Strabismus

Strabismus commonly known as crossed eye is a condition i decided to do more research on because , there is a boy in my church that was born with strabismus, he had it up to the age of 4 and when I went home for thanksgiving break his eyes were corrected. I found that strabismus is a condition when the muscles in the eye does not receive information correctly. I also found that there are two types of strabismus, accommodative esotrpia and intermittent exotropia. Accommodative esotropia occurs because of uncorrected hyperopia while intermittent extropia develop because the eyes can not coordinate together. Treatment  for strabismus includes prism lenses, vision therapy and eye muscle therapy. The boy in my church wore glasses until he was about 4 years, then had surgery.

http://www.aoa.org/x4700.xml 

Chapter 10

Ephrins ligands- Juxtacrine factors, binding between an ephrin on one cell and the eph receptor on an adjacent cell results in signals sent to each of the two cells
 
contact inhibition-the mechanism for directional cell movement wherein cells are prohibited from moving backwards due to interactions with the cell membrane of the other migrating cells.

dermal bone- bones that forms in the dermis of the skin such as most of the bones of the skull and face.

cranial Placodes-epidermal thickenings that form neurons and sensory epithelia.

Enamel knot-the signaling center for tooth development, a group of cells induced in the equithelium by the neural crest-derived mesenchyme that secretes paracrine factors that pattern the cusp of the tooth

Pathway secretion- axons travel along a route that leads them to a particular region of the embryo.

Target secretion- axons, once they reach the correct area, recognize and bind to a set of cells with which they may form stable connections

Address secretion- initial patterns are refined such that each axon binds to a small subset of its possible targets.

Chapter 9

Chapter 9

Microspikes-microfilament containing pointed filopodia of the growth cone that elongate and contact to allow axonal migration.

Astrotactin- adhesion protein that helps the neuron maintain adhesion to glial cell.

Dendrites- fine branching extensions of the neuron that are used to pick up electric impulses from other cells

Preplate- formed from the first cortical neurons to be generated and migrate out of the germinal zone

Neural retina- cells of the inner layer that proliferate rapidly and generate a variety of glia, ganglion cells, interneurons and light sensitive photoreceptor neurons.

Cyclopia- a single eye in the center of the face usually below the nose. The result of a mutated Shh gene.

Encounter

I recently started working at Takoma Academy as an after school tutor. While tutoring one young lady in biology. She told me that she saw her teacher's baby dance. I knew that her teacher was pregnant so I asked how, she then went on to explain that her teacher put earphones on her stomach and when she did that the baby started moving. This reminded me of what we were talking about in class, where scientist have figured out that babies hear sounds in womb.  

12th grade A&P class trip

Today in class we learned about teratomas after looking at the slides I realized that I have seen these before. In the twelfth grade for my honors A and P class we took a trip to the Bodies Exhibit museum in Brooklyn New York. One of the displays showed an ovary where there were teeth and hair growing, another exhibit that I remember seeing is was a foot with toe nails growing in the body. This trip intrigued me; although I already knew I wanted to be a doctor it showed me there was a lot to learn and it would be something I enjoy learning.  

Figure 1: teeth and hair from a mature cystic teratoma of the ovary. Called a dermoid cyst.

Hypoplastic left heart syndrome

While watching an episode of the new series Emily Owens M.D. I found the case she was working on very interesting as it pertains to developmental biology. In this particular case a woman was the surrogate mother to twins, one of the twins had Hypoplastic left heart syndrome and had to be operated on in vitro. At this point I decided to do farther research on this syndrome. I found that this occurs during development when the left side of the heart does not form correctly. studies done found that one cause of this syndrome could be genetic however it is unknown the true causes. This provides a challenge for it to be treated. Twenty percent of effect children die within the first month of life. In the article I found there was no mention of in vitro surgery but a series of surgeries done soon after birth. Some of the surgeries includes the Norwood Procedure done within the first two weeks of birth, Bi-directional Genn Shunt Procedure done 4 to 6 months of age and Fontan Procedure done 18 months to 3 years.  
In the TV series both babies were going to be were going to be in good health, however in reality children that suffer from hypoplastic left heart syndrome are never cured.

http://www.cdc.gov/ncbddd/heartdefects/HLHS.html
http://www.news-medical.net/news/2007/10/11/31066.aspx?page=2

Chicks

I recently downloaded an app on my Ipod called "WeirdButTrue" made by National Geography, while shuffling through the facts I came across one that said Chicks can breathe through their shells. I was very excited because this topic was covered in lab.

Chapter 3

Chondrocytes- precursor cells for cartilage.

Thanatophoric dysplasia- growth plates of the rib limb bones fail to proliferate. This is a lethal mutation because the ribs can not support breathing. This is the effect of prematurely activating the STAT pathway.

Cadherins- a class of proteins that are calcium dependent adhesion molecules.

