Embryology Flashcards

Flashcards based on embryology lecture notes.

Embryology

The study of an organism's development from fertilization of the ovum to the fetus stage.

Embryo

Juvenile stage prior to birth or hatching; features characteristic of adults of the species are not present at all.

Fetus

Juvenile stage prior to birth or hatching, where features characteristic of the species are present, but may not be in the fully.

Fetology

The branch of medicine concerned with the study, diagnosis, and treatment of the fetus, especially within the uterus.

Ontogeny

An organism’s own personal individual embryonic development (Also the life cycle of the individual.)

Phylogeny

The very slow development that a species as a whole experiences as natural selection occurs.

OPCTP

Common ancestry among all vertebrates has given us (vertebrates) the genes needed to build complex embryonic structures; these genes are shared among all vertebrate life forms.

Preformation Hypothesis

The idea that gametes carried within them little, tiny people just ready to grow in the uterus. Popular 1650-1850s- “Homunculus.”

Sexual Reproduction

Meiosis, gamete formation, and fertilization – Offspring show genetic variation.

Asexual Reproduction

Single parent produces offspring – Offspring are genetically identical.

Ectoderm

Epidermis of skin and its derivatives (including sweat glands, hair follicles) Epithelial lining of mouth and rectum Sense receptors in epidermis Cornea and lens of eye Nervous system Adrenal medulla Tooth enamel Epithelium or pineal and pituitary glands.

Mesoderm

Notochord Skeletal system Muscular system Muscular layer of stomach, intestine, etc. Excretory system Circulatory and lymphatic systems Reproductive system (except germ cells) Dermis of skin Lining of body cavity Adrenal cortex.

Endoderm

Epithelial lining of digestive tract Epithelial lining of respiratory system Lining of urethra, urinary bladder, and reproductive system Liver Pancreas Thymus Thyroid and parathyroid glands.

Blastomeres

Smaller cells created when cleavage partitions the cytoplasm of one large cell.

Morphogenesis

Orderly changes result in specialized tissues and early organs, Cells migrate, Whole sheets of cells expand and fold and Programmed cell death sculpts body parts.

Embryonic Induction

Development fate of embryonic cell lineages changes upon exposure to gene products from adjacent tissues, Cells behave as if they have positional memory, Demonstrated experimentally by transplanting embryonic cells.

Morphogens

Dorsal lip (embryonic signaling center) Influence’s other cells by producing a morphogen Diffusion of morphogen creates gradient that influences differentiation; influences which genes are turned on or off.

Semen

Sperm + Secretions Secretions from epididymis aid sperm maturation Seminal vesicle secretes fructose and prostaglandins Prostate gland secretions buffer pH in the acidic vagina Bulbourethral gland secretes mucus.

Spermatogenesis

Spermatogonium (2n) divides by mitosis to form primary spermatocyte (2n) Meiosis produces haploid spermatids Spermatids mature to become sperm.

Sertoli cells

Line the seminiferous tubules –Nourish the developing sperm.

Leydig cells

Lie between the seminiferous tubules – Secrete testosterone.

HCG

Hormone secreted by the blastocyst Stimulates corpus luteum to keep making progesterone and estrogens This maintains endometrium, prevents menstruation.