Skeleton Wrap Up

Today we finished the bones and our skeletons. Tomorrow we will be starting three days on HIV/AIDS and the immune system. Later today I will post a picture of some of the skeletons.

Build a skeleton!

Working in groups of 3 you and your partners will build a skeleton complete with bones and joints. You will even add muscles in select places.

Follow the steps below to help guide you. Your skeleton should be between 1 and 2 meters tall.

1. Using the bone diagram which you just labeled, you will start by recreating these bones to SCALE on paper. Each time you make a bone, label it!

2. Once you have cut out and labeled all of the bones, think about what types of joints are found between the bones. NOTE: you do not need to make all of the joints in the hands and feet, nor in the spine. Instead, for example, on the hands, write that there are 27 bones in the hand, these are connected by saddle joints.Use paper clips, string, hole punches or other fasteners of your choice to make the joints move correctly. Remember that ligaments connect bone to bone. This is supposed to be a challenge! Think creatively!

3. Using red paper, make muscles for the quadriceps, hamstrings, biceps and triceps. Label these muscles, as well as write a brief description of how muscles work.

class in biolab tomorrow

We will have class in our regular room tomorrow. The dance studio is unavailable.

Addiction & and Bones!

Today students took a quiz on the brain and addiction. We spent the latter part of class introducing the skeletal system. Tonight for homework please read sections 36.1 and 36.2. Take notes! You will have a reading quiz.

Quiz and Reflection

On Monday you will have a quiz on all of the information we learned last week on the brain and the effects of drugs on the brain. You will have 25 minutes for the quiz, after which we will start on the musculo-skeletal system.

There is an opportunity for extra credit....read on!

Write a reflection answering the following questions. Your reflections will be graded (spelling, punctuation, content and thoughtfulness all count!) Your grade on the reflection will replace your lowest quiz grade. You should write about one paragraph for each question and your responses should be typed. I will not accept emailed responses and you need to turn this in during class.

1. Explain what you think were the three most interesting things you learned about the brain and addiction. Why were these things so interesting?

2. Did what you learn in the past week change your perspective on the brain and drugs? Explain why or why not.

3. What additional information would you have liked on this topic? Be detailed

Drugs influence neurotransmitters

Today we examined how various drugs impact neurotransmitters and how the route of drug administration affects a drug user.

Homework: read the information below and take notes. You will have a reading quiz on Friday. I realize it looks like a lot of information, but it's really only equivalent to 4ish pages in your text book.

Basic Science–Health Connection

Drug addiction is a complex brain disease. Preventing drug abuse and addiction and treating the disease effectively require understanding the biological, genetic, social, psychological, and environmental factors that predispose individuals to drug addiction.

Background Information

Individuals make choices to begin using drugs. Some people begin using drugs to relieve a medical condition and then continue to use the drugs after the medical need is over. Children who are depressed or who have a psychiatric disorder sometimes begin using illicit drugs to self-medicate. Other people begin taking drugs to feel pleasure, to escape the pressures of life, or to alter their view of reality. This voluntary initiation into the world of addictive drugs has strongly influenced society's view of drug abuse and drug addiction and their treatment.

When does drug abuse become drug addiction? No one becomes addicted with the first use of a drug. Drug abuse and drug addiction can be thought of as points along a continuum. Any use of a mind-altering drug or the inappropriate use of medication (either prescription or over-the-counter drugs) is drug abuse, but the point when drug abuse becomes drug addiction is less clear. Different drug abusers may reach the point of addiction at different stages. Scientists continue to investigate the factors that cause the switch between the two points.

Figure 4.1: The continuum of drug abuse and addiction.

Currently, drug addiction is defined as the continued compulsive use of drugs in spite of adverse health or social consequences.¹ Drug addicts have lost control of their drug use. Individuals who are addicted to drugs often become isolated from family or friends, have difficulty at work or school, and become involved with crime and the criminal justice system. For addicts, continuing their drug habit becomes their primary focus in life.

