INTEGUMENTARY SYSTEM

- integument means covering

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

FUNCTIONS
1. Protection
- acts as physical barrier
- reduces water loss
- Part of our innate
- Protection against abrasion (magasgas ang paint) and ultraviolet light
2. Sensation
- has sensory receptors that can detect heat and cold – thermoreceptors and
nociceptors (sensory for pain)
3. Vitamin D Production
- the skin produces a molecule that can convert into Vitamin D (absorption of calcium)
when exposed in UV light
- overexposure to UV light can damage the skin and may lead to burns
4. Temperature Regulation
- the amount of blood flow beneath the skin’s surface and the activity of sweat glands in
the skin both help regulate body temperature.
5. Excretion
- merely a minor function
- waste products are lost through gland secretion

SKIN
- two major tissue layers:
1. Epidermis
- Is the most superficial layer
- A layer of epithelial tissue
- Responsible for protection
- It is a stratified squamous epithelium
- In its deepest layer , a new cells are produced by mitosis (cell division)
- As a new cells form they push older cells to the surface , where they
slough, or flake off
- keratinization
➢ It is a process here during their movement , the cells change
shape and chemical composition
➢ It reflects to the fact that the cells become filled with the protein
keratin , which makes the more rigid and durable
 ➢ As it proceed , epithelial cells eventually die and form an outer
layer of dead , rigid cells that resists abrasion and acts as a
permeability barrier (selective materials can pass through)
Note: mas importante ang rigid kaysa buhi

Strata
- Although keratinization is a continuous process , distinct cellular characteristics can be
recognized.
- These characteristics are used to divide the epidermis into layers called strata;
- Deepest to the most superficial
➔ Stratum basale
- The deepest or 5th of the epidermal
- Consist of cuboidal or columnar cells that undergo mitotic division every 19 days
- The first daughter cell remain in the stratum basale to divide again
➔ Stratum spinosum
- The 4th layer from the bottom
- Take on a flattened appearance and accumulate lipid-filled vesicles called
lamellar bodies
● Lamellar bodies - the act of insulating layer for cold and hot
➔ Stratum granulosum
- The 3rd layer , are flat and diamond shape
- Can accumulate more keratin and release the contents of lamellar bodies to
extracellular space
- If there is more keratin in the cell it will become more rigid cell and durable
- Look like granules
➔ Stratum lucidum
- The 2nd layer , a thin , clear zone
- This stratum has no longer have nuclei or organelles , and as a result , the cells
stain more lightly
- Skin is classified as thick or thin based on the structure of the epidermis

Thick Skin Thin Skin

- Found at areas that are subjected to - Found elsewhere in the body

PRESSURE or FRICTION such as the
palms of the hands , soles of the feet - Does not have the STRATUM LUCIDUM
and the fingertips

- Contains all 5 STRATA

➔ Stratum corneum
- Is the first layer , the most superficial layer of the epidermis
- It consists of dead squamous cells filled with keratin
- Keratin gives the stratum corneum its structural strength
- Are also coated and surrounded by lipids released from the lamellar bodies of
the skin
- Is composed of 5 or more layers of dead squamous cells joined by
desmosomes
 - Dandruff
● Excessive sloughing of stratum corneum cells from the surface of the
scalp
- Callus or Calluses
● Area subjected from friction

- Corn
● Bony prominence , can thicken to form a cone-shaped structure

Dermis
- A layer of dense collagenous connective tissue
- For structural strength
- Containing fibroblast , adipocytes , and macrophages
- Nerve , hair follicles , smooth muscles , glands . and lymphatic vessels extend into the dermis
- Collagen and elastic fibers are responsible for the strength of the dermis
- More collagen fibers are oriented in some directions that in others
- This produces cleavage lines or tension lines
1. An incision made across cleavage lines can gap increasing the time needed for healing
and resulting in increased scar tissue formation
- Gapped suture
2. An incision made parallel to cleavage lines result in less gapping , faster healing , and
less scar tissue.
- If the skin is overstretched for any reason , the dermis can be damaged leaving lines that are
visible through the epidermis
- These lines , called stretch mark , can be develop when a person increases in size quite rapidly
- Dermal Papillae
● The upper part of the dermis has projections
● In the palms of the hands , the soles of the feet , and the tips of the digits are arranged in
parallel ,curving ridges that shape the overlying epidermis into patterns called friction
ridges
- Types of injections;
1. Intradermal (ID)
- Into the dermis
- Slowest method of reaching the bloodstream
- Commonly used for allergic testing
- 15 degrees

