Module 03: Integumentary System Flashcards
This system is composed of the skin and accessory structures, such as the hair, glands, and nails.
Integumentary System
What does the word integument mean?
Covering
What does the integumentary system signify?
The appearance of the integumentary system is an indicator of physiologic imbalances within the body.
This is the most vulnerable organ since it is exposed to microorganisms, lacerations, temperature extremes, harmful chemicals, and uv radiation.
Skin
What are the three (3) barriers of the skin?
(1) Chemical
(2) Physical
(3) Biological
What is the importance of the skin’s chemical barrier?
(1) Secretions and melanin
(2) Low pH of skin secretions which creates an acid bundle which actually retards to the multiplication bacteria and foreign substances
(3) Dermcidin in sweat and bactericidal substances in sebum
(4) Defensins - natural antibiotics
(5) Cathelicidins - protective peptides from wounded skin that prevents group A streptococcus bacteria
What is the importance of the skin’s physical barrier?
(1) Continuity of skin and harness of keratinized cells
(2) The thicker the epidermis - the more impenetrable
(3) Stratum corneum - outermost layer of the skin
This is the outermost layer of the cell and even if there are dead flat cells biding in it, it still serves it purpose in protecting the body from foreign substances.
Stratum Corneum
What are the substances that penetrate the skin?
(1) Lipid-soluble substances (Oxygen, Carbon Dioxide, and fat soluble vitamins A, B, E, K and steroids)
(2) Oleoresins of certain plants (Poison Ivy and Oak)
(3) Organic Solvents (Acetone, Dry Cleaning fluids, Paint Thinners)
(4) Salts of Heavy Metals (Lead and Mercury)
(5) Selected Drugs
What is the importance of the skin’s biological barrier?
(1) Dendritic cells
(2) Dermal macrophage
- part of the immune system and can engender an immune response by transferring the foreign substances to the lymph nodes
Functions of the Protection
(1) Reduction in body water loss
(2) Protects underlying structures against abrasion
(3) Protects underlying structures UV lights (melanin)
(4) Hair and Nail protection
What is the use of the hair protection?
Heat Insulator and protects from foreign materials
Which functions of the integumentary system affects the rate of chemical reactions?
Body Temperature Regulation
The Body Temperature Regulation is dependent on what?
The amount of blood flow beneath the skin’s surface and the activity of sweat in the skin
How does body temperature regulation happen?
Blood vessel dilates, which increases blood flow; thus increasing thermal (heart) loss within the epidermis
This pertains to sweating under normal conditions with an environmental temperature below 31-32 degrees Celsius. In this type of sweating, 0.5 liter of sweat is secreted per day. This is known as routine unknown and unperceivable sweating.
Insensible Perspiration
This pertains to sweating that occurs when there is a rise in body temperature, where the nervous system stimulates the dermal blood vessels to dilate to prompt the sweat glands into invigorous secretory activity. It can account to about 12 liters a day.
Sensible Perspiration
This assists in the loss of heat through evaporative cooling.
Sweat (fever)
These have the capacity to respond to stimuli arising outside of the body.
Exteroceptors
These receptors are part of the central nervous system made to detect pain, heat, cold and pressure.
Cutaneous Sensory Receptors
This is a vascularized layer of dense connective tissue which rests on the subcutaneous tissue.
Dermis
This is usually found in the deeper dermis or near the sub cutaneous tissue that alerts us to any bumps concerning deep pressure.
Lamellar or Pacinian Corpuscles
The exteroceptors are found in the hair that reports us any pressure with regards to the hair or where the direction of the wind is going.
Hair follicle receptors report
These exteroceptors scattered throughout the body which senses painful stimuli, like chemicals, extreme heat or cold, etc.
Free Nerve Endings
What does UV Light generate in metabolic functions?
UV Light causes the skin to produce a precursor molecule of vitamin D which is then carried by the blood to the liver (converts) and kidneys to forms an active form of vitamin D
This stimulates the small intestine to absorb calcium and phosphate for many body functions.
Vitamin D
How does the body help in excretion?
It also eliminates nitrogen containing wastes through the sweat such as ammonia and uric acid.
This is an important avenue for water and salt loss.
Profuse Sweating
How many surface area does the skin encompasses?
1.2 to 2.2 to square meters which is about 70% of the total body weight
This is the most superficial layer and the outermost protective shield of the body. It is a layer of epithelial tissue that rests on the dermis.
Epidermis
This is a layer of connective tissue in the skin.
subcutaneous tissue
How does the nutrients reach the epidermis?
The nutrients reach the epidermis by diffusing through the tissue fluid from blood vessels in the dermis.
What kind of membrane is the epidermis?
Cutaneous
What composes the epidermis?
(1) Keratinized stratified squamous epithelium
(2) Distinct layers called the strata
What is the main function of the epidermis?
prevent water loss and resist abrasion
What are the cells found in the epidermis?
(1) Keratinocytes
(2) Melanocytes
(3) Dendritic Cells
(4) Tactile Epithelial Cells
These cells produces keratin (fibrous protein protective properties) and are tied together by desmosomes for strength and water movement prevention.
Keratinocytes
This is a fibrous protein with protective properties.
Keratin
This cells synthesizes melanin that look like spider legs.
Melanocytes
These are membrane bound granules that form melanin.
Melanosomes
These cells are star shaped cells that are key activators in the immune system.
Dendritic Cells
Dendritic Cells are also known as
Langerhans Cells
These cells are found in the epidermal-dermal junction.
Tactile Epithelial Cells
The Tactic Epithelial Cells are also known as ________________.
Merkel cells
This is the basal layer or the deepest layer which consists of a row of stem cells that are continuously renewing signifying the youngest keratinocytes.
Stratum Basale or Stratum Germinativum
These reflect the rapid division of the stem cells.
Mitotic Nucleicin
How many percentage of melanocytes are in the stratum Basale?
10 to 20% (where they branch out intro a superficial layer known as the stratum spinosum layer)
These contain thick bundles of intermediate filaments, which consist of tension-resisting protein called the pre-keratin. This is the most abundant in the epidermal layer.
Stratum Spinosum
These are tension-resisting proteins that help the stratum spinosum scatter within keratinocytes with dendritic cells.
Pre-keratin
This is the thin stratum granulosum that consists of one to five cell layers, This is where the process of keratinization begins.
Stratum Granulosum
This is the process wherein the cell starts being filled with keratin which compels the cells to flatten and their nucleic organs begin to disintegrate and start accumulate two types of granules.
Keratinization
What are the two types of granules accumulated in keratinization?
(1) Keratohyalin Granules - helps to form keratin in the epidermal layer
(2) Lemerand Granules - contains water resistant glycolipids which are secreted in the extracellular space
These exteroceptors are associated with their sensory nerve endings and allows us to sense the feeling of clothes.
Tactile (Meissner’s) corpuscles in the dermal papillae and tactile epithelial cells
This is known as the clear layer and is found only in thick skin. And is composed of thin translucent bands and consists of few rows of flat, dead keratinocytes.
Stratum Lucidum