body tissues

Part I- Body Membranes

  1. List the main functions of body membranes:

   

  1. Line or cover body surfaces, protect body surfaces, lubricate (add liquids/fluids to reduce friction) surfaces
    1. List the three types of epithelial membranes:

   

  1. Cutaneous, mucous, and serous membranes
    1. Describe the cutaneous membrane – what is it made of, where is it found, and is it wet or dry?

   

  1. A dry membrane: it is the only membrane exposed to air
  2. Outermost protective boundary (keeps pathogens out, water in)
  3. 2 layers – the superficial epidermis (stratified squamous epithelium with keratin on the top), underlying dermis (mostly dense connective tissue and a thin layer of loose connective tissue at the top)
    1. Describe mucous membranes – what are they made of, where is it found, wet or dry?

   

  1. A wet membrane: it continuously releases fluid
  2. Often adapted for absorption and secretion
  3. Mostly made of stratified squamous or simple columnar (the type of epithelial tissue layer depends on location)
  4. Lines connect to the opening of the body; hence this membrane is exposed to the environment
    1. Describe serous membranes – what are they made of, where is it found, and is it wet or dry? How do we name them?

   

  1. Two layers: simple squamous epithelium (surface layer), loose areolar connective tissue (underlying layer)
  2. Lines walls of body cavities that are closed to the environment, covers the surface of organs within body cavities
  3. Names of specific membranes: (purpose = to lubricate many organs in the respective cavities)

       1. Peritoneum = abdominal cavity 2. Pleura = around the lungs 3. Pericardium = around the heart 4. Visceral = covers (touches outside) organs, Parietal = lines (touches inner walls) cavities

  1. Describe the synovial membrane – what is it made of, where is it found, wet or dry?

   

  1. The synovial membrane is the inner layer of the joint capsule made up of intima and subintima (an outer layer of connective tissue). The intima is the inner layer of the synovial membrane consisting of two types of cells: fibroblast-like (type B) synovial cells and macrophage-like (type A) synovial cells.

Part II- Integumentary System- Skin

  1. What are the functions of your skin?

     1. Protects deeper tissues from mechanical, chemical, and infectious damages; aids in heat regulation; aids in the excretion of urea (normal embolic waste) ad uric acid; synthesizes vitamin D

  1. Describe melanocytes: (what do they do, where are they found?)

     1. Melanocytes are mostly in the bottom layer; they produce and secrete melanin into the upper epidermis

  1. Describe the stratum basale and the stratum corneum: (where are they, what is found there?)

     1. Stratum corneum: a top layer of epidermis; mostly made of keratin and melanin; functions = prevents foreign material from entering, keeps skin hydrated, is only present in thick skin 2. Stratum basale: bottom of the epidermis; functions = produces keratinocytes + melanocytes via mitosis, proliferation, attaches epidermis to dermis

  1. Describe the papillary and reticular layers: (where are they, and what is found there?)

     1. Papillary layer = top (thin) layer of the dermis; consists of collagen fibers and fat cells that are all under connective tissues 2. Reticular layer = bottom (thick) layer of the dermis; consists of blood vessels and connective tissue, involved in thermoregulation, net-like structure of elastic fibers + collagen fibers that surround it

  1. What do sebaceous glands do and why? What do sweat glands do and why?

     1. Sebaceous glands secrete a lubrication oily matter (sebum) into the hair follicles to lubricate the skin and hair; they also protect from friction

  1. What is a hair follicle?

     1. A hair follicle is a tube-like structure (pore) that surrounds the root/strand of a hair; it exists in the top 2 layers of skin, beginning at the surface of the epidermis 2. It is made of made cells that have turned into keratin and binding material (+ water)

  1. Describe the hypodermis: (where is it found, what is it made up of, what is its function?)

     1. The hypodermis/subcutaneous is the bottom/3rd layer of the skin, mostly full of adipose tissue 2. Function = insulates the body, protects from harm, stores energy, connects skin to bone/muscle

  1. Describe each type of skin condition and provide at least 3 examples: (how is it presented + treated?)

     1. Homeostasis Imbalance = infections, allergies, genetic disorders (treatment = antibiotics, steroids, medical attention) 2. Acne = pimples, black/whiteheads, cysts (treatment = Salicylic Acid, Benzoyl Peroxide, Antibiotics, Accutane) 3. Burns = first-third degree burns, sunburns, burns acquired from a fire, cooking negligence 4. Skin Cancers = benign, malignant; basal cell carcinoma, squamous cell carcinoma, malignant melanoma (treatment = chemotherapy, surgery, topical creams) 5. Wound Healings = Hemostasis, Proliferation, and Maturation (treatment = dressing wound, antibiotics, ointments)

  1. Describe each of the three types of burns:

     1. First Degree burn = only epidermis is damaged, skin is red and swollen, mild pain 2. Second Degree burn = epidermis + upper dermis is damaged, skin is red with blisters, open wound + water loss 3. Third Degree burn = destroys the entire skin layer up to muscle + bone, causing nerve damage, no regeneration

