A3_Toder_Meghan

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Feb 20, 2024

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Assignment 3 Answer Sheet The questions for your assignment come from your lecture notes and textbook readings (Chapters 4 (Section 4.5) and Chapter 5). Please provide your answers to the assigned questions on this answer sheet. Make sure you rename the file as your last name, followed by your first name, and A3 (i.e. Lastname_firstnameA3.xxx). 1. Fill in the table below with the correct information on connective tissue (3pts) Tissue Name Reticular tissue Dense irregular tissue Adipose tissue Hyaline Dense regular tissue Fibrocartila ge Descripti on Loose network of reticular fibers in gel-like ground substance Made primarily of collagen fibers with a few elastic fibers; major cell type is fibroblast s Matrix like areolar but very sparse and closely packed by adipocytes, or fat cells have nucleus pushed to the side by large fat droplet. Amorphous but firm matrix; collagen fibers form an imperceptib le network; chondrobla sts produce the matrix and when mature lie in lacunae Closely packed bundles of collagen fibers running in same direction Contains rows of chondrocyt es that alternate with rows of thick collagen fibers Function Fibers form a soft internal skeleton that supports other cell types including white blood cells, mast cells, and macrophag es. Withstan ds tension exerted in many different direction s; provides structural strength. Provides reserve food fuel, insulates against heat loss, supports and protects organs. Supports and reinforces; serves as a resilient cushion; resists compressiv e stress. Attaches muscles to bones or to muscles; attaches bones to bones; withstand s great stress when pulling force is applied in one direction. Tensile strength allows it to absorb compressiv e shock, Location Lymphoid organs Fibrous capsules Under skin in Forms majority of Tendons, most Intervertebr al discs;

(lymph nodes, bone marrow, and spleen). of organs and of joints; dermis of skin; submuco sa of digestive tract. subcutaneo us tissue, around kidneys and eyeballs, within abdomen, in breasts embryonic skeleton and covers ends of long bones ligaments, aponeuros es pubic symphysis, discs of knee joints. 2. Differentiate between the four cells of the epidermis (2pts). Keratinocytes (produces keratin), melanocytes (synthesizes the pigment of melanin), dendritic cells (ingest foreign substances and activate our immune system), tactile cells (functions as a sensory receptor for touch). 3. Briefly describe each layer of the epidermis (3pts) Stratum Basale, which is the basal layer, is the deepest layer of the epidermis. Stratum spinosum, which is the prickly layer is several cell layers thick mainly pre-keratin filaments and scattered among them is melanin granules and dendric cells. Stratum granulosum has one to five cell layers and is where the process of keratinization begins, it also slows water loss and helps to toughen the outer layer of the skin. Stratum Lucidem is the clear layer a thin translucent band that is considered to separate the stratum corneum from the rest of the layers. The Stratum Corneum, which is the horny layer, is the outermost layer of the epidermis and protects the skin against abrasion and penetration. 4. Name the tissue types composing the dermis. List its major layers and describe the function of each layer (3pts). The dermis consists of the Papillary layer and the Reticular layer. The papillary layer is thin and superficial. It consists of areolar connective tissue in which fine interlacing collagen and elastic fibers form a loose mat that has a lot of blood vessels. The loose mat allows for defense cells to wander the area and patrol for bacteria that has invaded the skin. It has dermal papillae that project from its surface. These are receptors for touch and make ridges which in turn help us grip and contribute to our sense of touch. The Reticular layer is about 80% of the thickness of the dermis. It has a network of blood vessels that nourishes it. It is made up of dense, irregular connective tissue and has collagen fibers that run mostly parallel to the surface of the skin. This enables the skin to keep in moisture, prevent penetration, and to provide stretch.

