Evaluate Your Understanding & Apply Your Knowledge - Integumentary System
Directions: Develop, and be able to explain and support responses/explanations to the following questions/scenarios.
Evaluate Understanding
1. Count Dracula, the most famous vampire, rumored to have killed at least 200,000 people, was based on a real person
who lived in Eastern Europe, about 600 years ago. He was indeed a “monster” even though he was not a real vampire.
The historical Count Dracula may have suffered from which of the following?
a) Porphyria, b) EB, c) halitosis, d) vitilago
Porphyria. Porphyria victims lack the ability to form the heme of Hb. Buildup of intermediate by-products
(porphyrins) in the blood causes lesions in sun-exposed skin. Dracula was said to have drunk blood and to have
shunned daylight.
2.
A man got his finger caught in a machine at the factory. The damage was less serious than expected, but nonetheless,
the entire nail was torn off his right index finger. The parts lost were the body, root, bed, matrix and eponychium of
the nail. Describe each of these parts and conclude whether the nail is likely to grow back.
Nail body; visible attached portion of the nail. Nail root: embedded portion of the nail. Nail bed: the epidermis
that extends beneath the nail. Nail matrix: the proximal, thickened portion of the nail bed responsible for nail
growth. Eponychium: the cuticle. If the matrix is damaged, the nail might not growth back or may grow back
distorted. In this case the nail probably will not grow back since everything, including the matrix, was lost.
3.
Mark of various regions on the diagram of the human body below according to the Rule of Nines. What percentage of
the total body surface is affected if the skin over the following body parts is burned? (a)The entire posterior trunk
and buttocks, (b) an entire lower limb, (c) the entire anterior left upper limb
a) 4.5% anterior + 4.5% posterior head & neck = 9%
b) 9%anterior + 9% posterior upper limbs = 18%
c) 18% posterior trunk + 18% anterior trunk = 36%
d) 18% anterior & 18% posterior lower limbs = 36%
e) Perineum (1%)
Apply Knowledge
4. Dean, a 40 year old aging beach-boy, is complaining to you that although his suntan made him popular when he was
young, now his face is all wrinkled and he has several darkly pigmented moles that are growing rapidly and are as big
as large coins. He shows you the moles and you immediately thing “ABCDE”. What does this mean and why should he
be concerned?
His long-term exposure to UV radiation in sunlight is considered to be a risk factor for the development of skin
cancer. In addition, moles or pigmented spots that show asymmetry (A), border irregularity (B), color variation
(C) and diameter greater than 6mm (D) are all signs of possible malignant melanoma. He should seek
immediate medical attention. If it is a malignant melanoma, the change for survival is not high, but early
detection increases the survival rate.
5.
Victims of third degree burns demonstrate the loss of vital functions performed by the skin. What are the two most
important problems encountered clinically with such patients? Explain each in terms of absence of skin.
The two most important problems encountered clinically with a victim of third-degree burns are a loss of body
fluid, resulting in dehydration and an electrolyte imbalance, and the risk of infection. Intact skin effectively
blocks no only the diffusion or water and water-soluble substances out of the body, but acts as a barrier limiting
the invasion of various microorganisms.
6.
A 30-year old mental patient named Thelma has an abnormal growth of hair on the dorsum of her right index finger.
The orderly comments that she gnaws at her finger continuously. How/why might this observation account for
Thelma’s hairy finger?
Chronic physical irritation or inflammation can lead to excessive hair growth in the region affected due to an
increase in blood flow to the area.
7.
Katarina, a model, is concerned about a new scar on her abdomen. She tells her surgeon that there is practically no
scar from the appendix operation done when she was 16, but this new gallbladder scar is “gross”. Her appendectomy
scar is small and obliquely located on the inferior abdominal surface – it is very indistinct. By contrast, the gallbladder
scar is large and lumpy and runs at right angles to the central axis of the body trunk. Explain to Katarina why her
scars are so different.
The appendectomy incision ran parallel to the less dense “lines of cleavage” that separate bundles of collagen
fiber in the dermis. The gallbladder incision cut across them.