Epithelial Tissue!

In this activity we were given cards with different types of epithelial tissues. With these cards, we arranged them into a simple squamous, a simple cuboidal, a simple columnar, a stratified squamous, a stratified cuboidal, a stratified columnar, and transitional.

(Left to Right; Cullen, Mandi, Bethany, Aricka, and Katrina)

- A simple squamous epithelial is a single layer of flattened cells with disc-shaped nuclei and sparse cytoplasm.

- Simple squamous epithelial cells function as mediators of filtration and diffusion. Due to their simple and thin construct, they allow for easy transmembrane movement of small molecules. The types of proteins that are present in a given simple squamous epithelial tissue partially determines the function of the tissue.

- As could be expected, simple squamous epithelium is found in locations where rapid diffusion or filtration take place. For example, it can be found in the kidney glomeruli, lining of the heart, blood vessels, lymphatic vessels and serosae or lining of ventral body cavity.

(Left to Right; Cullen, Aricka, Tiffany, Sierra, Nika, and Mandi)

- A simple cuboidal epithelial is a single layer of cubelike cells with large, spherical central nuclei.

- By lining the surface of various ducts or various glands and organs, simple cuboidal calls are able to provide a layer of protection from abrasion, foreign particles, invading bacteria and excessive water loss to the underlying tissue.

- Simple cuboidal epithelium lines the surface of small excretory ducts in various organs and glands in the body, compose some of the kidney tubules in the kortex of the kidney, and create the covering of the ovary.

(Left to Right; Zach(Me), Cullen, Aricka, Bethany, Mandi, Sierra, Nika, LeAnn, and Trevor)

- A simple columnar epithelial is a single layer of tall cells with oval nuclei; many contain cilia.

- The main function of simple columnar epithelial cells are protection, but they can also specialize to secret mucus that coats and protects the surrounding surface from damage. Lastly, simple columnar epithelium are very good at absorbing and transporting nutrients from multiple locations.

-Simple columnar epithelial cells are some of the most prolific cells in the body, mainly because they can fulfill so many functions. They are found throughout the body’s organ system, including the digestive tract and the female reproductive system. They are also found in the respiratory system, including the nasal passage.

(Top to Bottom; Top: Tiffany, Bethany: Bottom: Cullen, Aricka)

- A transitional epithelial is several cell layer, the basal cells being cuboidal and the surface cells being dome-shaped.

- Some functions of the transitional epithelium cells: accommodates fluctuation of volume of the liquid in an organ or tube (i.e. urinary bladder), and protection against the caustic effects of urine.

- Transitional epithelium is found lining the ureters, urinary  bladder, and part of the urethra.

(Left to Right; Aricka, Mandi, Bethany, and Tiffany)

- A pseudostrarified columnar epithelial is a single layer of cells with different heights; some do not reach the free surface. Also, the nuclei is seen at different layers.

-Function in secretion and propulsion of mucus

-Mainly, present in male sperm-carrying ducts(nonciliated) and the trachea (ciliated).

(Aricka on top of Tiffany, Sierra on top of Bethany)

-A stratified squamous epithelial is a thick membrane composed of several layer of cells.The cells gradually become  larger and more squamous as the cells migrate from the basal layer to the apical  layer.

-Stratified squamous epithelia are specialized to withstand the  mechanical stresses of abrasion. The apical layers of epithelial are designed to  give way to abrasive forces, protecting the deeper tissues from the mechanical  stress. As the apical layers of cells give way, they are continuously replaced  by the deeper layers of epithelial cells, all of which are derived from the  highly mitotic cuboidal cells of the basal layer.

-It can be found in areas such as the esophagus, mouth, and the outer portion of  the skin (epidermis).

(Top to Bottom; Aricka, Mandi, Cullen, Bethany)

- A stratified cuboidal epithelial is quite rare in the human body, but is usually two cell layers thick.

- Does not have an absorptive or secretory function but provides a more robust lining than that of simple epithelium.

- It is less common than other types of epithelial tissue, and it has several locations in the body: sweat gland ducts; egg-producing vesicles, or follicles, of the ovaries; and sperm-producing ducts, or seminiferous tubules, of the testis.

