Feb 11, 2011 Unbreakable vs. Osteogenesis Imperfecta

     Elijah Price (Samuel L. Jackson) is born with Type I osteogenesis imperfecta, a rare disease in which bones break easily.  He grew up with the nickname "Mr. Glass."  Drawing on what he has read in comic books during his many hospital stays, Price theorizes that if he is frail to the extreme, then perhaps there is someone strong to the opposite extreme.
     David Dunn (Bruce Willis) is Price's polar opposite which he discovers slowly throughout the film as Price tries to convince him that he is the mordern incarnation of a superhero.  Dunn eventually begins to believe it himself and after discovering he has a limited form of ESP begins to embody the idea of a minor hero.  He also finds that he has a weakness that nearly kills him.  By the end of the film Dunn confronts Price about his involvement in finding someone (Dunn) who is his archnemesis.

    The purpose of this blog is not to review a movie but to take a brief look at the disease osteogenesis imperfecta.

Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a congenital disease, meaning it is present at birth. It is frequently caused by defect in the gene that produces type 1 collagen, an important building block of bone. There are many different defects that can affect this gene. The severity of OI depends on the specific gene defect.

OI is an autosomal dominant disease. That means if you have one copy of the gene, you will have the disease. Most cases of OI are inherited from a parent, although some cases are the result of new genetic mutations.

All people with OI have weak bones, which makes them susceptible to fractures. Persons with OI are usually below average height (short stature). However, the severity of the disease varies greatly.

The classic symptoms include:

• Blue tint to the whites of their eyes (blue sclera)
• Multiple bone fractures
• Early hearing loss (deafness)

Because type I collagen is also found in ligaments, persons with OI often have loose joints (hypermobility) and flat feet. Some types of OI also lead to the development of poor teeth.

Symptoms of more severe forms of OI may include:

• Bowed legs and arms
• Kyphosis
• Scoliosis (S-curve spine)

Treatment

There is not yet a cure for this disease. However, specific therapies can reduce the pain and complications associated with OI.  In severe cases, surgery to place metal rods into the long bones of the legs may be considered to strength the bone and reduce the risk of fracture. Bracing can also be helpful for some people.

Fun Fact: In the movie GATTACA Vincent has this procedure done to increase his height.  He is attempting to impersonate someone else.  Consider what he is dong in light of the quotes below presented at the very beginning of the movie.

"Consider God's handiwork; who can straighten what He hath made crooked?" - Ecclesiastes 7:13

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"I not only think that we will tamper with Mother Nature, I think Mother wants us to." - Willard Gaylin

Feb 10, 2011 - The Long & Short of Bone Growth

Long Bone Growth

Long bones add materials at specific areas called growth plate. The growth plate, also known as the epiphyseal plate or physis, is the area of growing tissue called hyaline cartilage near the ends of the long bones in children and adolescents. Each long bone has at least two growth plates: one at each end. The growth plate determines the future length and shape of the mature bone. When growth is complete - sometime during adolescence - the growth plates close and are replaced by solid bone. In adults, who have stopped growing, the plate is replaced by an epiphyseal line. Because the growth plates are the weakest areas of the growing skeleton - even weaker than the nearby ligaments and tendons that connect bones to other bones and muscles - they are vulnerable to injury. Injuries to the growth plate are called fractures.

http://i39.tinypic.com/4qj1ih.jpg

This is the distal end of the tibia (left) and fibula (right).  

The thin lines most proximal on both bones are the epiphyseal (growth) plates.

http://upload.wikimedia.org/wikipedia/en/7/7a/Tib_fib_growth_plates.jpg

About 85 percent of growth plate fractures heal without any lasting effect. Whether an arrest of growth occurs depends on the treatment provided, and the following factors, in descending order of importance:

• Severity of the injury - If the injury causes the blood supply to the epiphysis to be cut off, growth can be stunted. If the growth plate is shifted, shattered, or crushed, the growth plate may close prematurely, forming a bony bridge or “bar.” The risk of growth arrest is higher in this setting. An open injury in which the skin is broken carries the risk of infection, which could destroy the growth plate.
• Age of the child - In a younger child, the bones have a great deal of growing to do; therefore, growth arrest can be more serious, and closer surveillance is needed. It is also true, however, that younger bones have a greater ability to heal.
• Which growth plate is injured - Some growth plates, such as those in the region of the knee, are more involved in extensive bone growth than others.
• Type of fracture

The most frequent complication of a growth plate fracture is premature arrest of bone growth. The affected bone grows less than it would have without the injury, and the resulting limb could be shorter than the opposite, uninjured limb. If only part of the growth plate is injured, growth may be lopsided and the limb may become crooked.

