Group Dissection Organisms:

  1. Iguana- Iguanas have fascinating camouflage so it would be cool to see underneath their skin, also I have never dissected a reptile.
  2. Microbat- Bats are also incredible and have quite interesting anatomical structures. Their echolocation and ultrasound produced by the larynx is interesting. I would love to see what the larynx looks like compared to other specimens.
  3. Proteidae (mudpuppy)- Mudpuppies not only have lungs, but they also have a gill set. I feel its worth investigating.

Granular and Mucous Glands Drafting (group project):

Amphibians possess two types of glands, mucous and granular (serous), both of which are structurally different and exhibit vast differences in function. Both of these glands are considered cutaneous and are composed of three different sections which all make up the gland as a whole. These sections include the first the duct, then the intercalary region, and lastly the alveolar gland (sac). Structurally, the duct is derived via keratinocytes and passes all the way to the outer region of the epidermal skin layer, allowing external secretions of the body. The gland alveolus is the basal layer of the granular gland located in the stratum sponganium with cell layers specializing in secretion. Inbetween the alveolar gland and the duct is the intercalary system which can be summed up as a transitional region connecting the duct to the grand alveolar beneath the epidermal skin layer. In general, granular glands are larger in size than the mucous glands, however mucous glands hold a much greater majority in overall number.

Granular glands can be identified as venomous and often differ in the type of toxin as well as the concentrations of secretions across various orders and species within the amphibians. They are located in clusters differing in concentration depending on amphibian taxa. The toxins can be fatal to most vertebrates or have no effect against others. These glands are alveolar meaning they structurally have little sacs in which venom is produced and held before it is secreted upon defensive behaviors.

(need to include information regarding structure).

Mucous glands are non-venomous and offer a different functionality for amphibians than granular. Mucous glands cover the entire surface area of the amphibian body and specialize in keeping the body lubricated. There are many other functions of the mucous glands such as controlling the pH, thermoregulation, adhesive properties to the environment, anti-predator behaviors (slimy to the grasp), chemical communication, even anti-bacterial/viral properties for protection against pathogens.[1]

(need to include information regarding structure).

Additional Citations:

  • Journal of Morphology - Necturus Integument - Mucous and Granular Glands...[2]

Peer Responses/ Draft 2:

  • Shawn - Thank you for the response, sounds like I need to add further citations beyond what I have given as well as increasing my overall fluency.
  • Riley - I will reduce my vague language and work to provide concrete examples where needed. I also plan on creating two completely different sections for the mucous and granular glands. They are both glands but both differ significantly in their overall functionality for amphibians.
  • Joe - Believe it or not that single source gave me ALL of that information. No worries though, I have two other stellar sources in which I will add more material regarding structure and functionality/mechanisms of the glands. Good looks though, I wouldn't want to accidentally plagiarize. I appreciate you looking out!
  • Grant - Thank you for the suggestions, I more or less just plotted down information as I came across it in the article. I will definitely restructure it for fluency sake. More citations are to come, I have 2-3 I am ready to add.
  • Andrew - With further research I have come to the conclusion that mud-puppies (at least not the one we are dissecting) do not seem to have granular glands, however they certainly do possess mucous glands. I plan on creating a new page for mucous and granular glands and then hyperlinking it to the "Amphibian" page.
  • Lexie - All of my information will most likely end up on a whole new page for Mucous and Granular glands altogether. Then I plan on hyperlinking it to the Amphibian page overall as the not all mudpuppies possess granular glands from my understanding. I feel this topic would be best associated with amphibians.
  • Liz - I definitely plan on adding images for both mucous and granular glands. I need to look over the wikipedia training segment that gives the tutorial on providing/adding proper images with citations as I want to avoid stealing credit for other's works (plagiarism). This is great advice and certainly merits addition to my article!
  • Chris - This is a little bit tricky as I will need to talk more with Dr. Schutz regarding where my material will ultimately end up. I posted on the amphibian talk page requesting if I should create a whole new page specifically for Mucous/Granular glands as they pertain to amphibians. They gave me the "go-ahead" to create a new page altogether...so this will require some careful planning.
  • Blanca - I plan on creating a whole new page as I was given the "okay" from the main Amphibian talk page to do so. I need to collaborate with Dr. Schutz to make sure I execute this process so it is both effective and appropriate.
  • Dr. Schutz - I was given the "okay" from the Amphibian talk page to create a new page altogether for the Granular and Mucous glands. There is already a mucous gland page present on wikipedia so I will have to meet with you and discuss how I will either add information for mucous glands as they pertain to amphibians specifically or create a new page and link it to the Amphibian page (same goes for granular glands). I can also hyperlink some vocabulary terms as Joe pointed out thoroughly in his review. I am in the midst of adding more sources and compiling information regarding the overall structure of both glands as we have covered a bit of this material in class so far. I plan on referencing and citing our textbook (it has good information on both glands) and I have just added a citation from the Journal of Morphology in the group response as it focuses on the Necturus integument. I need to start looking for images that pertain to both glands as well as review the wikipedia training that discusses proper image citations. In summary I need to fix fluency, structure/organization, add citations + images, and polish my work so far.

