Chapter 6 Integumentary system

This shit hard af

Cut-

(Skin) subcutaneous: beneath the skin

Derm-

(Skin) Dermis: inner layer of the skin

epi-

(upon) epidermis: outer layer of the skin

follic

(small bag) hair follicle tubelike depression in which a hair develops

kera-

(horn) keratin: protein produced by certain cells

melan (black)

melanin : dark pigment produced by certain cells

seb-

(grease) sebaceous Gland: gland that secretes an oily substance

sudor-

(sweat)- sudoriferous glands: exocrine glands that secrete glands

What is dermatology?

It is the medical speciality that investigates and treats issues with the skin.

what is an organ?

It is is a structure consisting of two or more tissues that performs a specialized function

Organ system

when two or more organs working toward the same goals are considered an organ system.

Main tissues of the skin are?

Eptihelial and connective they consitute the largest organ in the body by weight

Intergumentary system

organ system that includes the skin and its accessory structures (hair, nails. muscles, sensory receptors, and glands

what comes after tissues?

Your organs

Skin acts as a barrier between what and what?

internal environment and external environment

integument is meaning for what?

skin

what is the latest organ?

skin

The skin has two major layers what are they?

Epidermis and Dermis

epidermis

thin, outer layer of strafirired squamous epithelium

dermis

thick, inner layer of connective tissues, blood vessels, smooth muscle, nervous tissue, collagen and elastic fibers

What is a basement membrane?

separates the epidermis and dermis which also anchors them together

Subcutaneous Layer (Hypodermis)

It is underneath the skin but it is not considered skin it consists of two tissues areolar and adipose connective tissues. what it does is that it binds the skin to underlying tissues.

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adipose

it is a tissue that works as an insulator to keep body from the heat

contains major blood vessels that supply the skin

Subcutaneous layer (hypodermis)

does blood vessels run through the epidermis?

no but it runs through the dermis

Avascular

lacks blood vessels (epidermis lacks blood vessels)

How many layers does the epidermis have?

The epidermis has 4 layers where most areas are however its 5 layers if the thick skin is included. In the thick skin it includes your palms and sole of your feet. There is more friction in these areas that’s why we need thick skin.

what is the depest layer of epidermal cells?

stratum basale (germinativum) consiste of dividing cells it is well-nourished by dermal blood vessels. (cellular division)

what is it called when our basal cells divide and become older and older?

this is called keratinocytes ( due to accumulation of fibrous protein, keratin), migrate toward skin surface) - protein mechanisms are om vesicles they are pushed up to the outer layer of the skin.

what happens to these keratinocytes as they migrate outward?

They harden, dehydrate, and die, in a process called **keratinization**

Why is the epidermis important and what does it protect us from?

Because it protects us against water loss, microorganisms, mechanical injury and chemicals.

These 4 layers of the epidermis include

* Stratum basale- Innermost layer, diving layer 100% alive
* Stratum sinosum- 100 % alive
* Straum granulosum- Beginning to die but still alive
* Stratum Corneaum- outermost layer; dead flattened, keratinized cells; these are continually being shed from the outer skin surface. like the skin that falls off after we shower

Stratum basale

innermost layer, dividing layer 

Stratum corneum

•outermost layer; dead, flattened, keratinized cells; these are continually being shed from the outer skin surface 

What layer is found only in the skin of the palms and soles?

•**Stratum lucidum:** layer between the stratum granulosum and the stratum corneum

Stratum lucidum

layer between the stratum granulosum and the stratum corneum

The rate of cell division increases when?

The skin is rubbed or pressed regulary. This action causes growth of thickened areas called calluses on the palms and soles and keratinized conical masses on the toes called corns.

Melanocytes

Special cells that produce the pigment melanin found in epidermis (however they are not stratified squamous epthilium) within organelles called melanosomes

Where is melanocytes found?

It is found in stratum basale the deepest layer of the epidermis and in the dermis (it also produces up into the dermis since its got little branches or little arms sticking out to allow the melanin to be exocytosed out to the interstitial fluid so it can be observed by keratinocytes)

What does melanin protect?

Melanin protects DNA of skin cells against damaging effects of UV radiation from the sun

What does melanin pigment provide?

It provides skin and hair color; the more melanin is present, the darker the skin or hair will be

cytocrine secretion

is the process when Melanin is transferred from extensions of the melanocytes to other nearby cells 

Eumelanin

is brownish-black

pheomelanin

found in areas such as the lips) is reddish-yellow

How many melanocytes people have?

All people have about the **same number of melanocytes**

How is skin color determined?

genetically determined, and involves the amount of melanin that the melanocytes produce

Skin color results from what?

It results from a combination of genetic, environmental, and physiological factors

Genetic differences in skin color 

result from differing amounts of melanin produced, and in the size and distribution of melanin granules

Granules

is how much melanin is in the vacuole

What causes an increase in darker skin?

Exposure to sunlight, UV light from sun lamps, and X-rays cause darkening of skin, due to an increase in melanin production

What also affects skin color?

Circulation within dermal blood vessels

what causes the reason for our faces to get redder?

this happens when well oxygenated blood has a pinkish color due to hemoglobin (found in red blood cells) the color will be shining through the epidermis area. where people get embrrased or blush

Cyanosis

Poorly oxygenated blood looks blue, due to deep red tone the hemoglobin

How does a person get yellowish skin color?

