Images

itemprop="discussionURL"One Comment

The eye is a fascinating organ of the body that holds all the little components and connections that allow one to carry out one of their most important senses; sight. So how can the stimulus of the process of vision—visible light– also be something that can kill the receptors that allow for it. To understand how light can kill photoreceptors, one must first understand how light initiates the process of phototransduction, what photoreceptors do, and what they are.

The process of phototransduction occurs when light—or a photon—is converted into an electrical signal in the retina. This electrical signal will be sent to the brain to be formed into the images we see every day. In a more detailed description, phototransduction has four main steps; the receptor protein (rhodopsin) is activated, the activated rhodopsin stimulates the G-protein transduction (GTP) which is then turned into guanosine diphosphate (GDP). Next, the transducin activates phosphodiesterase (PDE), which works to convert cGMP to GMP—these are the secondary messengers. Due to the cGMP quantity decreasing, the transduction channels close. This in turn decreases the sodium (Na+) current completing the process of phototransduction.

The photoreceptor cells found in the retina are called rods and cones. There are approximately one hundred and twenty million rod cells, and six million cone cells in the human retina. Rods are cylindrical in shape. They are extremely sensitive to low-intensity light making them perfect for whatever amount of night vision we have. Rods also allow us to perceive the size, shape, and brightness of images we take in. Cones on the other hand, work best in brighter lights and are responsible for our ability to see in color, as well as allow us to identify fine detail.

I am sure we all have the shared childhood experience of staring directly into the sun as our parents yelled warnings of going completely blind and burning our retinas right off. Was there any validity to their warnings? The truth is, they were absolutely right—maybe not entirely accurate about the “burning retinas”— but a continuous light stimulating the process of transduction can indeed cause rod apoptosis (rod cell death). However, one does not require such a strong stimulant as sunlight; even a more moderate illumination given enough time can lead to rod apoptosis. If transduction is a natural process, then why can it kill photoreceptors? It is speculated that the continuous activation of visual transduction can lead the calcium (Ca2+) concentration that helps to keep one’s eye healthy to lower and keep doing so.

One of the most amazing things about the human body is that it has the ability to make small adaptions to solve problems. In this particular case, rods have evolved so that there are protective measures in place to keep the calcium from going too low. These measures are; the ability to modify channels and the transport of ions. Another adaption that occurred to deal with prolonged light exposure is the migration of transduction proteins to a different part of the cell than its previous location. The section of the cell that holds the pigment rhodopsin can be shortened as well as re-elongated to help with prolonged transduction activation.

All in all, it would take a lot for one’s rods and cones to be killed by light. However, it can happen—so let us heed our parents’ warnings and avoid spend hours staring at the fireball in the sky.

itemprop="discussionURL"2 Comments

My STEAM project is about the five major classes of Antibodies or immunoglobulins called IgM, IgA, IgD, IgG, and IgE. Though they are found throughout the body’s secretions they produced by effector B cells and are secreted by Plasma cells. Though some Antibodies vary in size and structure they each have the minimum characteristics of antibody monomers (four protein chains bound by disulfide chains), the lightest of which forms the antigen binding site. The heavy monomers (high molecular weight) contain variable and constant regions, the constant region means that the amino acids are the same throughout the classes of Antibodies, the variable region is unique for every Antibody. Antigens bind at the ends of each Antibody structure at the variable regions where it forms a y-shape. The other end of the Antibody binds to B-cells, phagocytes, mast cells, or simply float free in the plasma depending on which Antibody it is.I couldn’t figure out how to post multiple pictures so please go to the link to view the paintings. –Antibodies in Waterco

itemprop="discussionURL"One Comment

 

 

 

 

 

 

 

 

 

 

 

My visual aid is a cartoon stating the various componets of blood and the function of blood in the human body.

(Apologies that it’s difficult to see, this is as good of quality of a picture as I’m currently able to upload)

 

Blood is compromised of four main components; red blood cells, white blood cells, plasma, and platelets.

Plasma is the fluid in which red blood cells, white blood cells, and platelets are held and plasma is what allows these components to circulate throughout the body.

Primarily, red blood cells are responsible for carrying oxygen to tissue from the lungs.

White blood cells are commonly referred to as leukocytes which are responsible for the bodies immune system. Leukocytes is the group name of wide variety of immune system related cells.

Plateletes are resposible for blood clotting to expedite the healing of wounds and prevent excessive bleeding.

 

 

itemprop="discussionURL"One Comment

This is my STEAM project

I’ve assembled thin tubing, as if it were the filtration of air within some contraption, to represent the lymphatic system moving lymph through its tiny lymph vessels. I’ve added a T divider to help represent a filter or a lymph node. From one end of the T divider, the pathway continues to cycle within the mainline, like in the lymphatic system, but the other end is the pathway to the dust collector, which would be emptied when full. I used fish food to represent the “dust” which in turn represents whats left of bacteria when the white blood cells are done with them. Just as within the lymphatic system lymph nodes filter the lymph then what’s remaining ends up going to the urinary bladder which is later excreted from the body. Thus ending the filtration of the air in my representation as well as lymph in the human body.

.

itemprop="discussionURL"2 Comments

file:///C:/Users/Anna%20Green/Downloads/Untitled%20document%20(3).pdf    

For my project, I made a model of a chest with the rare heart condition, Ectopia Cordis. It was my goal to simulate the effects of this condition as it would appear on a newborn, and depict how the heart develops outside of the chest cavity, and is made visible from the abdominal wall. I based my topic on Course Objective #42, as I wanted to learn more about abnormalities in the formation and structure of the heart. I believe I also briefly touched on Objective #19 as well, as this defect is formed during the early development of a fetus. This condition is cause when the sternum doesn’t fuse properly in utero and as the heart forms, it does so from the protection of the chest cavity. Despite the high mortality rate at infancy, several patients with this condition are able to still maintain a lifestyle, but are at risk of higher health complications. To simulate the condition, I baked a loaf of bread to act as the chest area and inserted a potato in the center to act as the heart. I used red dye and spray glue to give my “heart” a more realistic, textured appearance at it emerges through the “cavity”.  

 

 

 

itemprop="discussionURL"One Comment

STEAM BIOL 112 Wilson’s Disease

My STEAM project this semester includes an abstract collage piece on Wilson’s Disease, a disorder that causes an accumulation and build up of copper in the body and several bodily organs. Thank you!

itemprop="discussionURL"One Comment