begins with the start of pregnancy and continues until the birth of the child; the nine months of gestation is usually divided into three months time spans or trimesters.
occur during both the preimplantation period and the embryonic period, thus involves the first trimester
is the first period and takes place during the first week after conception. a females ovum is penetrated by and united with a male's sperm during fertilization.
the photographic analysis of a person's chromosomes is done by orderly arrangment of the pairs in a...
the rest of the first week during preimplantation peroid it is characterized by...
mitotic cleavage, blastocyst splits into smaller and more cells as it undergoes successive cell division
Mitosis that occurs during cell division is the...
self-duplication of the chromosomes of the parent cell and their equal distribution to daughter cell.
implantation means that the blastocyst becomes embedded in the...
endometrium, the innermost lining of the uterus on its back wall
after a week of cleavage the blastocyst consists of a layer of peripheral cells(________), and a small inner mass of embryonic cells(______)
trophoblast layer, embryoblast layer
the second period,_____ extends from the beginning of the second week to the end of the eighth week.
Physiological patterning processes include...
induction,proliferation,differentiation, morphogenesis, and maturation.
the action of one group of cells on another, leads to the establishment of the developmental pathway in the responding tissue and which is now considered to be compartmentalized.
a change occurs in the embryonic cells. are identical genetically but later become quite distinct structurally and functionally. thus the cells perform specialized functions.
all major tissue types,organs, and organ systems are formed during...
first week of the embryonic period
process of development of specific tissue structures of shape. occurs due to the migration of embryonic cells, which is followed by the inductive interactions of those cells.
process of maturation
of the tissue types and organs begins during the embryological period and continues later during the fetal period
A ______ is eventually developed from the blastocyst and appears as a flattened circular plate of bilayered cells.
bilaminar embryonic disc
prenatal organ that joins the pregnant female and developing embryo, develops from the interactions of the trophoblast layer and endometrial tissue.
placenta provides what kind of bloodborne substances
oxygen, carbon dioxide, nutritional and hormonal substances
cells move between the hypoblast and epiblast layer and then become
mesenchyme, and embryonic tissue
after mesoderm is created the epiblast layer is now considered _____ and the hypoblast layer is now considered______
areas without mesoderm,_____ and ____ fuse together preventing the migration of mesoderm between them
ectoderm and endoderm
Origin, morphology of the structure, future systemic tissues: Ectoderm
Epiblast layers, columnar, epidermis, sensory epithelium of the eyes, ears, nose, nervous system, and neural crest cells, mammary and cutaneous glands
Origin, morphology of the structure, future systemic tissues: Mesoderm
migrating cells from epiblast layer, varies, dermis, muscle, bone, lymphatics, blood cells,and bone marrow, cartilage, reproductive and excretory glands
Origin, morphology of the structure, future systemic tissues: Endoderm
Hypoblast, Cuboidal, respiratory and digestive system linings, liver, and pancreatic cells
Origin, morphology of the structure, future systemic tissues: Neural Crest Cells
migrating neuroectoderm, varies, components of nervous system pigment cells, connective tissue proper, cartilage, bone, and certain dental tissues
end of the 3rd week the mesoderm additionally differentiates and begins to divide on each side of the tube into 38 paired cuboidal segments of mesoderm called
somites give rise to most of the
skeletal structures of the head, neck trunk as well as associated muscles and dermis of skin.
4th week of development
the disc undergoes embryonic folding which places forming tissue types into their proper positions.
during the development of the _______four pairs of pharyngeal pouches will form form evaginations on the lateral walls lining the pharynx
during the 4th week the...
face and neck begin to develope with the primitive eyes,ears,nose, oral cavity, and jaw areas.
Fetal period process involves
physiological process of maturation of the individual tissue types and organs but also further proliferation differentiation and morphogenesis, as discussed before with the embryo.