May 4th Lecture on Reproduction

Today was definitely an interesting lecture with lots of great questions!  We started on slide 49 and finished on slide 76.  Don’t forget about the two review sessions this week…Thursday at 6:30pm and Saturday at 2pm, both in SI 3081!  Dr. Hartley is going to buy pizza for the Thursday night session so don’t miss it!!

First Question…Why do girls cycles sync together when they live in close proximity?

After much research, I discovered that it’s not actually the cycles syncing together, but rather just though illusion.  Because a females cycle can last anywhere form 21-35 days, with a 3-7 day menstruation in there, it’s quite possible that cycles will overlap.  It may not be completely synchronized on purpose, but because of the vast differences in length of cycles, is quite possible to share a few days with your neighbor or close friend.  Many studies have been done to figure out why cycles seem to sync together, but there hasn’t been any beneficial evidence to prove the synchronization.  Many scientists have noticed that it seems to occur between close friend groups and roommates as opposed to neighbors that don’t care for each other or friends that don’t live together.  More research is being conducted as it is quite an interesting topic, but it is probably best to know, especially for those boys living in the dorms with lots of girls, that the chances of all the girls having PMS at the same time is very slim!

For more information, here is a website I found that seems to be fairly helpful on the topic: Women’s cycles

Question 2: Can a spike in temperature be used to predict ovulation?

Unfortunately, no.  Research has been done to prove that a woman’s temperature will increase around ovulation, but occurs 12-24 hours after ovulation due to the increase in progesterone.  Some researchers believe this is too late to utilize maximum fertility, but some researchers believe that upon detection of a temperature increase, a woman is still able to conceive.  The changes in temperature will be very slight, so a basal body temperature (BBT) thermometer needs to be used in the morning when a woman first wakes up before even getting out of bed.  The temperature increase can be anywhere from 0.4 – 1.0 degrees, thus the need for the BBT thermometer as it can detect small temperature changes better than a regular thermometer.  If it were possible, though it hasn’t been proven to be yet, a woman is most fertile 2-3 days before the spike in temperature.  Until that is something that can be determined, there are a few other ways to determine when a woman will ovulate.  There will be a change in the woman’s cervical mucus, with most women saying this resembles raw egg whites and some women can even feel ovulation.  This condition is called Mittelschmerz and can last a few minutes to a few hours with most women experiencing a vibrating sensation, to mild achiness all the way to intense pain.

For more information, visit Ovulation Calculator

Question 3:  What causes morning sickness?

First off, morning sickness is a misnomer!  Nausea and vomiting can occur at any time of day for a pregnant woman, though most experience the worst of it in the morning, hence the morning sickness.

Fun fact: 75% of women experience nausea and vomiting during their pregnancy!

There is really no known reason as to why morning sickness occurs, but many think it is due to the many physical and hormonal changes that occur in a woman’s body during pregnancy.  hCG (human chorionic gonadotropin) is one hormone that is seen to be a culprit for morning sickness.  There is no known reason as to why, but it’s a prime suspect because the timing is right: nausea tends to peak around the same time as levels of hCG.  And, conditions in which women have higher levels of hCG, such as carrying multiples, are associated with higher rates of nausea and vomiting.  Another suspected hormone is estrogen due to the rapid rise in estrogen levels in early pregnancy.

Another reason is the enhanced sense of smell and sensitivity to odors that most pregnant women experience.  It’s not a well researched cause, but because certain aromas instantly trigger the gag reflex in a pregnant woman, many researchers believe it’s a culprit.  Estrogen is believed to be the cause of the increased sensitivity to odors, but again, this is not well researched so it’s still unclear.

The final reason is the pregnant woman’s tricky stomach.  Because a pregnant woman’s stomach is very sensitive, this is usually the cause of nausea and vomiting.  Not very many studies have been done to research this topic, but this is a large culprit.

Moral of the story: not much is known about these three topics, so if you kiddies have any interest in reproductive biology, you may be the first to discover something about the interesting topics above!

Final fun fact: high levels of hCG is often found in men with testicular cancer and is often used to aid in diagnosing and tracking the chemotherapy/radiation effectiveness! Men can take pregnancy tests too 🙂

1 Comment

Filed under Uncategorized

May 5, 2011- Reproduction

Hey everyone! Just as a reminder, the last homework assignment is due on Wednesday. There will also be two review sessions this week.

The first question that came up in lecture was why do people eat placentas.

