Continuing with Coordination from Chapter 13 of the Coursebook, we analyzed in depth the eye organ as a receptor organ. In today’s class we learned how the Pupil Reflex works. In order to do that, we used the flash of our cellphones to focus CAREFULLY on a companions eye and we wrote down our observations.
-With bright light, the pupil constricted while the size of the iris stayed the same.
-With no/dim light, the pupil dilated while the iris was not affected.
• Search for a video in which the pupil reflex is explained.
• Complete the following diagram:
Circular & Radial muscles of the iris
• What is the effect?
In the case that the eye is exposed to bright light the circular muscles contract while the radial muscles relax. This way the pupil constricts so little light gets into the retina, and the cones there are not damaged.
In the case the the eye is exposed to dim light, the radial muscles are the ones that contract while the circular muscles relax. This way the pupil dilates/widens allowing as much light as possible into the retina, where rods can detect it.
For this last term, our biology teacher gave us a creative project to work on. This consisted on making a model of the urinary system with trash. To make this model, we went through a large process. First, all throughout the weekend we looked up for things that we thought it could be useful to our project like for example can of coke, sponges, caps and straws. We collected many things but we didn’t use all of them. It was not easy for us to decide which element was the correct one for each organ because we had to choose the one that fitted better for each. After a long time of research we had decided how our project would be. Carefully we started pasting all the objects we had chosen previously. We used an old sponge for the two kidneys. We cut the sponge in two equal pieces to form to kidneys that are identically to each other. Then, we used a big cup of jam to create the bladder. Furthermore, to make the urethra we used small caps of cokes and water that we had recycled. Moreover, we used many straws to make the aorta and the vena cava. To give color to both of them we covered the straws with elastic bands red and blue. And to make the renal artery and the renal vein we also used old elastic bands. To conclude, we made the urethra with an old wine cork. We cut it into two and used one half to make the organ. After all this work, we started to label each organ so that any person that looks at our project could recognize each of the organs. Finally, our project is know ready to present, here is a picture of it! Hope you like our work!
Functions of the organs:
- The kidneys are two organs found on the left and right sides of the body in vertebrates. They are located near the middle of your back, just below the ribcage. They receive blood from the paired renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the bladder. Kidneys produce hormones, absorb minerals, flitter blood and produce urine. Every kidneys process about 200 quarts of blood to sift out about 2 quarts of waste products and extra water. The waste and extra water become urine, which flows to your bladder through tubes called ureters. Each adult kidney contains around one million nephrons.
- The ureter is a tube that carries urine from the kidney to the urinary bladder. There are two ureters, one attached to each kidney. The upper half of the ureter is located in the abdomen and the lower half is located in the pelvic area. The ureter is about 10 to 12 inches long in the average adult. The tube has thick walls composed of a fibrous, a muscular, and a mucus coat, which are able to contract.
- The bladder, also known as the urinary bladder, is an expandable muscular sac that stores urine before it is excreted out of the body through the urethra. It is located in the lower abdominal area near the pelvic bones.
Urine is made in the kidneys, and travels down two tubes called ureters to the bladder. The bladder stores urine, allowing urination to be infrequent and voluntary.
During urination, the bladder muscles contract, and two sphincters (valves) open to allow urine to flow out.
- In both genders, the urethra works as a tube connecting the urinary bladder to the genitals. The bladder collects and stores urine until it is ready to be discharged through the urethra.
- The male urethra connects the urinary bladder to the penis. Once the bladder becomes full, urine flows through the urethra and leaves the body at the urethral meatus, which is located at tip of the penis. The urethra is more than just a urinary duct; it also serves as a conduit for semen and sperm during sexual acts.
- The female urethra is quite a bit shorter than its male counterpart and its opening is situated between a woman’s clitoris and vagina.
- There are two renal veins, a left and a right. They branch off the inferior vena cava and take away (drain) deoxygenated blood ( without oxygen) from the kidneys. As they enter the kidneys, each vein separates into two parts. The posterior veins assist in draining ( taking away) the back section of each kidney, while the anterior veins assist the front part. These veins also are responsible for draining blood from the ureter, which transports urine away from the kidneys to the urinary bladder.