Karyokinesis- the mitotic division of the cell's nucleus. The mechanical agent of karyokinesis is the mitotic spindle.

Commitment- describes a state in which a cell's development fate has become restricted even though it is not yet displaying overt changes.

Determination- the second and irreversible stage of cell or tissue commitment in which the cell or tissue is capable of differentiating autonomously even when placed into a non neutral environment.

Specification- the first stage of commitment of cell or tissue fate during which the cell or tissue is capable of differentiating autonomously when placed in an environment that is neutral with respect to the developmental pathway at the stage.

What I learned this week in class!!

I like taking different courses in Biology because  learn more about a subject I thought I knew every aspect of. This week's subject area is fertilization, I began this class thinking  that when sperm meets egg it's head only needed to enter the outer layer of the egg and the egg would be fertilized. This week I learned that the sperm must first travel through the cumulus layer, then bind to the zona pellucida and then the egg membrane. I also learned that the zona pellucida also has layers. First the SED1 from the sperm must make contact with ZP2 and ZP3 in the zona pellucida.

I perviously thought this was a simple process, however I now know how complex creating life  can be. This has made me realize how much God truly knows and cares for all His creations. In the bible when He is speaking to Jeremiah the prophet He says in Jeremiah 1:5 "Before  formed thee in the belly  knew thee". This means that God knew which sperm would make it to the egg. Which each science course I am amazed at how intimate and detailed God is.

My Babies

Today, when I  looked through the microscope I saw that my sea urchins were still alive and moving, I was surprised and in awe, because they survived in a colder temperature than that of their parents. I later found that the sea urchins were in the pluteus larva stage. This farther peaked my interest and I began to wonder if I would be able to farm sea urchins and how long it would take for then to reach juvenile stage. I found that it would take about 40 to 45 days for them to go into the metamorphosis stage. I believe they can develop into fully mature sea urchins however, due to the length of their development and the limitations of their environment they have a small percentage of surviving.  

http://www.asnailsodyssey.com/LEARNABOUT/URCHIN/urchRepr.php

Trisomy 18

     I was on youtube and found a video of parents talking about there experience. They had a child with trisomy 18 which is also known also Edwards syndrome. Doctors told them that this disorder was incompatible with life, hearing this news they decided to carry the pregnancy to term, they did not speak of the defects their child had so i decided to search for them. I found that there are three types of trisomy 18 there is full, partial and mosaic. In full trisomy 18 the individual has three 18th chromosome this occurs in 95% of all cases. Partial trisomy 18 can be caused by hereditary, in this case a part of the 18 chromosome becomes attached to another chromosome. Mosaic trisomy 18 occurs when an extra 18th chromosome is present in some but not all of the cells in the body. Physical defects include problems with the heart and kidney. Part of the intestinal track is outside the stomach, the esophagus does not connect to the stomach, there is excess amniotic fluid, clenched hands pocket of fluid in the brain, rocker bottom feet, delayed growth, small jaw, small head, low-set ears and a strawberry shaped head.
     After research i decided to watch more videos and found that most children die very young however there were cases where effected individuals survived. There is a small number of females that made it to there thirties.  

http://www.trisomy18.org/site/PageServer?pagename=whatisT18_whatis

Chapter 1,2, and 14

Inter Sex-phenotypes in which male and female traits are seen in the same individual

Pseudohermaphroditism-  Inter sex condition in which the secondary sex characteristics differ from what is expected of the gonadal sex 

Gynandromorph- Body parts are male and others female.

Genomic Equivalence-the theory that every cell of an organism has the same genome as every other cell

Polyspermy- the entrance of more than one sperm during fertilization

Chromatin- a protein composed of histones

Silencers- DNA regulatory elements that actively repress the transcription of a particular gene. 

Epigenesis- the belief that organs of the embryo are formed from scratch at each generation

Performation-the view that organs of the embryo are already present in a miniature form within the egg or sperm.

What does Karen have?

On thursday night I decided to organize my youtube channel, upon looking at  my homepage I realized that there was a new Skit Guys video, called Karen's Story after watching the video I decided to research what caused Karen's disease. Karen was born with Goldenhar syndrome, it is a inherited disease that effects the cardiac, renal, central nervous system and the genitourinary tract. Studies have shown that deletions on chromosome 5 are related to this syndrome. Another study I came across was of a intrauterin death of a child with Goldenhar syndrome, with ultra sound technology the parents knew that there were developmental defects with the child's heart. After the child was expelled from the womb further autopsy showed this child had an asymmetrical face and an inclined eye lid. There were many physical features consistent with Goldenhar syndrome in the child. I noticed that these were the same physical features that Karen had. Scientist are not certain of what cause the child's death.


link for article

http://resources.metapress.com/pdf-preview.axd?code=xg343h308gx75580&size=largest