- A stratified epithelial has limited distibution in the body, but is composed of column shaped cells arranged in  multiple layers

- Protection is really the main function of stratified columnar because

- They can be found in the pharynx, male urethra, and lining some glandular ducts.

A big thank you to Aricka for the pictures and information!

Integumentary System!

The Integumentary System better known as skin consists of three or more mayor regions. You're skin actually goes a lot deeper than you think. The three regions of the skin are the epidermis, dermis, and hypodermis. The epidermis is the outermost superficial region, the dermis is the middle region, and the hypodermis  is the deepest region of the skin. 

The epidermis is composed of keratinized stratified squamos epithelium, that consists of four different cell types and four of five layers. The cell types include kerationocytes, melanocytes, Merkel cels, and Langerhan's cells. The outer portion of the skin is exposed to the external environment and functions in protection. Since the epidermis is the top layer of skin, you shed skin every day without even knowing it! In the epidermis, there are different layers within it. The first is the Stratum Basale layer, usually just known as the Basal layer. It is the deepest epidermal layer, attached firmly to the dermis, and also consists of a single row of the youngest keratinocytes. The cells in the Basal Layer undergo rapid division. The next layer in the epidermis is the Stratum Spinosum, a.k.a the Prickly Layer. The cells in this layer have a weblike system of intermediate filaments attached to desmosomes. Melanin granules and Langerhans' cells are really big in this layer. The layer after that is the Stratum Granulosum (Granular Layer). This layer is a very thin layer that has three to five cell layers in which major changes in keratinocyte appearance happens. Keratohyaline and lamellated granules build up in the cells of this layer. Next is the Stratum Lucidum a.k.a as the clear layer. This layer is a very thin, transparent band superficial to the stratum granulosum. It is a few rows of dead, flat keratinocytes. It is only present in thick skin. The last layer of the epidermis is the Stratum Corneum a.k.a the Horny Layer, yes i know that is a funny name. This layer is the outermost layer of keratinized cells, and it accounts for three quarters of the thickness of the epidermis. It's functions include: protection from abrasion and penetration, waterproofing, and rendering the body relatively insensitive to biological, chemical, and physical assaults.
     The next major layer below the epidermis is the Dermis that has strong, and flexible connective tissue. The cels in this layer include fibroblasts, macrophages, and sometimes have mast cells and white blood cells. This layer consists of two layers, papillary and reticular. The papillary layer has Areolar connective tissue with collagen and elastic fibers. Its surface has peg like projections called dermal papillae. Dermal papillae contains capillary loops, Meissner's corpuscles, and free nerve endings. The reticular layer accounts for about 80% of the thickness of the skin, and has collagen fibers that add strength and resiliency to the skin. Elastin fibers provide stretch-recoil properties.
     The Hypodermis is the deepest layer of your skin, and it is composed of adipose and areolar connective tissue.

Skeleton Labeling Contest!

            This activity was very fun and more competitive than I thought it would be. I though it was going to be difficult to memorize my section of the skeleton. I also had a great group who helped me out a lot and gave me confidence in what we were doing. Our group memorized I think it was 134 bones and we won the competition by a long shot. I like doing group activities like this because I am quite competitive and it motivates me to try my best and learn as much as I can. All in all I couldn't have done as good as I did without my group members. I hope you enjoyed this brief description of the skeleton labeling contest.

Homeostasis

        Hello! Welcome to my Anatomy blog! This first post is going to be about homeostasis and the picture above is a Homeostatic Control System Chart.

I'm going to give you a short description of what homeostasis is and how it works. Hope you enjoy!

        The tendency of an organism or cell to regulate its internal conditions, such as chemical composition of its body fluids, so as to maintain health and functioning, regardless of outside conditions. In humans, homeostasis happens when the body regulates body temperature in effort to maintain an internal temperature of about 98.6 degrees Fahrenheit. Most homeostatic regulation is controlled by the release of hormones into the bloodstream. However, other regulatory processes rely on simple diffusion to maintain a balance. The picture if the spider is an example of a cold blooded creature on a warm blooded hand.