- There are two blood vessels leading off from the abdominal aorta that go to the kidneys. The renal artery is one of these two blood vessels. The renal artery enters through the hilum, which is located where the kidney curves inward in a concave shape. Under normal circumstances, once the renal artery enters through the hilum, it splits into two main branches, which each then split into numerous smaller arteries, which deliver blood to different areas of the kidneys, known as nephrons. Once the blood has been processed here, it is sent back through the renal vein to the inferior vena cava and to the right side section of the heart.
- The aorta supplies the blood that is being filtered by the kidneys. Because the blood is being filtered by the kidneys, it’s important that they be located somewhere that a lot of blood can filter through, and that a sufficiently big artery run through it. This is why the kidneys are located just below the ribs in the upper abdomen and that a major branch of the aorta runs through.
Inferior vena cava:
- The inferior vena cava is a large vein that carries de-oxygenated blood from the lower body to the heart. De-oxygenated blood means most of the oxygen has been removed by tissues, and therefore the blood is darker.
Its walls are rigid and has valves so the blood does not flow down via gravity.
I have worked with Lucia caviglione fraga and this is our project:
On November the 8th, we did a practical on our practical skills class about the reaction lime water has upon being in contact with Carbon Dioxide, as it is a carbon dioxide indicator. We have already analyzed this Practical, but now we are actually putting it into practice.
Our hypothesis is that like water will turn cloudy once it’s in contact with CO2. We placed four test tubes containing lime water in a rack. Then we used four straws, one for each test tube, and started to blow so that the carbon dioxide we expired came into contact with the lime water. We breathed out several times, 30 to be exact, with short intervals in between, and finally the lime water turned cloudy as expected.
I worked on behalf of Lucia Caviglione, Belen Brito Peret, Anouk Laferrere, Sofia Mele and Trinidad porretti.
these are the pictures before and after:
In our biology class our teacher told us to do this activity:
Activity: 11.3 (book page 143)
A1: It is important to boil the water so that any dissolved air can be driven away.
A2: Sugar solution must be cooled before adding the yeast because otherwise the yeast will be cooled and it won’t respire(as the practical requires).
A3: Liquid paraffin is added to isolate the solution of yeast in sugar from the air.
A4: In apparatus A the limewater solution turned cloudy, showing that the (living) yeast respires carbon dioxide and the limewater absorbed it. In apparatus B the limewater solution remained clear, showing that the yeast (dead as it was cooked) did not respire and therefore the limewater did not change as it did not absorbe carbon dioxide.
A5: In the sugar solution containing living yeast I would expect to find ethanol at the end of the experiment as the yeast respired (anaerobically) and this process is characterized by the producuction of ethanol as a result.
In our biology class, our teacher asigned us a project on human physiology. In groups, we had to choose an organ of our body and create a poster in which we should include some information about it, located in our teacher’s blog. Then we should record ourselves talking and explaining each of the concepts located in the poster. I worked with Valentina Re and Belén Brito Peret, and we choose the liver. This is our work:
In our biology class we were asked to take a picture of our teeth and then label the teeth that we see.
Enzymes are all functional proteins
There are enzymes whose function is to break down
And sometimes to build up
In saliva we have an enzyme whose name is amylase
What that amylase do?
The function is to break down bonds. Large molecules into smaller molecules
The molecule of starch is isolable
One characteristic of enzymes is that that the name end in ASE
Protease is an enzyme that work with proteins
Lipase is an enzyme that work with lipids
What type of energy is present in the food we eat?
We need to eat a balanced diet
To have a varied diet
Proteins. Contains energy
Carbohydrates. Contains energy
Lipids– fats and oils. Structural storage–Contains energy
Fibre— roughage. To keep large intestine working properly
Vitamins are organic substances. Organic means that are made by living organism. They help in metabolism
Minerals. As an example calcium, potassium, etc. minerals are inorganic. They come from the soil.
Obesity: too much food — diabetics– coronary heart disease
Coronary heart disease: too much saturated/ animal fat in the diet result in high cholesterols levels.