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.
Cranial nerve V:
(trigeminal nerve)
a pair of mixed nerves arising from the sides of the
metencephalon and semi-lunar ganglia; three divisions-the ophthalmic, maxillary and
mandibular rami-innervate the mandibular arch region.
Cranial nerve VII:
(facial nerve)
pair of mixed nerves arising from the myelencephalon
at the cranial margin of the otic vesicles and from the geniculate ganglia; they innervate
branchial arch 2.
Cranial nerve VIII:
(vestibulocochlear nerve)
a pair of sensory nerves arising from the
auditory ganglia; they innervate the otic vesicles.
Cranial nerve IX:
(glossopharyngeal nerve)
a pair of mixed nerves arising from the
myelencephalon at the caudal margin of the otic vesicles; and bearing the superior and
petrosal ganglion; they innervate branchial arch 3.
Cranial nerve X:
(vagus nerve)
pair of mixed nerves arising from the myelencephalon
and bearing the nodose and jugular ganglia; the innervate branchial arches 4, 5, and 6,
and extend parasympathetic fibers to the viscera. In aquatic vertebrates they innervate
the lateral line.
Cranial nerve XII:
(hypoglossal nerve)
A pair of nerves arising from many rootlets on
the ventral wall of the myelencephalon; they innervate the tongue muscles.
Descending aorta:
he principal artery of the trunk; a median vessel formed by the fusion
of the paired dorsal aortae; it extends from the subclavian to the common iliac arteries.
Diencephalon:
The caudal division of the prosencephalon to which the optic stalks and
epiphysis attach. Its cavity is the third ventricle of the brain. It forms the epithalamus,
thalamus, and hypothalamus. Its roof forms the choroid plexus.
Diverticulum:
Outpouching of a hollow (or a fluid filled) structure in the body. Example:
respiratory system formed from a diverticulum off of the foregut.
Dorsal aortae:
The primitive, paired, longitudinal arteries of the trunk that fuse together
caudal to the pharynx to form the descending aorta. In the pharyngeal region they
contribute to the external carotid arteries, descending aorta, and in mammals the right
subclavian artery.
Dorsal root ganglia
=spinal ganglia) sensory ganglia derived from the neural crest
lying laterally paired and dorsally to the spinal cord (in the embryo found ventral to the
spinal cord). Connects centrally with the dorsal horn of the spinal cord.
Ductus arteriosus:
forms from left aortic arch VI, serves as a shunt between the
embryonic/fetal pulmonary artery and the descending aorta. It normally closes at birth (if
not, pathological condition is called patent ductus arteriosus).
Ductus venosus
a vein in the liver of amniotes carrying blood from the vitelline and left
umbilical veins to the sinus venosus; it derives from the vetilline veins; allows oxygenated
blood from the placenta to shunt directly to the heart and it is obliterated after hatching in
birds or after birth in mammals.
Endocardial cushion
a pair of connective tissue outgrowths that undergo fusion to
divide the atrioventricular canal; it contributes to the atrioventricular valves.
Epaxial
Originally referring to the part of a fish’s body dorsal
to the centrally-located lateral line that runs the length of the body. In terrestrial animals,
this is the area dorsal to the transverse processes of the spine. Epaxial muscles are the
dorsal muscles of the back including the iliocostalis, longissimus, and transversospinalis system
Fistula:
abnormal connection or passageway between organs or vessels that normally
do not connect. Example: bronchoesophageal fistula.
Foregut:
the anterior portion (from the tracheobronchial diverticulum to the liver bud) of
the forming gastrointestinal tract (fore-, mid-, hind-), blood supply is from the Celiac artery,
will form esophagus, crop (birds), stomach, proximal half of duodenum, liver, biliary tract,
and pancreas.
Ganglion of Cranial Nerve V
Semilunar ganglion.
Ganglion of Cranial Nerve VII:
Geniculate ganglion.
Ganglion of Cranial Nerve VIII
Auditory ganglion.
Ganglion of Cranial Nerve IX
Superior ganglion and Petrosal ganglion.
Ganglion of Cranial Nerve X:
Jugular ganglion and Nodose ganglion.
Hypaxial
(hypo=under, axis=center line): Originally referring to the part of a fish’s body
ventral to the centrally-located lateral line that runs the length of the body. In terrestrial
animals, this is the area ventral to the transverse processes of the spine. Hypaxial
muscles include the subvertebral muscles (psoas muscles), flank muscles (external and
internal oblique and transverse), and the rectus abdominus.
