Medical Embryology BIO 4880 Lecture Notes

This set of flashcards covers key terms and concepts related to medical embryology, including gametogenesis, fertilization, chromosomal abnormalities, and various genetic disorders.

Gametogenesis

The process of formation and development of specialized generative cells (gametes) from bipotential primordial germ cells.

Fertilization

The union of an egg and sperm that occurs primarily in the ampulla of the fallopian tube, leading to the formation of a zygote.

Zygote

The fertilized egg resulting from the union of an egg and sperm, initiating embryonic development.

Primordial Germ Cells (PGC)

Cells that originate in the bilaminar disc during the second week and migrate to the yolk sac, eventually leading to gametogenesis.

Diploid

A cell containing two complete sets of chromosomes, 46 in humans (23 pairs), consisting of autosomes and sex chromosomes.

Gametes

Specialized reproductive cells (sperms and oocytes) that are haploid, meaning they contain only one set of chromosomes.

Meiosis

A type of cell division that reduces the chromosome number by half, producing gametes from germ cells.

Spermatogenesis

The process of male gamete development that begins at puberty under the influence of hormones.

Oogenesis

The process of female gamete development which includes the formation of primary oocytes and subsequent maturation into secondary oocytes.

Down Syndrome

A chromosomal disorder caused by an extra copy of chromosome 21, often resulting from nondisjunction during oocyte formation.

Klinefelter Syndrome

A condition in which males have an extra X chromosome (XXY), often resulting in infertility and other physical traits.

Turner Syndrome

A condition in females characterized by the presence of a single X chromosome (45, XO), leading to developmental issues.

Aneuploidy

A condition in which the number of chromosomes is not a multiple of the haploid number, often leading to genetic disorders.

Crossing over

The exchange of chromatid segments between homologous chromosomes during meiosis that contributes to genetic diversity.

Synapsis

The pairing of homologous chromosomes during meiosis, where they can exchange genetic material.

Zona Pellucida

A glycoprotein layer surrounding an oocyte that is essential for sperm binding and fertilization.

Cumulus Oophorus

A mound of granulosa cells that surrounds a developing oocyte in a mature follicle.

Chromosomal mutations

Alterations in chromosome structure including deletions, duplications, or rearrangements that can lead to genetic disorders.

Nondisjunction

The failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to aneuploidy.