Test 2: Lab Vocab Flashcards
Activation:
Initiation of development/exit from meiotic arrest of an oocyte due to
stimulation such as sperm fusion.
Acrosome
caplike saccular organelle, derived from the Golgi apparatus, containing
the proteolytic enzymes that allows the sperm to penetrate the zona pellucida (egg’s
extracellular matrix).
Acrosome reaction
the process by which the acrosome releases its proteolytic
enzymes to assists the sperm to penetrate the zona pellucida and fertilize the egg.
Adult stem cell:
unspecialized cell that is present in a differentiated (specialized)
tissue, renews itself, and can differentiate to yield specialized cell type(s) of that tissue
type.
Allantoic stalk
a canal in the umbilical cord connecting the cloaca, then later the
urogenital sinus with the allantois. Carries urine.
Allantois
extraembryonic membrane of amniotes, grows out of the hindgut and fuses
with the chorion; it contributes to the placenta of mammals.
Amnion
an extraembryonic membrane of amniotes that encloses the embryo and
amiotic fluid; usually arises from folds of somatopleure.
Amphimixis:
fusion of male and female pronuclei.
Androgenetic
being derived from the paternal genome.
Anencephaly
developmental abnormality, incomplete development of cerebral
hemispheres and cranium.
Anterior visceral endoderm (AVE)
in the mammalian embryo, the AVE is an important
signaling center essential for head structures formation that appears opposite to the
primitive streak at the time of implantation.
Aortic arches:
These begin as symmetrically arranged, paired vessels that develop
within the paired pharyngeal arches and link the ascending and descending/dorsal paired
aortae. Some arches degenerate. Left aortic arch IV becomes the Arch of the Aorta and
aortic arch VI is the ductus arteriosus on the left.
Aortic sac
formed from the fusion of the ventral aortae, ventral to the pharynx. The
aortic arches arise from the aortic sac.
Aplasia
congenital absence of an organ (renal aplasia)
Appendicular:
referring to the appendages/limbs (in contrast to axial which refers to
the spinal column and ribs). Note: tail would be axial, not an appendage
Archenteron:
the “primitive gut,” the innermost tube of an embryo; lined with
endoderm, it will become the digestive tract.
Atresia
congenital absence of an opening or lumen (atresia ani, atresia coli)
Atria
left and right) the heart chamber that in the embryo receives blood from the
sinus venosus and delivers it to the ventricle.
Autologous:
derived from self.
Branchial arch/cleft/pouch
see pharyngeal arch/cleft/pouch. “Branchial” refers to the
gill system found in fish and does not really apply to terrestrial animals.
Bulbar ridges:
Spiral thickenings of the bulbis cordis. Their fusion divides the bulbus
cordis into the aorta and the pulmonary trunk.
Bulbus cordis (conus truncus)
he heart chamber, originally most cranial in position,
connecting the ventricle with the ventral aorta (and later, the aortic sac).
Cloaca
The caudal chamber of the digestive tract. It receives the allantoic stalk, urinary
ducts, and reproductive ducts. In mammals it is partitioned to form the rectum, urinary
bladder, and the urogenital sinus.
Cloacal membrane
caudal end of the primitive streak formed by closely apposed
endoderm and ectoderm, future site of the anus.