It can come from eating too many orange foods with carotene, or from **jaundice** due to liver disease.

Three main major skin color

Melanin, blood flow and, the food you eat

Carotene

A diet high in colorful fruits and vegetables such as carrots, apricots, and sweat potatoes may turn skin orange-yellow, because these foods are rich in a pigment called Blank

Jaundice

Skin color can also be affected by disease. A pathological case of yellowish skin tone is blank which may indicate liver malfunction.

How do epidermal cells die?

they can die if their blood supply from the dermis, which brings nutrients is blocked. For example, when a person lies in one position for a prolonged period, the weight of the body pressing against the bed blocks the skin’s blood supply. If cells die (necrosis) the tissues begin to break down and a pressure ulcer ( also called decubitus ulcer or bedsore) may appear

Where does pressure ulcers usually form?

In the skin overlying bony projections, such as on the hip, heel, elbow, or shoulder. Frequently changing body position or massaging the skin to stimulate blood flown in regions associated with bony prominences can prevent pressure ulcers.

The dermis

binds the epidermis to underlying tissues

The dermis

border between epidermis and dermis is uneven, due to **epidermal ridges**(which extend down toward dermis) and **dermal papillae** (which extend upward toward epidermis)

The dermis consists of what?

areolar and dense connective tissue, with collagen and elastic fibers within a gel-like ground substance

This happens in dermis

•Genetically determined pattern of friction ridges formed by dermal papillae provide for unique **fingerprints**

Fibers provide what to the skin?

toughness and elasticity to skin

Dermal blood vessels carry nutrients to where?

carry nutrients to upper layers of skin, to help regulate body temperature

what does the dermis also contain?

It contains nerve fibers, sensory receptors, hair follicles, sebaceous glands, and sweat glands 

Where is dermal papillae found?

Found in the skin all over the body, but they are most abundant in the hands and feet.

Fingerprint

this is when ridges fromed by dermal papillae leave a patterned impression when a finger is pressed against a surface

Nerve cells processes

they are scattered throughout the dermis.

Moter cell processes

conduct impulses out from the brain or spinal cord to dermal muscles and glands

sensory cell processes

conduct impulses away from specialized sensory receptors, such as touch receptors in the dermis and into the spinal cord

nails

are protective coverings on the ends of the fingers and toes

what does each nail consist of?

Each nail consists of a nail plate that overlies a surface of a skin called the nail bed

How Is the nail bed produced?

it is produced by specialized epithelial cells continuous with the epithelium of the skin

Lunula

half-moon-shaped structure at base of nail plate; most actively growing region of the nail root (nail matrix)

As the new cells in the nails are produced what happens to the old ones?

•As new cells are produced, older ones are pushed outward and become **keratinized**, just as in other parts of the skin 

Keratin of nails

is harder than that of the stratum corneum of the rest of the skin

In time what happens to the nail plate?

It extends beyond the end bed and with normal use gradually wears away

Observing nails of a pt can be an important diagnostic tool

For example, a red appearance to the lunula may be indicative of carbon monoxide poisoning and a yellow coloring may be due to liver disease.

what happens when a person gets older what happens to their nails?

As a person ages cell division shows resulting in thinner brittle nails that commonly show vertical ridges

Hair

It can be found in nearly all regions of the skin expect palms, soles, lips, nipples and portions of external genitilia.

Hair follicle

Each hair develops from epithelial stem cells at the base of tube like depression

Where does hair follicles dip into?

They dip down into the dermis or sometimes the subcutaneous layer

what is the deepest part of the hair root?

its is called the hair bulb it is located at the base of the hair follicle

Hair shaft

this is when new cells are formed in the bulb the old cells are pushed outward and become keratinized and die forming it sicks beyond the dermis

hair is composed of what

Hair is composed of dead keratinized epithelial

A sweat gland that drains from the hair follicle is going to be part of what?

It is going to be part of the apocrine sweat gland when its is a smaller one on the side its a merocrine.

Hair color is determined by what?

It is determined by genetics melanin produced by melanocytes is responsible.

What is Eumelanin

It is brownish black

Pheonmalnin

Is redish-yellow

Albinism

It is white this genetic is lack of the melanin

What is gray?

It is the mixture of pigmented and unpigemted hair

Arrecttor pilli muscle

Is a bundle of smooth muscles that is attached to each hair follicle when its contracts in response to cold temp or emotional upset and its causes goose bumps.

Sabacous Glands

They contain groups of specialized epithelial cells and are associated with hair follicles.

Sabacous glands are what type of glands?

They are holocrine glands and their cells produce globules of fatty material that accumulate, swelling and bursting the cells. The resulting oily mixture of fatyy material and cellar debris is called sebum that move through small ducts into the hair follicles.

What is sebum?

It is an oil substance that waterproofs and mostitures the hair shaft and skin.

How do we get acne?

This is by sebaceous glands called acne vulgais overactive and inflamed glands are in some body regions become plugged producing blackheads (comedones) or are surrounded by small, red elevations producing pimples (pustules).

What is comedones?

Blackheads

What is pustules?

Red elevations producing pimples

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