Research Blog:Spare Parts for Humans: Tissue Engineers Aim for Lab-Grown Limbs, Lungs and More

In this article I learned of the amazing things scientists can make our bodies do. At the start of the video it shows a marine named Mile O'Brien who has most of the skin and some of the muscle in his leg destroyed. His muscle is literally visible on his leg. However working with the these amazing tissue engineers they are working on ways to be able to grow tissue or even organs to repair damaged human bodies. Using stem cells and a lot of rigorous physical therapy they found that they were able to turn the cells into muscle. With the help of the scientists Mr. O'Brien was able to regenerate around 10 to 15 percent of the muscle he lost. However, the muscle has gotten so strong that it is the same as him regenerating 50% of the muscle. They might even be able to make extra body parts for people being able buy.They have been working on over 30 different tissues and organs and even extra appendages like ears and even a beating heart valve. Most of these experiments have been testing on salamanders and seen on the movie they actually regenerate limbs. There was also another example of a man that dove into the shallow end of a pool and was completely paralyzed. With the help of stem cells though he was able to talk move his arms and getting stronger. He is believing that he will be able to walk again at the rate he is going. I had no idea that it was possible to repair the body this much. Its awesome that we have this technology to give people there lives back that were injured. After watching this video I am amazed at the things that we are able to do with science
http://www.freerepublic.com/focus/f-news/2822704/post

Sliding Filament Model

We already made a short video of this process but I would like to also post a blog on here to show my individual understanding of the process as well. This is mostly about the contraction and relaxation of the muscles and what goes on inside the body. Inside the muscle fibers are the sarcomeres and they help with contraction of the muscles in the skeleton. When the muscle contracts the sarcomeres do not change length like you would thnk, instead they simply slide past each other. In our video it is shown as the two forks and the match box. Instead of the fork pokers(I do not know the correct term for them)bending into the match box,them simply slide past them fitting in almost perfect fashion.The fork pokers do slighty overlaap each other but they do not change in length by any means. As the muscle relaxes the forks or sarcomeres are pulled away from the match box and are slid back to their resting spot. Working almost like a machine the muscle is able to smoothly flex and relax.

This is a different example than the one we used in our video but it is explaining the same thing. As you can see instead of the sarcomere(fingers) changing length the simply just slide through each other and stay the same length. Going back to the start of this blog i didnt go all the way through the process of the sliding filament model because it can be explained in the video I helped create. Hopefully this blog does somewhat show my knowledge of the Sliding Filament Model

Skeletal System

Called the framework of the body the Skeletal System is what supports and holds up the the body. The bones can be split into two different catagories: Axial Skeleton and Appendicular Skeleton. The Axial Skeleton is the bones of the skull the vertebral column also know as the spine and the rib cage. The Appendicular Skeleton is the bones of the upper and lower limbs the shoulders, and hips. The bones can also be classified by the different shapes they can be in. The first type is the long bones. These bones are longer than wide and example of these bones would be the Humerus or Femur. The opposite of the long bones would of course be the short bones. These bones are cube shaped and are on the wrist and ankle. These bones usually from within the tendons for example the patella and the trapezoid. Flat bones are of course thin and flattened and a bit curved for example the sternum and most skull bones. The last type of bone is Irregular Bones and these bones live up to their name by being oddly shapped like the vertebrae and hip bones.
Function of Bones
Bones have many important functions to making sure the body is up and running. Bones are the support of the body and are the framework of the body and support the soft organs. They also help to protect the brain, spinal cord, and vital organs. They also help for movement of the body and provide levers for the muscles. The bones also are a storage systom for minerals, mostly for calcium and phosphorus. The last function of the bones is the formation of the blood cells.
Bone Fractures
Bone fractures are classified by the position of the bone ends after the break, the completeness of the break, orentation of the bone on the long axis, and whether or not the bone penetrates the skin.There are multiple types of bone fractures. Nondisplaced fractures are when the bone retains its normal position. A complete break is when the bone is broken all the way through. Mostly common in sports, a spiral break is when the bone is excessively twisted. The most common injury among children is the greestick fracture and it occurs when one side of the bone breaks and the other side bends.