Infundibulum
a ventral evagination of the prosencephalon: it lies in the floor of the
diencephalon and forms the neural lobe of the hypophysis (pituitary gland).
Intersegmental arteries
Originally small paired branches of the dorsal aortae arising
between the somites. They contribute to the vertebral, subclavian, intercostal, and
lumbar arteries.
Interventricular foramen
an opening in the ventricular septum allowing blood to cross
between the right and left ventricles; it closes during division of the conotruncus and the
atrioventricular canal.
Interventricular septum
muscular partition arising from the caudal wall of the primitive ventricle; it grows cranially, fuses with the endocardial cushion and the bulbar
septum and divides the ventricle into the right and left ventricles.
Meckel’s Cartilage
derived from the ventral part (Mandibular Arch) of Pharyngeal Arch I, it provides shape for the mandible as it forms, and then Meckel’s cartilage mostly degenerates except for two small parts at the dorsal end that form the incus and malleus
of the ear.
Mesonephros:
the second kidney of amniotes. It contains tubules and glomeruli that produce urine during the embryonic period. Mostly degenerate in adult amniotes except that in males the caudal parts form the part of the male reproductive tract, including
efferent ductules, ductus epididymis, ductus deferens, and seminal vesicles.
Mesencephalon
(=midbrain). Major derivatives include optic tectum and tegmentum.
Mesonephric ducts:
The excretory ducts of the mesonephros. They formed initially as
the pronephric ducts by the caudal growth of the pronephric buds to the cloaca. They
contribute to the metanephros of amniotes by forming one of its rudiments on each side,
the ureteric bud. They mostly degenerate in female amniotes, but in males they form the
ductus epididymis, ductus deferens, and seminal vesicles. They form the ducts of the
adult kidney of amphibians.
Mesonephric tubules:
the tubules of the mesonephros. They are excretory during the
embryonic period of amniotes. Most degenerate but some form the efferent ductules of
male amniotes. They form the adult kidney tubules of amphibians.
Metanephric duct:
ureter) the excretory duct of the metanephros; it derives from the
stalk of the metanephric diverticulum, connecting at first with the mesonephric duct, its
site of origin; it later shifts to the cloaca in birds or to the urinary bladder in mammals.
Metanephrogenic mesenchyme:
Dense mesenchyme surrounding the developing
pelvis of the metanephros; it forms the metanephric tubules.
Metencephalon
cranial-most region of the hindbrain. Major derivatives include
cerebellum and pons.
Midbrain:
(=mesencephalon). Major derivatives include optic tectum and tegmentum.
Myelencephalon:
caudal-most region of the hindbrain. Gives rise to the medulla.
Olfactory pits:
Cavities on the lateral surfaces of the head. They arise by invagination
of the olfactory placodes. They deepen and break through the roof of the mouth in air
breathers to form the nasal cavities.
Optic cups
Double-walled chambers formed by the invagination of the optic vesicles. Its
outer wall forms the pigmented epithelium of the retina: its inner wall forms the sensory
layer of the retina and the optic nerve fibers. The rim of the cup contributes to the iris and
ciliary body.
Oropharyngeal membrane:
(=buccopharyngeal membrane) at the anterior end of the
primitive streak and primitive gut, where ectoderm and endoderm are closely apposed.
Will degenerate to form the opening between the mouth and pharynx.
Otic vesicles:
(=otocyst) closed chambers formed by the invagination of the otic
placodes. Each forms an inner ear.
Pharyngeal Arch:
=Branchial Arch) Bars of mesenchymal tissue derived from paraxial
mesoderm, lateral plate mesoderm and neural crest cells that are found in the pharyngeal
region of the embryo and will form many skeletal and connective tissue structures in the
face, jaw, mouth and larynx.
Pharyngeal Cleft:
=Branchial cleft) Clefts/invaginations of external ectoderm that
separates the pharyngeal arches. There are 4 to begin with, only the first cleft becomes
a structure: the external auditory meatus.
Pharyngeal Pouch
=Branchial pouch) Inside the pharynx, these are where the
pharyngeal epithelium pushes out laterally to form 4 pairs of pouches between the
pharyngeal arches. These give rise to the auditory tube, wall of the tonsil, thymus gland,
parathyroids and thyroid.
Prosencephalon
=forebrain). Will form two secondary brain vesicles: the telencephalon
and the diencephalon.
Pulmonary trunk:
the trunk of the pulmonary arteries; it connects with the right ventricle
and derives from the conotruncus by longitudinal division of the latter.
Rathke’s pouch (pocket)
A dorsal evagination of the stomodeum: it becomes isolated
from the stomodeum and forms the pars distalis, the pars intermedia and the pars
tuberalis of the hypophysis.
