Spermatozoa in the Female Tract: Transport, Capacitation, & Fertilization

Vocabulary practice flashcards covering sperm transport phases, barriers, capacitation, the acrosome reaction, fertilization, and insemination methods.

Retrograde Transport

The loss of sperm resulting from semen flowing backward out of the female reproductive tract post-insemination.

Neutrophils

White blood cells mobilized into the female reproductive tract following insemination to phagocytose foreign substances and sperm, preventing infection.

Rapid Phase

A phase immediately post-copulation during which sperm are transported rapidly to the oviducts, aided by muscular contractions and fluid motion.

Sustained Phase

A gradual transport phase of sperm through the female reproductive tract that is vital for sperm survival and fertilization.

Sialomucin

A low-viscosity cervical mucus that creates privileged pathways through the cervical grooves, facilitating the forward transport of motile sperm.

Sulfomucin

A high-viscosity cervical mucus located in the cervical lumen that entraps and washes out non-motile or abnormal sperm.

Capacitation

The biochemical maturation process that sperm undergo in the female reproductive tract (or in vitro) enabling them to bind to the oocyte and fertilize it; it is reversible.

Hyperactive Motility

An enhanced, vigorous, and non-linear swimming pattern acquired by capacitated sperm upon reaching the oviduct.

Zona Proteins (ZP1, ZP2, ZP3)

Glycoproteins comprising the zona pellucida of the oocyte that serve as binding sites for spermatozoa and trigger the acrosome reaction.

Acrosome Reaction

The fusion of the outer acrosomal membrane with the sperm plasma membrane, resulting in vesiculation and release of acrosomal enzymes necessary to penetrate the zona pellucida.

Vesiculation

The formation of microscopic pores or vesicles caused by multiple fusion points between the sperm plasma membrane and outer acrosomal membrane during the acrosome reaction.

Acrosin

An acrosomal enzyme that hydrolyzes zona pellucida proteins and aids sperm binding and penetration through the zona.

Proacrosin

The inactive zymogen precursor to acrosin that binds the sperm to the zona pellucida prior to being converted to acrosin for penetration.

Perivitelline Space

The fluid-filled region between the zona pellucida and the vitelline (plasma) membrane of the oocyte where sperm settle onto the oocyte microvilli.

Equatorial Segment

The specific region of the sperm head membrane that remains intact post-vesiculation and fuses with the oocyte plasma membrane.

Cortical Reaction

The exocytosis of cortical granules from the oocyte cytoplasm into the perivitelline space upon sperm-oocyte fusion to establish blocks against polyspermy.

Zona Block

Biochemical changes in the structure of the zona pellucida triggered by cortical granule release that prevent additional sperm from penetrating.

Vitelline Block

A membrane-level alteration of the oocyte plasma membrane that prevents the attachment and fusion of additional spermatozoa.

Polyspermy

The fertilization of an ovum by more than one sperm, an abnormal condition prevented by the zona block and vitelline block.

Male Pronucleus

The decondensed and enlarged sperm nucleus formed inside the oocyte cytoplasm after sperm entry, which pairs its chromosomes with the female pronucleus.

Glutathione

A tripeptide reducing agent present in the oocyte cytoplasm that reduces disulfide cross-links in sperm chromatin, driving nuclear decondensation.

Syngamy

The fusion of the male and female pronuclei following fertilization, restoring a diploid complement of chromosomes.

Induced Ovulators

Species (such as felids) that require copulatory stimulation, often via multiple copulations, to induce the LH surge necessary for optimal ovulation.

Transcervical Insemination

An artificial insemination technique in which an insemination pipette bypasses the cervix to deposit semen directly into the uterus (e.g., in cattle).

Intracervical Insemination

An artificial insemination technique in which semen is deposited directly into the cervix using an insemination pipette (e.g., in swine).

Intravaginal Insemination

An artificial insemination technique where semen is deposited directly into the cranial vagina (e.g., in dogs and cats).