Flashcards in Preimplantation, Emryonic, Fetal Deck (31)
Day 4- 8 weeks
8 weeks- birth
Mitosis- 1 parents cells divides and creates 2 daughter cells with same genetic complement.
Meiosis- creates daughter cells with half the # of chromosomes compared to the parent cell.
Union of sperm and ovum
Newly formed cell with diploid # of chromosomes
*different from parent, undergoes meiosis
Solid mass of cells
Fluid filled collection of cells
Blastocyst to embryo stage-
From 2nd to 8th week
Cytodifferentation- what are the 2 types
Still more receptors-
Cells will die
Cell receives hormone or receptor stimulation from a substance produced by itself
cell receives hormone or receptor stimulation from a substance produced by a different cell
Types of growth:
Programmed cell death.
*babies have webbed hands before birth. Aptosis kills those cells and cause fingers.
1 group of cells starting development of another cellular group.
Types of growth:
More cells (a lot of)
Additional outer layers of cells *outside ball
occurs deep within a tissue *inside ball
Development of different tissues.
Development of different form = structure or shape
Process where tissues evolve into more complex structures. *shape very specific (complex) ex-enamel
Ongoing physiological processes which impacts the final form/function.
Blaminar embryonic disc-
Forms directly from the blastocyst
*epiblast layer, hypoblast layer
Provides nourishment until placenta is established.
Outer layer, highly invasive layer
Formed from migration of epiblast.
*Complete migration=trilaminar disc
Epiblast to ectoderm
Mesenchymal to mesoderm
Hypoblast to endoderm
From proliferation of ectoderm at the mid-line or the disc
Neural crest cells:
Neural crest cells-
Trilaminar embryonic disc-
Arise from proliferation of ectoderm adjacent to primitive streak
Primitive streak matures into notocord who supports the primitive embryo
Skin, CNS & PNS, hair, nails, enamel, and lining of oral cavity
Bone, muscles, circulatory and reproductive systems, internal organs, Dentin, pulp, and cementum.
Lining of respiratory passages, glandular organs, and digestive system.
Will cause endoderm to become the deepest tissue. Ectoderm will be most superficial tissue.
Orientation of tissues-
Disc is now tubular in shape. Only 2 membranes have only 2 tissue layers: buccopharyngeal and cloacal
Buccopharyngeal- will become the primitive mouth
Cloacal- will become the anus
Neural tube development-
Anterior end- gives rise to brain
Posterior end- gives rise to the spinal cord
What is it and what causes it(4)?
Problems in development, interacts with differentiation *making of a monster
1. Infectious disease (rubes,German measles)
4. Nutritional deficiencies
General steps in development (3)
1. Initiation *start --> simple mitosis
3. Differentiation *different types of tissues
Stomodeum or stomatodeum (3)
1. Primitive mouth
2. Disintegration-oropharyngeal membrane joins primitive mouth and primitive pharynx
3. Will give rise to the mouth