Human Developmental Biology and Gametogenesis Flashcards

Vocabulary flashcards covering human developmental biology, spermatogenesis, spermiogenesis, oogenesis, female and male reproductive structures, and relevant hormones.

Human Developmental Biology

The field of study that examines the changes an organism undergoes, including formation, fertilization, and overall organismal development.

Embryology

The branch of medicine that studies the development of the organism.

Reproduction

The process involving the fusion of the ovum and spermatozoon, duplication of cellular material, and the role of the sexual organs (gonads).

Gonads

The primary sexual organs responsible for producing gametes.

Gametogenesis

The biological process by which the body develops sexual cells (gametes) to create a new organism, comprising spermatogenesis and oogenesis.

Testes

Paired male reproductive organs measuring $5\text{ cm}$ in length and $2.5\text{ cm}$ in diameter, covered by a white tunica albuginea and containing seminiferous tubules.

Sertoli Cells

Cells located inside the seminiferous tubules that provide nutrients, structural support, and protection to developing sperm, as well as regulate their movement.

Leydig Cells

Testicular cells responsible for secreting testosterone.

Testosterone

The hormone responsible for the formation and development of spermatozoa.

Mitosis

Cell division that produces daughter cells with genetic material identical to the mother cell.

Meiosis

Cell division resulting in daughter cells containing half the original chromosome count ($23$ chromosomes).

Spermatogenesis

The complete biological process of spermatozoa formation that begins between $11$ and $13$ years of age and lasts between $64$ and $72$ days.

Spermiogenesis

The final phase of spermatogenesis occurring within the seminiferous tubules, during which spermatids differentiate and mature into functional spermatozoa.

Golgi Phase

The first phase of spermiogenesis characterized by the formation of the acrosomic vesicle.

Cap Phase (Fase de casquete)

The phase of spermiogenesis where the acrosome develops and covers the nucleus, forming a protective cap.

Acrosome Phase

The phase of spermiogenesis during which the flagellum extends, the nucleus flattens, and the intermediate piece containing mitochondria is formed.

Maturation Phase (Spermiogenesis)

The final stage of spermiogenesis that produces a complete spermatozoon composed of a head, intermediate piece, and tail.

Acrosome

An organelle structure located at the head of the spermatozoon that forms a protective covering over the nucleus.

Estrogens

The principal female hormones responsible for regulating the menstrual cycle.

Progesterone

A female sex hormone that prepares the uterus for pregnancy.

Relaxin

A hormone that relaxes pelvic muscles and assists in the processes of childbirth.

Uterine Cervix (Cuello uterino)

The lower part of the uterus serving functions in protection, immunology, sperm transport, exit of menstrual flow, and childbirth.

Uterus

The internal female organ in which the embryo develops during pregnancy.

Ovaries

Female internal gonads that descend from the pelvic inlet during the $3\text{rd}$ month of intrauterine life to produce mature ova and secrete hormones.

Oogonium (Ovogonia)

A diploid ($2n$) precursor cell containing $46$ chromosomes that initiates oogenesis.

Primary Oocyte

A diploid cell ($2n$) with $46$ chromosomes formed from an oogonium that enters a dormant diplotene state until reactivated at puberty.

Secondary Oocyte

A haploid cell ($n$) containing $23$ chromosomes produced alongside the first polar body following Meiosis I.

Polar Body

A non-functional haploid cell produced during meiotic divisions in oogenesis; a total of $3$ polar bodies are ultimately formed and degenerate.

Prenatal Stage of Oogenesis

The phase of female gamete development occurring exclusively before birth during embryonic development, divided into multiplication, growth, and maturation phases.

Multiplication Phase (Oogenesis)

The prenatal phase during which oogonia multiply; no new oogonia form after birth, and millions degenerate before adulthood.

Growth Phase (Oogenesis)

The prenatal phase occurring by the end of the $5\text{th}$ month where the oogonium increases in size and is surrounded by flattened follicular cells.

Diplotene State

The arrested stage of Meiosis I during the prenatal maturation phase in which primary oocytes remain dormant until puberty.

Postnatal Stage of Oogenesis

The stage of female gametogenesis beginning at puberty when hormonal secretion reactivates the primary oocyte to resume meiosis.

Luteinizing Hormone (LH)

The hormone responsible for triggering the reinitiation of meiosis in the secondary oocyte during the postnatal stage.