Gametogenesis HARD MCQ

The precursor cells that will eventually develop into sperm or egg cells. They originate in the epiblast, migrate to the yolk sac, and then back into the embryo to reach the developing gonads.

The complex journey PGCs take from their origin in the epiblast to their final destination at the developing gonads, involving movement through the yolk sac and the dorsal mesentery.

A type of germ cell tumor that can develop in the gonads or other locations. It contains cells that differentiate into tissues from all three embryonic germ layers, leading to the presence of unexpected tissues like hair, teeth, or bone.

Gametogenesis involves four phases: 1) Formation and migration of PGCs, 2) Increase in PGC number, 3) Reduction of chromosomal number by meiosis, and 4) Maturation of egg and sperm.

The correct migration of PGCs is crucial for the development of healthy reproductive organs. If the migration process fails, it can lead to abnormalities and potentially the formation of teratomas.

Teratomas can be mature, immature, or a mix of both. This refers to how well differentiated the cells are, and the tumor's potential for growth and spread. They can form in various locations, including the ovaries, testes, and tailbone.

Errors in PGC maturation and migration can lead to various abnormalities, including the development of teratomas.

Primordial germ cells in females that undergo meiosis to form oocytes (eggs).

Meiosis in females is accompanied by the development of a follicular complex and involves two divisions. The first division begins during fetal development and is completed after fertilization.

Primordial germ cells in males that undergo mitosis to produce more spermatogonia and eventually enter meiosis to form sperm.

In males, meiosis is asynchronous, meaning not all spermatogonia start and finish meiosis at the same time. Meiosis I takes 24 days, and Meiosis II occurs immediately after and takes 8 hours.

The final stage of spermatogenesis where spermatids transform into mature sperm cells, acquiring their characteristic shape and motility.

Somatic support cells in the seminiferous tubules of the testes; they provide nourishment and support to developing sperm cells and form the blood-testis barrier.

A barrier formed by Sertoli cells that separates the developing sperm cells from the immune system, preventing autoimmune responses against them.

Endocrine cells in the interstitial tissue of the testes that produce testosterone.

Highly coiled tubules within the testes where spermatogenesis occurs. They are divided into two compartments: the basal compartment and the adluminal compartment.

Sperm motility in the epididymis is driven by fluid pressure from the seminiferous tubules, ciliary movements, and contractile cells.

Sperm must be motile (able to move), recognize the oocyte (egg), and pass through the oocyte's membranes.

Sperm stays in the epididymis for 12 days, acquiring maturation and acquiring motility through the influence of the Factor Motility protein.

FMP triggers tubulin phosphorylation, increased calcium (Ca++) levels, and increased cAMP, ultimately regulating flagellar activity and leading to motility.

The head of the sperm becomes coated with glycoproteins, a crucial step in its maturation process.

Capacitation is the final stage of sperm maturation in the female genital tract. It involves the removal of glycoproteins from the sperm membrane, re-organizing lipids and proteins. This allows the sperm to penetrate the egg.

The acrosomal reaction involves the digestion of the zona pellucida (egg's outer layer), fusion of the sperm membrane with the egg's membrane, and the sperm head entering the egg.

The pituitary gland produces FSH and LH. FSH stimulates Sertoli cells, which produce ABP and AMH. LH stimulates Leydig cells, which produce testosterone.

ABP binds to testosterone and transports it to the seminiferous tubules, where it exerts a strong effect on spermatogenesis.

Testosterone is essential for spermatogenesis, with higher concentrations found in the adluminal part of the seminiferous tubules.

A structure released during ovulation containing the oocyte, zona pellucida, corona radiata, and sticky matrix.

A layer of cells surrounding the oocyte in the ovulated complex; part of the cumulus oophorus.

The fluid surrounding the oocyte, rich in hyaluronic acid, found in the antrum cavity.

The remaining structure in the ovary after ovulation, formed from theca and granulosa cells; produces progesterone and estrogen.

The process by which the corpus haemorrhagicum transforms into the corpus luteum.

Sertoli cells convert some testosterone into estrogens. These estrogens are then transported back to Leydig cells, along with a stimulating factor, in a paracrine fashion.

Inhibin, a hormone produced by Sertoli cells, travels through the bloodstream to the pituitary gland, where it inhibits the secretion of FSH (follicle-stimulating hormone).

A sperm count of less than 10 million spermatozoa per ml of sperm is a common cause of male infertility.

Besides low sperm count, other factors like motility dysfunction, abnormal sperm morphology, altered genome, medication/drugs, endocrine disorders, environmental factors, smoking, and genital duct obstruction can lead to male infertility.

Male infertility is found in 30-50% of couples experiencing involuntary childlessness.

Oogenesis is the process of oocyte (egg cell) maturation and development, which occurs alongside the maturation of the follicle, forming a functional unit.

There are three types of ovarian follicles: primordial follicles (the earliest stage), growing follicles (primary and secondary), and mature (Graafian) follicles.

Primordial follicles contain an oogonia (immature egg cell) surrounded by a layer of support cells called follicular cells.

All oogonia in primordial follicles enter meiosis I by the 5th month of gestation. These cells are then referred to as oocytes.

Follicular cells are somatic cells that surround the oocyte. They transform from squamous to simple cuboidal and then to stratified granulosa cells as the follicle grows.