Rhombencephalon:
(=hindbrain). Will form two secondary brain vesicles: the
metencephalon and myelencephalon.
Septum transversum:
Transverse mesodermal tissue between the heart and caudal
foregut (stomach, liver bud) that gives rise to the central tendon of the diaphragm,
connective tissue of the liver, and ventral mesentery.
Sinus venosus:
nitially the most caudal chamber of the heart. It receives venus return
and delivers it to the atrium. It disappears as a heart chamber by atrophy, and by
incorporation into the atria. It originates the heartbeat, and later transfers that function to
the atrium by forming the sinoatrial node.
right anterior= atrium and cranial vena cava
right posterior= caudal vena cava
left = coronary sinus
Stomodeum:
the ectodermal rudiment of the mouth. An invagination in the cranioventral
ectoderm of the head that contacts the cranial wall of the foregut. Its floor is the oral
membrane. Rupture of the membrane opens the mouth into the pharynx. The Rathke’s
pouch evaginates from its dorsal wall.
Subclavian artery:
the arteries of the shoulder and forelimb; they arise by the
enlargement of the 7th intersegmental arteries; in mammals, the right subclavian also
receives contributions from the right aortic arch 4 and the right dorsal aorta.
Telencephalon:
egion of forebrain. Major derivatives include cerebral hemispheres and
olfactory bulbs.
Tuberculum impar:
A median elevation of the mandible in the floor of the mouth; it
fuses with the lateral lingual swellings to form the body of the tongue.
Umbilical artery
(allantoic arteries) the atrial blood supply to the chorioallantois of birds
and the placenta of mammals; a pair of vessels arising from the caudal end of the aorta;
it forms the common iliac and hypogastric arteries in mammals, and after birth, the lateral
umbilical ligaments.
ROUNG LIGAMENT OF THE BLADDER
Umbilical veins
Initially, paired vessels which drain the allantois of birds, or the
placenta of mammals.
left =round ligament of the liver
Urogenital sinus:
a chamber split from the ventral part of the cloaca in mammals; it
receives the mesonephric ducts, Mullerian ducts and allantoic stalk; it contributes to the
bladder and forms the urethra; in females it forms the vestibule of the vagina.
___ , which will form most of the future mouth.
stomodeum
The mass of tissue intervening between the two sections of the GI tube is the ____, the tongue rudiment, which is relatively large at this stage.
tuberculum impar,
The darkly staining ___ is located ventral to the pharynx in a section which is more caudal (toward the rump) to the section containing the developing tongue.
thyroid gland
Continue tracing the stomach caudally until it narrows and locate the cross section of the duodenum. Trace sections caudally until a duct joins the duodenum. This is the ___
common bile duct
As the common bile duct ends, another discrete mass of cells is visible in its place. This is the ____
ventral pancreas
Ventral to the developing pancreas, the cystic duct expands as the ___ which is “embedded in the liver
gall bladder,
part of the ___ is herniated into the umbilicus, or umbilical stalk/cord until the abdominal cavity can accommodate it
intestine
at the median side of the kidney are
some very large areas bounded by a very flat epithelium and filled with cells; these
are the ___ of the mesonephric tubules.
Bowman’s capsules
The cells inside the Bowman’s capsules are the walls of the blood vessels, which constitute the ___
glomeruli
singular - glomerulus
Within the umbilical cord there is a slit-like opening with oval openings on each side of it. The central slit-like opening is the ___, the round openings which are lateral to the allantoic stalk are the right and left ___
allantoic stalk
umbilical arteries.
As you follow the umbilical cord, you may observe that the diameter of the ___ increases quite suddenly; this is the junction of allantoic stalk with the much larger allantois proper. It is removed when the specimen is processed for making slides.
allantoic stalk i
The ___ is a solid core of cells, This zipper-like structure is continuous with the ventral ectoderm
of the tail.
cloacal membrane
The cloaca becomes divided into the ___ and the ____
rectum
urogenital sinus
One ___ connects to the lateral expansion on
each side of the urogenital sinus.
mesonephric duct
future ureter aka the ____
metanephric duct
continue to follow the future ureter caudally until it has no connection to the mesonephric duct. Its
distal end becomes expanded, foreshadowing its fate as the ___
renal pelvis.
