ANAPHY #5 - Integumentary System

Integumentary system

consists of the skin and accessory structures such as hair, glands, and nails

Protection, Sensation, Temperature regulation, Vitamin D production, Excretion

major functions of the integumentary system

Vitamin D

an important regulator of calcium homeostasis, molecules produced after being exposed to ultraviolet light can transform into this

Epidermis

means upon the dermis

Epidermis

the superficial layer of the skin, consisting of stratified squamous epithelial tissue

Dermis

a layer of connective tissue where the epidermis rests on, it is responsible for most of the strength of the skin

Subcutaneous tissue

also called hypodermis

Subcutaneous tissue

a layer of loose connective tissue

False

true or false. subcutaneous tissue is a part of the skin and integumentary system

Subcutaneous tissue

connects the skin to the underlying muscle or bone

Stratified squamous epithelium

the epidermis is what kind of tissue

True

true or false. The epidermis has no blood vessels

Keratinocytes

most cells of the epidermis are __

Keratin

a protein mixture that makes cells more durable

Keratinocytes, Melanocytes, Langerhans cells, Merkel cells

cells of the epidermis

Melanocytes

this cell produces pigment that contributes to skin color

Merkel cells

specialized epidermal cells associated with nerve endings responsible for detecting light touch and superficial pressure

Keratinization

as keratinocytes move from the deeper epidermal layers to the surface, the cells change shape and chemical composition through __

Keratinization

when cells eventually die and produce an outer layer of dead, hard cells that resists abrasion and forms a permeability barrier

Psoriasis

large scaled of epidermal tissue are sloughed off in __

Strata

layers of cells in the epidermis are divided into regions or __

Stratum: basale, spinosum, granulosum, lucidum, corneum

5 strata from deepest to most superficial

Stratum germinativum

stratum basale is also called

Single layer of cuboidal or columnar cells

what kind of cells make up the stratum basale

8-10

stratum spinosum has a total of __ layers of many sided cells

Stratum granulosum

this strata has two to five layers of flattened, diamond-shaped cells

Stratum lucidum

this strata has three to five layers dead cells, it appears transparent, present in thick skin

Stratum corneum

most superficial stratum, 25 or more layers of dead squamous cells

Cutaneous receptors

detect touch, pressure, vibration, pain, heat, and cold

Free nerve endings

detect pain, temperature, itch, and crude touch

Merkel receptors

touch receptors found in stratum basale, detect light touch

Meissner corpuscles

found in the superficial part of the skin, detect fine touch

Pacinian corpuscles

respond to deep pressure and vibration

Hair follicle receptors

detect hair movement

Integument

means covering

Skin and accessory structures

Integumentary consists of:

Hair and hair follicles, nails, eccrine and apocrine sweat glands, sebaceous (oil) glands

accessory structures include

Epidermis and dermis

major layers of skin

Epidermis

superficial keratinized stratified squamous epithelium, avascular

Dermis

deeper connective tissue, vascular and innervated

Subcutaneous tissue

lies deep in the dermis but not part of the skin proper

Epidermis

this major layer of the skin is durable, relatively water-resistant, and is a protective barrier

Stratum lucidum

strata of the epidermis that has thick skin only

Desquamation

this is when surface corneocytes are continuously shed

Corneocytes

when cells flatten, lose nuclei and organelles and die to become __

Dermis

this major layer of the skin is composed of connective tissue

Papillary layer and reticular layer

two layers of the dermis

Superficial loose areolar connective tissue

the papillary layer has what kind of tissue

Dermal papillae

form friction ridges

Reticular layer

contains hair follicles, sebaceous glands, sweat glands, deep sensory nerve endings and arrector pili

Cleavage (tension) lines

orientation/direction of collagen fibers in the dermis, where skin is stronger along these lines

Cleavage (tension) lines

wounds parallel to the __heal better with less scarring

Melanin

skin color is determined by __ in the epidermis, major pigment responsible for skin, hair and eye color

Stratum basale

melanocytes are found in what strata

Melanosomes

melanin is packaged into __ and transferred to keratinocytes

Melanin, blood circulation, carotene, thickness of the stratum corneum

factors determining skin color

Hemoglobin and cutaneous blood flow

in blood circulation __ contributes to pink or red tones

Carotene

yellow-orange pigment that accumulates in the stratum corneum and adipose tissue

Albinism

inherited reduction of absence of melanin production

Vitiligo

loss/destruction of melanocytes producing well-defined depigmented patches

albinism , vitiligo, freckles and many nevi (moles)

examples of pigmentation disorders

Loose connective tissue and adipose tissue

subcutaneous tissue is mainly composed of

padding/cushioning, insulation, and energy storage

functions of subcutaneous tissue

Shaft, root, bulb, dermal papilla

Hair structure includes:

Medulla, cortex, cuticle

layers of the hair include:

Shaft

visible portion of hair above the skin

Root

portion of hair below the skin within the follicle

Dermal papilla

dermal projection into the bulb containing blood vessels that nourish growing hair

Keratinized epithelial cells

hair is composed of what cells

Medulla

soft inner core/region of the hair

Cortex

hard major portion of the hair

Cuticle

outermost layer of overlapping cells

Hair follicle

epidermal invagination extending into the dermis

Sebaceous glands

usually empty sebum into the follicle

Arrector pili

smooth muscle attached to the follicle

Piloerection

sympathetic contraction pulls hair upright in other words goose bumps

Anagen, catagen, telogen, exogen

Phases of hair growth

Anagen

Phase of hair growth: growth phase

Catagen

Phase of hair growth: brief transition phase

Telogen

Phase of hair growth: resting phase

Exogen

Phase of hair growth: shedding phase

Sebaceous glands

secrete oily sebum by holocrine secretion, lubricates skin and hair

Eccrine sweat glands

watery sweat opens directly into skin surface; mejor role in thermoregulation

Apocrine sweat glands

concentrated in axillary/anogenital regions, open into follicles, active at puberty

Acne vulgaris

skin condition when hair follicles become plugged with oil and dead skin cells

Closed comedone

whitehead

Open comedone

blackhead

Nail plate/body, free edge, nail root, nail matrix, lunula, eponychium (cuticle), nail bed

Parts of nails

Nail plate/body

Parts of nail: visible hard keratin plate

Free edge

Parts of nail: distal portion extending beyond the digit

Nail root

Parts of nail: proximal part covered by skin

Lunula

Parts of nail: whitish crescent-shaped area at the base of the nail

Eponychium (cuticle)

Parts of nail: stratum corneum extending over the nail root

Nail bed

tissue underneath the nail body supports the plate

4.5-5.5

acid mantle is what acidity

Acid mantle

inhibits microbial growth

UVB

acts of a cholesterol-derived precursor in the skin to form vitamin D3

Vitamin D3

modified in the liver then kidney to form active vitamin D (calcitriol)

Active vitamin d

supports calcium and phosphate absorption and normal bone mineralization

UVB + skin, Vitamin D3, Liver, Kidney, Active Vitamin D

vitamin d production process