Integumentary System

Langerhans cells

Also known as dendritic cells. Dendritic immunological cell that patrol for invaders can reach out and touch other cells far away from them. Looks for foreign invaders and breaks down anything that shouldn't be there. Functions as a macrophage (WBC's) by engulfing bacteria, foreign particles, and damaged cells that occur in this layer.

What area of the skin structure is responsible for "goose bump" formation of the skin?

Arrector Pili Muscle

What is hair made of?

Flexible strand of dead keratinized cells (hard keratin)

The ________ acts as an insulator for the body?

Hypodermis

Stratum basale (germinativum)

Is a single layer of cells primarily made of basal cells. A basal cell is a cuboidal-shaped stem cell that is a precursor of the keratinocytes of the epidermis. All of the keratinocytes are produced from this single layer of cells, which are constantly going through mitosis to produce new cells. As new cells are formed, the existing cells are pushed superficially away from the stratum basale.

containment

_____ for the bodies structure and vital organs

protection

_______ from environment (abrasion, fluid loss) keratinized stratified squamos epithelial cells act as a barrier against dehydration, microorganisms, UV, chemicals It keeps bacteria out and foreign objects outside our body.

where do the 2 layers meet? (epidermis & dermis)

at the dermoepidermal junction

eumelanin

dark brown, better at absorbing UV radiation

stratum basale (germinativum)

deepest epidermal layer made of a single row of cuboidal cells that undergo rapid cell division (mitosis) Function: produce new cells (keratinocytes), protects from UV rays, makes melanin (melanocytes)

Eccrine sweat glands

or merocrine glands, these glands are distributed across the surface of the skin and produce a dilute, salty sweat.

Stratum corneum

*Dead cells* Surface layer of the epidermis, which consists of keratin, which accumulates within maturing cells and effectively waterproofs the cells, blocking diffusion of nutrients and waste. Causing the cells to die and slough off. ** Remember coroner's office, dead bodies go for autopsy *cells are fully keratinized and dead; they are continually shed*

Stratum lucidum

*clear layer* lost its nuclei and organelles, why it has no color a layer of the epidermis found only in the thick skin of the fingers, palms of hands, and soles of feet. Extra layer of dead cells on thick skin. Function: extra protection *flat, closely packed cells, also dead and full of keratin*

Stratum granulosum

*grany* layer, [2-4 layers] in the process of dying Function: Begin to produce keratin, cells contain granules that make keratin. *cells begun to degenerate first quasi-living layer but actively dying (actively filling with keratin)*

Stratum spinosum

*spiny* layer, [8-10 layers] Structure: cells in very close contact, bound when dehydrated create little spikes that indicate where they are bonded. The cells accumulate desmosomes (structure that join adjacent cells together) Function: phagocytosis, gives skin strength and flexibility, *cells become keratinized*

The stratum basale (germinativum) Layer has 4 M's?

1. Mitosis 2. Merkel cell 3. Melanocytes 4. Macrophage

Dermis Layers

2 Layers

The skin divided into

2 layers

The skin is composed of _________ layers.

2, epidermis and dermis

melanin, carotene, hemoglobin

3 pigments that contribute to skin color

Epidermis layers

5 layers

Melanocytes

A cell in the skin that produces the pigment melanin for UV protection.

Dermal papilla

A finger-like projection, or fold, is found in the superficial portion of the dermis. Dermal papillae increase the strength of the connection between the epidermis and dermis; the greater the folding, the stronger the connections made. They create your fingerprint pattern. Function: it holds the epidermis on the dermis which is below it.

arrestor pili muscle

A small, involuntary muscle located along the side of the hair follicle that is responsible for 'goose bumps'

Melanin

Any of a group of naturally occurring dark pigments responsible for the color of skin. Is a pigment molecule, determines *skin color* and protects from *UV radiation*

Which of the options is not considered an appendage of the skin? - Carotene - Nails - Hair & Hair Follicles - Sweat Glands

Carotene

Hypodermis layer (subcutaneous)

Composed of connective and adipose (fat) tissue that connects the skin to the surface muscles. Functions: mode of fat storage and provides insulation and cushioning for the body. Fats helps insulate our body from the cold and acts as a cushion for our internal structures (such as muscles and organs) when something hits us.

