Ex: 7 Skin & Membranes

1. to recount important functions of the skin/integumentary system
2. to recognize and name the following structures from a slide, model or diagram
• epidermis (including strata), 
• dermis (papillary & reticular layers
• hair follicles & hair
• sebaceous glands & sweat glands
3. to compare the properties of the dermis & epidermis
4. to describe the distribution and function of the sebaceous glands, sweat glands, and hair 
5. to differentiate between eccrine & apocrine sweat glands
6. to ennumerate the factors determining skin color
7. to describe the function of melanin
8. to compare the structure and function of the major membrane types
9. to list the general functions of each membrane type and note its location in the body
10. to recognize by microscopic examination epidermal, mucous, and serous membranes

II. Hypothesis

Part 1: Basic structure of the skin: If students read about structures as they locate them on a skin model then they will be able to write out a response to each objectivePart 2: Appendages of the Skin: If students examine a prepared slide of human skin then they will be able to identify skin structures on a drawing.Part 3: Plotting the Distribution of sweat glands: If bond paper is taped to skin coated with iodine and left for 20 minutes, then a distribution of sweat glands will be mapped out because the sweat glands will dissolve the iodine, which will then be absorbed by the paper.  As it reacts with the starch in the bond paper each sweat gland will produce a blue/black dot.Part 4: Classification of Membranes: If students examine slides from trachea and small intestine, heart, as well as a freshly cut joint, then they can compare mucous, serous and synovial membranes.II. Materials

    “See Lab instructions”

IV. Procedure

“See Lab Instructions” (you may include pictures of procedure)

Part 1: Basic structure of the skin:
Part 2: Appendages of the Skin:
Part 3: Plotting the Distribution of sweat glands:
Part 4: Classification of Membranes:

V. Results/Observation/Data
List answers to questions from each section of the lab

Part 1: Basic structure of the skin:

1. 
   
1. stratified squamous epithelium tissue
2. keratin
3. carotene
4. freckle
2. It insulates body tissues, cushions the body tissues, keeps water out, prevents from mechanical damage
3.  hair shaft, arrector pili, epidermis, dermis, hypdermis, hair root, hair follicle, eccrine, sebaceous gland
4. Cyanosis is when skin turns blue due to lack of oxygen
5. Translucent cells containing keratin fibrils: D. stratum lucidum
6. Dead cells: D. A. stratum lucidum, stratum corneun
   dermis layer responsible for fingerprints: E. papillary layer
   major skin area where derivatives arise: G. epidermis as a whole
   epidermal region exhibiting rapid cell division: B. stratum germanitivum
   scalelike dead cells, full of keratin, that constantly slough off: A. statum corneum
   composed of two strata, the basale and the spinosum: G. epidermis as a whole
   site of elastic and collagen fibers: H. dermis as a whole
   site of melanin formation: B. stratum germanitivum

Part 2: Appendages of the Skin:

1. e. sebaceous glands
   a. arrector pili
   g. eccrine
   d. hair folllicle
   f. apocrine
   e. sebaceous glands
   c. hair
   b. cutaneous receptors
   e. sebaceous glands,
   g. eccrine

Part 3: Plotting the Distribution of sweat glands:

1. Iodine painted on the skin reacts with sweat glands
2. The palm has more sweat glands.
3. If tested, the armpits, face, and feet would prove to have a high density of sweat glands.
4. The nervous system controls the activity to eccrine sweat glands.

Part 4: Classification of Membranes:

1. Membrane/Tissue Type/Location/Function
1. cutaneous/epithelial/all over skin/absorption and secretion
2. mucous/epithelial/on loose connective tissues/prevents friction of epidermis and dermis
3. serous/epithelial/lines body cavities/prevents parts from drying out
4. synovial/connective/between joints/lines cavities around
2. associated with skeletal system structures: D. synovial
   formed of simple squamous epithelium: A. cutaneous
   not found in the ventral body cavity: D. synovial, A. cutaneous
   goblet cells: B. mucous
   external membranes: A. cutaneous
   wet membranes: B. mucous
   adapted for absorption and secretion: B. mucous
   has paretial and visceral layers: C. serous

VI. Conclusion: Respond to each objective. What did you learn?

1. The integumentary system protects everything inside the body, protects against infectious organisms, dispose of waste materials, and is a receptor for different senses. 
2.  yes 
3. yes
4. yes
5.  yes
6.  The dermis is the layer of skin that lies underneath the epidermis. It is composed of a papillary layer and a reticular layer and contains collagen, elastic fibers, and extrafibrillar matrix. The epidermis is the outermost layer of the skin that helps to protect the body from foreign objects and is made up of stratified squamous epithelium.
7.  Sebaceous glands are located everywhere in the skin except for on palms and soles of feet. They produce sebum which is an oily substance that keeps the skin soft and moist. Sweat glands are also located all over the body and regulate heat through perspiration. Hair are found all over the surface of the body except for the palms, soles of feet, nipples, lips, and parts of the external genitalia. 
8. Eccrine sweat glands produce clear perspiration that are mostly made up of water, salts, and urea. These are located all over the body. Apocrine glands produce a milky protein-based substance and are located in the axillary and genital areas. 
9.  Factors include melanin, carotene, and the degree of oxygenation of the blood.
10. Melanin functions as a natural sunblock that (badly) protects the skin from UV radiation. People who have less melanin are more pale and therefore get sunburned more easily.
11. The cutaneous membrane is present throughout the body and skin and protects the body's internal organs and tissues from damage. Mucous membranes line the respiratory, digestive, and urinary tracts, secreting mucous. Serous membranes line body cavities that are closed to the exterior. They also are located in blood vessels and the heart. They secrete serous fluid which lubricates the organs and body walls so their is less friction when they move. Synovial membranes line the cavities surrounding the joints and provide a smooth surface and secrete a lubricating fluid. 
12. Yes