Lecture 3 8/28/23 Flashcards
How are metastasizing cancers named?
they keep the name of the original cancer
What is a teratoma?
-a tumor with elements of all three germ layers
-often arise in gonads due to increased levels of undifferentiated cells
What is the notochord?
-tube of mesoderm
-becomes part of vertebral column
-runs full length of body
What is the neural tube?
-ectoderm over the notochord
-becomes neuroectoderm
-pinches off to form neural tube, which becomes brain and spinal cord
What is the lumen?
the space inside a tubular structure (such as the neural tube)
What does the lumen of the neural tube contain?
cerebrospinal fluid
What is spina bifida?
failure of the neural tube to fully close?
What are the types of spina bifida?
-occult: skin still closes despite neural tube not properly closing
-classic: skin over the neural tube does not fully close
What are neural crest cells?
-cells that emerge during the pinching off of the neural tube
-not classified into the germ layers
What do neural crest cells become?
-cells of the nervous system
-melanocytes
-adrenal medullary cells
Why is it bad if neural crest cells fail to migrate?
-regions of the body can be lacking the cells that neural crest cells differentiate into
-can cause problems in development that can be fatal
How do we name tumors that arise from neural crest cells, since they do not fit into any of the germ layers?
-benign tumors: name of cell + -cytoma
-malignant tumors: malignant + name of cell + -oma
What does it mean for something to be multi-focal?
there are multiple spots (typically tumors)
What are the 4 extra-embryonic membranes of the placenta?
-amnion
-yolk sac
-allantois
-chorion
What is the chorioallantoic?
a fusion of the allantois and chorion membranes