The dark halo of cells surrounding the renal pelvis will eventually give rise to the ____ (cortex) of the metanephric kidney.
secretory tubules
the halo around the renal pelvis is called the metanephrogenic mesenchyme or the ___
future
metanephros
The spiral septum separates the bulbus into a vessel (to the right and dorsal) the
___and a vessel (to the left and ventral) the ___
aortic trunk/ascending aorta
pulmonary trunk
Cranially, the pulmonary trunk extends dorsally towards the trachea so as to be cut lengthwise, and then gives rise to the two ___.
6th aortic arches
left side= pulmonary trunk and ductus arteriosus
right side= regresses
the 6th aortic arches will join the dorsal
aortae. The end of the left 6th aortic arch connecting to the left dorsal aorta is the
____ which persists until birth as an important blood channel between the pulmonary trunk and arch of the aorta.
ductus arteriosus
continue tracing the ascending aorta cranially until the 4th aortic arches arise from it. Follow the 4th aortic arches cranially until they join the
___
dorsal aortae.
Typically, the left 4th aortic arch is larger than the right, foreshadowing the inclusion of the former into the arch of the aorta, and the latter into the ___
right subclavian artery.
Observe the union of these two aortae to form the single ___
descending aorta
Note the origin of the pair of ___ from the
dorsal side of the descending aorta, and trace the subclavian arteries into the anterior limb buds
subclavian arteries
___ a generic term for small, paired arteries arising dorsally from the descending aorta and extending towards the spinal cord, and ventrolaterally
to the glomeruli of the mesonephros
intersegmental arteries
___ artery, arising ventrally from the descending aorta
superior mesenteric
Eventually the aorta is cut somewhat
longitudinally (because of curvature of the embryonic body in this region), and the
two ___ arteries
allantoic (umbilical)
dentify the region of the umbilical cord again and note the presence of two veins, very large ___ vein and a small ___ vein
left umbilical (allantoic) right umbilical (allantoic)
The right umbilical vein is degenerating now and the ____ returns most of the blood from the placenta to the liver.
left umbilical vein
Follow the left umbilical vein into the
substance of the liver. In this section two other major veins should be identified, the
___ and ___
hepatic portal vein
inferior vena cava
___ veins originating from vitelline veins
hepatic portal vein
____ is beneath the dorsal aorta and between the two mesonephros
inferior vena cava
The passageway through the liver for blood reaching the liver via the left umbilical vein is the ___
ductus venosus
Continue to follow the inferior vena cava cranially into the ___, and trace the latter into the right atrium.
sinus venosus
These ___ will form the inner ear.
otic vesicles
A small vesicle appears on the medial side of the otic vesicles; this is the ___
endolymphatic duct
Another section of brain may now be encountered near the pointed apex of the metencephalon section, but not connected to it. This is the
___ the midbrain
mesencephalon,
A ventral evagination of the floor of the diencephalon is called the ___
infundibulum,
The infundibulum and the ___, a
dorsal evagination of the stomodeum, will combine to form the hypophysis (pituitary).
Rathke’s pouch
Note the ___ on the lateral edges of the diencephalon.
optic cups
the telencephalon becomes constricted into two
(future) ____
cerebral hemispheres
Note the ____ which are
cavities on the lateral surfaces of the head, adjacent to the cerebral hemispheres.
olfactory pits
Observe that the ___ of the retina, in
which the axons constituting the optic nerve fibers will be aggregated, is continuous with the optic stalk, providing a pathway for future optic nerve fibers to grow back towards the diencephalon
sensory layer
Emerging from the wall of the metencephalon where the neural canal is broadest is the root of the ___
trigeminal (V) cranial nerve.
Adjacent to the narrowed ear rudiment, on the
side closest to the trigeminal ganglion, a group of nerve fibers emerges from the wall of the myelencephalon; these are the roots of the ___ nerve
vestibulocochlear (formerly auditory) (VIII) cranial nerve,
These fibers constitute the root of the vagus (X) cranial nerve, (Davis, fig. 68 and 73). A few
sections more caudally they connect to a ___ of the vagus. If you follow the vagus nerve caudally, a second ___appears in its place.
(jugular) ganglion
(nodose) ganglion
These are the roots of the glosso-pharyngeal (IX) cranial nerve. A few sections more caudally these fibers connect to a ___ of the glossopharyngeal nerve. If you continue following the glossopharyngeal nerve caudally, in its place a second ___ then appears. These 2 ganglia will appear on the opposite side of the otic vesicle in comparison to the trigeminal nerve.
(superior) ganglion
(petrosal) ganglion
Emerging from the marginal zone of the myelencephalon where the neural canal is narrowest is a number of bundles of nerve fibers, the roots of the ___
hypoglossal (XII) cranial nerve.