This picture shows a complete break,and as you can see the fracture has taken place throughout the entire bone.

This picture shows an greenstick fracture. As you can see the one side of the bone breaks as the other side bends.

Integumentary System

The skin at times may seem like it isn't very important while in all reality it is incredibly important to the well being of the body. The integumentary system is split into three major regions the Epidermis,Dermis, and Hypodermis. The Epidermis is the outer layer of the skin that is exposed to the outside environment. It also serves as protection of the inner skin. This layer of the skin includes waterproofing and protection from abrasion and penetration. The next region of skin is the Dermis. In this second region of the skin it contains the strong flexible connective tissues of the body. There are also white blood cells and fibroblasts. It also split up into two layers,the papillary and reticular. The deepest region of the skin is the Hypodermis. It is composed of adipose and areolar connective tissues. The Integumentary systems is critical to our bodies being able to function properly and have many important functions. The Integummentary system protects the inner body from chemical,physical and mechanical harms. It also helps to cool and warm the body by using cooling and constriction. They also help to increase sweat glands to cool off the body. There are also the Cutaneous sensation that sense touch and pain.The skin also helps when excretion takes place and it gets rid of wastes through sweat.

While skin is wodnderful to the body and helps it,it can also get infected and make the body sick. There are three types of skin cancer which are Basal cell carcinoma, squamous cell carcinoma,and Melanoma.The least deadly and most common type of skin cancer is the Basal Cell Carcinoma. It is very slow growing and it almost never mestasize. 99% of the time this cancer can be surgically removed. The next type of cancer is the Squamous Cell Carcinoma. It is mostly found on the scalp, lower lip, and the ears. It grows much faster thatn the Basal Cell and will metastasize if it is not removed. It will most likely be removed it is treated by radiation therapy or by surgery.The last type of skin cancer is the most deadly and it is called Melanoma. There is a rule for telling when it is a melanoma skin cancer called the ABCD rule.
A: Asmmetry: The infected area has two sides that do not match.
B:The borders are irregular and have jagged sides.
C: The color is either,black,brown,tan,and red or blue.
D: The diameter is larger than the size of a pencil eraser,or 6mm.
Chances of surviving this cancer are very low if the pigment is over 4mm thick.
The next type of problem to happen to the skin is when the skin gets burned. When a burn occurs it is split into three different degrees. First Degree is when the Epidermis or the outtermost layer of the skin is burned and damaged. This is the most minor of the burns and usually does leave much of a mark. Second degree burns is when the epidermis and the top of the dermis is burned and damaged. At first the symptoms look like a first degree burn but often have blisters appear and rashes occur. Third-degree burns is ehen the entire thickness of the skin is damaged and this can often lead to death. Because the nerve endings are destroyed no pain is initially felt.
There is a rule to determine the severity of burns and it is called the Rule of Nines. Burns are considered critical if over 25% of the body has second degree burns or if 10% has third degree burns.

The picture above shows how the Rule of nines is divided between the different parts of the body. As you can see the legs and anterior are the major parts and can not be damaged. When those parts are damaged in increasing the chances of the injury becoming fatal.

Organization of the body

The anatomical position is the basic position of to decribe. The characteristics are body erect, feet slightly apart,palms facing forward, and the thumbs pointed away form the body.

This picture shows the anatomical position.

The first directional term I am going to discuss is Superior and Inferior. Superior is up toward the head or the upper part of the body. For example the chest is superior to the knees.
Inferior in the opposite of superior so it is away from the head and towards the bottom part of the body. For example the toes are inferior to the belly button. Anterior is toward the front of the body or in front. An example would be the belly button is anterior of the spine. The opposite of Anterior would be Posterior. Posterior is towards the back of the body or in the behind. The heart is posterior to the breast bone would be an example of this. Medial is going towards the middle of the body so the heart would be medial to the shoulder.

