus.

What are the layers of the uterine wall?

Endometrium (mucosa), myometrium (muscle layer), perimetrium (serosa).

What is the function of the vagina?

Conveys uterine secretions, receives the penis during intercourse, and provides a passageway for offspring during birth.

What are the labia majora?

Rounded folds of adipose tissue and skin that enclose and protect external reproductive organs.

What is oogenesis?

The process of maturation of an oocyte through meiosis.

What happens during Meiosis I in oogenesis?

Primary oocytes undergo meiosis, resulting in a large secondary oocyte and a small polar body.

What is the zona pellucida?

A glycoprotein layer that forms between the oocyte and granulosa cells.

What is the role of granulosa cells in follicle maturation?

They proliferate and form several layers around the oocyte.

What happens to primordial follicles after birth?

90% are lost to apoptosis between birth and early adulthood.

How many oocytes are typically released during a female's reproductive life?

300 to 400 oocytes.

What is the function of the vestibular glands?

Secrete mucus into the vestibule during sexual stimulation.

What is the structure of the ovaries?

Made up of an outer cortex and an inner medulla, containing follicles.

What is the function of the endometrium?

It is the mucosal layer of the uterus that receives and sustains the embryo.

What is the cervix?

The lower third of the uterus that partially extends into the upper part of the vagina.

What is the significance of the hymen?

A thin layer of connective tissue that partially encloses the vaginal orifice.

What is the role of the fimbriae?

Extensions that help pick up the ovulated egg cell from the ovary.

What is the primary function of the ovaries?

Produce female sex cells (oocytes) and hormones.

What is the function of the myometrium?

Muscle layer of the uterus that contracts during childbirth.

What separates the oocyte from the granulosa cells in a follicle?

The zona pellucida

What is the role of the theca interna in follicle maturation?

It produces steroids.

What occurs to the primary oocyte during ovulation?

It undergoes meiosis I, producing a secondary oocyte and first polar body.

What triggers ovulation?

A surge of luteinizing hormone (LH) released from the anterior pituitary gland.

What happens to the dominant follicle during the menstrual cycle?

It fully develops while other follicles degenerate.

What is the corpus luteum?

It is formed from the remnants of the follicle and secretes estrogen, progesterone, and inhibin.

What are the three phases of the ovarian cycle?

Follicular phase, ovulation, and luteal phase.

What characterizes the follicular phase of the menstrual cycle?

The dominant follicle matures under the direction of follicle-stimulating hormone (FSH).

What occurs during the luteal phase if fertilization does not happen?

The corpus luteum degenerates into a corpus albicans.

What are the uterine phases during the menstrual cycle?

Proliferative phase, secretory phase, and menstrual phase.

What hormonal changes occur during menopause?

Ovaries become unresponsive to gonadotropins, producing low levels of estrogens and progesterone.

What are common symptoms of menopause?

Hot flashes, dizziness, headaches, insomnia, and depression.

What is the structure of mammary glands?

Composed of 15 to 20 lobes containing alveolar glands that drain into lactiferous ducts.

What are warning signs of breast cancer?

Thickened tissue, changes in contour, nipple discharge, and abnormal nipple direction.

What is the purpose of birth control?

To voluntarily regulate the number of offspring and the timing of conception.

What are some methods of contraception?

Coitus interruptus, rhythm method, mechanical barriers, chemical barriers, hormonal contraceptives, IUDs, and sterilization.

What are sexually transmitted infections (STIs)?

Infections transmitted through sexual contact, which may not always show symptoms.

What are common symptoms of STIs?

Burning during urination, lower abdominal pain, fever, discharge, and sores.

What is pelvic inflammatory disease?

A complication from STIs like gonorrhea or chlamydia that can lead to infertility.

What is acquired immune deficiency syndrome (AIDS)?

A condition caused by HIV that deteriorates the body's immune defenses.

What hormones control the female reproductive processes?

Gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH).

What are the effects of estrogens in females?

They stimulate the enlargement of reproductive organs, thickening of the endometrium, and development of secondary sex characteristics.

What is the function of progesterone?

It stimulates uterine changes during the menstrual cycle and affects mammary glands.

How long does it take for a primordial follicle to develop into a mature antral follicle?

About 300 days.

What is menarche?

The first reproductive cycle, marking the beginning of menstruation.

What happens to the endometrium during the secretory phase?

It becomes more vascular under the influence of progesterone.