Integumentary system

Consists of the skin, hair, nails, glands, and nerves. Contains organs and glands that are vital to protecting the body and regulating temperature.

The process of cells

Creating new cells on the bottom, then those new cells migrate up and eventually we have dead cells up on the top

What layer does a first degree burn , burn through?

Epidermis

The skin is considered a tissue. TRUE or FASLE?

FALSE, It is a ORGAN not tissue.

What layers does a third degree burn, burn through?

Full-thickness burn; epidermis, dermis and some deeper tissue

What section of the integument(epidermis, dermis and hypodermis) is the first to have a blood supply?

Hypodermis

Which layer is not part of the Integumentary system?

Hypodermis (subcutaneous) Layer

Filaggrin

Intermediate filament binding protein which bundles keratin filaments in skin cells

What area of the skin structure is responsible for the skin's sensitivity to light touch? - Meissner's Corpuscle - Pacinian Corpuscle - Dermal Papillae - Hair Plexus

Meissner's Corpuscle

Sudoriferous glands are found everywhere expect? - Nipples and parts of the external genitalia - Palms & Soles - Arms & Legs - Feet

Nipples and parts of the external genitalia

Hemoglobin

Oxygen carrying pigment in red blood cells, iron-containing protein in red blood cells that carries oxygen for delivery to cells. (Red when oxygenated)

The sebaceous glands are found everywhere on the body except? - Palms & Soles - Back - Neck & Ears - Head

Palms & Soles

What kind of connective tissue is found in the first layer of the dermis?

Papillary layer; areolar tissue

What layers does a second degree burn, burn through?

Partial-thickness burn; epidermis and part of dermis

Melanosome

Pigment carrying granules that produce melanin, a complex protein.

Keratinization

Process by which newly formed cells in the stratum basale are pushed upwards away from source of nutrients & oxygen; become filled with keratin protein filaments; move upward, & eventually lose their nucleus and other organelles then disintegrate, and the cells die. They undergo apoptosis (cell death) and when they reach stratum corneum they are sloughed off and are replaced by underlying cells going through keratinization. When they die they form tough, resistant structures such as skin and nails.

What kind of connective tissue is found in the second layer of the dermis?

Reticular layer; dense irregular connective tissue

The ________ is responsible for why you would feel something touch your hair.

Root Hair Plexus

In what layer of the skin are melanocytes and keratinocytes found?

Stratum basale, stratum spinosum

Which layer of the epidermis is the first to contain dead or dying cells?

Stratum lucidum

Dendritic cells are found in the stratum ___________ and have what function?

Stratum spinosum and stratum granulosum; stand guard against toxins, microbes, and other pathogens that penetrate into the skin

The Pacinian corpuscle is a nerve ending responsible for sensitivity to pain and pressure. TRUE or FALSE?

TRUE

The Reticular Layer account for 80% of the dermis and is made up of collagen networks. TRUE or FALSE?

TRUE

The skin is considered an organ. TRUE or FALSE?

TRUE

Keratohyalin granules

The cells become flatter, their cell membranes thicken, and they generate large amounts of the proteins keratin the protein Keratohyalin forms dense cytoplasmic granules that promote dehydration of the cell as well as aggregation and cross-linking of the keratin fibers. The nuclei and other organelles then disintegrate, and the cells die

Desmosome

The stratum spinosum is spiny in appearance due to the protruding cell processes that join the cells via a structure called a _____. The _____ interlock with each other and strengthen the bond between the cells.

The reticular layer

Thickest layer, dense and irregular connective tissue. This layer serves to strengthen the skin and also provides our skin with elasticity. Also has fibers, blood, nerves, muscles, hair follicles, sweat glands, and sebaceous glands.

The papillary layer

Thin, loose areolar connective tissue, which makes the collagen and elastin fibers of this layer form a loose mesh. Has CT and blood vessels that give nutrients to the epidermis and that help control the temperature of the skin. Provides the layer of the epidermis with nutrients to produce skin cells called keratinocytes. Made up of dermal papillae, these ridges cause us to have *fingerprints* and footprints.

