midterm 4 Flashcards
current
measure of number of charged particles moving
voltage
the difference in electrical potential between two points; the force that pushes charged particles against a resistance
microelectrode
a device frequently made from a glass capillary tube that can be inserted into a cell’s plasma membrane to detect voltage
resting potential
the voltage observed across the plasma membrane of cells, for animals is negative inside
permeability
ability of a substance to pass through or across the plasma membrane
conductance
measure of permeability of a charged particle; inverse of resistance
acetylcholine
excitatory to vertebrate skeletal muscles, excitatory or inhibitory at other sites. secreted at CNS,PNS, and vertebrate neuromuscular junctions
morula
clump of cells
morula
solid ball of cells
blastula or blastocyst
after morula formed, have blastocoel (cavity of blastula)
ectoderm forms
future epidermis and nervous system
endoderm forms
linings of gut, blood vessels, and urethra. secretory portions of endocrine and exocrine glands
mesoderm forms
bones and other connective tissue and muscles
invagination
cells attached in a layer move inward, by changing shape result in change in shape of layer
involution
individual cells move inward by actively crawling through, beneath, around other cells
epiboly
many stacked layers of cells reorganize their attachment resulting in longer but fewer layered tissue that stretches over surface of embryo
passive envelopment
yolk filled cells that do not actively move but are covered by other cells undergoing epiboly. look like they move inward but really stay in the same place while other cells cover them
fate
what cell would become if development is normal
determination
commitment of cell to specific path of differentiation, location no longer impacts what the cell will become
multipotent
makes cell types in the same family, least flexible
progenitor cells
in blood, are stem cells, and can maintain themselves but cannot produce all blood cell types. produce amplifying cells
not all progenitor cells are stem cells, just the prog. cells in blood or bone
erythropoietin
produced by specialized kidney cells when concentration of oxygen is too low. type of growth factor. encourages formation of erythroblasts
satelite cells
next to muscle fibers, stem cells for skeletal muscle. can form new skeletal fibers
pluripotent
can make all cells in the adult except the embryonic tissue
totipotent
8 cell stage in humans, can make all embryonic and extraembryonic cells