2. Subcutaneous (SC OR SQ)

- Into the hypodermis
- Much faster than ID
- 45 degree
3. Intramuscular (IM)
- Directly to the muscle
- Faster than ID & SQ
- 90 degree
4. Intravenous (IV)
- Directly to the bloodstream
- Instantaneously
 - Fastest of all the parental medication

Subcutaneous
- Also a layer of connective tissues
- The sq tissues is not part of the skin , but it does connect the skin to underlying muscle or bone
- Is loose connective tissue , including adipose tissue that contains about half the body’s stored
lipid
- Also called hypodermis

Hair
- In humans hair is found everywhere on the skin , except on the palms , the soles , the lips , the
nipples , parts of the genitalia , and the distal segments of fingers and toes
- Hair follicle
● An invagination of the epidermis that extends deep into the dermis

Hair Anatomy
- shaft
➢ Protrudes above the surface of the skin
- root
➢ Is below the surface
- hair bulb
➢ Is the expanded base of the root
➢ Medulla (inner and soft)
➢ Cortex (middle and hard)
➢ Cuticle (outer and a)

Hair Growth
- Is produced in cycles of growth and rest
- During growth stage
➢ Hair is formed by epithelial cells within the hair bulb
➢ Stratum basale in the skin
➢ Divide and undergo keratinization
➢ The hair grows longer as these cells are added to the base of the hair within the hair bulb
➢ The hair root and shaft consist of columns of dead keratinized epithelial cells
➢ 3 years
- During resting stage
➢ Growth stops and the hair is held in the hair follicle
➢ When the next growth stage begins , a new hair is formed and the old hair falls out
➢ 1-2 years

Arrector Pili
- Associated with each hair follicle are smooth muscle cells
- Contraction of the muscle causes the hair to become raise and produce a “goose bump”

Glands
 - Sebaceous glands
- Sweat glands
● Eccrine
● apocrine

sebaceous eccrine apocrine

- Secret sebum (oily white - Secretes sweat (mostly - Sweat (thick secretion
substance that water , very few salts) rich in organic
lubricates the hair and - In palms and soles substance)
the skin) - Exits through ducts that - Exit through the pores
open on the pores of the except for the armpits &
skin genitalia where it exits in
- Commonly secrete as a the hair follicle
reaction to warm - Active mostly during
temperature puberty
Note: both sweat are odorless except for when there’s breakdown by bacteria which causes body odor

Nails
- A thin plate
- Consisting of layers of dead stratum corneum cells that contain a very hard type of keratin
- Nail Body
➢ Visible part of the nail
- Nail Root
➢ The part of the nail covered by skin
➢ Extends distally from the nail matrix
- Lunula
➢ Small part of the nail matrix
➢ Whitish crescent shaped
➢ Can be seen with thin nails
- Nail matrix
➢ Where the growth starts
➢ Cell division will occur
- cuticle
➢ Stratum corneum that extends on to the nail body
- The nail bed and nail matrix epithelial tissue with STRATUM BASALE (cell division and
growth)
Burns
- injury to a tissue caused by heat, cold, friction, chemicals, electricity
- first degree burns
➢ affected in the epidermis only
➢ common cause is sunburns
- second degree burns
➢ affects epidermis and dermis
➢ first and second degree burns are usually painful
- third degree burns
➢ will burn off epidermis, dermis, and hypodermis
➢ both epidermis and dermis are completely destroyed
➢ they are painless because at that depth, it has already destroyed the nociceptors
- fourth degree burns
➢ burns deeper the subcutaneous tissues (sometimes include muscles and bones;
painless)
➢ because they’re so severe, they will sometimes be amputated. due to amputation, there
is a chance of increased susceptibility to infection which can cause to death

RULE OF NINES
- assessment tool used to calculate the percentage of the body affected by burns.