Human Anatomy Exam 1 Torres The integumentary system

Functions of the integumentary system

protection, sensation, temperature regulation, vitamin d production, excretion

Function for protection of the integumentary system

- outer layers act as a protective armor against physical and chemical threats

Ruffini's corpuscles detect

touch and pressure

Krause Corpuscles detect

cold receptors

Meissner's corpuscles detect

sensitive touch

Pacinian corpuscles detect

pressure

What is the function of Thermoregulation (Skin)

The skin helps to regulate body temperature. Blood conducts heat from the core of the body to the skin, dissipated by evaporation and radiation.

What is the function of vitamin D synthesis in the integumentary system

UV radiation is absorbed by the skin, triggering synthesis of various forms of vitamin D

Why is the function of vitamin D important ?

it is crucial to the formation of many types of white blood cells

What is vitamin D essential for absorption of what two elements ?

calcium and phosphorus

Misshapen bones in children due to lack of calcium resulting from insufficient vitamin D is what deficiency disease

rickets

Order of Layers of Skin from most superficial to most deep.

Epidermis, Dermis, Hypodermis

Thick skin has how many layers? Only on where ?

5 epidermal layers and only on palms of hands and soles of feet

Thin skin has how many layers? Only on where ?

4 epidermal layers and everywhere else in the body

What are the cells that produce keratinocytes ?

keratin

What is keratin ?

intracellular fibrous proteins that gives structures hardness and water resistance

What is the first layer of skin in the epidermis ?

stratum basale, it is a single layer of cuboidal or columnar cells

What is the dermal papillae?

projections of dermis that hook into the stratum basale

What are the three major cell types in the epidermis ?

Merkel, melanocyte and basal cells

Merkel cells are

touch receptors

Melanocytes do what

produce the pigment melanin

Basal cells are

stem cell precursors to keratinocytes

Basal cells are constantly undergoing mitosis and producing new

keratinocytes

Stratum spinosum are

keratinocytes that are hooked together by spiny desmosomes. They then begin producing keratin and water-resistant glycolipids

What are langerhans cells ?

macrophages that destroy bacteria, foreign particles and damaged cells

What happens when new keratinocytes are added from below ?

new keratinocytes added from below push older ones upwards

Stratum granulosum are

keratinocyte shape change - flatten, cell membrane thickens. Keratin production continues

What happens to keratinocytes in the stratum granulosum?

start to die - organelles disintegrate, leaving behind keratin (and few other proteins)

stratum lucidum is

only in THICK SKIN - palms and soles; cells are dead and flat

What is the protein in stratum lucidum ?

eleidin

Stratum corneum is

exposed to the external environment; dead cells are highly keratinized (aka cornified)

What is important about the stratum corneum ?

It is the dry, dead, protective layer - outermost cells are continually shed and replaced

What is the dermal papillae?

projections of dermis that hook into the stratum basale

What are the two layers of the dermal papillae ?

papillary layer and the reticular layer

What functional structures of the skin does the dermis contain ?

blood vessels, lymph vessels, nerves, hair follicles and sweat glands

What is the papillary layer of the dermis?

loose areolar connective tissue where all the dermal papillae are

What are some common structures in the papillary layer ?

fibroblasts, blood vessels, sensory receptors, adipocytes and phagocytes

What is the reticular layer of the dermis?

dense connective tissue

Why does the reticular layer look reticulated ?

due to mesh of fiber proteins elastin and collagen

What are the common structures in the reticular layer of the dermis ?

rich blood and nerve supply

What is the hypodermis? (what's unique about it)

sometimes not considered part of the skin, always a part of the integumentary system. DEEPEST SKIN LAYER

Other names of the hypodermis

subcutaneous layer or superficial fascia

What is fascia ?

connective tissue that encases body parts underlying fascia; bones, tendons, ligaments

The hypodermis is loose areolar connective tissue, what are the major structures within it ?

rich vasculature (blood supply) and rich in adipose

What are melanocytes?

cells in stratum basale that produce melanin

What is melanin ?

most common pigment in humans

More melanin means __________ protection, but __________ vitamin

more, less

Melanin does what with UV radiation

absorbs

what is a hair follicle

epidermal pore that produces hair strands

How does hair growth happen ?

1) Basal cells in the hair bulb produce new keratinocytes

2) Older keratinocytes become keratinized as they are pushed up out of the follicle as the hair strand

The external hair is entirely made of

keratin

Follicle shape determines _________ , while genetics determines ____________ .

hair shape, follicle shape

What are arrector pili ?

smooth involuntary muscle that causes hair to "stand up"

The nail root forms from the .... . What is it constantly producing ?

stratum basale and is constantly producing keratinocytes

What is a sudoriferous gland?

Sweat gland epidermal projection into dermis

What are the two types of sudoriferous glands ?

eccrine and apocrine

Eccrine sweat gland function

secrete directly to skin surface; found all over the body but MOSTLY abundant on soles, palms and forehead.

Apocrine sweat gland

secrete into hair follicles; found MOSTLY in armpits and genitals

What is the main function of the apocrine sweat gland ?

mostly functions in stress response

When the apocrine sweat gland activates, what is the body's response ?

body odor occurs when bacteria break down apocrine sweat

What does deodorant do ?

kill the bacteria

What do antiperspirants do ?

physically block the sweat gland

What are sebaceous glands?

secrete a lipid substance called sebum;

The secretion of sebum is __________ . It is ___________ and timed with the stages of puberty.

hormonally, controlled