Reproductive System Flashcards
Basic development of an egg
Diploid cell in embryo (2n) undergoes meiosis 1
Primary oocyte (2n) arrested in prophase 1
At menarche completion of meiosis 1 forms polar body and secondary oocyte (n) arrested at metaphase of meiosis 2 and waits in the Fallopian tube
Entry of sperm triggers meiosis 2 completion to form second polar body and ovum (n)
What a video about the menstrual cycle graph as it is often on mcat
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What happens when the cell membranes of the sperm and oocyte fuse
Triggers a cortical reaction which causes chemical changes in the oocyte preventing fusion of multiple sperm
Oocyte also goes through its second meiotic division to become an ovum
Ovum and sperm fuse forming diploid zygote
Totipotent stem cells
Can become any cell , placenta or embryo
Pluripotent stem cells
Can become any 1 of 3 germ layers
Multipotent stem cells
Can replace cells of particular lineage
What is gastrulation
Blastocyst transforms into gastrula when embryo becomes 3 layered
Gives rise to 3 primary germ layers
What develops from the ectoderm
Integumentary - skin
Lens of eyes
Nervous system
What develops from the endoderm
Epithelial lining of digestive/ respiratory tracts Liver Pancreas Thyroid Bladder
What structures develop from mesoderm
Muskuloskeletal Circulatory Excretory Connective Digestive systems
Dual embryonic origin of adrenal gland
Cortex - mesoderm
Medulla - ectoderm
Just worry about understanding not memorizing
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