Male Infertility and Sperm Analysis

Reactive oxygen species (ROS) are molecules that can damage cells. While they are needed for some sperm functions, excess ROS causes problems like poor sperm movement, abnormal shape, DNA damage, and cell death.

A process used to freeze and preserve sperm cells, usually involving cooling, freezing, and thawing with special chemicals.

A rapid cooling technique for preserving sperm cells, which prevents ice crystal formation and improves sperm survival by avoiding the use of freezing agents.

This test mimics the natural female reproductive tract to assess sperm movement and viability.

This process prepares sperm for fertilization. Changes occur within the uterus or oviduct, enabling sperm to interact with the egg.

DNA damage in sperm, which can affect fertility. It's not easily repaired by sperm, but the egg can try to fix it.

This process is a series of events involving several factors, from sperm being deposited in the vagina through their journey to the oviduct.

This part of the female reproductive tract is the meeting place for the sperm and egg.

The process of converting food into usable energy for cells. Includes breaking down carbohydrates, fats, and proteins.

A type of metabolism that uses oxygen to produce energy. More efficient but slower.

A type of metabolism that doesn't require oxygen. Less efficient but faster.

The process of breaking down fats to release energy. Particularly important during later stages of development.

A hormone that enhances the uptake of glucose by cells.

Hormones that stimulate growth and metabolism.

The stage of development before implantation in the womb. The embryo relies on maternal nutrients.

The stage of development after implantation in the womb. The embryo's metabolic demands increase.

The cycle that breaks down glucose to produce energy. Requires oxygen and occurs in mitochondria.

The process of breaking down glucose without oxygen. Occurs in the cytoplasm.

The process of rapid cell division in the early embryo.

The stage where the embryo forms a fluid-filled cavity called the blastocoel.

The fluid-filled cavity inside the blastocyst.

The outer layer of the blastocyst, which will eventually develop into the placenta.

The inner cell mass of the blastocyst, which will develop into the embryo itself.

A series of changes that sperm undergo after ejaculation, enhancing their ability to fertilize an oocyte. This process involves removal of glycoprotein coats and changes in the sperm membrane, leading to increased motility and the ability to undergo the acrosome reaction.

The release of enzymes from the acrosome (a cap-like structure on the sperm) upon reaching the zona pellucida (the outer layer of the oocyte). These enzymes digest the zona pellucida, allowing the sperm to penetrate.

The fusion of the sperm and oocyte membranes, allowing the sperm nucleus to enter the oocyte and create a zygote.

A reaction triggered by the sperm entering the oocyte, where cortical granules release their contents into the perivitelline space, modifying the zona pellucida to prevent further sperm entry, ensuring fertilization by only one sperm.

The completion of the second meiotic division of the oocyte upon fertilization, resulting in the formation of a second polar body and the mature ovum, contributing half of the genetic material to the zygote.

The fusion of the sperm nucleus and the oocyte nucleus, resulting in a diploid cell containing genetic material from both parents. This marks the beginning of the development of the embryo.

The outer layer of the oocyte, composed of glycoproteins (ZP1, ZP2, ZP3, ZP4 in humans). ZP3 and ZP4 are crucial for sperm binding and triggering the acrosome reaction.

The process by which the blastocyst (the early embryo) escapes from the zona pellucida, exposing the trophoblast (outer layer responsible for implantation) for interaction with the uterine lining.

The initial, loose contact between the blastocyst and the endometrial surface, occurring during the 'receptive window' (6-10 days post-ovulation) when the uterine lining is prepared for implantation.

The firm attachment of the blastocyst to the endometrium through specific cell surface receptors (integrins, cadherins, selectins).

Projections on the endometrial surface that increase its area and help absorb fluid, bringing the blastocyst closer for implantation. These are regulated by progesterone and estrogen.

The invasion of the endometrium by trophoblast cells, establishing connections between the mother and fetus.

Proliferative precursor cells within the trophoblast that contribute to its growth.

Invasive, multinucleated cells arising from the cytotrophoblast, responsible for digesting the maternal extracellular matrix for deep embedding of the embryo into the uterine lining.

The period of time during early development when the epigenome undergoes significant changes, primarily through methylation and demethylation.

The sum of all the epigenetic modifications to DNA and chromatin, influencing gene expression.

The phase in the menstrual cycle after ovulation. The ruptured follicle turns into the corpus luteum, which produces progesterone. If pregnancy doesn't occur, the corpus luteum degenerates into the corpus albicans.

The shedding of the uterine lining due to low progesterone and estrogen levels. It marks the beginning of a new menstrual cycle.

The phase where the uterine lining regenerates and thickens under the influence of estrogen. It prepares the uterus for a potential pregnancy.

The phase where the endometrium is prepared for implantation by progesterone. Glands secrete nutrients for a fertilized egg.

Hormones produced by the ovaries responsible for regulating the menstrual cycle and influencing cell growth and activity in the uterus.

The hormone that prepares the uterus for pregnancy by promoting endometrial growth and the expression of progesterone receptors.

The hormone that supports gland secretion after ovulation and allows for the implantation window by creating a receptive environment for the embryo.