5. Identify and describe the three concentric layers of keratinized cells (1.5pts) The three concentric layers of keratinized cells are the medulla, the cortex, and the cuticle. The medulla is the central core and consists of large cells and air spaces. The medulla is the only part of the hair that contains keratin and is absent in fine hairs. The cortex is a bulky layer surrounding the medulla and it consists of several layers of flattened cells. The Cuticle is the outermost layer and is formed from a single layer of cells overlapping one another like roof shingles. 6. Explain why nails normally appear pink in color (1pt). Nails appear pink in color because there is a rich bed of capillaries in the underlying dermis. 7. Compare the structure and location of sweat and oil glands (2pts). There are two sweat glands Eccrine and Apocrine and one type of oil gland which is Sebaceous. The Eccrine glands are abundant on the palms, soles of feet, and forehead they are comprised of a simple, coiled, tubular gland. The secretory part lies in the dermis and the duct extends to open in a funnel shape channel at the skin’s surface. The Apocrine are multiple and mostly on the axillary and anogenital areas. They are larger than eccrine glands and lie deep in the dermis or even hypodermis, their ducts empty into hair follicles. There are also ceruminous and mammary glands which are modified apocrine glands. The sebaceous oil glands are simple branched alveolar glands that are found all over the body except in very thick skin like the palms and soles. They are small on the body, trunk, and limbs but large on the face, neck, and upper chest. They tend to develop as outgrowths of hair follicles and secrete sebum into the hair follicle. 8. Name and describe the five different functions of the skin (2.5pts) Protection, the skin protects us from germs, environmental damage, and physical dangers. Body temperature regulation, the skin regulates our body temperature either through sweating or through dermal blood vessel constriction. Cutaneous sensation, the skin has sensory receptors that are part of the nervous system. This can warn us of danger through pain. Metabolic functions, the skin is a chemical factory that is fueled in part by the sun’s rays. It makes chemical conversions that can disarm cancer causing chemicals that penetrate the epidermis and activate some steroid hormones. They also make some important proteins that work as enzymes to aid the natural turnover of collagen. The skin also works as a blood reservoir holding about 5% of the body’s entire blood volume and the skin also helps by excreting limited amounts of waste. 9. Describe what the ABCD rule is in terms of skin cancer (2pts) The ABCD rule in terms of skin cancer is to assess for the below issues when looking at spots, moles, or skin issues: Asymmetry, border irregularity, color, and diameter.

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Read the following case study and answer the questions below: On the first day after arriving in Australia for Christmas vacation, New York University student plans to lie out in the sun for 6 hours. Later that night he notices that the skin on his arms and legs has become red, swollen and extremely painful and morning all of the afflicted areas have developed numerous blisters. The areas cover about 27% of his trunk (each front and back) and about 42% of his arms and legs (each front and back). 1. What organ system has been damaged? (0.5pts) The integumentary system 2. Name all the tissues that have been afflicted? (1pt) The upper region of the dermis and the epidermis 3. What type of burn has the student received? (i.e Is it a second or third degree burn?) Explain you answer. (1pt) Second degree burns, I believe this because the student has noticed redness, swelling, pain, and lots of little blisters. The burned area does not appear to be gray-white or cherry red. There is also swelling so these things tell me it is not a third degree burn. 4. What type of radiation has caused the burn? (1pt) The sun, solar radiation. 5. List all the layers of the skin that have been damaged. (2pts) The papillary layer of the dermis and the stratum basal, the stratum spinosum, the stratum granulosum, the stratum lucidum, and the stratum corneum. 6. Why is this type of burn so painful? (1pt) It is so painful because the nerve endings are still intact and are sending messages to the brain that you are in danger. 7. The percentage of total body surface that has been burned is 35% is this considered critical and should the student seek medical attention? (1pt) Yes, this is considered critical. Anything over 25% of the body with second degree burns is considered critical and the student should seek medical attention. 8. List all of the body functions that may be disrupted by such a burn. (1.5pts) Respirations, sweat and oil functions, metabolic functions, blood reservoir function, body temperature regulation, physical and chemical barrier disruption. 9. When the student returns to New York one of his friends tells him that now is the best time for him to get/keep his tan and that he should immediately start visiting a tanning salon. Is this a wise decision, why or why not and explain your answer. (1pt)

Absolutely not. This student has already placed himself at risk for skin cancer, more burns, and multiple other things as stated above. The skin is only about as thick as a paper towel and this student has damaged it. Not only does he have to worry about skin cancer but he also has to worry about the healing process and if he is vain now he has to worry about wrinkling of the skin.