Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
What is the worst period in embryogenesis to be exposed to teratogens?
|
Between weeks 3-8.
|
|
|
How does the neural tube form?
|
The neural plate, derived from ectoderm, thickens, and folds inward to produce a tube.
|
|
|
Where does neural tube closure (zipping up like a zipper) begin?
|
At the level of the neck
|
|
|
What do the pharyngeal arches become?
|
They develop into your face, by meeting and fusing together
|
|
|
How many brain ventricles are there? What is the name of the fourth one? From which ventricle do the cranial nerves arise?
|
There are four brain ventricles. The name of the fourth one is the rhombencephalon. The cranial nerves arise from the rhombencephalon.
|
|
|
From which part of the brain do the olfactory nerves come from? The optic nerves? Oculomotor?
|
The olfactory nerves from the telencephalon. The optic nerves come from the diencephalon. The oculomotor comes from the mesencephelon
|
|
|
What are the eight segments of the hindbrain called?
|
The rhombomeres
|
|
|
What is a lack of closure of the spinal tube called? What glycoprotein is present in this condition? What supplement can prevent this problem in pregnant women?
|
Spinda bifida. Alpha feto protein. Folic acid.
|
|
|
What are the four characteristics of the chordate body plan?
|
1. Notochord 2. Dorsal CNS 3. Pharyngeal gill slits 4. Post anal tail
|
|
|
What are the divisions of mesoderm, and what structures do they give rise to? What does the lateral plate differentiate into?
|
The axial mesoderm (gives rise to notochord), the paraxial mesoderm (give rise to somites), intermediate mesoderm (gives rise to kidney), lateral plate mesoderm (here, there are two important divisions, the visceral or splachnic mesoderm which surrounds the endodermal organs, and the parietal or somatic mesoderm, which forms the body wall).
|
|
|
What space forms between the visceral and parietal mesoderm?
|
The coelom, which eventually becomes the peritoneal space (the peritoneum is the membrane covering this space)
|
|
|
What structure brings vasculature to the gut?
|
The mesentery. This structure runs along the entire gut
|
|
|
Where are the blood islands located? What cells give rise to blood islands? What do the blood islands form when they connect?
|
The blood islands are located in the lateral plate mesoderm, in the cardiogenic region. Hemangioblasts give rise to blood islands. When the blood islands connect, they form blood vessels
|
|
|
How is the heart formed?
|
Two heart tubes fuse to form the endocardial tube. This eventually leads to formation of the four chambers of the heart, through a folding process.
|
|
|
What cell types will the somites of the paraxial mesoderm form?
|
The sclerotome, giving rise to bones and tendons, the myotome, giving rise to skeletal muscle, and the dermatome, giving rise to the dermis, and connective tissue under skin
|
|
|
How do you know what part of the spinal cord innervates each dermatome?
|
Each dermatome is innervated by the nerves next to the somite from which it originated
|
|
|
What are the three divisions of the developed endoderm? What are the organs that arise from the endoderm?
|
The foregut (tonsils, thymus, thyroid, parathyroid, esophagus, trachea, lung buds, stomach, liver, gall bladder, pancreas and part of the duodenum), the midgut (epithelium of posterior duodenum, small intestine and part of transverse colon), and the hindgut (epithelium of posterior duodenum, small intestine and part of transverse colon)
|
|
|
Do the three divisions of the gut share one source of arterial blood?
|
No, all three divisions have individual sources of arterial blood
|
|
|
What is the so called fourth germ layer? What structures arise from this layer?
|
The neural crest. This gives rise to most of the cranium, the pharyngeal arches, melanocytes of the skin, schwann cells of the PNS
|
|
|
What drug particularly affects the neural crest? What genes are affected?
|
Retinoic acid (accutane). HOX genes are affected
|