A key component of the immune system that aids in embryo implantation by stimulating the production of other cytokines and preparing the endometrium.

Hormone secreted by the embryo that plays a role in implantation by affecting both the embryo and the maternal tissues.

A protein that acts as a barrier during the early stages of pregnancy but is reduced locally at the implantation site to allow the embryo to attach.

A protein regulated by progesterone that supports adhesion of the embryo to the uterine lining.

The process where the uterus undergoes changes to become receptive for implantation.

The stage where the fertilized egg rapidly divides, forming a solid ball of cells called a morula.

The tight junctions between the cells in the morula that are essential for subsequent differentiation and polarization of cells.

The fluid-filled cavity formed inside the morula, transforming it into a blastocyst.

A temporary gland that forms from the follicle after ovulation. It produces progesterone, which prepares the uterine lining for pregnancy.

The cycle of changes in the uterine lining (endometrium) that occur during a menstrual cycle. It involves three phases: menstrual, proliferative, and secretory.

Hormone produced by the implanted embryo, which maintains the corpus luteum, ensuring a healthy pregnancy.

The period of time (6-10 days after fertilization) when the endometrium is most receptive for implantation. It is critical for successful pregnancy.

The uterine lining in a prepared state to receive a fertilized egg (blastocyst), essential for successful implantation. It occurs during the luteal phase.

The process by which the ovary stops ovulating and producing hormones, ending menstruation. This marks the end of a woman's reproductive years.

Hormone therapy used to replace declining hormones in women going through menopause. It helps relieve symptoms and prevent osteoporosis. However, there are potential risks.

A cluster of cells found at one pole of the blastocyst. It's the source of embryonic stem cells and eventually develops into the embryo proper and some extraembryonic tissues.

The outer layer of cells surrounding the blastocyst. It plays a critical role in implantation into the uterine wall and develops into part of the placenta.

A glycoprotein layer that surrounds the oocyte and early embryo. It protects the embryo and prevents fertilization by multiple sperm.

The transformation of endometrial stromal fibroblasts into secretory decidual cells. It happens independently of pregnancy and is driven by progesterone.

A process that occurs in the luteal phase of the menstrual cycle, independent of pregnancy. It is driven by progesterone and involves changes in the endometrial lining.

Stimulates proliferation and differentiation of uterine epithelial cells.

Stimulates stromal cells, crucial for sustaining pregnancy until the placenta takes over (around 12 weeks).

A hormone synthesized by trophoblast cells. It prolongs progesterone secretion, which is essential for early pregnancy.

A major limiting factor in assisted reproductive technology (ART) success. It can be caused by factors in the endometrium, the embryo, or both.

A low sperm count, which can affect male fertility.

Poor sperm motility, meaning the sperm can't move properly.

Abnormal sperm morphology, meaning the sperm have irregular shapes.

The absence of sperm in the semen, which can make it impossible to conceive naturally.

A procedure to retrieve sperm from the epididymis, a coiled tube near the testicle.

A procedure to retrieve sperm directly from the testicle.

The Hypothalamic-Pituitary-Ovarian (HPO) axis is a complex system of hormones and organs that control female reproductive function, encompassing the menstrual cycle, ovulation, and fertility.

The hypothalamus is the command center of the HPO axis, responsible for releasing gonadotropin-releasing hormone (GnRH), which triggers the pituitary gland to release its own hormones.

The pituitary gland, located at the base of the brain, responds to GnRH by releasing follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which directly influence the ovaries.

Follicle-stimulating hormone (FSH) is responsible for stimulating the growth and maturation of ovarian follicles, which contain developing eggs. It also plays a role in regulating the menstrual cycle.

Luteinizing hormone (LH) triggers ovulation, the release of a mature egg from the ovary. It also stimulates the production of estrogen and progesterone by the ovaries.

The HPO axis relies on a delicate balance of hormones and feedback mechanisms. Estrogen and progesterone produced by the ovaries can negatively regulate the hypothalamus and pituitary, controlling the release of GnRH, FSH, and LH.

When estrogen levels reach a certain threshold, they can positively feedback on the pituitary, causing a surge in LH and triggering ovulation.

Disruptions to the HPO axis, such as stress, hormonal imbalances, or certain medical conditions, can lead to irregular menstrual cycles, anovulation, fertility issues, or delayed puberty.

The ovarian cycle encompasses the maturation of ovarian follicles, the release of an egg during ovulation, and the subsequent hormonal changes that prepare the body for potential pregnancy.

Primordial follicles are immature follicles and the earliest stage of follicular development. They contain primary oocytes surrounded by a single layer of granulosa cells.

During follicular development, follicles progress from primordial to primary and then to antral stages. Antral follicles are characterized by a fluid-filled cavity called the antrum.

As follicles mature, they secrete increasing amounts of estrogen, which leads to a surge in LH. This LH surge triggers ovulation.

The LH surge causes the mature follicle to rupture, releasing the secondary oocyte into the fallopian tube, where fertilization can occur.

Estrogen, produced by the ovaries, plays a crucial role in the regulation of the menstrual cycle, secondary sexual characteristics, and bone health.