1A Foundations 1 - Embryology Flashcards
Sperm + Oocyte = ?
Zygote
Next step after zygote?
Morula (meaning = Mulberry)
Next step after morula?
Blastocyst
Parts of a blastocyst?
Trophoblast + Inner cell mass
On what day does implantation into the endometrium happen happen?
Day 6
What does the trophoblast turn into (finally)?
Placenta
What does the inner cell mass turn into (finally)?
Fetus
What does the trophoblast turn into?
Cytotrophoblast
Syncytiotrophoblast
What does the Syncytiotrophoblast make?
hCG. This hormone tell the corpus luteum that a successful implantation has taken place and thus prevents menstruation.
What does the Cytotrophoblast make?
Cells
What does the corpus luteum secrete? And what is the effect?
Progesterone.
Maintains endometrial lining and thus prevents menstruation
The next step after formation of cytotrophoblasts and syncytiotrophoblasts?
Formation of Chorion with villi (that grows into the maternal part of the placenta)
What structure does the Chorion with villi make up?
Fetal part of the placenta
What is the name of the maternal component of the placenta and what is it made up of?
Decidua basalis.
Endometrium
When is the embryonic phase?
Between week three and eight
What is neurulation?
Formation of a neural tube
When are the three germ layers produced?
At the end of the third week
Where is the notochord? And what does it give rise to?
Mesoderm.
Gives rise to overlying ectoderm to differentiate into neural plate
What does the neural plate give rise to? And which germ layer do they arise from?
Neural tube and neural crest cells. They arise from Ectoderm.
What neural crest derivatives are found in the Peripheral nervous system?
Autonomic NS (Vagus nerve, Sympathetic ganglia), Dorsal root ganglia, sensory nerves, Schwann cells, Cranial nerves
What neural crest derivatives are found in the Ear?
Ossicles of the middle ear (Malleus, Incus, Stapes)
What neural crest derivatives are found in the Eye?
Anterior chamber (cornea, sclera, ciliary muscle, iris pigment cells)
What neural crest derivatives are found in the Adrenal gland?
Chromaffin cells of the adrenal medulla
What neural crest derivatives are found in the Mouth?
Odontoblasts
What neural crest derivatives are found in the Heart?
Aorticopulmonary septum (spiral septum)
What neural crest derivatives are found in the Digestive system?
Enteric nervous system, celiac ganglion, enterochromaffin cells
What neural crest derivatives are found in the Thyroid?
Parafollicular (C) cells
What neural crest derivatives are found in the Skin?
Melanocytes
What does the neural tube become?
Brain and spinal cord
What does chromaffin cells make?
Catecholamines: Epinephrin and norepinephrin
What does odontoblasts give rise to?
Dentin of teeth
What does enterochromaffin cells secrete?
Serotonin
What does the parafollicular cells secrete?
Calcitonin
What does neuroectoderm give rise to?
Neurons of brain and spinal cord Oligodendrocytes Ependymal cells Optic nerve Retina Pineal gland Post pituitary (neurohypophysis)
What is the function of oligodendrocytes?
Myelinate the CNS neurons
What is the function of Astrocytes?
Support the neurons of the CNS
Function of Ependymal cells?
Secrete CSF
Why is surface ectoderm not neurological?
Did not get influenced by the notochord
What does the Surface ectoderm give rise to?
"Head structures" Lenses of the eye Olfactory epithelium Inner ear Ant. pituitary Oral epithelium Salivary glands Epidermis Sweat glands Mammary glands Anal canal distal to pectinate line
What does the endoderm give rise to?
Gi tract (esophagus to pectinate line) Liver, Gallbladder, Pancreas Lungs Thymus Parathyroid glands Follicular cells of thyroid Epithelium of bladder/urethra and lower 2/3 of vagina
What does the mesoderm give rise to?
Bone muscle bone marrow blood cells heart blood vessels lymphatics Upper portion of vagina Kidneys, adrenal cortex Gonads Dermis of skin