Growth plate injuries at the knee have the greatest risk of complications. Nerve and blood vessel damage occurs most frequently there. Injuries to the knee have a much higher incidence of premature growth arrest and crooked growth.   http://www.niams.nih.gov/Health_Info/Growth_Plate_Injuries/default.asp#8

      

     Using the principal that bone will grow (relatively) rapidly to fill in areas of fracture Ilizarov discovered that by carefully severing a bone without severing the periosteum around it, one could separate two halves of a bone slightly and fix them in place, and the bone would grow to fill the gap. He also discovered that bone regrows at a fairly uniform rate across people and circumstances.

     These experiments led to the design of what is known as an Ilizarov apparatus, which holds a severed bone in place, by virtue of a framework and pins through the bone, and separates halves of the bone by a tiny amount; by repeating this over time, at the rate of the bone's regrowth, it is possible to extend a bone by a desired amount.

http://en.wikipedia.org/wiki/Ilizarov_apparatus

Ilizarov Apparatus

• Bone infections
• Poliomyelitis Sequelae (limb lengthening and correction of deformities)
• Treatment of non-unions and malunited fractures
• Correction of deformities, both congenital & acquired, of the limbs 
• Badly comminuted fractures (multiple fragments) in the limbs, even with skin loss.

This procedure is accepted for the conditions listed above but is very controversial for cosmetic limb lengthening.  The article at the following link provides multiple viewpoints on the procedure.  It is very interesting.   http://www.shortsupport.org/News/0432.html 

Fun Fact:  I the movie GATTACA the character Vincent has this procedure done as he gets ready to take the identity of Jerome.  This is part of the plot that follows the following Title Cards:

[first title card]

"Consider God's handiwork; who can straighten what He hath made crooked?" - Ecclesiastes 7:13

---

[second title card]

"I not only think that we will tamper with Mother Nature, I think Mother wants us to." - Willard Gaylin

Feb 8, 2011 - Throw me a Bone Here! - Extra Bones?

Reminder - The Histology Comprehensive Test is this Friday 2/11. It will be run as a practical exam.

Wormian Bones & Accessory Bones

http://upload.wikimedia.org/wikipedia/commons/9/93/Wormian_bones.jpg

Wormian bones are a subset of the small intrasutural bones that lie between the cranial sutures formed by the bones of the skull vault. The title Wormian bones is given to abnormal intrasutural bones that are typically found around the lambdoid suture.
Erroneously, these bones are named after the person who was supposed to have first described them:

• Ole Worm (1624-1639): professor of Anatomy at Copenhagen, Denmark

http://radiopaedia.org/articles/wormian-bones

Accessory Bones

The image above shows a common form of often problematic accessory bone.

     These are "extra" bones resulting, most often, from altered patterns of ossification. The accessory bones (also called ossicles) occur most often in the hands, wrists and feet. Examples include the os naviculare secundarium, carpal boss, os trigonum, os vesalianum, os intermetatarsale, and os supratrochleare dorsale. These ossicles are generally not considered significant and are believed to represent variations of normal development. It is not uncommon for both the wrists and/or the feet to contain extra small ossicles, that occasionally cause pain. It is important to note that other problems such as avulsions or chip fractures may sometime be misidentified as accessory bones.    http://www.medcyclopaedia.com/library/topics/volume_iii_1/a/accessory_bones.aspx

 Fun Fact: The soft spot(s) on a baby's head called fontanelles are the places that Wormian bones most often
                form due to the pattern of ossification in the baby's head.

Feb 8, 2011 - Bone Construction

Reminder - The Histology Comprehensive Test is this Friday 2/11.
                  It will be run as a practical exam.
               - Check out this website for reviewing for the test, it is the best one yet
                  http://nhscience.lonestar.edu/biol/tissue.html

Anatomy of a Bone

http://www.baileybio.com/plogger/images/biology/powerpoint_-_integumentary__skeletal__and_muscular_systems/bone_tissue.jpg

     The image above gives a good overview of the gross anatomy and the micro-anatomy of a long bone.  You should become familiar with the definitions of these terms as well as be able to identify them on images in a  quiz setting.

     Bone tissue is "living"  in that it is constantly changing and is very responsive.  The bone material will change its shape to meet the demands of forces put on it.  

     The image below shows the result of Chinese foot binding.  The bones in the foot change shape in response to the external pressures exerted on them.

Foot Binding (纏足)

In the 10^th   century, in China, legend says a prince began the practice of foot binding because he loved the small "Lily Feet" of his concubine. The tiny foot became the mark of a wealthy and well-born woman.