The placenta is the organ that connects the fetus to the uterine wall. It allows for nutrient uptake, gas exchange and waste elimination. There are actually many rituals and customs regarding the placenta once the baby has been born. Interesting examples include naming the placenta or hanging it from a tree for scavengers to eat. Placentas are often ceremoniously buried to symbolize the relationship between humans and the earth. Placenta is also used in many beauty products because it is a pure source of protein.

(I like how they mention the cucumber. . .)

The practice of eating the placenta is called placentophagy. It is actually very common amongst mammals because it is a very good source of nutrition. Humans usually have adequate diets so do not need to eat placenta for this purpose.  It is believed that eating the placenta will prevent post partum depression and possibly encourage milk production in new mothers. The placenta contains high levels of prostaglandin, which shrinks the uterus. The placenta also contains iron and small amounts of oxytocin, which can the decrease the stress of childbirth and stimulate milk production. Placenta is eaten by men as well, although it is dangerous to eat another person’s placenta because of illnesses transmitted through blood (HIV, Hepatitis, etc).

Here is a video. Enjoy!

Caution: does show footage of a placenta and a cooked placenta

And if you fancy making yourself a plate of placenta spaghetti or perhaps a nice cocktail….

http://www.mothers35plus.co.uk/plac_rec2.htm#cocktail

The next question was what happens if two sperm penetrate an egg at the same time. This occurs in less than 1% of fertilizations.

So as we learned in lecture today, fertilization occurs in the fallopian tubes. There are two fallopian tubes, but only one contains an egg. According to an article on discovery health only 1000 sperm actually reach the fallopian tubes. And then they must make a choice…. two roads diverged in uterus. . . lol. According to the article I found (http://health.howstuffworks.com/sexual-health/sexuality/human-reproduction10.htm) half of the sperm go to the wrong fallopian tube, which I thought was interesting.

A molar pregnancy can occur if two sperm fertilize the same egg. It’s estimated that 1/1,500 pregnancies in the U.S. are molar pregnancies. A complete molar pregnancy happens when there are two sets of chromosomes from the father and none from the mother. The fertilized egg develops into a growth called a mole. There is no embryo, amniotic sac, or normal placenta. Most partial molar pregnancies occur when there are two sets of chromosomes from the father and one set from the mother, so there are 69 total chromosomes instead of 46. This can occur when chromosomes from the sperm are replicated or if two sperm fertilize an egg.

Women with molar pregnancies might have normal symptoms of pregnancy at the beginning. Later in the molar pregnancy they might experience heavy spotting and bleeding or abdominal cramping. Some women develop preeclampsia. However, an ultrasound can usually diagnose a molar pregnancy long before these conditions develop.

Semi-identical twins are also a result of two sperm fusing with a single egg, before becoming two embryos.  The embryos usually do not survive. There is only one known case of semi-identical twins. The twins were born in the US in 2007. They have identical genes from their mother, but share only half the genes from their father. One of the twins is male, but the other is a hermaphrodite (has both ovarian and testicular tissue). The most likely explanation is that two sperm cells – one with an X chromosome and one with a Y chromosome – fertilized the same egg, which later split into two embryos.

7 Comments

Filed under Uncategorized

Lecture: Wednesday 27, 2011

Announcements:

  • Final Exam will be on Wednesday, May 11, 2011, from 9:30a.m. to 11:30a.m. The final will be held in our regular classroom.
  • Study Session Dates: Thursday, May 5, 2011, at 6:30p.m. The room is TBA. The next is on Saturday, May 7, 2011, at 2:00p.m. The room is TBA.
  • The new material for lecture and the upcoming homework assignment is on Black Board.
  • The last homework will be due Wednesday, May 4, 2011.
In class today we continued our discussion on Ch. 50, The Endocrine System.
We began the discussion with the slide on what happens when hormones are no longer needed.
Below are  charts, diagrams, and questions that are going to be useful to take a look at for the final.
This chart is displaying the three types of hormones.
Also, there is a table in your Biology textbooks, table 50.2 that shows the hormones involved in the hypothalamus of the brain and the anterior pituitary. To remember these hormones use FLAT PEG. In the FLAT portion, the F stands for the Follicle-stimulating hormone (FSH), L is the Luteinizing hormone (LH), A is the Adrenocorticotropic hormone (ACTH) and T is the Thyroid-stimulating hormone (TSH). For the PEG portion, the P stands for Prolactin (PRL) the E does not represent anything and the G is the Growth hormone (GH).
The chart below is showing the hormones that are important for METABOLISM and ENERGY BALANCE.

