integumentary system study questions

What are the three types of protective barriers provided by the integumentary system?

Chemical barriers, physical barriers, and biological barriers

What are the chemical barriers?

Sebum, defensins, pH, melanin

How does melanin protect us?

it protects us from the UV

what are the physical barriers?

• stratum corneum and lipids

• keratin and glycolipids

• limited penetration by organic solvents, heavy metal salts and drugs

what are the biological barriers?

skin and DNA

How do dendritic (Langerhans) cells contribute to immune defense?

present foreign atingens to white blood cells

What role do dermal macrophages play in protection?

present foreign antigens to white blood cells, they initiate inflammatory responses, and promoting wound healing

How does DNA act as a biological barrier against UV radiation?

Its electrons absorb UV radiation and convert it to heat

What is insensible perspiration, and how much occurs daily?

The unnoticeable, constant, and passive loss of water vapor from the body. 500ml/day is lost

Sensible perspiration

the sweat that is actively secreted by eccrine glands

What physiological changes occur when body temperature rises?

sensible perspiration (increased sweating)

How does the skin respond to a cold external environment to reduce heat loss?

dermal blood vessels constrict and skin temp drops to slow passive heat loss

What is the difference between sensible and insensible perspiration?

Insensible perspiration is continuous, unnoticed water loss through the skin, while sensible perspiration is sweating which is visible

Which epidermal cell type produces keratin?

keratinocytes

Which cell of the epidermis produces melanin?

Melanocytes

Which cell of the epidermis produces macrophages they key activators of the immune system?

Dendritic

Which cell of the epidermis acts as a touch receptor?

Tactile (Merkel) cells

How do melanosomes protect keratinocyte nuclei?

They protect them from UV damage

Why are desmosomes important in the epidermis?

providing structural integrity between keratinocytes

List the layers of the epidermis from deep to superficial.

1. stratum basale

2. stratum spinosum

3. stratum granulosum

4. stratum corneum

What cellular activity occurs in the stratum basale?

rapid stem cell increase, and mitosis

In which layer does keratinization begin?

Stratum granulosum

Why is the stratum corneum an effective physical barrier?

it contains 20-30 layers of dead cells

Where is the stratum lucidum found, and why is it unique?

The statum lucidum is only found in thick skin on the hands

True or false? the stratum lucidum is a layer of dead keratinocytes only found in thick skin

True

Compare the papillary and reticular layers of the dermis.

The papillary is the areolar connective tissue, while the reticular dermis is the dense irregular connective tissue

What structures are found in dermal papillae?

1. capillary loops

2. free nerve endings (pain receptors)

What are epidermal ridges, and why are they important?

friction ridges, they help with grip, sense of touch and fingerprint pattern

Why are cleavage lines clinically important to surgeons?

they contain collagen fibers parallel to skin surface

What are flexure lines, and where are they found?

dermal folds at/near the joints, they are tightly secured to deeper structures

What is striae distensae

stretch marks

What causes striae distensae ?

1. pregnancy

2. steroids

3. dramatic changes in weight or muscle mass

What is cyanosis

blue skin color - low oxygenation of hemoglobin

What is erythema?

Redness, caused by fever, hyperextension, inflammation, allergy

What is pallor (blanching)?

pale look due to anemia, low blood pressure, fear, anger

What is jaundice?

A yellow cast caused by liver disorder

What is bronzing?

Inadequate steroid hormones in Addison’s disease, darkens the skin

What are bruises?

clotted blood beneath skin

Basal Cell Carcinoma

most common and least malignant skin cancer, cured by surgery

Squamous cell carcinoma

skin cancer with scaly red papule on scalp, ears, lips, or hands. It is metastatic, treated with radiation or surgery

Melanoma

highly metastatic

Explain the ABCD rule for melanoma detection.

A: asymmetry (two sides do not match)

B: border irregularity

C: color (black, brown, tan, can be red or blue)

D: diameter (6mm or larger)

What are the main functions of hair?

1. Warn of insects on the skin

2. limit physical trauma

3. thermoregulation (trap heat)

4. protect from sun

Where is hair not present?

1. palms

2. soles

3. lips

4. nippes

5. portions external genitalia

What is the function of the arrector pili muscles?

1. thermoregulation (trapping air for warmth)

2. expressing emotion

3. assisting in the secretion of sebum from glands.

vellus hair

pale, fine body hair pf children and adult females

terminal hair

coarse, long hair of eyebrows and scalp at puberty that appear in the armpits and genitals, as well as the face and neck of males

What factors influence hair growth?

1. nutrition

2. hormones

What causes male pattern baldness (androgenetic alopecia), and how is it treated?

Male pattern baldness is a hereditary condition caused by genetic sensitivity to dihydrotestosterone. It is treated with minoxidil and finasteride

What is the function of the nail matrix?

• protects distal, dorsal surface of fingers and toes

• nail growth

eccrine sweat glands (location, secretion, function).

The most numerous type, found on palms, soles, and forehead, secretes sweat and metabolic wastes.

• FUnctions in thermoregulation

Apocrine sweat glands (location, secretion, function).

• axillary and anogenital areas, functions unknown, but can act as a sexual scent gland

• mammary glands secrete milk

• ceruminous glads secret cerumen (earwax)

What is dermcidin, and why is it important?

a microbe-killing peptide that kills bacteria

What are the four major causes of burns?

1. heat

2. electricity

3. radiation

4. chemicals

First degree burn

epidermal damage only, ,localized redness, edema (swelling), and pain

second degree burn

epidermal and upper dermal damage, blisters appear

what are the partial thickness burn

1. first degree

2. second degree

what is the full thickness burn

third degree burn

third degree burn

entire thickness of skin is involved, skin is gray-white, red or black. Not painful or swollen

Why are third-degree burns often not painful?

nerve ending are destroyed

What criteria make a burn critical?

1. 25% of body has second-degree burns

2. 10% of body has third-degree burns

3. face, hands or feet bear third-degree burns

When is a skin graft required?

severe skin loss and third degree burn

What is the purpose of the Rule of Nines?

to estimate the Total Body Surface Area (TBSA) affected by second- and third-degree burns. By dividing the body into sections representing 9%