Footbinding was a custom practised on young females for approximately one thousand years in China, and ended in the early 20th century.  In Chinese foot binding, young girls’ feet, usually at age 6 but often earlier, were wrapped in tight bandages so that they could not grow and develop normally; they would, instead, break and become highly deformed, not growing past 4-6 inches (10-15 cm).  Bound feet had to be washed and cared for daily.  If toe nails grew into the instep, infection could set in.  If the bindings were too tight, gangrene and blood poisoning could occur.  The bound foot was painful and tender forever.  It often had an unpleasant smell.  Today, the result of foot binding is a prominent cause of disability among some elderly Chinese women.

Plagiocephaly

http://bloximages.chicago2.vip.townnews.com/heraldextra.com/content/tncms/assets/editorial/e/cd/da4/ecdda4ec-e86c-514f-8b87-b838075143b7.image.jpg

What is Plagiocephaly? - Plagiocephaly occurs when a baby's head develops a flat spot or becomes asymmetrical due to some kind of external pressure. Many babies are born with an abnormally shaped head as a result of the pressure exerted on them during birth, but most babies' heads will correct themselves within about six weeks.  Plagiocephaly can also occur after childbirth and is not uncommon in neglected infants who are left to lie unattended for long periods.  The weight of the baby's head presses down on the back of the skull and the bones respond by forming to that shape.  http://www.babycenter.com/0_plagiocephaly-flat-head-syndrome_1187981.bc

 

http://t2.gstatic.com/images?q=tbn:ANd9GcQIdBEyEIx6kda4AO790xIWbQVVgScdjSkXevDDHluYilYzHhwT

Fun fact:   The crystal skulls (upon which the Indiana Jones movie are based) are a number of human skull hardstone carvings made of clear or milky quartz rock, known in art history as "rock crystal", claimed to be pre-Columbian Mesoamerican artifacts by their alleged finders. However, none of the specimens made available for scientific study have been authenticated as pre-Columbian in origin. The results of these studies demonstrated that those examined were manufactured in the mid-19th century or later, almost certainly in Europe.

Feb 7, 2011 - Boning Up

Welcome back from the weekend.  I hope you had fun.  I spent 6 hours shoveling my roof and scraping my driveway. WooHoo!!!

Reminder - The Histology Comprehensive Test is this Friday 2/11. It will be run as a practical exam.

 

The following unit will deal with the skeletal system.  We will be examining the skeletal system from the micro-anatomy to the gross anatomy as well as studying how it grows and repairs itself.  We will also do some comparative anatomy and finally discuss the affects of aging and disease on the skeletal system.

Fun Fact - Our bones are six times stronger than steel if both are the same weight.

 

Feb 4, 2011 - Cardiac Muscle Tissue

Reminders:  

• The C.T. Quiz has been moved to Mon 2/7.
• The due date for the Histology project is now Mon 2/7.
• The Muscle/Nervous Tissue Quiz will now be Wed 2/10.

When trying to identify cardiac muscle tissue there are some easy markers to look for to help you
make your choice.
• The most important marker is the presence of intercalated disks which are special extensions of the cardiac cell membrane that has many functions.
• The cells are often branched.
• Each cell has only one nucleus but it may not always be visible. (It depends on the depth of the section taken through the cell.)

Fun fact:   Chocolate can actually improve cardiovascular health, according to the Northwest Health Sciences University.  Chocolate contains cocoa which has antioxidants that help protect the cardiovascular system. The antioxidants help lower blood pressure and help reduce deaths related to cardiovascular disease. A 4-5 gram (less than an ounce) serving per day is enough to gain the benefits from the antioxidants found in cocoa. (If this is the case my heart may never die!)

Read more: Fun Facts of the Cardiovascular System | eHow.com http://www.ehow.com/about_5079091_fun-cardiovascular-system.html#ixzz1Cvnv4P8D

Feb 3, 2011 - C.T. Quiz Primer

Reminders:  (Ok I lied we have moved the dates.  See below.)

• The C.T. Quiz has been moved to Mon 2/7.
• The due date for the Histology project is now Mon 2/7.
• The Muscle/Nervous Tissue Quiz will now be Wed 2/10.

(Click the images to enlarge them.)

The drawings above give a quick overview of Connective Tissues using an artist's representation.  The fiber types and cell types are well represented.  Make sure to review Table 5.4 to help prepare for the upcoming quiz.