Certain drugs, including opiates and alcohol, cause strong physical reactions in the body when drug use stops. When a heroin addict stops taking heroin, he or she can experience a variety of symptoms ranging from watery eyes and a runny nose to irritability and loss of appetite and then diarrhea, shivering, sweating, abdominal cramps, increased sensitivity to pain, and sleep problems.² In general, withdrawal from heroin makes the abuser feel miserable. Withdrawal from other drugs, such as cocaine and amphetamines, does not lead to strong physical reactions. For most drugs, physical withdrawal symptoms can usually be controlled effectively with medications. Even though withdrawal from some drugs does not cause the abuser to have physical reactions, stopping drug use is difficult because of the changes the drugs have caused in the brain. Once the drugs stop, the abuser will have cravings, or intense desire for the drugs.³ Craving arises from the brain's need to maintain a state of homeostasis that now includes the presence of the drug. A person may experience cravings at any stage of drug abuse or addiction, even early in the experimentation phase of drug abuse. Cravings have a physical basis in the brain. Using PET imaging, scientists have shown that just seeing images of drug paraphernalia can stimulate the amygdala (part of the brain that controls memory) in drug addicts.⁴

Drugs of addiction do not merely cause short-term changes in an individual's cognitive skill and behavior. A drug "high" lasts a short time, ranging from less than an hour to 12 hours, depending on the drug and dose. The changes in the brain that result from continued drug use, however, can last a long time. Scientists believe that some of these changes disappear when drug use stops; some disappear within a short time after drug use stops, and other changes are potentially permanent. One of the first changes in the brain that occurs in response to repeated drug abuse is tolerance. Tolerance develops when a person needs increasing doses of a drug to achieve the same "high" or "rush" that previously resulted from a lower dose of the drug. Two primary mechanisms underlie the development of tolerance.³ First, the body may become more efficient at metabolizing the drug, thereby reducing the amount that enters the bloodstream. Second, the cells of the body and brain may become more resistant to the effect of the drug. For example, after continued cocaine use, neurons decrease the number of dopamine receptors, which results in decreasing cocaine's stimulatory effect. Opiates, on the other hand, do not cause a change in the number of receptors. Instead the opiate receptors become less efficient in activating the second messenger system, thus reducing the effects of the opiates.

Drugs can cause other long-term changes in the anatomy and physiology of the brain's neurons. Alcohol, methamphetamine, and MDMA (Ecstasy) can kill neurons.³ Unlike other types of cells in the body, neurons in many parts of the brain have little or no capability to regenerate. (Recent studies have shown that the adult human brain can generate new neurons in the hippocampus, a part of the brain important for learning and memory.⁵ Other parts of the brain do not show this ability.) Alcohol kills neurons in the part of the brain that helps create new memories. If those neurons die, the capability for learning decreases. Methamphetamine kills dopamine-containing neurons in animals and possibly in humans as well.⁶ MDMA kills neurons that produce another neurotransmitter called serotonin.⁷ In addition to neurotoxic effects, drugs can significantly alter the activity of the brain. PET scans of cocaine addicts show that the metabolism of glucose, the primary fuel for cells, is drastically reduced in the brain, and that this decrease in metabolism can last for many months following cessation of drug abuse.⁸

In addition to the functional and anatomical changes in the brain, drug abuse puts addicts at higher risk for other health problems. For example, inhalant abuse can lead to disruption of heart rhythms, and snorting cocaine can lead to ulcerations in the mucous membranes of the nose. In addition, drug addicts are at increased risk of contracting HIV or AIDS through shared needles. Similarly, hepatitis B and hepatitis C are much more common among drug addicts than the general population. Tuberculosis is another concern. Drug abuse and addiction also are contributing factors in motor vehicle accidents.

Animals as Research Models

Why do scientists study the brains of nonhuman animals? Scientists use animals in research studies because the use of humans is either impossible or unethical. For example, when scientists investigate the effects of drugs of abuse on brain function, either the question they are asking cannot be answered in a living human or it would be inappropriate to give drugs to them.

The use of animals as subjects in scientific research has contributed to many important advances in scientific and medical knowledge. Scientists must analyze the goals of their experiments in order to select an animal species that is appropriate. Scientists often use fruit flies (Drosophila melanogaster) when they want to learn more about genetics. However, fruit flies are not a very good model if a scientist is investigating muscle physiology; a mouse may be a better model for those experiments. Although scientists strive to develop nonanimal models for research, these models often do not duplicate the complex animal or human body. Continued progress toward a more complete understanding of human and animal health depends on the use of living animals.

