That of the Organization of the Body

     Throughout my blogs I have explained various functions of the body, but I've never focused on the bod as a whole. How can we address what the body is capable of without first understanding it's awesome organization. Aside from it being really helpful and essential to body knowledge review, this post will go over terms that are used in scans, terms that are applied to areas of the body and directional terms. Okay cool let's go.

     When looking at the body in a dissection or in a science book, it will always be placed in a certain way referred to as the anatomical position. It has the body lying on it's dorsal side (on it's back, but that comes later.) with palms facing up and thumbs away from the body. The position also has the feet set slightly apart. To show you this position I used a really old Raggedy Andy doll... Because he had thumbs.

Totally anatomically accurate.

     The body has directions which are referred to by Doctors and old guys (i.e. "My posterier aches!"), but it's important to know, though you may already know some- like Dorsal (like the fin on marine beauties) and posterior (previously mentioned in reference to the booty).  The next set of pictures will display other directions and planes.

Inferior is the direction toward the feet and superior is the direction toward the head.

Anterior is the direction toward the front of the body while posterior is the direction                             toward the back of the body, hence the posterior being a synonym for booty.

Proximal is the direction from the extremity to the point of                                                                     attachment in this case from the wrist or foot to the shoulder or thigh/hip.

Distal is basically the opposite of proximal. So it's the direction from the                                                 attachment point towards the extremity, or from the shoulder to the hand.

From the middle line in the body, the direction going away from the middle is Lateral.

Alternatively, Medial is the direction towards the middle division of the body.

     The body can be divided into various 'planes' which are 'slices' that would be scanned. Different planes are required for different types of scans, such as a CAT scan takes a Median plane scan. The transverse plane would vertically scan from the top of the head to the feet (or vice-versa I don't make the rules){This will divide the body into superior and inferior}. The median plane would be scanned from one hand to the other. Frontal scans would take from the tip of the nose to the end of the booty (dividing the body into Anterior and Posterior). An oblique is rarely seen on purpose, as it is mostly an accidental diagonal scan due the movement of the patient. Not shown in the picture is the way your body can be divided as you may see on some displays. The first is Sagittal, which divides the body into left and right halves and the second is Midsagittal which would divide the body into a top and bottom half.

      With planes aside, we can focus on the inside of the body and it's cavities. The Dorsal cavity protects the nervous system, the cranial houses and protects the brain (who'd have thought?!), the vertebral contains and protects the spine, and the ventral holds all internal organs and can be divided into thoracic region and Abdominal-Pelvic region. The pleural cavity encases the lungs; the mediastinum cavity surrounds the thoracic organs and the pericardial cavity houses the heart. The abdominal cavity (abs aha) contain abdominal organs like the intestines and stomach while the pelvic encases the pelvic organs like the bladder and reproductive organs.

     The skin also has it's own levels, being deep and superficial. Deep is below the surface and superficial is at skin level. Here's a less than accurate representation.

                          See the superficial?                                                             See how crazy deep that is?

     Thus concludes the incredible organization of the body represented through an antique doll.

That of Epithelial Tissues (feat. Human Bodies)

     A tissue is a group of cells with similar functions; one tissue type is Epithelial. An epithelial tissue is composed almost entirely of cells and can form sheets held together by junctions. Epithelial tissue is regenerative, meaning it rapidly replaces loss of cells through cell division. This tissue can be classified firstly as simple or stratified. Once that has been decided, the cell will be named squamous, cuboidal or columnar according to it's layers, shapes and placement of nuclei. Just to make it harder, there is a category, pseudostratified, that can occasionally take place of simple or stratified.

     A simple epithelial cell will have a single layer whereas stratified will have multiple layers. Squamous will have disc shaped nuclei and be thin and flat. Cuboidal will have a single layer of cube-like cells with circular nuclei. Columnar has tall cells with round and oval nuclei. When these are stratified, they will be stacks and layers of the shaped cells; when psuedostratified, the cells will have nuclei in a matter of all different places. Psuedostratified Columnar will have different lengths of columns with nuclei in many different places (it is the least likely to be found). To make this more complicated, there is a property called 'transitional', which means that at the top layer, nuclei will be uniform but as they go down the layers, they begin to get 'messy' and are placed randomly.

Now that the science part is over, we can get on to the fun!

     Thanks Bill Nye for that smooth transition. During class, we were divided into two groups to do a photo based activity. We were instructed to use our actual entire bodies to form the cells...... With our bodies. So we gave it our best shot and hopefully the Caption Crew can assist in informing you throughout the Photo Journey. 

Simple Squamous - Single layer of flat cells, disc nuclei and scarce cytoplasm. (This cell provides a friction reducing liner that allows for diffusion.)

Stratified Squamous- Consisting of a thick membrane (no offense girls) made of many cell layers. (This cell protects things underneath it that have frequent abrasion.)

Simple Columnar- Single layer of tall column like cells. This cell will sometimes have cillia, which allows it to absorb and secrete accordingly. The non-cilliated form of this tissue can be found in the gallbladder and digestive tract.

Transitional- Several Cell layers, the top being dome shaped. This cell allows the tissue to stretch, which is a useful property in the bladder and uterus... which is where these tissues can be found.

Simple Cuboidal- single layer of cube shaped cells that have large spherical nuclei. This cell also has the ability to secrete and absorbe and can be found in the kidney tubules and in the lining covering the ovaries.

Stratified Columnar- usually two cell layers that are pretty thick, but they are rarely found in the body. They can occur in transition areas between other types of epithelia.

Pseudo-Stratified Columnar- single cell layer at different heights with the nuclei scattered randomly, instead of uniformly throughout the columns. This cell also secretes but it also propels mucus (ew) and are present in the male sperm carrying ducts.

     Thus concludes our cellular lesson using the ever-so-kind members of my classroom. Until next time......