Devo 12

Front 1

what does the endoderm become

Back 1

endoderm
->digestive tube
-->liver, gall bladder, pancreas, stomach, and respiratory tube
->respiratory tube -> lungs, pharynx, eustacian tubes, tonsils, thyroid, thymus, parathyroid glands, esophagus
-> also forms extraembryonic membranes like yolk sac and allantois

Front 2

how does the endoderm form

Back 2

development begins at two sites that migrate toward each other and fuse in the center. the anterior intestinal portal (AIP) and the caudal intestinal portal (CIP) migrated together and form the midgut. stromodeum blocks the oral end but eventually breaks creating the oral opening of the digestive tube

Front 3

The posterior opening of the developing foregut region of the primitive gut tube; it opens into the future midgut region which is contiguous with the yolk sac at this stage.

Back 3

anterior intestinal portal

Front 4

The anterior opening of the developing hindgut region of the primitive gut tube; it opens into the future midgut region which is contiguous with the yolk sac at this stage.

Back 4

caudal intestinal portal

Front 5

oral plate

Back 5

stromodeum

Front 6

what is the region of ectoderm that blocks the oral end of the gut tube and eventually breaks to create the oral opening of the digestive tube

Back 6

stromoedum or oral plate

Front 7

what is the region of the digestive tube anterior to the point where the respiratory tube branches off called.

Back 7

pharynx

Front 8

meeting of endoderm and ectoderm at the anus in the formation of the digestive tube

Back 8

anorectal junction

Front 9

pharyngeal pouches

Back 9

Inside the phar-ynx, these are where the pharyngeal epithelium pushes out laterally to form 4 pairs of pouches between the pharyn-geal arches. These give rise to the audi-tory tube, wall of the tonsil, thymus gland, parathyroids and thyroid.

Front 10

pharyngeal arches

Back 10

these are bars of mes-enchymal tissue derived from paraxial mesoderm, lateral plate mesoderm, and neural crest cells. Found in the pharyngeal region ( near the pharynx) of the vertebrate embryo, the arches will form gill supports in fishes and many skeletal and connective tissue structures in the face, jaw, mouth, and larynx in other vertebrates.

Front 11

what forms from the anterior endodermal portion of the digestive and respiratory tubes

Back 11

pharynx
-4 pairs of pharyngeal pouches
-4 pharyngeal arches between the pouches

Front 12

what forms from the 4 pairs of pharyngeal pouches

Back 12

1. auditory cavities (eustachian tubes)
2. tonsils
3. thymus and one pair of parathyroid glands
4. other pair of parathyroid glands
5. thyroid

Front 13

what genes are responsible for formation of the pharyngeal structures

Back 13

sonic hedgehog and FGFs

Front 14

what is responsible for specifying endodermal fate

Back 14

regional transcription factors are stabilized by interaction with local mesoderm

Front 15

explain the course of interactions between the endoderm and the splanchnic mesoderm

Back 15

there are localized txn factors in the endoderm such as sonic hedgehog that were activated by retinoic acid gradients

local mesoderm has receptors of sonic hedgehog protein

reception of sh protein activates Hox gene expression in mesoderm

Hox genes specify the mesoderm and activate specific genes like BMPs and FGFs

BMPs and FGFs signal endoderm specification and differentiation

specified endoderm secretes paracrine factors to mesoderm which leads to differentiation of mesoderm

Front 16

what is the bud of endoderm that extends out from the foregut into the surrounding mesenchyme

Back 16

hepatic diverticulum

Front 17

how does the pancreas develop

Back 17

from the hepatic diverticulum, a dorsal pancreatic bud forms the dorsal pancreas and a ventral pancreatic bud forms the ventral pancreas. the ventral pancreas migrates and fuses with the dirsal pancreas

Front 18

what interactions are responsible for liver specification

Back 18

the developing heart and blood vessel endothelial cells (by secreting FGFs) induces the liver to form and the presence of the notochord inhibits liver formation. for the endoderm to respond to heart cell FGF signals, the endoderm becomes competent by the forkhead txn factors which open chromatin surrounding liver-specific genes

Front 19

what interactions are responsible for pancreas specification

Back 19

the notochord may actively promote pancreas formation while the heart blocks the pancreas from forming. lack of shh expression from notochord activates pancreas development.

Front 20

what is the ventral extension between the fourth pair of pharyngeal pouches that bifurcates into the branches that form the paired bronchi and lungs

Back 20

laryngotracheal groove

Front 21

what becomes of the laryngotracheal endoderm

Back 21

the lining of the trachea, the two bronchi, and the alveoli of the lungs

Front 22

what is the digestive and respiratory condition called where the separation of the two tubes branches is not complete and a baby is born with a connection between the two tubes

Back 22

tracheal-esophageal fistula

Front 23

what signaling is needed to specify trachea and esophagus

Back 23

retinoic acid induces FGFs and Tbx
Wnt signaling for lungs
b-catenin accumulation in lung and trachea

Front 24

Vertebrates whose embryos form an amnion: the reptiles, birds, and mammals.