This chart was also on Dr. Hartley's slide show.

The chart below shows the hormones that are important for MINERAL BALANCE.

Chart available on Dr. Hartley's slide show.

The chart below shows the hormones that are important for GROWTH and DIFFERENTIATION.

Chart available on Dr. Hartley's slide show.

The chart below shows the hormones that are important for REPRODUCTION.

Chart available on Dr. Hartley's slide show.

The chart below shows the hormones that are involved in STRESS.
Chart available on Dr. Hartley’s slide show.
There were a few clicker questions on the slide show that Dr. Hartley had mentioned could possibly be on the final. The questions and answers are as follows.
Q: If an animal has less fat (adipose tissue)…
A: Leptin will decrease, appetite will increase.
Q:If you ingest a lot of salt, aldosterone will..
A: Decrease
Q: If you ingest a lot of salt, ADH will…
A: Increase
Q: If you ingest a lot of salt, atrial natriuretic peptide will…
A: Increase
The video below discusses how Hypothyroidism can occur.
The class ended with FCQ’s. Dr. Hartley mentioned that at the beginning of next class we will finish up a couple more clicker questions and then move on to the Reproductive System.
Blog Today By:  Megan Granzella

3 Comments

Filed under Uncategorized

April 6 Lecture

Here are a few interesting questions that came up in class:

1. What is insulin resistance?

Insulin resistance is a condition in which the body produces insulin but does not use it properly. Insulin, a hormone made by the pancreas, helps the body use glucose for energy. Glucose is a form of sugar that is the body’s main source of energy.

The body’s digestive system breaks food down into glucose, which then travels in the bloodstream to cells throughout the body. Glucose in the blood is called blood glucose, also known as blood sugar. As the blood glucose level rises after a meal, the pancreas releases insulin to help cells take in and use the glucose.

When people are insulin resistant, their muscle, fat, and liver cells do not respond properly to insulin. As a result, their bodies need more insulin to help glucose enter cells. The pancreas tries to keep up with this increased demand for insulin by producing more. Eventually, the pancreas fails to keep up with the body’s need for insulin. Excess glucose builds up in the bloodstream, setting the stage for diabetes. Many people with insulin resistance have high levels of both glucose and insulin circulating in their blood at the same time.

Insulin resistance increases the chance of developing type 2 diabetes and heart disease. Learning about insulin resistance is the first step toward making lifestyle changes that can help prevent diabetes and other health problems.

“Insulin Resistance and Pre-diabetes.” National Diabetes Information Clearinghouse. Oct. 2008. Web. 10 Apr. 2011.http://diabetes.niddk.nih.gov/dm/pubs/insulinresistance/#what.
2. What is an insulin resistant diet?
– no potatoes
– no simple sugars/carbohydrates (fructose, sweets, cookies, ice cream)
– almost no grain products (bread, pasta, popcorn)
– only whole grains in small amounts
– small amounts of fruit (mostly berries)
– eggs
– nuts
– lean meat, seafood, and fish
3. Why do elephants have a lower BMR?
– larger species have a lower mass specific BMR
– since elephants weigh more and they are much larger,they do not have to eat as often as a rat
Camille

6 Comments

Filed under Uncategorized

Summer Jobs

Hi Class,

I’d like to use the blog to share summer job opportunities.  As I mentioned in class, I think you would all benefit by pursuing summer jobs that will allow you to explore career options and allow you to gain experience relevant to your major.  I think there are plenty of paid positions out there and I would recommend looking for a paid position over an unpaid position.

The National Science Foundation supports programs called Research Experiences for Undergraduates.  Here is a website where you can search these opportunities – http://www.nsf.gov/crssprgm/reu/reu_search.cfm.  I did an REU in college and it changed my career path.  I spent the summer in the Dominican Republic studying seed dispersal by herbivorous iguanas.  I learned a lot about ecology, earned a $3000 stipend,  got a nice tan, and met people who helped me get into graduate school.

I encourage you all to use the blog to share details about potential positions that your classmates might be interested in.

Dr. Hartley

 

4 Comments

Filed under Uncategorized

Lecture: March 30, 2011

Announcements:
On Monday Dr. Hartley will be gone and Dr. Jones will be teaching class. Be nice to Dr. Jones!

Today we talked about talked about Ch. 45 which covers Nutrition, Digestion and Absorption.

