The Eye

In Biology we are studying the eye. Male gave us some activities to do.

1. Structure of the eye.

2.  Functions of the eye structures.

 

4. Animation showing how the eye works.  

5. Booklet page 9 exercise 2: The cornea bends or refracts the light rays for the lens to bend and focus them on the fovea (if there is a bright light, on cones) or throughout the retina (if there is dim light, on rods).

6. VIDEO explaining the pupil reflex.

-stimulus: a bright light. >> receptor: cones >> coordinator: brain >> effector: radial and circular muscles >> effect: circular muscles contract while radium relax >> response: the pupil constricts.

-stimulus: a dim light. >> receptor: rods >> coordinator: brain >> effector: radial and circular muscles >> effect: circular muscles relax while radium contract >> response: the pupil gets dilated.

CIRCULAR MUSCLE vs RADIUM MUSCLE: Antagonistic muscles

7. : In the dark room light is focused all over the retina, where the rodes are. Rodes are stimulated the, but rodes are of black and white vision only. So you see only shapes, not colors.

8. Animations to learn how the eye focuses on a nearby and a distant object.

9.  If a close object is focused, the light rays coming will be diverging so they will need a lot of bending.  The ciliary muscles contract, the suspensory ligaments go slack and the lens becomes shorter and fatter.

 

Nervous System.

In Biology we started working with the Nervous System. Here is anentry on Male´s blog with a few interactive activities and videos.

Activities:

1.

b. 

Sensory Neuron: transmits nerve impulses from receptors to coordinators.

 

Relay Neuron: Transmits nerve impulses from Sensory Neurons to Motor Neurones.

Motor Neurones: Transmits nerve impulses from the central nervous system (brain &  spinal cord) to effector nerve cells.

c. Reflex Action:

Stimulous >> recept cells >> coordinators (CNS) >> effector cells

d. Synapse:

A synapse is what happens when chemical signals pass from one cell to another. It occurs in the synaptic cleft, which is the tiny gap between the pre-synaptic neuron and the post-synaptic neuron.
Every pre-synaptic neuron has vesicles inside, near the pre-synaptic membrane. Each vesicle contains thousands of neurotransmitters. When the pre-synaptic neuron gets “excited” by an axon potential it’s vesicles diffuse through the cell membrane and release their content into the  synaptic cleft.
Following, the tiny receptors of the post-synaptic neuron interact with the neurotransmitters. These ones bind into the receptors and cause an action as result. Likelihood can be increased and the cell becomes activated firing an action potential or it can be decreased.
Finally, the neurotransmitters molecules left in the synaptic gapdrift away by diffusion, or go back to the vesicles to be reused by a process called re-uptake, or are broken down by enzymes and component parts go back to the pre-synaptic neuron.

Yellow Wallpaper Essay

Since school started we have been analyzing “The Yellow Wallpaper” by Charlotte Perkins Gilman. Now that we have finished the story, our Literature teacher asked us to write statements for an essay and then write an essay in pairs. I worked with Rochi Hartmann and this is our essay on The Yellow Wallpaper.

“The Yellow Wallpaper” is written upon a paradox: the man and woman’s relationship.


In the story “ The Yellow Wallpaper” by Charlotte Perkins Gilman we can see how the husband and wife are not who they seem to be throughout the story. We see how they change towards the end causing a paradox in their roles as ‘crazy’ characters making us have to reevaluate the whole story.

On the one hand, we have the husband, a doctor, a man of science. We see an important reflection of positivism through his character. A man who in that time had the upper hand on decisions, he was the one who provided for the family and was basically ‘the king of the house’. At the start of the story we see how he portrays his wife as the crazy one, keeping her away from her own  child, imprisoning her in the house, not letting her work until she is ‘well again’. That being left to his own criteria, his own idea of what being well is like. But towards the end  tables are turned, the wife takes the power, when he’s trying to open the door and she tells him to go get the key himself. “The key is down by the front door, under the plantain leaf”. She kept trying for him to just go and do the job for once instead of her having to obey him every single time. After this is one of the most crucial moments in the story, where roles change. The husband opens the door and faints and she doesn’t even recognize him as her husband anymore, he’s a stranger for her: “Now why should that man have fainted?” He isn’t John for her anymore, he isn’t her husband, he’s a complete stranger.

On the other hand, we’ve got the wife and her role change. She’s a stay at home mother who was dragged to this huge house three miles from the village to be with herself until she gets better. Again, emphasizing on the fact that John will be the one who decides when she is better. “[The house] is quite alone standing”, a reflection of her situation since her husband is working all the time and she’s always in the room with the yellow wallpaper. The narrator makes us think she’s the crazy one throughout the whole story but at the end, comes the change in roles. “”I’ve got out at last,” said I, “in spite of you and Jane.” This is the moment in the story where we have to rethink it all and wonder who the crazy really is. She feels liberated from her controlling husband. “And I’ve pulled off most of the paper, so you can’t put me back!”” Maybe it is John, the one manipulating her. It is left to open interpretation.