Back 24

amniote

Front 25

Water sac.” A membrane enclosing and protecting the embryo and its surrounding amnionic fluid. this epithelium is derived from somatopleure. Ectodermal tissue supplies epithelial cells, and the mesoderm generates the essential blood supply.

Back 25

amnion

Front 26

somatopleure

Back 26

the combination of ectoderm and mesoderm that forms the amnion and chorion

Front 27

splanchnopleure

Back 27

the combination of endoderm and mesoderm that forms the yolk sac and allantois

Front 28

what is the purpose of the chorion

Back 28

gas exchange

Front 29

what is the purpose of the amnion

Back 29

protects the embryo

Front 30

what is the purpose of the yolk sac

Back 30

nutrients

Front 31

what is the purpose of the allantois

Back 31

nitrogenous waste

Front 32

what are the four extraembryonic membranes

Back 32

chorion
amnion
yolk sac
allantois

Front 33

what is the chorion in mammals and its functions

Back 33

placenta - for endocrine, immune and nutritive function in addition to those of respriation

Front 34

collecting cord derived from the allantois that brings the embryonic blood circulation to the uterine vessels of the mother

Back 34

umbilical cord

Front 35

dorsal layer of the lateral plate underlying the ectoderm

Back 35

somatic mesoderm

Front 36

the ventral layer of the lateral plate overlying the endoderm

Back 36

splanchnic mesoderm

Front 37

the combination of the somatic mesoderm and the overlying ectoderm

Back 37

somatopleure

Front 38

combination of the splanchnic mesoderm and the underlying endoderm

Back 38

splanchnopleure

Front 39

the space between the somatic mesoderm and the splanchnic mesoderm that becomes the body cavity. stretches from the future neck region to the posterior of the body

Back 39

coelom

Front 40

what are the three cavities derived from the coelom

Back 40

pleural cavity, pericardial cavity, peritoneal cavity

Front 41

pleural cavity

Back 41

envelops the thorax

Front 42

pericardial cavity

Back 42

envelopes the heart

Front 43

peritoneal cavity

Back 43

envelopes the abdomen

Front 44

cardiogenic mesoderm

Back 44

Two groups of cardiac cells in the lateral plate mesoderm, at the level of the node. The cardiac cells of the heart field migrate through the primitive streak during gastrulation such that the medial- lateral arrangement of these early cells will become the anterior-posterior axis of the developing heart tube

Front 45

heart field

Back 45

cardiogenic mesoderm

Front 46

what is the cardiac outflow tract. the precursor of both ventricles

Back 46

conus arteriosus

Front 47

what is the cardiac outflow tract precursor that will form the roots and proximal portion of the aorta and pulmonary artery

Back 47

truncus arteriosus

Front 48

all the cells of the heart that form the muscular layers

Back 48

cardiomyocytes

Front 49

all the cells of the heart that form the internal layer

Back 49

endocardium

Front 50

all the cells of the heart that form the coronary blood vessels that feed the heart

Back 50

epicardium

Front 51

cells that coordinate the heartbeat

Back 51

purkinje fibers

Front 52

what two clusters generate all the cells of the heart

Back 52

outflow tract precursors (conus arteriosus and truncus arteriosus) and inflowtract precursors

Front 53

how are the cardiogenic mesoderm cells specified

Back 53

endoderm adjacent to the heart uses BMP and FGF signaling

Front 54

migration of the cardiac precursor cells.

Back 54

presumptive heart cells move anteriorly between the ectoderm and endoderm toward the middle of the embryo. the endodermal component responsible for this movement is an AP gradient of fibronectin

Front 55

a multipotent stem cell type that generates a series of intermediate progenitor cells whos potency is restricted to certain blood cell lineages. these lineages are then capable of producing all the blood cells and lymphocytes of the body

Back 55

hematopietic stem cells

Front 56

GATA4

Back 56

expressed in the endoderm and is required for migration of cardiac precursor cells to the midline and also for their division and specification. activates Nkx2-5 gene

Front 57

Nkx2-5

Back 57

activated by GATA5 protein, in cardiac precursor cells

Front 58

in heart development, what determines the anterior and posterior domains

Back 58

as cardiac cells migrate, the posterior region becomes exposed to more and more RA (produced in the post. mesoderm). RA specifies the post. cardiac cells as inflow or venous portions of the heart (sinus venosus and atria)

Front 59

in heart development how are heart cells differentiated

Back 59

GTA4 txn factor is expressed in precardiac cells emerging from the primitive streak. it activates heart specific genes. Nkx2-5 instructs mesoderm to become heart tissue and activates synthesis of numerous cardiac txn factors.

endocardial tubes form separately, then fuse. heart looping converts anterior posterior axis to left right

Front 60

explain the heart looping and formation of the heart chambers

Back 60

endocardial tubes form separately, then fuse. heart looping converts anterior posterior axis to left right

Front 61

structures that form from the endocardium and divide the tube into right and left atrioventricular channels. the atrioventricular valves are also derived from endocardial cells

Back 61

endocardial cushions

Front 62

a partition that divides a chamber, one in atrial that split the developing atrium into left and right atria

