ISP- Integumentary System

integumentary system

organ system that provides protection to the outer body

epidermis

outermost layer of skin

dermis

second layer of skin composed of elastic connective tissue, blood vessels, lymph vessels, nerves, involuntary muscle, hair follicles, sweat, and oil glands

hypodermis

(subcutaneous fascia) innermost layer of skin consisting of connective tissue and adipose (fatty) tissue

sebaceous glands

oil glands

sudoriferous glands

sweat glands

macules

flat spots on the skin such as freckles

papules

small, firm skin elevation caused by inflammation, fluid accumulation, or hypertrophy of tissue

vesicles

a small abnormal elevation of the outer layer of skin enclosing a watery liquid

pustules

a small circumscribed elevation of the skin containing pus and having an inflamed base

crusts

encrusting deposits of serum, cellular debris, and bacteria present over or about lesions in some skin diseases

wheals

a suddenly formed elevation of the skin surface with associated burning or itching

ulcer

a break in the skin or mucous membranes with loss of surface tissue; may extend into the dermis and cause bleeding or scarring

keratinization

the process in which the cytoplasm of the outermost cells of the mammalian epidermis is replaced by keratin

skin layers

epidermis, dermis, hypodermis

__________________ and ________________ are anchored to underlying surfaces because of the hypodermis/subcutaneous layer

epidermis and dermis

dermis binds epidermis to

underlying tissues

dermis thickness

1.00-2.00mm

dermis is thinner on _____________, thicker on ______________

eyelids, palms/soles

dermis consists of

dense connective tissue, muscle fibers

dense connective tissue function

provides a tough elasticity to the skin

muscle fibers function

skeletal muscles anchor the skin to provide voluntary movement (ex. facial expressions)

two layers in dermis

papillary and reticular

papillary layer

layer in dermis; consists of papillae (finger-like projections connecting the dermis and epidermis, and contains ridges and fingerprints)

reticular layer

layer of dermis; consistss of dense, irregular tissue; characteristics→strength/elasticity

accessory structures

hair follicles, nails, sebaceous glands, nerves, blood vessels, sweat glands (endocrine and apocrine)

how hair follicles develop

epidermal cells divide and older cells keratinize and move outwards; growth cycle of about 2-6 years

what are sebaceous glands

specialized epithelial cells located near/connected to hair follicles all over (except palm/sole); produce sebum (oil) composed of keratin, fat, and cellulose debris

what are sweat glands

found throughout the skin; consist of a tiny tube originating in the dermis as a ball-shaped coil; endocrine glands (sweat through skin because of increased temp) or apocrine glands (open into hair follicles, develop scent as bacteria decomposes fluids, found in hair follicles)

what are nails

protective covering located on the distal surface of the end of each finger/toe; half-moon shaped lunula grows most actively

how nails form

epithelial cells divide, keratinize, and form scales covering nail plate; continued growth forms the nail body and pushes nail forward

adipose (fatty) tissue

white adipose cells; connective tissue

fibroblast (most common cells of connective tissue)

synthesizes extracellular matrix and collagen, structural framework (stroma) for animals, and play a critical role in wound healing

funciona of integumentary system

protection, sensory reception, thermoregulation, synthesis/storage of nutrients, excretion/secretion

how does the skin protect

tightly-packed keratinized cells are located in the stratum corneum and are the waterproof protector blocking passage of chemical agents; melanin is a broadband and absorbs UV radiation

how do the nails protect

keratinized scales provide a protective covering over the ends of the fingers and toes

how does the hair protect

head and body hair acts as insulation; nasal and ear hair acts as filter

pressure receptors respond to

excessive pressure/pressure causing pain; mild pressure/touch causing pleasure

temperature receptors respond to

hot and cold; extreme temperatures trigger pain receptor response

what do muscles do when cold

contract

what increases when one is cold

cellular respiration and heat production

what do muscles do when one is hot

relax

percentages of radiation, conduction, and evaporation when hot

60%, 15%, 22% (respectively)

vitamin D

fat-soluble vitamin produced endogenously when UV rays strike skin

roles of vitamin D

promotes calcium absorption, supports bone cell development and growth, reduces inflammation, supports cell growth, supports neuromuscular and immune function

adipose tissue is located

under the skin as subcutaneous fat

white adipose tissue function

stored fuel source of free fatty acids

brown adipose tissue function

generates body heat; insulation from heat and cold

subcutaneous gland secretions do what

inhibit water loss

sweat gland secretions do what

respond to changes in core body temperature

specialized sweat glands and the fluids they secrete

ceruminous glands, ear wax; mammary glands, milk

why do fluids leak into injured tissue

to speed up healing process by increasing supply of nutrients and oxygen

what might predispose humans to specific skin conditions

environmental irritants and genetic makeup

pimples develop when

sebum occludes in the duct opening

acne

most common skin disease; affects roughly 80% of people in the course of a lifetime

eczema symptoms

dry, scaly, itchy, and recurring rashes; over time, may lead to rough, leathery patches of skin

psoriasis symptoms

psoriatic plaque formation, may lead to depression as a result

skin cancer types

squamous cell, basal cell, melanoma

melanoma formation occurs in

melanocytes of the skin

melanoma

malgnant, usually aggressive tumor composed of atypical neoplastic melanocytes

symptoms of melanoma

asymmetry, border irregularity, color changes, large diameter, pain, fatigue

what happens to cell cycle in aging

cell cycle slows and produces larger and less cells; cells are less elastic→thinner skin

how do wrinkles occur

fatty layer underneath the skin thins

what happens to blood vessels as the body ages

they shrink; less blood flow to sweat glands→ greater risk of heat stroke

what happens to nerve endings as the body ages

they decrease→decreased sensitivity to pain→injury risk increases

because blood flow decreases as the body ages, healing ______

slows

skin is more vulnerable to UV when the body ages because

melanocyte production slows

when the body ages, vitamin D levels decrease, meaning that

there is greater risk of skeletal injury/depression