Bones, Bones, Bones!

For the section of skeletal system we had to split into groups of about 4-5 people.  After that, we had to decide the section of the body we would like to memorize.  My group consisted of Carla, Gena, Bri, Cassidy, and myself.  Carla chose the midsection of the body such as the ribs and pelvis.  Gena had the inside of the skull.  Bri had the arms and fingers.  I chose the bones on the outside of the skull, thinking it would be easy.  After getting our assigned parts, I began looking at diagrams portraying certain parts of the skull and specific bones.  After looking at multiple diagrams, I realized the skull has a ton of different bones!  After about a day or two I started to get the hang of it and remember what certain bones were where.  The bones I had to memorize are displayed in this picture!

Out of all these bones, I only missed about four.
Overall, I learned that there are multiple different bones not only in the body, but in the skull alone.  I also learned not to wait last minute for memorizing certain bones! :)

Skeletal Muscle Fatigue-Eccentric Contractions and Muscle Damage

The muscle is stretched by outside forces or antagonist muscles frequently occur in normal conditions like walking down the stairs.  When these contractions are repeated by someone out of shape, they make muscles weak and a characteristic muscle pain and tenderness; which become known a day or so after the workout.  This type of damage to the muscle is linked with inflammation, hypercontracture of some fibers and protein loss from the damaged fibers.  This type of pain and weakness can be the cause of some muscle symptoms in muscle diseases.
**Fun Fact**-Skeletal muscle fibers from rats with heart failure are more liable to mechanical damage, which shows that these muscles are more easily damaged during eccentric contractions.

Eccentric muscle damage includes characteristic changes to the sarcomeres with over- or under-stretched sarcomeres and wavy Z-lines.  These are changes which have been explained by instability of sarcomeres in these situations.  Evidence also shows that increased resting may act as a stimulus for inflammation and reduce Ca^2+ transients during these contractions, which add to the decreased force.  A recent study has given researchers new information on possible early membrane damage after eccentric contractions.  Vacuoles which were attached to the t-tubules were examined after contractions. Their figure could be held back by blocking the Na^+-K^+ pump.  It was suggested that overstretched sarcomeres led to membrane tears, which allows the influx of ions like Ca^2+ and Na^+.  The T-tubular-associated vacuoles are also a common thing in the damage of muscles and disease.  Vacuoles and linked damage to t-tubules could hurt many cellular processes, such as, the action of exchangers and pumps in t-tubules, which can further hurt cellular dysfunction following the eccentric damage.

Overall, eccentric muscle damage can further damage other bodily processes if not taken care of in time. They are trying to find more and more things to cure this type of muscle damage.

Research Article:
http://www.medscape.com/viewarticle/444388_5

A&P Body Parts, Positions and More!

Just a few weeks ago we learned about the many different body positions and regions we have.  I found out that our body can be classified with many different regions.  My Popplet explains some of the regions and the anatomical position (: I also learned about the different body cavities that humans have. I further explain these in detail in a different popplet that I made. If you go to my site you can see the other popplet (:

The Integumentary System =]

The integumentary system is the skin. It has three primary functions which are to guard the body's physical and biochemical integrity, maintain a constant body temperature, and provide sensory information about the environment around them.

The skin is a big organ that is made up of all four tissue types. It is 22 square feet and 1-2 mm thick, and believe it or not, the skin is 10 pounds!

There are different parts to human skin starting with epidermis. The epidermis is the fake part of the skin and made of epithelial tissue. Within the epidermis there are four principle cells. The keratinocytes produce keratin, which helps keep the skin safe and protects underlying tissue from heat, microbes, and chemicals. It also has lamellar granules which gives off a waterproof sealant. The epidermis also includes melanocytes which make the brown pigment melanin. Langerhans' cells are also in the epidermis. These are epidermal macrophages that help start up the immune system. In the epidermis there are also Merkel cells, which function as touch receptors working with sensory nerve endings.

Layers of the Epidermis (:

Stratum Basal (Basal Layer) :

• Made of a single row of the youngest keratinocytes
• Deepest epidermal layer attached to the dermis
• The cells go through rapid division.

Stratum Spinosum (Prickly/Spiny Layer) :

• Cells are made of a weblike system of intermediate filaments that are connected to desmosomes.
• There are a lot of melanin granules and Langerhans' cells in this layer.

Stratum Granulosum (Granular Layer) :

• Very thin, 3-5 layers which big changes in keratinocyte appearance happens.
• Keratohyaline and lamellated granules gather in this layer of cells.

Stratum Lucidum (Clear Layer) :

• Very thin, see-through band that is superficial to the stratum granulosum
• Made of a few rows of flat, dead keratinocytes
• Only found in think skin.

Stratum Corneum (Horny Layer) :

• Keratinized cells
• Responsible for 3/4 of the epidermal thickness
• 3 different functions which include:
• Waterproof
• Protects against abrasions and penetration
• Helping the body closely insensitive to biological, chemical, and physical attacks.

What is the dermis?

    The dermis is the 2nd major skin region which is made of strong, flexible connective tissue. The cell types include fibroblasts, macrophages, and sometimes mast cells and white blood cells.

Layers of the DERMIS =)

PAPILLARY LAYER :)

• The layer is made with areolar connective tissue with collagen and elastic fibers
• Its major surface contains peg like projections called dermal papillae
• Dermal papillae is made with capillary loops, Meissner's corpuscles, and free nerve endings!

RETICULAR LAYER (:

• This layer is responsible for about 80% of the skins thickness.
• The layers of collagen in this layer make the skin stronger and more resilient.
• The elastin fibers provide stretch-recoil properties.

