Epithelial Tissue Organizational Types

There are eight different types of epithelial tissues. They include simple squamous, simple cuboidal, simple columnar, pseudostratifled columnar, stratified squamous, stratified cuboidal, stratified columnar, and transitional. 

Simple Squamous

Simple Quarmos is a single layer of flattened cells with disc shaped nuclei and sparse cytoplasm.

Functions: Diffusion and filteration- provide a slick friction reducing lining in lymphatic and cardiovascular systems. 


Examples: kidney, glomeruli, lining of heart, blood vessels, lymphatic vessels, serosae. 

Simple Cuboidal

Simple Cuboidal epithelium is a single layer 

single layer of tall cells with oval nuclei: many contain cilia

Goblet cells are often found in this layer
function in absorption and secretion
nonciliateted type line digestive tract and gallbladder
ciliated type line small bronchi, uterine tubes, and some regions of the uterus
cilia help move substances through internal passageways


Function: absorption: secretion of mucus, enzymes and other substances

Simple Columnar

single layer of tall cells with oval nuclei: many contain cili
-goblet cells are often found in this layer
-function in absorption and secretion
-nonciliated type line digestive tract and gallbladder
-ciliated type line small bronchi, uterine tubes, and some regions of the uterus
cilia help move substances through internal passageways
Function: absorption: secretion of mucus, enzymes and other substances

Pseudostratified Columnar Epithelium

single layer of cells with different heights; some do not reach the free surface
nuclei are seen at different layers
function in secretion and propulsion of mucus
present in the male sperm carrying ducts (nonciliated) and trachea (ciliated)
Function: secrection: particularly of mucus by ciliary action

Stratified Squamous Epithelium

Thick membrane composed of several layers of cells
Function in protection of underlying areas subjected to abrasion
Forms the external part of the skin's epidermis (kertinized cells) and linings of the esophagus, mouth, and vagina (nonkeratinized cells)

Function: protects underlying tissues in areas subjected to abrasion

Stratified Cuboidal and Columnar

quite rare in the body

-found in some sweat and mammary glands
-typically two cell layers thick

Stratified Columnar

limited distribution in the body
-found in the the pharynx, male urethra, and lining some glandular ducts
-also occurs at transition areas between two other types of epithelia

Transitional

several cell layers, basal cells are cuboidal, surface cells are dome shaped.
-stretches to permit the distention of the urinary bladder
-lines the urinary bladder, ureters, and part of the urethra
Function: stretches readily and permits distention of urinary organ by contained urine

Medical Terms

The first few weeks of school is hard to get used to. All the homework you have to do and things you need to get learned isn't always easy. When we first got taught the medical terms, there was no way i was going to be able to remember all of them. But as we took notes and actually were able to learn it physically, it wasn't so hard after all. There are eleven directional terms when it comes to the human body and those include superior, inferior, anterior, posterior, medial, lateral, intermediate, proximal, distal, superficial, and deep. Superior is from the feet up, or the upper part of the body. Inferior, on the other hand, is the total opposite. So it means from the head down, or the lower part of the body. Anterior, also known as ventral, is the front of the body (infront of). And posterior, is the opposite again. This is behind the body. Medial is pretty easy because medial is middle. So this is the midline of the body. Lateral is going away from the midline. Intermediate is between a more medial and more lateral structure. An example of this would be the colloarbone which is intermediate between the breastbone and shoulder. Next is proximal. Proximal is the part that is closest to an attachment to the limb. An example of this would be the elbow being proximal to the wrist. The next is distal. Distal is farther from the attachment of a limb. An example is the knee being distal to the thigh. Superficial, also known as external, which is the toward or at the body surface. Finally the last one is deep, or internal. Which is away from the body surface.

Within our body direcional terms, we have planes. They include frontal, medial, and transverse. Frontal is the section through the torso. Transverse is the section through the torse, or the superior view. And the transverse plane is the midsagittal plane.

Homeostasis Lab

Levels Of Our Body

As we first started learning about anatomy one of the first things we learned was the different levels of organization. Of all these levels there are five different ones. They include chemical, cellular, organ, organ system, and organismal level. Chemical level is when atoms combine with each other to form molecules such as water and proteins. Then the cellular level  deals with cells. They each are different in size and shape, so they each have unique functions in the body. The tissue level has to do with groups of similar cells that have a common function. With tissues, there are four different types. These include epithelium, muscle, connective tissue, and nervous tissue. All of these tissues have their own role in the body. Next is the organ level. This is composed of two types of tissue which they perform a specific function in the body. At this level, extremely complex functions become possibe. Each organ of the body has its own specific functions that only one specific organ can do. The next level is the organ system. A system is when multiple organs work together to make one. Finally, we get to the highest level of organization and that is the organismal level. The organismal level is all of these levels together which then gives us life.

Homeostasis.. What is it?

Homeostasis. What is it? Homeostasis is the ability to maintain relatively stable internal conditions as the outside world changes. For instance, when were running, what is exactly happening to our bodies? So many things are happening all at once, it is hard to keep up. All the different levels, including glucose and temperature levels, that we have in our bodies move up and down when were working out or running. And although we never think about it, every organ in our body plays a specific role in order to keep us functioning when were moving or burning calories. Another thing that has its role to be controlled as much as possible is body temperature. When we work our bodies, we have to be careful and make sure we are taking care of our bodies as much as possible. Two control mechanisms of homeostasis is negative and positive feedback. Negative feedback is when the variable changes in a direction opposite to that of the initial change. In this case, when were done running, negative feedback plays its role and puts our body temperature back to where its supposed to be. In positive feedback, the response is accelerated in the same direction as the initial disturbance.