Male Reproductive System | Spermatogenesis & hormones

Location of spermatogenesis?

Seminiferous tubules of the testes

Function of non‑differentiating spermatogonia?

Self‑renewing stem cells that replenish the germ cell pool

Ploidy of spermatogonia

Diploid (2n)

Spermatogenesis is apart of?

Meiosis

What is the formation of spermatocytes?

Spermatogenesis

What are produced during the first mitotic division?

• Cell produced after mitosis of spermatogonia?

Primary spermatocyte (2n)

In a mitotic division, you end up with?

Two daughter cells that are genetically the same

Event occurring in primary spermatocytes?

Meiosis I

What produced by the meiotic 1 division?

Secondary spermatocytes

Ploidy of secondary spermatocytes?

Haploid (1n) with duplicated chromosomes

At the end of meiotic divisions (meiosis 1 and 2), we end up with?

• Number of spermatids formed from one primary spermatocyte

Four Haploid cells

Event producing spermatids?

Meiosis II

Secondary spermatocytes have half the number of?

Chromosomes

• Haploids

Spermiogenesis occurs after?

Spermatogenesis

What is the process in which spermatocytes undergo a change in shape and become spermatids?

• Transformation of spermatids into mature spermatozoa?

Spermiogenesis

Spermatids still have to mature into?

Sperm

Structure formed from the Golgi during spermiogenesis

Acrosome

Function of the acrosome?

Contains enzymes for penetrating the oocyte

Where does spermatids mature?

Within the epididymis

Cells that support and nourish developing sperm?

• Cell type responsible for maintaining the blood-testis barrier?

Sertoli cells

Hormone produced by interstitial (Leydig) cells

Testosterone

When spermatids mature into sperm, what are the changes?

• Head with acrosome

• Midpiece with mitochondria

• Tail for propulsion

Hormone released by the hypothalamus to start spermatogenesis?

GnRH (Gonadotropin‑releasing hormone)

Target of GnRH (Gonadotropin‑releasing hormone)?

Anterior pituitary gland

Hormones released by the anterior pituitary in response to GnRH (Gonadotropin‑releasing hormone)?

FSH and LH

FSH target cells in the testes?

Sertoli cells

• begins spermatogenesis

LH target cells in the testes?

Leydig cells

Main function of LH in males?

Stimulates Leydig cells to produce testosterone

Main function of FSH in males?

Stimulates Sertoli cells to support spermatogenesis

Hormone produced by Sertoli cells that inhibits FSH

Inhibin

Hormone providing negative feedback to the hypothalamus and pituitary

Testosterone

Two hormones classified as gonadotropins?

FSH and LH

Hormone required for meiosis and spermiogenesis?

Testosterone

Feedback effect of inhibin?

Decreases FSH secretion

Feedback effect of testosterone?

Decreases GnRH and LH secretion

What is the cycle of sperm development?

Spermatogonia → Primary spermatocyte → Secondary spermatocyte → Spermatid → Spermatozoon

How long does sperm survive in the female tract?

4-5 Days