Integumentary System | Second Test

10/14 test

What are the 5 functions of the integumentary system?

• Preventing dehydration

• help regulating internal body temperature

• maintaining protective covering/preventing harmful substances and microorganisms from entering 

• producing vitamin D when exposed to sunlight

• Gathering sensory information

Dermis 

• middle layer of the skin, located beneath the epidermis and above the subcutaneous tissue

• made up of connective tissue

• containing smooth muscles 

Epidermis

• outer layer of the skin

• composted of keratinized stratified squamous epithelium

Subcutaneous layer (hypodermis)

• beneath the dermis

• composed of loose connective tissue and adipose tissue (fat)

Adipose Tissue

• specialized connective tissue that stores energy in the form of triglycerides 

• composed of adipocytes

Keratinization

• Accumulation of Keratin in the epidermal cells that harden the epidermis 

  • result of keratinization, many layers of tough + tightly packed cells accumulate in the epidermis 

• Physiology: epidermis of the skin producing a waterproof outer layer

Melanocyte

• Specialized cells in the epidermis to produce melanin

Melanin

• Providing skin color and absorbing UV radiation 

Dermal papillae

• small, finger like projections that extends from the dermis into the epidermis

• creating an uneven boundary 

  • fingerprints are large dermal papillae

Hair Follicle

• hair growing from a group of epidermal cells at the base of a tube-like depression in the dermis 

  • extends from the surface of the skin into the dermis 

Nail 

• protective coverings on the ends of fingers and toes

Nail plate

• Overlying the surface of the skin which is called the nail bed

Lunula

• Whitish, thickened, half-moon shaped region at the base of a nail plate with the most active growth

Sabaceous Gland

• associated with hair follicles that produce sebum 

Sebum

• a mixture of oil and cell parts

• secreted into hair follicles and helps keep hair and skin soft, pliable and waterproof

Eccrine glands

• responding to body temperature

• most in the forehead, neck, and back

Aprocrine Glands

• become active at puberty

• sweat when one is nervous/stressed 

• arm pits and groin

Pacinian Corpuscles

pressure

Meissner Corpuscles

touch

Nociceptor

pain

Thermoreceptors

temperature

Keratin

waterproof protein

Regulation of Internal Body Temperature

DIVIDER- NOTHING HERE

Heat Production

• Heat, a product of cellular metabolism in every cell 

• during physical activity, active muscles release heat, which blood carries away 

• body maintain a normal temperature of deeper body parts remaining to 37^oC

Control 

• dermal blood vessels dilate (open up), heat escapes to the outside world- skin reddens 

• sweat glands in skin secrete sweat onto the surface of the skin

• body temperature rises above the set point, nerve impulses stimulate structures in the skin and other organs to release heat

Regulation of Internal Body Temperature: LOSS OF HEAT

DIVIDER- NOTHING HERE

radiation

• spread heat from warm surfaces to cooler surroundings 

Evaporation

• change of liquid to a gass 

• sweat evaporates, it carries heat away from the skin surface 

Regulation of Internal Body Temperature: Other Transfers of Heat

DIVIDER- NOTHING HERE

Conduction

• movement of heat into molecules of cooler objects

Convection

the continuous circulation of air over a warm surface

Reg of Internal Body Temp: BODY TEMPERATURE FAILS

DIVIDER- NOTHING HERE

Dermal Blood Vessels Constrict 

• muscles of dermal blood vessels constrict (close down), decreases the flow of blood through the skin minimize heat loss 

• sweat glands become inactive 

• muscles may contract rhythmically to produce shivering and heat 

Problems in Maintaining Body Temperature

NOTHING HERE— DIVIDER

Hyperthermia

• rise in body temperature

  • air temperature is high = heat loss by radiation is less effective 

Hypothermia

• Low body temperature

  • resulting from prolonged exposure to cold 

Inflammation

• normal response to trauma (injury or stress)

• during inflammation, blood vessels open = letting more fluid into the area of trauma

  • inflamed skin may become reddened, swollen, warm, and painful

  • open blood vessels provide the tissues with more nutrients and oxygen = aids healing

Maintain Protective Cover: Cuts

DIVIDER-NOTHING HERE

Shallow Cut

• if a break in the skin is shallow, epithelial cells stimulated to divide more rapidly than normal 

Extends into the dermis

• blood vessels break and escaping blood forms a blood clot

Blood clot

• consists mainly of fibrin and platelets 

scab 

• blood clot and dried fluids 

First Degree Burn

• only affects the epidermis

second degree burn

• affects a part of the dermis and epidermis, blisters appear

third degree burn

• destroys the epidermis, dermis, and accessory structures 

Second Degree Burns Healing

• depends on accessory structures of the skin that survive the burn

Third degree burn treatment

• physicians uses the rule of nine to treat third degree burns

• dividing the skin’s surface area using multiples of 9

Bacteria, Viruses, And Eukaryotic Parasites | Prevent Harmful Substances from Entering

• skin acting as a fortified barrier to keep microogranism from entering the body from the outside world 

Melanin 

• skin protecting the skin from environmental factors such as sunlight and artificial light which can cause cancer

  • factors stimulate melanocytes to produce more pigment

Benign

• tumors stay in location without spreading

Malignant

• tumors can spread

Vitamin D 

• Exposed to sunlight some cells in the skin which produces the inactive form of Vitamin D 

  • active form is made active in the liver 

• necessary for strong bones and tooth development

• get it from food sources (dairy products)