What is the difference between determinate and indeterminate cleavage?
Determinate cleavage refers to cell division that results in cells having definitive lineages; that is, at least one daughter cell is programmed to differentiate into a particular cell type.
Indeterminate cleavage refers to cell division that results in cells that can differentiate into any cell type (or a whole organism)
From zygote to gastrula, what are the various stages of development?
Zygote > 2-. 4-, 8-, and 16-cell embryo > Morula > Blastula (blastocyst) > Gastrula
During which stage of development does implantation occur?
Blastula (blastocyst) stage
What are the primary germ layers and what organs are formed from each?
Ectoderm: Integument (including the epidermis, hair, nails, and epithelia of the nose, mouth, and anal canal) , lens of the eye, nervous system (including adrenal medulla), inner ear
Mesoderm: Musculoskeletal system, circulatory system, excretory system, gonads, muscular and connective tissue layers of the digestive and respiratory systems, adrenal cortex
Endoderm: Epithelial linings of digestive and respiratory tracts, and part of the liver, pancreas, thyroid, bladder, and distal urinary and reproductive tracts
What is induction and how does it influence development?
Induction is the process by which nearby cells influence the differentiation of adjacent cells. This ensures proper spatial location and orientation of cells that share a function or have complementary functions.
What tissues do neural crest cells develop into?
Neural crest cells become the PNS (including the sensory ganglia, autonomic ganglia, adrenal medulla, and Schwann cells) as well as specific cell types in other tissues (such as calcitonin-producing cells of the thyroid, melanocytes in the skin, and others)
What is the difference between determination and differentiation?
Determination is the commitment of a cell to a particular lineage.
Differentiation refers to the actual changes that occur in order for the cell to assume the structure and function of the determined cell type.
What are the three types of potency?
Totipotency
Pluripotency
Multipotency
What lineages can a Totipotent cell type differentiate into?
Any cell type in the developing embryo (primary germ layers) or in extraembryonic tissues (amnion, chorion, placentra)
What lineages can a Pluripotency cell type differentiate into?
Any cell type in the developing embryo (primary germ layers)
What lineages can a Multipotency cell type differentiate into?
Any cell type within a particular lineage (for example, hematopoietic stem cells)
What are the four type of cell-cell communication?
Autocrine (the signal acts on the same cell that secreted it)
Paracrine (the signal acts on local cells)
Juxtacrine (a cell triggers adjacent cells through direct receptor stimulation)
Endocrine (the signal travels via the bloodstream to act on cells at distant sites)
What is the difference between apoptosis and necrosis?
Apoptosis is programmed cell death and results in contained blebs of dead cell that can be picked up and digested by other cells.
Necrosis is cell death due to injury and results in spilling of cytoplasmic contents.
What is the oxygenation status of the blood in the umbilical arteries?
The umbilical arteries carry deoxygenated blood.
What is the oxygenation status of the blood in the umbilical vein?
The umbilical vein carries oxygenate blood.
What are the three fetal shunts?
Foramen ovale
Ductus arteriosus
Ductus venosus
Foramen ovale:
What vessels or heart chambers does the connect?
What organ does this shunt bypass?
Connects right atrium to left atrium
Lungs
Ductus arteriosus:
What vessels or heart chambers does the connect?
What organ does this shunt bypass?
Connects pulmonary artery to aorta
Lungs
Ductus venosus:
What vessels or heart chambers does the connect?
What organ does this shunt bypass?
Connects umbilical vein to inferior vena cava
Liver
What are some of the key developmental features of the 1st trimester?
Organogenesis occurs
(development of hart, eyes, gonads, limbs, liver, brain)
What are some of the key developmental features of the 2nd trimester?
Tremendous growth occurs
Movement begins
The face becomes distinctly human
Digits elongate
What are some of the key developmental features of the 3rd trimester?
Rapid growth and brain development continue
Transfer of antibodies to the fetus
What occurs in each of the three phases of birth?
1st: cervix thins out and the amniotic sac ruptures
2nd: uterine contractions, coordinated by prostaglandins and oxytocin, result in birth of fetus
3rd: placenta and umbilical cord are expelled.