Digestive & Excretory Systems Review

As a review for the Digestive & Excretory Systems Quiz on Thursday, you may create a multiple choice question (with at least four answer choices) for 1 point of extra credit toward your test/quiz score. The question may be on content that is related to the digestive system or excretory system. Use the textbook, notes, and worksheets to help you. Post the question, along with your name and period, in the comments section by the start of class on Thursday. Secondly, the Digestive System PowerPoint slides have been posted under "Lectures." Work on your notebooks and start reviewing for the quiz. Thirdly, work on your CST Final Review Study Guide.

EXTRA LEARNING:
In class, we learned about lactose intolerance (or lactase deficiency). Here is a related condition known as hereditary fructose intolerance in which the body lacks the enzymes to digest fructose (source: NIH).

The Human Appendix

Today we learned a lot about the structures and functions of the human digestive system. Your Digestive System worksheet is due next Monday, April 30th. Also remember to work on your CST Final Study Guide. There are roughly 100 questions, so work on them a few each day. Don't wait until the last minute. That assignment is due on May 7th.

EXTRA LEARNING:

In class, I talked about the human appendix and how the most recent research gives evidence that it is not a vestigial organ like people in Darwin's time thought. Read about those recent findings in this article: "Evolution of the Human Appendix: A Biological 'Remnant' No More." 

Circulatory & Respiratory Systems Quiz Tomorrow

Remember to review your notes, worksheets, and the textbook for your Circulatory & Respiratory Systems Quiz Tomorrow. The PowerPoint slides have been posted under "Lectures." Come in during tutorial to ask questions if you have them. I am also available via email.

Your Respiratory System worksheet is also due tomorrow. =)

Circulatory & Respiratory Systems Review

As a review for your Circulatory & Respiratory Systems Quiz on Wednesday, you may create a multiple choice question (with at least four answer choices) for 1 point of extra credit. Post a question in the comments section along with your name and period by Wednesday.

Secondly, the CST Final Study Guide has been posted under "Documents." This is a long-term assignment intended to help you review for the class final as well as the CST. The study guide is due on May 7th, so you have a few weeks to complete it (but don't wait until the last minute).

Green Blood?

EXTRA LEARNING:
One of my students asked if blood is ever a color other than red. The answer is complicated. The color that we see in blood is the result of different elements bonding with each other. An important note to remember is that though most (or all) biology textbooks represent deoxygenated blood vessels as blue, human blood is never blue. Blood that is rich in oxygen (such as the blood in your arteries) is bright red. Blood that is poor in oxygen (such as the blood in your veins) is dark red. Because blood contains iron, if it is left lying exposed to the air for a while, it will start to turn brownish-red because the iron starts to "rust." In some very rare cases, blood that interacts with other elements will be different colors. For example, here is a somewhat famous case of a man with dark green blood because a medication caused sulfur to bind to the hemoglobin, resulting in this unusual blood color. Once he stopped taking that medication, his blood returned to red. Read about that case in these news articles: BBC News and CBC News. Doctors discovered the rare case when they had to do surgery on this patient. Those who read the articles will also learn about how important blood circulation is and why this patient had to undergo surgery to begin with.

Open House Tonight

Remember to work on your Circulatory System worksheet (the one with the heart anatomy diagram on the front). We will correct this worksheet in class tomorrow. Also remember that tonight is Open House. Bring your parents to LHHS to see what you've been learning at school. =)

EXTRA LEARNING:

In class, I showed you part of a documentary about how scientists are doing research in regenerative medicine to replace body organs such as the heart. Here is the documentary on National Geographic in case you are interested: "How to Build a Beating Heart."

Open House is Tomorrow

Open House is this Thursday from 5:30-8:30pm. Classroom visits are from 7:00-8:30pm. Click on this link to view a schedule of when activities are occurring during Open House. This is a great time for your parents to come see your classrooms and to speak with your teachers. =)

EXTRA LEARNING:
Today, we learned about the importance of the heart, including how it is carefully protected within the rib cage. Some people, however, are born with hearts outside of their bodies, a rare condition known as Ectopic cordis. In these cases, surgeons have to intervene through a series of surgeries to correctly position the heart back inside the body. Read about it in this ABC News article. 

Welcome Back!

Welcome back from Spring Break. I hope you all had a relaxing and/or productive week. Now it's time to get back to work. Your Nervous System Quiz is tomorrow so review your notes, the textbook, and the lab. The Nervous System PowerPoint slides have been posted on the class wesbite under "Lectures." Other assignments due tomorrow include your Nervous System Reaction Time Lab, your notebooks, and all worksheets for the Nervous System Unit. Notebook grading sheet #10 is posted under "Documents."

EXTRA LEARNING:
Sleep is very important for the proper functioning of the nervous system. So remember to get your work done early so you can get enough sleep tonight. However, if you are done with all your work, and want to enjoy some educational entertainment, then watch this video clip about sleep on NOVA Science Now. And here is a clip from a longer documentary on Frontline specifically about sleep and the teenage brain.