One of the topics that came up was Diabetes. Here is some information on the disease:
Diabetes is a lifelong disease that arises when the body cannot produce or use insulin resulting in high blood glucose levels. Insulin is a hormone that takes glucose from the blood into the cells and is needed to convert sugar and starches into energy.
Type 1 Diabetes or Juvenile Diabetes occurs in children and young adults. Their bodies don’t make insulin or don’t know how to use it. People with Type 1 diabetes are put on Insulin therapy. Only 5% of people with diabetes have type 1.

Type 2 diabetes is the most common form of diabetes that affects millions of people. In type 2 diabetes the person either does not produce enough insulin or the body ignores the insulin being produced. People with type 2 diabetes have to ensure they are within adequate glucose levels to avoid any complications with glucose building up in the blood.
Gestational Diabetes is when an expecting mother develops diabetes after the 28th week of pregnancy. Often times gestational diabetes disappears after the baby is born.
For more information you can visit:
http://www.diabetes.org/diabetes-basics/?utm_source=WWW&utm_medium=GlobalNavDB&utm_campaign=CON

Another question that came up in class was if it was better to add salt while cooking or after cooking. Here is what I found:
The longer food is cooked the more flavor is masked. Adding salt while you are cooking is not as healthy as adding it after because the salt being added while cooking loses flavor and often people add more salt to maintain that flavor. It is healthier to simply add salt after the cooking process is complete. Less salt is being added to the food but the flavor will remain the same. If salt should be added to a recipe try adding it last to reduce overall salt input.
For more information you can visit:
http://www.eat-healthy-live-healthy.com/minimizing-your-salt-intake

The next question that came about was why we weigh less in the morning that at night?
We weigh less in the morning because our bodies have been asleep for the past 8 or so hours. While the body is sleeping it still respires however there is no energy intake. So essentially your body is burning more energy that it’s getting. Also while you respire you lose water and CO2 through respiration. These gases have mass which contributes to the overall loss of mass. ☺

Dr. Hartley was talking about an SNL video with Alec Baldwin that talked about the body systems. I couldn’t find it, but I’ll keep looking and post it if I do!

11 Comments

Filed under Uncategorized

March 9, 2011

So we had some announcements, pieces of advice, and reminders before class. 

#1 – First, don’t forget to fill out the mid-semester feedback form that’s due Monday!

#2 – Here’s a helpful piece of advice: write down all the due dates in your calendar 🙂

#3 – Don’t forget that the mid-term is next Wednesday, March 16th!!!!  It will be like the quizzes we’ve had (about 50% the same as the quizzes), and it will cover up through chapter 40 (what we got done on the 9th.)  We will review on Monday.

Then we started into the lecture, and some questions were brought up.

One of the questions that was asked in class was, “Why are vertebrates less efficient in keeping in energy than invertebrates?”  We came up with some reasons.  Invertebrates are cold-blooded and they don’t need to respire as much, so they can keep more energy in.  Vertebrates, however, do respire more, and they digest more and have less feces, therefore they are not as efficient in keeping energy in.

 

Another question that was asked that I am particularly interested in was “What is blue-baby syndrome?”  Those of you who know me know that I LOVE babies!  I want to be a neonatologist, so it’s natural.  So, I did some research and I found that blue-baby syndrome is also called methemoglobinemia.  This occurs when there is a rise in the level of methemoglobin in an infant’s blood.  (Methemoglobin is a non-oxygen carrying enzyme that is produced by the body, which is converted to hemoglobin.)  The reason there could be a rise in the levels of methemoglobin in the blood is because if there is a high level of nitrates in drinking water, the nitrates are converted to nitrites in the infant’s digestive system.  These nitrites react with the hemoglobin in the infant’s blood, causing a high level of methemoglobin.  Because methemoglobin does not carry oxygen, the infant’s organs may not get enough oxygen, so the infant may turn blue, hence the term “blue-baby syndrome.”  The infant may also start vomiting or may have a harder time breathing.  If this happens, then the infant should be taken to a doctor, in which the doctor can give the infant methylene blue, which will make the infant’s blood go back to normal.  I found this extremely interesting!  And now you know what blue-baby syndrome is.  Here is the URL if you want to read the whole article.

http://www.bhia.org/articles/childrens-health/bluebabysyndrome.html

We also wanted to know what potash is made out of.  So, I did a little investigating, and I found that it is potassium carbonate, which almost all came from wood ashes.  Here’s the URL for the whole article about it if you want to know more!

http://www.lenntech.com/chemistry/potash-industry.htm

And that was it for this class period! 😀

7 Comments

Filed under Uncategorized