Guidelines for the Use of Animals in Scientific Research

Scientists who use animals as research subjects must abide by federal policies that govern the use and care of vertebrate animals in research. The Public Health Service established a policy that dictates specific requirements for animal care and use in research. This policy conforms to the Health Research Extension Act of 1985 (Public Law 99-158) and applies to all research, research training, biological testing, and other activities that involve animals.¹⁴ The principles for using and caring for vertebrate animals in research and testing are as follows:

• The transportation, care, and use of animals should be in accordance with the Animal Welfare Act and other applicable federal laws, guidelines, and policies.
• Procedures involving animals should be designed with consideration of their relevance to human or animal health, the advancement of knowledge, or the good of society.
• The animals selected should be of an appropriate species and quality and the minimum number required to obtain valid results. Methods such as mathematical models, computer simulation, and in vitro biological systems should be considered.
• Procedures should minimize discomfort, distress, and pain to the animals.
• Procedures that may cause more than momentary or slight pain should be performed with appropriate sedation, analgesia, or anesthesia.
• Animals that would suffer severe or chronic pain or distress that cannot be relieved should be painlessly killed.
• The living conditions of animals should be appropriate for the species. The housing, feeding, and care of animals must be directed by a veterinarian or a trained, experienced scientist.
• Investigators who work with animals must be appropriately qualified and trained for conducting procedures on living animals.
• Exceptions to any of these principles must be reviewed and approved by an appropriate committee prior to the procedure.
• An Institutional Animal Care and Use Committee (IACUC) oversees all animal use in each institution where animal research is conducted. The IACUC must give approval for the research plan and species to be used. IACUCs include both scientists and nonscientists from outside the institution. The nonscientists are often representatives of humane

Information from the NIH's lessons on Drugs, Brain & Behavior.

Neurons & Neurotransmitters

The goal for today was for students to understand the parts of a neuron and understand how signals are transported between neurons.

The major concept for today was: Neurons convey information using electrical and chemical signals.

After reviewing the homework, we moved on to what a neuron looks like and how signals are transported between neurons.Click the picture above to link to the animation that describes the role that electrical and chemical signals and the transmission of signals between neurons.Click the picture above to see how neurotransmitters influence the electrical activity in neurons.

Homework:
Click on the picture below to link to the animation. You should skip Case A because it doesn't seem that the animation is working properly. You should practice with Cases B, C and D. In order to be successful with this you need the following information:

Dopamine: The neurotransmitter that produces feelings of pleasure when released by the brain in the reward system. Dopamine is inhibitory.

GABA (gamma-aminobutyric acid): The major inhibitory neurotransmitter in the brain

Glutamate: the most common excitatory neurotransmitter in the brain.

Starting our new section: Drugs, Brain & Behavior

Is this elephant missing a leg?

Today we started our new section on Anatomy & Physiology with the brain. Students completed a "What I know, What I think I know, What I want to know" about the brain & drugs. We focuses on the parts of the brain and their functions. Students examined PET Scans of brains to see how different regions of the brain are responsible for different functions.

Homework:
1. Finish the complete the activity on interpreting PET Scans, you can link to it here.

Bonus Point:
2. Read the story about Phineas Gage below and answer the two questions at the end of the article.

Phineas Gage Article & Questions

Read this article below and answer the two questions at the end of the article.

Due to an accident while he was working, Phineas Gage made a contribution to the under-standing of how the brain works. In 1848, 25-year old Phineas Gage worked for the Rutland and Burlington Railroad Company laying railroad tracks across Vermont. Before railroad track could be laid, however, the uneven ground needed to be leveled. Gage and coworkers had to drill holes in the stone, put explosive in the holes, cover the explosive with sand, and then use a fuse and tamping iron to trigger an explosion. One day, an accident occurred that changed Gage’s life forever. The explosive went off early sending the tamping iron, which was 1.25 inches in diameter and 43 inches long, shooting into Gage’s face, through his skull and brain, and out the top of his head. The tamping iron landed about 25 yards away. Gage regained consciousness within a few minutes. Amazingly, he not only survived the blast, but he was able to talk and to walk! His coworkers took him to the doctor who cleaned and bandaged the wounds, the standard medical treatment at the time.

