(ZOOLOGY LEC) integumentary system

integumentary system

Complex set of organs that includes the skin and its derivatives (sweat and oil glands, hairs, and nails)

protection

manjor function of integumentary system

integument

other term of the skin

covering

Integument means

epidermis

a keratinized stratified squamous epithelium

epidermis

Outer most protective shield of the body

Dermis

Underlying epidermis and Makes up bulk of skin

Fibrous connective tissue & Blood vessels

dermis is composed of

keratinocytes

cells of epidermis that produces keratin

keratinocytes

Arise in the deepest part of the epidermis from a layer of cells (stratum basale) that undergo almost continuous mitosis

callus

thickening of the epidermis

melanocytes

Spider shaped cells that is Found in the deepest layer of the epidermis

melanocytes

Synthesize the pigment melanin

melanosomes

Made and accumulated in membrane-bound granules

black

melan means

langerhan’s cells

Star-shaped Arise from bone marrow and migrate to the epidermis

epidermal dendritic cells

other term for langerhan’s cell

langerhan’s cells

Are macrophages (WBC) that help activate our immune system

merkel’s cell

Present at the epidermal-dermal junction and shaped like a spiky hemisphere

merkel’s cells

Shaped like a spiky hemisphere

Merkel disc

This combination functions as a sensory receptor for touch

Stratum Basale

Deepest epidermal layer & attached to the underlying dermis along a wavy borderline

Stratum Basale

Consists (mostly) of a single row of cells representing the youngest keratinocytes (has mitotic nuclei)

stratum germinativum

other term for stratum basale

prickly

Spinosum means?

statum spinosum

Several cell layers are thick that contain a weblike system of intermediate filaments, which span their cytosol to attach to desmosomes

statum spinosum

Keratinocytes appear irregular (spiny) in shape, causing them to be called prickle cells

Melanin granules & Langerhan’s cells (highest concentration)

Scattered among the keratinocytes are:

stratum granulosum

Consist of 3-5 layers in which keratinocyte appearance changes drastically

flatten and disintegrating

Cells, Nuclei and organelles events in stratum granulosum

Keratohyaline granules

Help to form keratin in the upper layers

Lamellated granules

Contain a waterproofing glycolipid that is spewed into the extracellular space and is a major factor in slowing water loss across the epidermis

thicken and coats the external membrane

Cell membranes and lipids event in stratum granulosum

stratum lucidum

Thin translucent band, few rows of clear, flat, dead keratinocytes with indistinct boundaries

thick skin

stratum lucidum is visible only in?

stratum corneum

Horny (hard, callous) layer. 23-30 cell layers thick (3/4 of epidermis)

glycolipids

what is between cells that waterproofs stratum corneum

stratum corneum

the outermost protective layer of the epidermis composed of a thick layer of dead keratinocytes

dermis

Composed of strong, flexible connective tissue, Its cells are typical of those found in any connective tissue proper

microfiblasts

cells that form the fibers of connective tissue

microphages

protective cell capable of phagocytosis

mast cells

immune cell that initiates inflammation

white blood cell

cell for protection

• Collagen:

• Elastin:

• Reticular fibers

Its semifluid matrix is heavily embedded with:

collagen

 strong, fibrous (threadlike) insoluble protein

elastin

extracellular connective tissue protein

reticular fibers

 supporting framework tissue

dermis

binds the entire body together like a body stocking

dermis

It is your hide and corresponds exactly to animal hides used to make leather products

dermis

Major portions of hair follicles, as well as oil and sweat glands, are derived from epidermal tissue but reside here

superficial papillary

thin layer is highly vascularized areolar connective tissue containing a woven mat of collagen and elastin fibers

dermal papillae

superior surface is thrown into peglike projections that indent the overlaying epidermis

nipple

papill means

dermal ridges

On the palms of the hands and soles of the feet, these papillae lie atop larger mounds

dermal ridges

patterns are genetically determined and unique to each of us

reticular layer

Deeper & accounts for 80% of the thickness of the dermis

collagen fibers

it give skin strength and resiliency

collagen fibers

Binds water, helping keep the skin hydrated

elastin fibers

it provide the stretch-recoil properties of skin

dermal stretching

Stretching of the skin during pregnancy (Stretch marks)

blisters

Separation of the epidermal and dermal layers by a fluid-filled pocket

• Melanin

• Hemoglobin

• Carotene

three pigments of skin color

melanin

Only pigment made in the skin

melanin

Polymer of tyrosine amino acid

yellow to reddish-brown to black

color range of melanin

tyrosinase

Synthesis depends on an enzyme in melanocytes

melanocytes

All humans have the same relative number of melanocytes

freckles and moles

local accumulations of melanin

melanin

reflect the relative kind and amount of made and retained

Clumping of elastin fibers

Depresses the immune system

Alters DNA

Excessive sunlight damages the skin:

sunlight

Melanocytes are stimulated by

carotene

Yellow to orange pigment found in certain plant products such as carrots

carotene

Tends to accumulate in the stratum corneum and in the tissue of the hypodermis

soles and palm

Where is carotene most obvious?

hemoglobin

Pinkish hue of fair skin people

erythema

Redness color of skin

pallor

is an unusual lightness or loss of color in the skin and mucous membranes, caused by a reduced supply of blood, oxygen, or red blood cells (hemoglobin)

Jaundice (yellow)

Liver disorder (yellow bile pigment accumulates in the blood and deposited in body tissues)

Bronzing

Metallic appearance of skin, Addison’s disease, Hyperfunction of adrenal cortex

Black and blue: bruises

Blood escaping from the blood vessels and clotting under the skin

sweat glands

Distributed over the entire skin surface except the nipples and parts of the external genitalia

Sudoriferous

other term for sweat

Eccrine

Apocrine 

two types of sweat glands

Eccrine sweat glands

produce true sweat, are the most numerous of the sweat glands, and are particularly abundant on the palms of the hands, soles of the feet, and forehead

merocrine sweat glands

other terms for eccrine sweat glands

dermis

Simple, coiled, tubular gland, secretory part of eccrine lies coiled in

Hypotonic filtrate

(lower osmotic pressure than a reference) of the blood that passes through the secretory cells of the sweat glands and is released by exocytosis

Dermicidin

microbe-killing peptide

Lactic acid

chemical that attracts mosquitoes

4-6

ph level of eccrine sweat glands

sympathetic nervous system

Sweating is regulated by?

prevent overheating of the body

major role of eccrine gland

appocrine glands

Largely confined to the axillary and anogenital areas (Larger than eccrine glands)

appocrine glands

Ducts empty into hair follicles

odorless

scent of appocrine glands

body odor

when its organic molecules are decomposed by bacteria on the skin, it takes on a musky and generally unpleasant odor

appocrine glands

Little role in thermoregulation

ceruminous gland

Modified apocrine glands found in the lining of the external ear canal

cerumen or earwax

a sticky, bitter substance found in ears