The image below provides some microscope images of many of the same tissues.

http://www.nicerweb.com/doc/class/bio1151/Locked/media/ch40/40_05ConnectStructFunc.jpg

I have included some links below to help you practice for the upcoming quiz.

http://www.unomaha.edu/hpa/2740connectivetissue.html#dense


https://staff.rockwood.k12.mo.us/fullertonheather/hap/Documents/Unit%204%20Tissues%20and%20Integumentary%20System/Connective%20tissue%20practice%20test.ppt

http://faculty.sdmiramar.edu/KPETTI/Bio160/MiscImages/ConnTissuChrt.jpg

Fun Fact - In general, an excess of 3500 Calories will create 1 lb of body fat.  So removing 500 Calories a day whether by diet, exercise or both combined will allow the average person to drop 1 lb a week.  That doesn't sound like much until you realize that would be 52 lbs in one year!

Feb 2, 2011 - Skeletal Muscle

Reminders: (None of these dates will change due to the weather!)

1. Don't forget your connective tissue quiz is on Friday 2/4.
2. The Histology Project is due Friday 2/4.
3. Muscle & Nervous tissue quiz next Tuesday 2/8.
4. Due to the many weather related issues we have had you may use the internet to research two of your histology drawings. Please include the following on your poster:
1. The url as a reference
2. The magnification (if possible)

Skeletal Muscle Tissue

                                                        http://clcpages.clcillinois.edu/home/bio567/pages/newtissues/skeletalmuscle.htm

Pictured above is a good example of skeletal muscle tissue.  It is important to note a few things about this tissue when trying to identify it:

• the cells are generally parallel and unbranched (distinguishes it from cardiac or smooth muscle tissue)
• each cell is multinucleated (distinguishes it from cardiac or smooth muscle tissue)
• the cells have striations (stripes) running perpendicular to the length of the cell (distinguishes it from smooth muscle tissue)

In a later unit we will investigate: some of the myths surrounding muscle/cell growth, how these cells produce force, what allows us to specify the strength of a muscle contraction, how training specificity changes a muscle, red vs. white fibers, and many more topics.

If you have any questions regarding muscle anatomy for our class in the future please post them in the comments section.

Fun Fact- It is a total myth (but commonly believed) that you can turn fat into muscle with training.

Jan 31, 2011 - Up and Running!

Welcome to my first blog - of any sort, ever! 

I am starting this blog to communicate with my Anatomy and Physiology students, Trimester 2, 2011. I will be posting a variety of materials here including: pictures, diagrams, informational links, practice tools and games, assignment updates, snow event information, a body-part of the day, and possible addendums to class materials and discussions.  I will check the comments often with the last check at around 8:30 in the evening (whenever possible). 
I will try to post daily (but not often on weekends).  I expect to set the Blog up with some enrichment/extra credit assignments that expand upon the current information.  I'm sure I will run into snags and consider differnt formats and ways to use this as time goes on.
I look forward to hearing from you and would appreciate suggestions for making this more useful as well as constructive criticisms of the posts as things progress.

Fun Fact - An average human scalp has 100,000 hairs. Mr. Bernier's scalp has far less than that.

Feb 1, 2011 - Blood

Reminders:

• Histology Projects are due Friday, 2/4 
• Connective Tissue Quiz will be the same day.

Part of the day - Blood
Blood is considered a connective tissue for two basic reasons: (1) embryologically, it has the same origin (mesodermal) as do the other connective tissue types and (2) blood connects the body systems together bringing the needed oxygen, nutrients, hormones and other signaling molecules, and removing the wastes. In circulating blood two different cell types are found: enucleated erythrocytes or red blood cells and nucleated leukocytes or white blood cells. (http://lifesci.rutgers.edu/~babiarz/bloodtx.htm)

 Note - the part of the blood that is missing  (Difficult to do since it is not labeled!) the plasma.

Plasma is the liquid component of blood, in which the red blood cells, white blood cells, and platelets are suspended. It constitutes more than half of the blood's volume and consists mostly of water that contains dissolved salts (electrolytes) and proteins. The major protein in plasma is albumin. Albumin helps keep fluid from leaking out of blood vessels and into tissues, and albumin binds to and carries substances such as hormones and certain drugs. Other proteins in plasma include antibodies (immunoglobulins), which actively defend the body against viruses, bacteria, fungi, and cancer cells, and clotting factors, which control bleeding.

Plasma has other functions. It acts as a reservoir that can either replenish insufficient water or absorb excess water from tissues. When body tissues need additional liquid, water from plasma is the first resource to meet that need. Plasma also prevents blood vessels from collapsing and clogging and helps maintain blood pressure and circulation throughout the body simply by filling blood vessels and flowing through them continuously. Plasma circulation also plays a role in regulating body temperature by carrying heat generated in core body tissues through areas that lose heat more readily, such as the arms, legs, and head.
(http://www.merckmanuals.com/home/sec14/ch169/ch169b.html)

Red Blood Cells get most of the press but it is vital not to ignore the importance of the blood plasma.

Fun Fact - Each square inch of human skin consists of twenty feet of blood vessels.