Lateral is away from the medial or middle of the body so it would be going out towards the arms or shoulders. The fingers would be lateral to the heart is an example. Proximal is closer to the origin of a body part or an limb. Like the shoulder is proximal to the elbow. Distal is going farther away from the the origin like for example, the shin is distal to the knee. Superficial is toward the the body surface. An example is the skin is superficial to the skeleton. Deep is away form the body surface and is more toward the inner organs of the body. The Kidneys are deep to the skin would be a prime example of this.
The axial view of the body is the head neck and trunk area. This is the top of the body as seen in the picture above.

There are also Appendicular appendages or limb. One of these limbs would include the Brachial which is the arm.

The next classification of the body would be the body planes or the ways the body can be split. The first one would be sagittal which divides the body into left and right parts. If you were to cut a person in half using this plane you would have the left ear, eye,leg , and arm on one side and the right side of everything on the other side.

Frontal or Coronal Plan divides the body into anterior and posterior parts. This would be dividing the body from front to back. This will be shown wonderfully from the picture seen below.

Transverse or horizontal plane divides the body into superior or inferior parts. Simply put it is dividing the body from top and bottom. The last plane is the Oblique section and this is simply cuts that are made diagonally.

The next part of the body is the body cavities. The Dorsal cavity protects the sensitive nervous system and is divided into more subdivisions. The first division is the cranial cavity that is inside the skull and is what holds the brain. The other subdivision is the vertbral cavity and that is what holds the spinal cord.

This photo shows both of the Dorsal cavity subdivisions, the cranial and vertebral. As you can see the cranial cavity is on the head and is where the brain is held. the vertebral is on the back and is what holds the spine.
The ventral cavity holds the internal organs and just like the Dorsal cavity, has two subdivisions the thoracic and abdominopelvic.

From this picture you can infer that the ventral does indeed hold the internal organs and you can also see the two subdivisions.

Connective tissue

There is another type of tissue and it is the Connective Tissues. Just like epithelial tissues, Connective tissues are also found all throughout the body. These tissues have a variety of different duties around the body. The main job of these tissues is to provide support and protection, and is the framework for the body. For example when you are first setting up for a house you put up the framework for it made out of wood. The wood framework of the house is a good example because it is sturdy, protects the house and of course provides support. The connective tissues also have other jobs like storing fat producing blood cells and helps repair tissue damage.
One way connective tissues are different is that cells inside the tissues are more spread out than the epithelial cells. Also in connective tissues you will find extracellular matrix between the cells. This matrix is made up of a ground substance and protein fibers. The matrix can either be a solid or a fluid, or in between.
There are different types of cells included in connective tissues and the first one is fixed cells. These cells stay in a specific area of connective tissue for a certain length of time. There are also cells like macrophages that are wandering cells the move throughout the tissue usually due to and injury. Fibroblasts are another type of cells and they help produce fibers by secreting proteins into the matrix.
Macrophages are very common throughout the connective tissues just like the fibroblasts.. The macrophages are usually attached to the fibers but can move about on their own. These macrophages are important to carry on phagocytosis often police the tissues and get rid of unwanted particles. This of course is important in the bodies protection against sickness and infection.

Mast Cells are largely used throughout the connective tissues. They are almost always near blood vessels and because of this they release heparin that helps prevent blood clots. This is very crucial and without it the body would not be able to live.

Now I am going to go into the Connective tissue fibers. The first one I am going to talk about is Collagenous fibers. These are thick threads of collagen which is a protein. They are grouped in long parallel bundles and are very strong. The two big Connective tissues however, is the Ligaments and Tendons. A ligament is a fiber that connects bones to the other bones and tendons are what keep the muscles onto the bones.

Areolar Tissue are mainly fibroblasts which are seperrated by a gel like substance that has many elastic fibers. This tissue keeps the skin on the organs where there are many blood vessles.