Last but not least is the hypodermis. It is the subcutaneous layer which is deep to the skin. It is made of adipose and areolar connective tissue.

Resource!

http://ljhs.moodlehub.com/pluginfile.php/766/mod_resource/content/2/Integumentary%20Notes.pdf

Types of Tissues (:

Well first of all, tissues are a group of similar cells that do are responsible for a specific function.  The study of tissues is called histology.  There are four major types in the human body which are epithelial, connective, muscle, and nervous.  These tissues are responsible for the association, assembly, and interactions to form organs that have certain functions. I am going to talk about epithelial tissues and what they do.

Epithelial tissues: Responsible for covering all free body surfaces

• Covers the organs
• Forms the inner lining of the body cavities and lines our hollow organs.
• The basement membrane holds epithelial tissue to underlying connective tissue.
• Lack blood vessels
• Tightly packed

Epithelial tissues are classified by shape and the number of layers of cells. 

 Squamous: Thin, flattened cells

 Cuboidal: Cubelike cells

Columnar: Elongated cells

Simple:Single layer of cells

Stratified:2 or more layers

Simple Squamous-Single layers of thin, flattened cells. They fit tightly together and their nuclei are usually broad and thin.

-Common at sites of diffusion and filtration.

-Lines the alveoli of the lungs

-Forms the walls of capillaries, lines the blood and lymph vessels, and covers membranes that line body cavities

Simple Cuboidal-Single layer of cube-shaped cells which usually have a central location for the spherical nuclei.

-Lines the follicles of the thyroid gland, covers the ovaries, and lines the kidney tubules and ducts of glands

           *salivary glands

           *pancreas

           *liver

Simple Columnar-Single layer of elongated cells with nuclei that are at the same level near the basement membrane.  

-Cells can be ciliated or non ciliated. 

-They move constantly

-Some simple columnar cells are used for absorption.

Psuedostratified Columnar Epithelium-Appear stratified or layered, but really aren't.
-This layered effect occurs because the nuclei are at 2 or more levels in the aligned cell row.
-These cells vary in shape and reach the basement membrane.
-These types of cells have cilia

Stratified Squamous Epithelium-Many layers of cells, which make the tissue relatively thick.
-Cells nearest the free surface get flattened the most.
**Fun Fact-the epidermis is stratified squamous epithelium.

Stratified Cuboidal Epithelium-2-3 layers of cuboidal cells that form the lining of a lumen.
-Provides more protection for cells
-Lines the larger ducts of the mammary glands, sweat glands, salivary glands, and pancreas

Stratified Columnar Epithelium-Made of several layers of cells
-Elongated cells
-Found in part of the male urethra and ductus deferens.

What in the world is Homeostasis??

In middle school, teachers begin teaching us about homeostasis, but the question is; do we really understand it?  In fancy terms, homeostasis is the ability to maintain a relatively stable internal environment in a constantly changing outside world.  The process of homeostasis involves chemical, thermal, and neural factors that interact.  In simple terms, I understand homeostasis as the body's ability to stay cool and collected internally while the outside world is constantly changing.  Homeostasis involves many different things like receptors, a control center, and effectors. 
Receptors are responsible for keeping an eye on the body and responding to the changes it makes.  After the receptors see what the body needs it forwards it to the control center.  The Control Center gains the information from the receptors and it sets the range at which a variable will be maintained.  The control center makes the decision of an appropriate response to the stimulus.  Many scientists consider the control center as the brain in homeostatic mechanisms.  The control center sends signals to an effector, which can range anywhere from muscles to other structures that get signals from the "brain".  When the effector receives the signal, changes can occur to correct the difference by either increasing it with good feedback or decreasing it with negative feedback.

When homeostasis is disturbed, our bodies try to fix it by changing one or more physiological processes.  This helps us adapt to stress which includes activating the Hypothalamic-Pitauitary-Andrenal Axis with the nervous system and endocrine reactions of our bodies.  This can cause psychological distress and possibly even psycho-somatic disorders.

Diagram of homeostasis (:

Sources:
http://www.biology-online.org/dictionary/Homeostasis

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

Homeostasis lab!

This graph shows how the temperature changed with the different intervals of jumping jacks

Just recently we started learning about homeostasis.  Homeostasis is the ability to remain stable.  My group and I decided to do jumping jacks to test our temperature and how quickly it would rise.  After ten jumping jacks the temperature of Tenchita's body began to rise.  She had a three minute rest to let her body cool down, making the temperature drop about four degrees.  After she was rested, she did 25 jumping jacks.  After 25 jumping jacks her temperature rose from 27 degrees to almost 33 degrees.  This represented that the more jumping jacks or more activity you do, the higher your temperature increases.  Homeostasis was exemplified in this lab due to the fact that it showed how the body heats up, but also cools itself down when relaxation takes place. 

The graph below shows what her temperature started out as then as it progressed with 10 jumping jacks, cooled while at rest and then shot back up after 25 jumping jacks.

In order to complete this experiment on your own, you could follow these few simple steps (=

Materials Needed

• Thermometer
• Person capable of doing jumping jacks
• Time

First you would go to a room temperature area so that it wouldn't affect the temperature change.  Next you would take the temperature of the participant that is going to be doing the jumping jacks. Write how high the temperature is on a piece of paper.  Then have the participant do 10 jumping jacks approximately for 25 seconds.  After they complete that task, take the temp. right away.  Write that number down.  Next step is to take the temperature of the person's body after they rest for about five minutes.  After that temperature is taken have the participant do 25 jumping jacks for approximately 25 seconds.  After all of this is completed, graph the numbers and see how much the numbers changed from doing 10 jumping jacks to 25 in the same time interval.