  1. Describe the different types of skin cancer: (what part of the skin do they affect? what is the prognosis?)

     1. Basal cell carcinoma = arises from stratum basale (where cells typically divide) 2. Squamous cell carcinoma = arises from stratum spinosum (layer about stratum basale) 3. Malignant melanoma = most deadly metastasizes rapidly to lymph and blood vessels

  1. What are the ABCDEs you should look for to determine if a mole might be cancerous?

     1. A = asymmetry, B = border, C = color, D = diameter, E = evolution

  1. What are the steps of wound healing? Hemostasis, Proliferation, and Maturation

Part III- Friction Ridges and Finger Printing

  1. What part of the dermis determines your fingerprints? Created by the papillae in the dermis bumping up into the epidermis
  2. List the fingerprint types in order from most common to least common: loop, whorl, arch
  3. When do your fingerprints form? Formed during embryonic development (present by the end of the 4th month of gestation, persists through life unless injured)
  4. Define the following Unique Fingerprint markers, Crossover, Island, Ridge Ending, and Bifurcation:

   

  1. Loop = the ridges enter from either side, recurve and pass out on the same side they entered

Arch = the ridges enter from one side, make a rise in the center, and exit generally on the opposite side

Whorl = the ridges are usually circular

  • Crossover = a connecting friction ridge made up of two junctions
    • Island = a single small ridge inside a short ridge or ridge ending that is not connected to any other ridges
    • Ridge Ending = the point where a ridge ends abruptly
    • Bifurcation = the point where a ridge forks or diverges into branch ridges

Part IV – Characteristics of Skin Lab

  1. How do you interpret two-point threshold data?

   

  1. Start with the fingertip and then continue through the five testing areas using a gap size of 1mm. After testing each area, record whether the participant perceives one or two points on the skin surface
    1. How do you interpret tactile localization data?

   

  1. Lightly touch the applicable body regions with the piece of cotton using consistent and minimal contact pressure. Ask the patient to indicate where he/she was touched precisely. Vary the time between stimuli to avoid developing a rhythmic pattern. Repeat throughout suspected areas.
    1. How do you tell the difference between human hair and animal hair?

   

  1. The key difference between human and animal hair is that human hair does not stop growing; hence, it is longer, while animal hair stops growing when it reaches a certain length and is shorter.
    1. How do you tell the difference between growing hair and resting hair?

   

  1. In growing hair, 90% of hair follicles are inside the skin. The hair follicle in this situation lasts 3-5 years inside the skin. Around 10-15% of the hair follicle in resting hair is inside the skin.

Part V – Evolution of Skin Color

  1. What is melanin? How does it relate to UV exposure?

   

  1. Melanin protects the skin from the sun's ultraviolet rays. These can burn the skin and reduce its elasticity, leading to premature aging. People tan because sunlight causes the skin to produce more melanin and darken
    1. What is skin cancer? How does it relate to UV exposure?

   

  1. Most skin cancers are a result of exposure to UV rays in sunlight. Both basal cell and squamous cell cancers (the most common types of skin cancer) tend to be found on sun-exposed parts of the body, and their occurrence is typically related to lifetime sun exposure
    1. What is folate? How does it relate to UV exposure?

   

  1. UV radiation can degrade folate and folic acid in human blood, which has been confirmed in several studies.
    1. What is Vitamin D3? How does it relate to UV exposure?

   

  1. When your skin is exposed to sunlight, it manufactures vitamin D. The sun's ultraviolet B (UVB) rays interact with a protein called 7-DHC in the skin, converting it into vitamin D3, the active form of vitamin D.
    1. Explain how (if) the following are related to natural selection and skin color; skin cancer, folate levels and vitamin D3 levels.

   

  1. Melanin production due to the UV ray basis is the main reason for impacting skin color in populations. People in lower latitudes have darker skin tones because of higher exposure to UV rays, and vice versa. Vitamin D and blood folate levels result from low exposure to UV rays. Depending on one’s environment and diet, a person’s skin tone can vary.

Part VI – Frog Dissection

  1. What body cavities were we able to observe during the frog dissection? Abdominal cavity, pelvic cavity
  2. What body membranes were we able to observe during the frog dissection? Cutaneous membrane (skin), Pericardium, Peritoneum, and Parietal Pleura
  3. What body organs could we observe in the frog dissection? The heart, lungs, liver, small intestine, large intestine, stomach

Part VII – Tattoos

  1. What is a tattoo? Why is the pigment inserted into the dermis?

   

  1. A tattoo is a permanent body art. A design is made by puncturing the skin with needles and injecting tattoo ink into the deep layer of the skin.
  2. The ink must travel through the epidermis into the dermis to give the ink to stay permanent.
    1. What are the risks of getting a tattoo?

   

  1. Allergic reactions, bloodborne diseases, MRI complications, and numerous skin infections