Draft #2:

Overview:

Amphibians possess two types of glands, mucous and granular (serous). Both of these glands are part of the integument and thus considered cutaneous. Mucous and granular glands are both divided into three different sections which all connect to structure the gland as a whole. The three individual parts of the gland are the duct, the intercalary region, and lastly the alveolar gland (sac). Structurally, the duct is derived via keratinocytes and passes through to the surface of the epidermal or outer skin layer thus allowing external secretions of the body. The gland alveolus is a sac shaped structure which is found on the bottom or base region of the granular gland. The cells in this sac specialize in secretion. Between the alveolar gland and the duct is the intercalary system which can be summed up as a transitional region connecting the duct to the grand alveolar beneath the epidermal skin layer. In general, granular glands are larger in size than the mucous glands, however mucous glands hold a much greater majority in overall number.[1]

FrogSkin

Granular Glands:

Granular glands can be identified as venomous and often differ in the type of toxin as well as the concentrations of secretions across various orders and species within the amphibians. They are located in clusters differing in concentration depending on amphibian taxa. The toxins can be fatal to most vertebrates or have no effect against others. These glands are alveolar meaning they structurally have little sacs in which venom is produced and held before it is secreted upon defensive behaviors.[1]

Structurally, the ducts of the granular gland initially maintain a cylindrical shape. However, when the ducts become mature and full of toxic fluid, the base of the ducts become swollen due to the pressure from the inside. This causes the epidermal layer to form a pit like opening on the surface of the duct in which the inner fluid will be secreted in an upwards fashion.[2]

The intercalary region of granular glands are more developed and mature in comparison with mucous glands. This region resides as a ring of cells surrounding the basal portion of the duct which are argued to have an ectodermal muscular nature due to their influence over the lumen (space inside the tube) of the duct with dilation and constriction functions during secretions. The cells are found radially around the duct and provide a distinct attachment site for muscle fibers around the gland's body.[2]

The gland alveolus is a sac that is divided into three specific regions/layers. The outer layer or tunica fibrosa is composed of densely packed connective-tissue which connects with fibers from the spongy intermediate layer where elastic fibers as well as nerves reside. The nerves send signals to the muscles as well as the epithelial layers. Lastly, the epithelium or tunica propria encloses the gland.[2]

(Need Images--currently consulting with non-open sources)

Mucous Glands:

Mucous glands are non-venomous and offer a different functionality for amphibians than granular. Mucous glands cover the entire surface area of the amphibian body and specialize in keeping the body lubricated. There are many other functions of the mucous glands such as controlling the pH, thermoregulation, adhesive properties to the environment, anti-predator behaviors (slimy to the grasp), chemical communication, even anti-bacterial/viral properties for protection against pathogens.[1]

The ducts of the mucous gland appear as cylindrical vertical tubes which break through the epidermal layer to the surface of the skin. The cells lining the inside of the ducts are oriented with their longitudinal axis forming 90 degree angles surrounding the duct in a helical fashion.[2]

Intercalary cells react identically to those of granular glands but on a smaller scale. Among the amphibians, there are taxa which contain a modified intercalary region (depending on the function of the glands), yet the majority share the same structure.[2]

The alveolor of mucous glands are much more simple and only consist of an epithelium layer as well as connective tissue which forms a cover over the gland. This gland lacks a tunica propria and appears to have delicate and intricate fibers which pass over the gland's muscle and epithelial layers.[2]

(Need Images--currently consulting with non-open sources).

  1. ^ a b c d "Cutaneous granular glands and amphibian venoms - ScienceDirect". www.sciencedirect.com. Retrieved 2017-03-18.
  2. ^ a b c d e f g Journal of Morphology. Wistar Institute of Anatomy and Biology . 1920-01-01.