Integumentary System

what does the integumentary system refer to

refers to bodys external surface, including skin, nails, and sweat and oil glands

what are the layers of skin

epiderms

dermis

hypodermis

what five layers make up the epidermis

stratum corneum

stratum lucidem

stratum granulosum

stratum spinosum

stratum basale

which layer is avascular (no blood vessels)

epidermis

which layer of skin contains connective tissue, glands, and blood vessels

dermis

what protein do keratinocytes produce and why is it so important

keratin, provides strength and waterproofing

what is primary role of melanocytes

produce melanin, which protects DNA from UV damage and gives skin colour

what happens to keratinocytes as they move from the stratum basale to corneum

they mature, flatten, die, and shed

why does thick skin (palm/soles) have a stratum lucidum

extra protection and durability against friction

which gives skin its toughness and elasticity?

dermis (collagen and elastic fibers)

what is sebum and what does it do?

oily secretion from sebaceous glands that lubricates and waterproofs skin and hair

what triggers arrector pili muscles to contract

cold temp, or emotional stress

what sweat gland type plays a role in body odor?

apocrine glands (bacteria break down their secretions)

main functions of integumentary system?

protection, thermoregulation, sensation, excretion, vitamin D synthesis, and appearance/communication

what kind of cells make up majority of epidermis

keratinocytes

why do cuts in the dermis bleed, but cuts in epidermis dont?

dermis contains blood vessels, the epidermis does not

what is the role of the skin in thermoregulation

sweat evaporation and blood vessel dilation/constriction regulate heat

what tissue mainly makes up the dermis?

dense connective tissue

what are the two major components of the dermis?

superficial papillary layer

deeper reticular layer

what is the role of the skin in thermoregulation

sweat evaporation, blood vessel dilation/constriction

what type of tissue primarily makes up the dermis

dense connective tissue

why is the stratum spinosum called the spiny layer?

cells appear spiny due to desmosome connectionsw

which epidermal layer contains melanocytes?

stratum basale

difference between eccrine and apocrine sweat glands?

eccrine: thermoregulation

apocrine: scent/emotional stress