Back 62

septa

Front 63

constraints on the construction of blood vessels

Back 63

blood vessels form independently and link up with heart afterward.

physiological - embryonic blood vessels have different functions than adult vessels due to the extraembryonic structures

evolutionary - blood vessels extend to yolk sac even tho there is no yolk inside

physical - wider vessels move fluids faster but diffusion is more efficient when blood is slow moving

Front 64

process where a network of blood vessels is created de novo from the lateral plate mesoderm

Back 64

vasculogenesis

Front 65

process where the primary network of vessels is remodeled and pruned into a distinct capillary bed, arteries, and veins

Back 65

angiogenesis

Front 66

steps to vasculogenesis

Back 66

mesoderm cells leaving primitive streak in posterior signaled by CDx4 become hemangioblasts. in presence of notch become blood cell precursors and in absence of notch become endothelial blood vessel. hemangioblasts aggregate into blood islands and the inner cells become blood, outer cells become angioblasts. angioblast cells multiply and differentiate into endothelial cells that form the lining of blood vessels. endothelial cells form tubes and connect to form a primary capillary plexus

Front 67

what is an angioblast

Back 67

blood vessel pregenitor cell

Front 68

what is a blood island

Back 68

condensed aggregations of hemangioblasts in the splanchnic mesoderm

Front 69

Anetwork of capillaries formed by endothelial cells during the third phase of vasculogenesis.

Back 69

primary capillary plexus

Front 70

where does vasculogenesis occur

Back 70

extraembryonic vasculogenesis in the blood islands of the yolk sac

intraembryonic vasculogenesisforms the dorsal aorta and vessels from there connect with capillary networks that form mesodermal cells with each organ

Front 71

blood islands that line the yolk sac produce these veins that bring nutrients to the embryo and transport gases to and from the sites of respiratory exchange

Back 71

vitelline veins

Front 72

what growth factors are responsible for initiating vasculogenesis

Back 72

basic fibroblast growth factor or bFGF2

vascular endothelial growth factors or VEGFs

angiopoietins

pericytes

Front 73

growth factor required for the generation of hemangioblasts from the splanchnic mesoderm

Back 73

bFGF2

Front 74

proteins involved in vasculogenesis that direct the expansive growth of blood vessels in the placenta. organize cells into blood vessels

Back 74

VEGFs

Front 75

proteins that mediate the interaction between endothelial cells and the pericytes during vasculogenesis

Back 75

angiopoietins

Front 76

smooth muscle-like cells that the endothelial cells recruit to cover them during vasculogenesis

Back 76

pericytes

Front 77

explain the two ways for the lumen in vascular tubes can be formed

Back 77

vacuoles form within the endothelial cells by endocytosis. These vaculoes merge with other vacuoles to form larger vacuoles. Large vacuoles then fuse with the cell membrane at the point where the cells come together, forming the lumen.
OR
the vacuoles may form intracellular lumina within each cell; these individual lumina then fuse such that in any sin-gle portion of the final lumen, the lining is made up of mem-branes from the same cell.

Front 78

what is the important factor for angiogenesis

Back 78

VEGF-A will induce the migration of endothelial cells from existing blood vessels into the organ and cause them to form capillary networks there

Front 79

how are arteries and veins differentiated

Back 79

artery precursors contain ephrin B2 and vein precursors contain Eph b4 tyrosine kinase receptor. at the borders of vein and artery capillaries the receptor ligand interaction ensures that arterial and venous capillaries connect. it also ensure that the fusion of capillaries to make larger vessels occurs only between the same type of vessel...

angioblasts experiencing activation of notch upregulate the gridlock txn factor. these cells express ephrin B2 and become aorta. those angioblasts experiencing significantly less notch activation dont express gridlock and they become eph b4 expressing cells of the cardinal vein. once committed the cells migrate toward the midline

Front 80

how are organ-specific capillaries formed

Back 80

low oxygen activates HIF-1a txn factor that activates VEGF-A which activates angiogenesis

Front 81

what is important for the commitment of cells to the lymphatic lineage

Back 81

Prox1 txn factor which downregulates blood vessel-specific genes and upregulates genes involved in forming lymphatic vessels

Front 82

hematopoietic stem cell

Back 82

cell type that is capable of producing all the blood cells and lymphocytes of the body

Front 83

hormone that acts on the erythroid progenitor cells to produce proerythroblasts, which will generate red blood cells

Back 83

erythropoietin

Front 84

cell that matures from the proerythroblast and synthesizes enormous amounts of hb

Back 84

erythroblast

Front 85

the mature red blood cell that enters the circulation where it delivers oxygen to the tissues. can not divide, synthesize rna or proteins

Back 85

erythrocyte

Front 86

cell that derived from the mammalian erythroblast that has expelled its nucleus. although reticulocytes, lacking a nucleus, can no longer synthesize globin mRNA they can translate existing messages into globins

Back 86

reticulocyte

Front 87

paracrine factors that are collected and concentrated by the extracellular matrix of the stromal (mesenchymal) cells at the sites of hematopoiesis and are involved in blood cell and lymphocyte formation

Back 87

cytokines