Although Gage survived the physical injuries from the blast, he was a changed man. He appeared to be just as intelligent as before the accident, and he did not have any impairment in movement, speech, or memory. But, something was different. Prior to the accident, he was a responsible, intelligent and likeable person. After the accident, he was irresponsible, used profanity extensively, and demonstrated no respect for social customs. His friends commented that “Gage was no longer Gage.” He could not hold the responsible jobs that he had prior to the accident and apparently wandered for the next several years. Phineas Gage ended up in San Francisco in the custody of his family where he died approximately 12 years after the accident.
Twenty years after the accident, the physician who treated Gage correlated the behavioral changes with damage to the frontal region of the brain. At the time, the brain was thought to control language and movement, but the suggestion that the brain functioned to process emotions and social behavior was new. In addition, scientists at the time believed the brain lacked localized functions. Unknowingly, Phineas Gage contributed to our understanding of how the brain processes information.

In the 1990s, scientists used their improved understanding of brain function, computer modeling techniques, and new data from Gage’s skull. Based on this information, they found that the accident damaged both hemispheres of the frontal lobe, which is the part of the brain that influences social behavior. Today, physicians see patients with damage to the frontal lobe that has occurred through motor vehicle accidents, gun accidents, or major falls. These individuals, like Phineas Gage, often have dramatic changes in their emotional and decision-making abilities.

1. How did Phineas Gage change after the accident?
2. How did Phineas Gage’s accident change scientists’ understanding of the brain?

Cell Cycle & Cancer Test

Today students had their test on the cell cycle and cancer. Yesterday and on Wednesday students presented their cancer flyers and we all learned a lot about different types of cancer, such as:

Kaposi Sarcoma
Bone Cancer
Leukemia
Eye Cancer
Brain Tumors in Adults and in Children
Melanoma
Lung Cancer - Small Cell
Liver Cancer
and many others.

After the test students were given review questions for the final exam. Can you believe we only have 17 more class periods until the final exam?! These review questions are due on Monday.

History of Cancer

Click the image below to link to a timeline on cancer.

Types of Cancer Flyers

Today in class students started to work flyers about different types of cancer. The guidelines are posted below and I will put up a sample later today.

G Block: yours is due on Wednesday Nov. 11

D & F blocks: yours is due on Thursday Nov. 12

Go to: www.cancer.org

Under “learn about cancer” click choose a topic. No students in the same class may have the same topic.

Here are the guidelines:

1 page

2-3 figures/pictures

Name of your type of cancer:

Causes/treatments

Signs/symptoms

Diagnosis

Stages

2-3 key stats

A footer or use footnotes to cite your sources. Print the flyer on the colored sheet of paper you were given in class. You most certainly may embellish your flyer with markers/crayons/colored pencils. You will share this with the class the day it is due.

NOTE: The majority of students in F and G blocks did not remember to bring their computer to class, so they picked their cancer topics and spent the remainder of class reading and answering questions from the "What is Cancer?" packet. If you are in F or G block, please make sure you bring your computer to class on Tuesday.

Welcome Family!

It's family weekend, which means that parents were able to sit in on classes and see what a day in the life of their student is like at TASIS. Yesterday we used an animation from the Nobel Prize Website to examine how the cell cycle is controlled. We also watch a video clip on bacterial replication (called binary fission) and played some trivia on cancer.

Mitosis & Microscopes

Today students had a "fake" quiz on Mitosis to see how well they know the material. After going over the quiz and last night's homework, students continued to practice finding the stages of mitosis using whitefish blastula and onion root cells.


Homework: None! Enjoy the night off :)

Microscopes, Limits to cell size, stages of mitosis

Today students took notes on the three types of microscopes, limits to cell size and the stages of mitosis.
Homework: Complete "Mitosis Homework #1."

Starting Mitosis

Today students examined cells undergoing mitosis. Here's what happens in the cell:



Homework: Read pages 246-248. Draw the stages of mitosis, in order, with labels (centrioles, nuclear envelope, chromatin, centromere and spindle -- where appropriate).