Male Reproductive Development and Spermatogenesis

In male embryonic development (XY), the Y-chromosome SRY gene promotes the formation of _____ (TDF).

During male organogenesis, testosterone stimulates the development of internal reproductive organs including the epididymis, vas deferens, and _____.

Development of external male genitalia—including the penis, scrotum, and prostate—requires _____, which is converted from testosterone by 5-alpha reductase.

In male brain differentiation, testosterone is converted into estradiol (E₂) by the enzyme _____.

The developmental disorder characterized by the presence of both ovarian and testicular tissue is termed _____.

Individuals with testicular feminization syndrome lack functional _____ receptors, resulting in a feminine external appearance despite an XY genotype.

A deficiency in the enzyme _____ causes incomplete development of the penis, scrotum, and prostate, often resulting in ambiguous or female-like external genitalia at birth.

The clinical term for the failure of one or both testes to descend from the abdominal cavity into the scrotum is _____.

Spermatogenesis occurs specifically within the _____ tubules of the testes.

The interstitial tissue located between seminiferous tubules contains _____ cells, which are the primary site of testosterone production (steroidogenesis).

During spermatogenesis, primary spermatocytes undergo meiotic divisions to form secondary spermatocytes, which then give rise to haploid _____.

The final transformation process in which haploid spermatids differentiate into mature spermatozoa is called _____.

Sertoli cells within the seminiferous tubules support and nourish developing sperm and form the protective _____ barrier.

To maintain a high concentration of testosterone within the seminiferous tubules, Sertoli cells secrete _____ (ABP).

In addition to ABP, Sertoli cells secrete Müllerian inhibition factor (MIF), as well as the protein hormones activin and _____.

In human males, the _____ testis is often positioned lower in the scrotum, whereas the right testis is often heavier.

Sperm maturation, concentration, storage, and the acquisition of motility and fertility occur within the _____.

The duct that stores and transports sperm from the epididymis toward the urethra, a segment of which is cut during a vasectomy, is the _____.

The _____ vesicles produce approximately two-thirds of total semen volume and secrete fructose as an energy source for sperm motility.

Secretions from the _____ gland are alkaline, which helps neutralize the naturally acidic environment of the female vagina.

Pre-ejaculatory lubricating mucus-like fluid is secreted by the _____ glands.

Penile erection is a vascular response mediated primarily by the neurotransmitter _____ released by parasympathetic postganglionic neurons.

Androgen-dependent secondary sex characteristics in males include hairline recession, aggression, and laryngeal growth causing vocal cord _____.

Testosterone stimulates the kidneys to increase production of red blood cells through the process of _____.

In the central nervous system, the hypothalamic _____ nucleus (SDN / INAH) is larger in males and plays a key role in sexual behavior.

Testosterone promotes bone growth during adolescence and eventually induces the closure of _____ plates.

In the HPG axis, the hypothalamus releases _____ in a pulsatile manner to stimulate the anterior pituitary.

Anterior pituitary LH acts specifically on _____ cells to stimulate testosterone production.

Anterior pituitary FSH acts on _____ cells to support and promote spermatogenesis.

Pulsatile secretion of GnRH, LH, FSH, and testosterone is biologically critical because it prevents target-organ _____.

Removal of the testes (castration) causes a sharp rise in blood levels of LH and FSH due to the loss of testicular _____ feedback.

The hormone _____ secreted by Sertoli cells selectively inhibits FSH release without directly affecting LH secretion.

The testicular peptide hormone _____ selectively stimulates FSH secretion from the anterior pituitary.

Anterior pituitary hormone _____ can increase the number of LH receptors on Leydig cells, enhancing testosterone sensitivity.

Pathologically elevated prolactin levels, known as hyperprolactinemia, can impair testicular function and lead to erectile dysfunction and reduced _____.

The hormone _____ secreted by the pineal gland may exert inhibitory effects on GnRH, LH, FSH, and testosterone secretion.

Androgens promote protein synthesis and cellular hypertrophy in both skeletal muscle and _____ muscle.

Sertoli cells protect developing germ cells from autoimmune attack by establishing tight junctions that comprise the _____ barrier.

Spermatogenesis is the complete developmental sequence progressing from primary spermatocytes to secondary spermatocytes, spermatids, and finally _____.

The scrotum houses the testes outside the main body cavity to maintain a lower _____ required for optimal sperm maturation.