Apocrine sweat glands

a sweat gland that secretes a viscous fluid into a hair follicle (as in the armpit or groin), is lined with a single layer of usually columnar cells with eosinophilic cytoplasm, and typically does not become active until puberty

The Pacinian corpuscle

a type of nerve ending located in the subcutaneous layer that is sensitive to pain and pressure; also described as "lamellated"

Sweat glands (sudoriferous glands)

are associated with the body's homeostatic relationship of thermoregulation. Also, serve as excretory organs and help rid of the body of metabolic wastes. simple cuboidal epithelium, exocrine glands, and merocrine glands

Albinism

congenital hereditary condition characterized by partial or total lack of pigment in the skin, hair, and eyes. (Is a person who is unable to produce melanin, *no melanin production*)

sensation

contains millions of somatosensory receptors to detect stimuli tactile receptors deep in the skin that will allow us to sense touch and pain.

5 layers of epidermis

corneum, lucidum, granulosum, spinosum, basale (germinativum) (come lets get sun burned)

immunity

dendritic cells help trigger immune reactions

Meissner's corpuscles (tactile corpuscles)

detect fine touch and pressure. located in dermal papillae

flexibility

elastic properties of skin allows body to move without injury

2 layers of skin

epidermis and dermis layers

2 main types of melanin

eumaelanin and pheomelanin

Merkel cells

function as *touch receptors*, tactile epithelial cells in basale layer connect to sensory nerve endings (light touch receptors) which functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch. These cells are especially abundant on the surfaces of the hands and feet.

Melanin

gives hair and skin its color, and also helps protect the DNA in the nuclei of living cells of the epidermis from ultraviolet (UV) radiation damage.

skin appendages

includes cutaneous glands, hair and hair follicles, and nails Cutaneous glands: sebaceous glands and sweat glands (sudoriferous glands) Sweat glands: Eccrine sweat glands Appocrine sweat glands

Epidermis cell types

keratinocytes, melanocytes, langerhans cells (dendritic cells), merkel cells -cytes means cells

pheomelanin

lighter, reddish color

how does pigment production work/what does the pigment do?

pigment produced and stored in organelles called melanosomes, which are released and picked up by keratinocytes forms a protective layer over nucleus of keratinocyte thereby protecting the DNA (reflects light- reflect UV away from nucleus)

excretion

plays a minor but important role in the regulation of fluid volume and concentration of wastes by regulation chemical makeup of sweat

Cermunious glands

produce a waxy secretion in the ear canals, produce sebum.

functions of skin

protection, sensation, flexibility, excretion, hormone production, immunity, thermoregulation (endothermy), containment

epidermal growth and repair

protective properties of integument depend upon the epidermis' ability to repair itself as keratinized cells from stratum corneum flake off, they are replaced with cells from lower levels abrasion of the skin stimulates mitosis and shortens turnover time

Lamellar granules

release a lipid-rich secretion that functions as a water-repellent sealant in the stratum granulosum

Sebaceous glands

secrete sebum (oil) that lubricates (waterproofs) the skin and discourages the growth of bacteria on the skin holocrine glands The sebaceous glands are found throughout all areas of the skin except the *palms* of the hands and *soles* of the feet. produce sebum, which supplies hair shafts and skin with oily secretions.

Vitiligo

skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due an autoimmune reaction that leads to loss of color in patches

hormone production

skin exposed to UV begins the initial steps of vitamin D production. We need sunlight to synthesize vitamin D.

thermoregulation

skin helps maintain homeostasis of body temperature. Temp. must be precisely regulation within optimal ranges. goosebumps- the bumps created by hairs standing up on the skin in response to cold, fear, etc. vasodilation- widening of the blood vessels that allows for increased blood flow. vasodilate and move blood near the surface, and that carries heat away.

Dendritic cells

specialized white blood cells that patrol the body searching for antigens that produce infections someone that reports the danger, it's a macrophage that learns firsthand what comes into the body and then it will report to other immune cells, look what came into the body.

Keratinocytes

squamous cells that produces keratin (tough, fibrous protein). *Become fully keratinized when dead*

how are keratinized cells replaced?

stratum basale cells divide and push up, becoming the successive layers this process is tightly controlled so that cells divide at the same rate that they are shed regeneration time is approx. 35 days

Carotene

the *yellow-orange* pigment of the skin

Integumentary system

the skin and its appendages (hair, nails, etc.)