integumentary system Nurse Hub

What are the three main layers of the integument?

Epidermis, dermis, and hypodermis

What is the epidermis made of?

Stratified squamous epithelial tissue

What is the dermis primarily made of?

Loose connective tissue with collagen, nerves, glands, and vessels

What is another name for the hypodermis?

Subcutaneous layer

Which layer contains adipose tissues stores energy and insulates the body?

Hypodermis

Which layer stores adipose energy and insulates the body?

Hypodermis

Which layer is avascular (contains no blood vessels)?

Epidermis

Which layer nourishes the epidermis?

Dermis (via diffusion)

What is the main function of the epidermis?

Protection from external environment

What are the five strata of the epidermis (superficial to deep)?

Corneum, lucidum, granulosum, spinosum, basale

What layer is only found in palms and soles?

Stratum lucidum

What layer contains dividing stem cells?

Stratum basale (stem cells)

What layer is known as the first line of defense?

Stratum corneum

Which layer helps form a waterproof barrier?

Stratum granulosum

What protein strengthens and waterproofs the skin?

Keratin

What cells produce keratin?

Keratinocytes

What cells produce melanin?

Melanocytes

What layer are melanocytes and stem cells found in?

Stratum basale

What determines skin color — number or activity of melanocytes?

Activity of melanocytes

What type of UV light stimulates melanin production?

UVB radiation (~320 nm)

What disease is caused by malignant melanocytes?

Malignant melanoma

What condition causes rapid keratinocyte division and flaky skin?

Psoriasis

What structures anchor the epidermis to the dermis?

Basement membrane and dermal papillae

What is the function of dermal papillae?

Strengthen attachment and regulate hair growth

What are 'prickle cells,' and where are they found?

Keratinocytes with desmosomes in stratum spinosum

Which layer is the site of basal cell carcinoma?

Stratum basale (carcinoma)

What vitamin does the skin help synthesize?

Vitamin D (cholecalciferol)

What organ systems activate vitamin D after its creation in the skin?

Liver and kidneys

What is the main function of vitamin D in the body?

Promotes calcium absorption and transport

Which layer contains sensory receptors and glands?

Dermis

What are the main accessory structures of the dermis?

Hair follicles, sweat glands, sebaceous glands, receptors, blood vessels

What connects the dermis to the epidermis and makes fingerprint?

Dermal papillae

What is the smooth muscle attached to each hair follicle?

Arrector pili muscle

What causes goosebumps?

Contraction of the arrector pili muscle

Where does hair growth begin?

Hair bulb at the base of the follicle

What provides blood and nerve supply to the hair bulb?

Hair papilla

What is the main component that gives hair hardness?

Keratin

What gives hair its color?

Melanin

How many hairs does the human body approximately have?

About 2.5 million

What type of hair is soft and fine?

Vellus hair

What type of hair is coarse and pigmented?

Terminal hair

What substance do sebaceous glands secrete?

Sebum

What triggers the secretion (release) of sebum from sebaceous glands?

The contraction of the arrector pili muscle triggers the release of sebum by squeezing the sebaceous gland.

What are the main components of sebum?

Triglycerides, proteins, cholesterol, electrolytes

What is the main function of sebum?

Lubricates and waterproofs hair and skin (OIL)

What are sweat glands also called?

Sudoriferous glands

What are the two main types of sweat glands?

Apocrine and eccrine

Which sweat glands open into hair follicles?

Apocrine glands

Which sweat glands open directly to the skin surface?

Eccrine glands

Where are apocrine glands found?

Axilla and genital regions

What type of sweat glands help regulate body temperature?

Eccrine glands

What causes body odor?

Bacterial breakdown of apocrine secretions

What makes eccrine sweat slightly antibacterial?

A peptide with antibiotic properties in sweat

What structures detect pain, pressure, and temperature?

Sensory receptors in dermis(ans)

What gives nails their pink color?

Blood vessels under the nail bed

What is the visible part of the nail called?

Nail body

What is the growing region of the nail called?

Nail matrix/root

What is the cuticle’s anatomical name?

Eponychium

What part of the epidermis extends over the nail base?

Stratum corneum

What is the main function of the integument?

Protection, temperature regulation, sensation, and vitamin D synthesis

How does the skin regulate body temperature when overheated?

Sweat glands activate; blood vessels dilate

How does the skin conserve heat in cold conditions?

Sweat glands close; blood vessels constrict; shivering may occur

What brain region controls body temperature?

Hypothalamus

What is the body’s normal core temperature set by the hypothalamus?

About 98.6°F (37°C)

What type of heat transfer occurs when body heat radiates to the environment?

Radiation

What type of heat transfer occurs through direct contact?

Conduction

What type of heat transfer occurs via moving air around the body?

Convection

What type of heat loss involves evaporation of sweat?

Evaporation

What condition results from dangerously low body temperature?

Hypothermia

What are symptoms of hypothermia?

Shivering, confusion, lethargy, loss of reflexes, unconsciousness

What condition occurs from overheating in humid conditions?

Hyperthermia

What are symptoms of hyperthermia?

Dizziness, headache, cramps, fatigue, nausea

What does the hypothalamus do when body temp rises?

Activates sweat glands and dilates vessels

What does the hypothalamus do when body temp drops?

Closes sweat glands and triggers shivering

What structure of the skin is responsible for touch and pressure detection?

Sensory receptors in dermis

What type of connective tissue predominates in the dermis?

Loose connective tissue with collagen and elastic fibers

What kind of tissue predominates in the hypodermis?

Adipose and connective tissue

What happens to skin cells as they move from deep to superficial?

They die and become keratinized

What skin structure makes fingerprints?

Dermal papillae

What layer of skin contains nerve endings for pain and temperature?

Dermis

What layer of skin produces new skin cells?

Stratum basale

What pigment protects against UV radiation?

Melanin

What is the largest organ of the body?

Skin

What happens to melanin production with sun exposure?

Increases, darkening the skin