Homeostasis: Control of Blood Sugar Levels

In our Biology class we have been studying Homeostasis, and in order to understand how it works, in terms of the control of blood sugar levels, our teacher, Male, asked us to make a flow chart showing what happens when the levels of glucose in blood increase and decrease.

This is the flow chart I made:

*flow chart*

NEGATIVE FEEDBACK: the negative feedback control system responds when conditions change from the ideal or set point and returns conditions to this set point. If the level of something rises, control systems reduce it again and if the level of something falls, control systems raise it again.



This is a comparison table between Diabetes type 1 and type 2:


GENETIC ENGINEERING: process to make sure there is enough insulin for everyone who needs it. It involves transfering artificially selected genes from one living organism to another living organism of the same species.



High blood glucose – insulin is secreted – Liver cells use glucose in respiration and some is stored as glycogen – blood glucose consentration falls – normal levels of blood glucose.


Low blood glucose – glucagon is secreted – liver breaks glycogen into glucose – glucose is released from the liver into the blood and glucose consentration rises –  normal levels of blood glucose.

Endocrine System

These are some questions we did in class to introduce the topic of Endocrine System. I worked with Catu Grosso.

1) A hormone is a chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs.


hwhh  ger

Testis produces testosterone, and ovary produces oestrogen.

3) Adrenaline is produced in the medulla in the adrenal glands as well as some of the central nervous system’s neurons. Within a couple of minutes during a stressful situation, adrenaline is quickly released into the blood, sending impulses to organs to create a specific response. It triggers the body’s fight-or-flight response, it prepares your body for a vigorous action. Gives you more energy, your heart beats faster. It  also triggers the blood vessels to contract to re-direct blood toward major muscle groups, including the heart and lungs. The body’s ability to feel pain also decreases as a result of adrenaline, which is why you can continue running from or fighting danger even when injured. Adrenaline causes a noticeable increase in strength and performance, as well as heightened awareness, in stressful times. After the stress has subsided, adrenaline’s effect can last for up to an hour.

4) video

Presentation on Cocaine

In our Biology class we have been studying drgus; I had to make a presentation about Cocaine with Agos, Cata and Gonzalo. We explained the main concepts and ideas of this drug, its effects, and a case of a famous person which was addicted to it. We made an Easel.ly, hope you like it.

The Eye as a Sense Organ

In our biology class we have been studying the eye. This is an activity me and Catu Grosso did. We watched the animations in Male’s blog and answered the questions in the booklet. 

This is the video we found for question 6.

Our flow chart: 

bright light – cones in retina – brain – muscles in iris

*effect: circular muscles contract, radial muscles relax. These are antagonist muscles, muscles that work against each other.

*response: pupil constricts.

dim light – rods in retina – brain – muscles in iris

*effect: circular muscles relax, radial muscles contract.

*response: pupil dilates.

9) 2)b) When object O comes closer to the eye, the ciliary muscle contracts, the suspensory ligaments are slackened (are loose), and so the lens is allowed to bulge.

4)a) ciliary muscle contracts – allows lens to become fatter for focusing on close objects. (ACCOMMODATION)

iris circular muscle contracts – pupil constricts (PUPIL REFLEX)

5)a i) They detect light and send it to the brain as electrical impulses. (Change light into electrical impulses)

ii) Rod cells are sensitive to dim light but do not respond to colours. Cones are sensitive to bright light and distinguish different colours of light (blu, red and green).

b) sensory neurone. They have a long axon, this way they can send the impulses to the brain.

c) Cornea, lens, retina.

d) i) biseps contracts and triceps relaxes.



Nervous system

On our Biology class we started seeing the Nervous System, one of the topics for the IG. This is an activity I did in class, with Catalina Grosso. 

B)These are the three types of neurons:

-Sensory neurons: they recieve impulses and send them to the interneurons.

-Relay neurone: passes the impulse on to the brain.

-Motor neurons: transmit signals from the brain to the spinal cord to the muscles to initiate action or response to stimuli.

C) Photo

D) Video 1

Video 2



In Biology we have been studying the process of Respiration, and our teacher Male usked us to work in gruoups and gave us this task. I worked with Tomas, Cata and Luna. These are pur answers:

  1. The cells in our body need energy to: Contract muscles, so we can move; make protein molecules by linking together amino acids into long chains; repair damaged tissues through cell division so we can grow; carry on active transport; transmit nerve impulses, so we can transfer information quickly; to produce heat  inside the body, to keep the body temperature constant if the environment is cold.

3. When we run in a race, for example, we need a lot of oxygen in order to release energy to contract our muscles. We keep on running, maybe faster, and we need every time more and more energy. Our heart starts to beat faster because we need energy to reach our blood more quickly since we are constantly losing it. But eventually we can’t breath more quickly than we have been doing. There is when we produce “extra energy” by anaerobic respiration. Glucose is broken down without combinating it with oxygen. This action releases lactic acid and energy. “Oxygen Debt” is this action. When we “borrow” some extra energy without “paying” for it with oxygen. As a consequence of this we have a lot of lactic acid left in our muscles and blood which can be broken down by combinating by aerobic respiration.


Respiratory system

In Biology we have been studying the circulatory system, respiration and gas exchange. This is a table Male, our teacher copied for us to study.


Comparing the amount of carbon dioxide in inspired and expired air we lead to a hypotesis, the expired air contains more carbon dioxide than the inspired air.



Cholera and diarrhoea

In Biology we are now studing the diseases of Diarrhoea and Cholera. We watched a video about it and then had to answer some questions based on it. I worked with Lucila Giambruni.


1) Cholera signs are diarrhoea, vomiting, low blood pressure, rapid heart beat, irritability and fever; and the symptoms are weakness and dehidration.

2) In the video, Cholera spread through the village by transmitting the bacteria through the vomit and diarrhoea that went to the river and then the water of the river was used by people to cook and wash their hands. Also, the flies fed on this water and so caught the disease, and then transmitted it to the food which would be then eaten by the people.

3) Diarrhoea is a conition in which feaces are discharged from the bodies frequently and in a liquid form.

4) The Cholera bacterium lives in the small intestine where it produces a toxin that stimulates the secretation of chloride ions. This ions accumulate in the lumen of the small intestine and increase the concentration of fluids, lowering the water potential.

5) The boy treated his father by giving him a mixure of pure water, salt and sugar. After this, after his father regained some strenght, he took it to the hospital to be treated in better conditions.

6) Ways to prevent the disease:

-Wash your hands often
-Boil water in order to kill Cholera bacteria
-Peal food which might be contaminated by bacteria an also boil it
-Put toilets at least 30 meters way from the river so as no o contaminate it with the bacteria of the feaces.