Anatomy & Layers
Name the outermost layer of the skin composed of stratified squamous epithelium.
epidermis
Give one primary function of the skin related to protection.
protective covering, prevents water loss, etc
Name three accessory structures that originate from the epidermis.
nails, hair follicles, sebaceous and sweat glands
this is the medical term for abnormally high body temperature
hyperthermia
term that describes tissue grafts taken from the same individual for repair
autograft
List the five layers of the epidermis in correct order from outermost to innermost.
Stratum corneum, Stratum lucideum, Stratum granulosm, Stratum spinosum, Stratum basle
The skin helps regulate this vital physiological parameter that must be kept within narrow limits
body temperature
Identify the part of the nail that is the white crescent near the base.
lunula
This burn is described as superficial, involves partial thickness of the skin, and often blisters.
What is second degree
Name two lifespan changes in skin structure or function that commonly occur with aging.
nail growth slows, fewer hair follicles, less oil production, epidermis thins
The epidermal layer that is the mitotic layer located on the basement membrane and contains melanocytes
Stratum basale
Explain how dilation and constriction of dermal blood vessels help maintain thermal homeostasis.
dilation increases blood flow to skin allowing heat loss, constriction reduces blood flow to skin conserving heat
List the three parts of a hair and indicate which part is composed of dead epidermal cells found outside the follicle.
root, bulb, shaft- hair shaft is dead, keratinized cells
Name the skin disease caused by loss of pigment leading to lighter patches of skin.
vitiligo
Explain why elderly individuals may have increased risk of hypothermia and reduced vitamin D activation.
decreased temperature regulation due to less subcutaneous fat, reduced capacity to produce vitamin D
This layer of the skin lies beneath the dermis and is composed primarily of areolar and adipose connective tissue
hypodermis or subcutaneous
Name two substances or processes the skin performs that contribute to homeostasis (e.g., synthesis or excretion).
synthesizes chemicals (vit D), excretes sweat, houses sensory receptors
Describe the main secretion product of sebaceous glands, how the product is released and where these glands are typically absent.
they secrete sebum (fatty material & cellular debris), empties into the hair follicle, absent on soles and palms
Define a keloid and explain how it differs from a typical scar
Larger, raised scar caused by excess collagen
Describe the inflammatory response in skin: one vascular change and one cellular action that aid healing
vascular: blood vessels dilate & become more permeable, macrophages remove dead cells & debris
Describe two structural differences between thick skin and thin skin and give two locations where thick skin is found.
thick has stratum lucidum, located on palms and soles. this covers most of the body and no stratum lucidum
Explain how the skin participates in vitamin D activation and why this is important for overall physiology.
with UV exposure, important in calcium absorption and therefore bone health
Compare eccrine sweat glands and apocrine sweat glands in terms of distribution, activation (age), and primary function.
eccrine are widespread and have been active since birth- control temperature, apocrine are activated at puberty and usually have an odor
Choose one of: acne, impetigo, psoriasis, or malignant melanoma — give a brief (1–2 sentence) clinical description and one primary cause or risk factor.
melanoma: cancer of melanocytes, most deadly, likely to spread
acne: hair follicle plugged by oil
impetigo: bacterial infection, common in childre
psoriasis: autoimmune, causes thick scaly patches commonly on elbows and knees
A deep full-thickness burn destroys the epidermis and dermis. Describe two clinical consequences and one standard surgical or therapeutic intervention used to treat large third-degree burns.
loss of barrier causes increased risk of infection, fluid loss, impaired temp regulation. Would require a skin graft, infection control, and fluid replacement