Have a Wonderful Spring Break!

Next week is Spring Break so I wish you all a wonderful time going on vacation or just relaxing at home. For those who unfortunately find themselves somehow overcome by boredom or want to fill their time doing academic things, below are some things you can do:

1) Work on your notebooks. The Nervous System PowerPoint slides have been posted under "Lectures." 
2) Do the Science Book Review extra credit opportunity. You may still sign up to do the extra credit at this point, with a penalty of a 2-point deduction to be fair to those who signed up on time. Remember that an electronic copy is due on Turnitin.com on Sunday, April 15th and a hard copy is due in class on April 16th. The class IDs for Turnitin are the same as last semester: 4633054 for 6th period and 4633052 for 7th period. The password is "hawks."
3) Work on your Nervous System reaction time lab. 
    The class data is posted under "Documents." Your lab report is due on April 17th, the day of the quiz.
4) Study for the Nervous System Quiz. You will take the quiz on Tuesday, April 17th.
5) Educational entertainment. Below is a list of science documentaries that relate to neuroscience:
     a) How Does the Brain Work? (NOVA Science Now) 
     b) Inside the Teenage Brain (Frontline)
     c) How Smart Are Animals? (NOVA Science Now)  
     d) Fatal Insomnia (National Geographic)
     e) Parkinson's Disease (Frontline)
      f) Alzheimer's Disease (PBS)

See you after Spring Break!

Mirror Neurons and Magnetic Mind Control

Remember to print out your Nervous System Lab and bring it to class tomorrow.

EXTRA LEARNING:

Since we're learning about the nervous system, I thought I'd share with you some other fascinating findings in the field of neuroscience (the science of the brain). In the 1980s and 1990s, neuroscientists in Italy (accidentally) discovered mirror neurons. These are neurons that allow us to sort of experience what others are doing simply by watching them; they are thought to be the root of human empathy. Watch a clip about mirror neurons on NOVA Science Now. You'll also see Dr. Ramachandran again. (He's pretty famous in the field of neuroscience.) Secondly, remember how our brain is sort of electric? Electricity and magnetism are related, so neuroscientists have been able to use special magnets to perform "mind control." This can be as simple as making your muscles twitch or applying the findings to medicine in the form of tricking your brain to feel less pain after surgery. Watch a clip about it here: "Magnetic Mind Control" (NOVA Science Now).

Congenital Insensitivity to Pain

Sections 35-4 and 35-5 as well as your brain diagram and conceptual map of the nervous system are due tomorrow, Thursday. Also, print out your Nervous System Lab from the "Documents" section. We will do this very short lab on Friday.

EXTRA LEARNING:
In class, we learned about how the nervous system integrates sensory information through various types of receptors, such as pain receptors (nociceptors). Pain detection is important to survival because pain indicates to us that something is wrong within our body. Some people, however, are born without pain receptors and are thus unable to feel pain at all. Here is a clip from 20/20 that reports on this medical condition, known as congenital insensitivity to pain (or more formally known as hereditary sensory autonomic neuropathy).

Split Brain

EXTRA LEARNING:
Some of you were interested in the condition known as split brain. Sometimes, there are electrical miscommunication problems between the two hemispheres of the brain, leading to severe seizures. So neurosurgeons usually sever the corpus callosum to prevent the two hemispheres from communicating with each other and thus stop the seizures. Some of you asked about the consequences of this procedure. On levels of both behavior and personality, neurologists have discovered that they essentially create two human beings, so to speak, since the two hemispheres do not communicate with one another and are not aware of what the other is doing (or thinking). Dr. Ramachandran of the University of California in San Diego (UCSD), for example, documented a patient whose split brain resulted in one hemisphere being atheistic and the hemisphere being theistic. In his lecture, Ramachandran talks about the case and makes a funny remark about its implications. And here is an older study about behavioral consequences from the perspective of a split brain patient.

The Amazing Nervous System

Work on your nervous system worksheets this week. This is an ongoing assignment, so different sections will be due on different days. The first two sections, 35-2 and 35-3, will be due on Wednesday.

EXTRA LEARNING:

Today, we learned about the basic structures of neurons, including some diseases and disorders that result from neuron deterioration. One example was Tay-Sachs Disease, which results when harmful cell membrane components (known as gangliosides) accumulate in cerebral nerve cells and eventually lead to their death. Another genetic neuro-degenerative disease that was the featured in the film Lorenzo's Oil is adrenoleukodystrophy (ALD). (Those who are interested in watching Lorenzo's Oil may find it on YouTube.) In ALD, over-accumulation of a certain fatty acid leads to damage of myelin. Without the myelin sheath, neurons cannot conduct impulses normally, leading to damage of the brain and peripheral nervous system.