Adipose Tissues are easy to remember to because they are pretty much just fat. These are formed when a lot of other cells store droplets of fat in their cytoplasm. As the cells get bigger they no longer look like fibers but instead they become a fat when their nuclei is pushed to the side. These joints are pillows for certain joints and organs so they are protected. Also right beneath the skin the fat cells store energy. The amount of these cells varies by the diet of the person. For example a marathon runner probably would not have as many adipose cells as would an overweight couch potato.

Homeostasis Lab

Epithelial Tissue

Epithelial Tissues are found all over the body. They mostly cover body surfaces, organs, and the inner lining of body cavities. These cells divide very often, causing injuries to heal quickly.  Epithelial cells are all tightly packed so they are protected very well. Epithelial Tissues are divided into many different classifications including, squamous, cubiodal and columnar. They are also divided between simple and stratified. These tissues, however, do not have blood vessels. On the other hand, connective tissues which are under these epithelial tissues do have blood vessels.

One type of Epithelial is squamous. These cells are flattened and make a smooth surface usually used for forming the walls of capillaries and membranes. To me they remind me of a smooth tile surface that lines the walls of a house or the floor. However, since the squamous cells are so thin they can be damaged or destroyed fairly easily. From this picture you can see the shape of the squamous cells.

You can see that they are thin and smooth, like the tile surface I explained earlier. It would make sense from seeing this picture that these cells would form as a wall inside the body.

The next type of cell is the Cuboidal cells. Just saying the name of the cell can help you determine what this cell looks like. These cells are simple cube shaped cells that help with secretion and absorption of a material. In the middle is usually a large spherical nucleus.  You can usually find these cells in the kidney tubules and in the small portions of small glands.
This photo shows the shape of these unique cells. From the picture you can see that the cells are indeed cube like and have a large circle nucleus.

Columnar is the next type of cell and its name also helps reveal the shape of the cell. Columnar cells are tall cells that almost look like large columns; also the nuclei in the columnar cells are oval shaped. Some of these cells have cilia which are constantly moving. The cilia help in situations like for females moving the egg cell through the uterine tube to the uterus.

This picture shows that the long columnar cells. These cells look like large tall columns and on top of the cells, are the hair looking cilia.  The main purpose of the columnar is to absorb nutrients from digested food.

The next Epithelium is the Transitional Epithelium.   Transitional epithelium is used to change in response to increased tension. It is found in the inner ling of the urinary bladder and in the ureters. When the wall of one the organs reduces in size or contracts the tissue is usually made up of layers of cuboidal cells. Pseudo stratified Columnar is a single layer of cells that are all at different heights. Many of these cells do not even reach the free surface.  The nuclei are never in the same place they are always seen in different layers. These cells main purpose is for the secretion of mucus.

This is an example of Pseudo stratified columnar. As you can see the nuclei are in different layers.

All of these cells are split into another two division being simple and stratified.  Simple is defined usually by only a single layer of cells while as stratified cells usually have several layers of cells. Stratified cells are usually not as common as simple Epithelia cells, but they are equally as important.

The photo above shows a stratified squamous epithelia cells. As you can see there are a several layers of cells all piled up onto each other.

Homeostasis

Homeostasis is the process of the keeping the body in balance. Without this process organisms would not be able to live properly. The state of balnce is controlled by positive and negative feedback.Negative feed back is when a part of the body sends a signal to the brain when one part of the body is off balance. The liver, kidneys, and brain help with maintaining homeostasis. The liver helps with metabolizing toxic substances like alchol. The kidneys are responsible for regulating blood water levels, and the brain of course helps witht the whole process. One of the most common examples of homeostasis is sweating. When the body starts to get too hot it releases the sweat and heat. When the sweat onto the skin it quickly evaporates thus cooling off the body.

After being phyiscally active for a while the body runs out of energy and must find another source for  energy.  This is when the body goes to its body fat for energy. The body can only relay on this source for so long. If the body is not properly hydrated it can lead to a high heart rate, the temperature of the body increasing, and even muscle cramps.