Early Embryogenesis Flashcards
defined as the state of embryonic development marked by rearrangement of the cells of the embryonic disk
Gastrulation
During gastrulation, three parallel tissues called germ layer are formed. What are these?
Ectoderm
Mesoderm
Endoderm or Entoderm
Why is gastrulation considered a critical period of embryonic development?
Because during this period the potentials of a particular tissue to develop into organs begin to be restricted. Also, during this period developing organs become more sensitive to external agents (teratogens) which produce birth defects.
When does gastrulation occur in primates and domestic animals?
It starts at the end of the second week of gestation. Meanwhile in laboratory animals such as guinea pigs and rabbits, start several days earlier.
What do you call the cavity of the hypoblast tube?
Archenteron or Primitive Gut
epiblast cells delaminate from the inner surface of the embryonic disk and expand beneath the trophoblast to form a thin continuous sheet lining the interior of the blastocyst and forming a tube of hypoblast inside a tube of trophoblast
Mammalian Blastula Stage
a relatively small area of the blastocyst when compared to the extraembryonic trophoblast
Formation of the primitive streak
study of the prenatal development of an organism
Embryology
It is the study of the growth and differentiation of an organism from zygote into a highly complex and independent living being like its parents.
Embryology
formation of the body structures and organs
Embryogenesis and Organogenesis
increase in the number of cells as a result of cell growth and cell
division
Cell Proliferation
result of cells expressing some genes and suppressing others within
a common genome
Cell Differentiation
branch of embryology that deals with the causes and results of abnormal development or congenital malformation
Teratology
an abnormality that arises during prenatal development due to hereditary or environmental factors
Congenital Malformation or Congenital Defect
a developmental disturbance that involves an organ or a portion of
an organ
Anomaly
a developmental disturbance that involves several organs and causes great distortion of the individual
Monstrosity
cell division that results in two daughter cells having diploid number of chromosomes that are identical to the parent cell
Mitosis
sheet of cells which gives rise to all tissues and organs of the body
Germ Layer
What are some functions of Ectoderm?
Ectoderm gives rise to the epidermis of the skin, nervous
tissues and some skeletal and connective tissues of the head.
What are some functions of Mesoderm?
It gives rise to most of the skeletal and muscular tissues, the heart and blood vessels and the urogenital system (kidney, ovary and testis).
The germ layer form the lining of the digestive (stomach, intestine) and respiratory (trachea, bronchus) tracts.
Endoderm
single layer or several layer of cells that rest on a basal lamina and are closely joined together at their lateral surfaces
Epithelium
lines blood vessels
Endothelium
lines body cavities and covers the surfaces of visceral organs
contained in these cavities
Mesothelium
a group of loosely and irregularly arranged cells separated by a large amount of extracellular matrix
Mesenchyme
a tissue which connects and support other tissues of the body
Connective tissue
process of development and maturation of sex cells called gametes
Gametogenesis
mature reproductive cells capable of fertilization
gametes
What are the three functions the gametes must accommodate?
a. survive in environment different from that of the gonad
b. recognize homologous cells of the other gender and participate in events related to fertilization
c. provide sufficient genetic and cytoplasmic materials to support development of a new organism
refers to the development and maturation of female gamete (ovum)
Oogenesis
refers to the maturation and development of male gametes (spermatozoa)
Spermatogenesis
After the primordial cells migrate to the embryonic gonad, the primordial cells differentiates into […] in order to undergo mitosis.
Spermatogonia (Diploid Cells)
What are the specialized tubules inside the testes where the development of spermatozoa are formed?
Seminiferous tubules
Increase production of these hormone stimulates spermatogonia to enter Meiosis I.
Testosterone
When does the primary spermatocytes complete Meiosis I to give rise to two secondary spermatocytes?
During sexual maturity.
What process does the secondary spermatocytes undergo in order to give birth to spermatids?
Meiosis II
The transformation of spermatids to become spermatozoa.
Morphogenesis or Spermiogenesis
It is where sperm cells are stored and continue to mature until released to the outside environment.
Epididymis
indicates the location of the nucleus and cytoplasm of the zygote
embryonic disk (blastodisk)
develops during the 2nd week following the rupture of the zona pellucida
Blastocyst
It is the surface cells of blastocyst.
Trophoblast
fluid-filled cavity formed during blastulation stage
blastocoel
During early blastula stage, trophoblasts overlying the inner cell mass eventually degenerate, exposing the inner cell mass which is now called the […]
embryonic disk
True or False.
During early stage of blastula stage, zona pellucida ruptures and the blastocyst hatches and elongates.
False. It happens during late blastula stage.
defines the longitudinal axis of the embryo and indicates the start of germ layer formation
primitive streak
It is the fifth and last stage of early embryonic development
Neurulation
