Integumentary System Flashcards
Functions of body membranes:
- Cover body surfaces
- Line body cavities
- Form protective sheets around organs
These are simple organs, also called covering and lining membranes
Epithelial membranes
Epithelial membranes contains:
Epithelial tissue layer
Connective tissue layer
Types of Membrane
Cutaneous membrane = skin
Mucous membranes (mucosae)
Serous membranes (serosae)
Synovial membranes
It is a loose areolar connective tissue only (no epithelial tissue)
- line fibrous capsules surrounding joints
Synovial membranes
- line open body cavities that are closed to the exterior of the body
- occur in pairs, separated by serous fluid, with a visceral and parietal layer
- construction: simple squamous epithelium and areolar connective tissue
Serous membranes (serosae)
line all body cavities that open to the exterior body surface
o adapted for absorption or secretion
o construction: epithelium type depends on site and loose connective tissue (lumina propria)
Mucous membranes (mucosae)
dry membrane
o outermost protective boundary
Cutaneous membrane
Cutaneous membrane consist of:
epidermis is composed of keratinized stratified squamous epithelium and
dermis is mostly dense (fibrous) connective tissue
The Integumentary System includes:
(parts)
include the skin and its accessory structures
including hair, nails, and glands, as well as
blood vessels
The medical specialty that deals with the structure, function, and disorders of the integumentary system
Dermatology:
T or F
The skin (cutaneous membrane) covers the body and is the largest organ of the body by surface area and weight
- 2 square meters (22 square feet)
- 4.5-5kg (10-11 lb) *about 16% of BW
- 0.5-4 mm thick
TRUE
Functions of the skin
Protection
Regulation of body temperature
Sensation
Excretion
Blood reservoir
Synthesis of Vitamin D
outer, thinner layer, epithelial tissue
- avascular
Epidermis
Epidermis is composed of ?
composed of: keratinized stratified squamous epithelium
4 Major type of cells of the integumentary system
Keratinocytes
Melanocytes
Langerhan cells (Intraepidermal macrophages)
Merkel Cells (Tactile epithelial cells)
What does sweat remove?
Excretion
▪ sweat removes water and small amounts of salt, uric acid, and ammonia from the body surface
T or F
For protection
physical barrier: protects underlying
mechanical barrier: part of a non-specific immunity: in the form of saliva or tears
TRUE
__________ (increases blood flow)
__________ (decrease in blood flow)
vasodilation (increases blood flow)
vasoconstriction (decrease in blood flow)
Keratinocytes (90% of the cells) produce ____which is tough fibrous protein that provides protection
keratin
How long does it take for keratinocytes to regenerate?
regenerates every 24-45 days
Keratinocytes produce ________which release a water-repellant sealant that decreases water entry and loss and inhibits the entry of foreign materials
lamellar granules
(8% of the cells) produce the pigment melanin that protects against damage by UV radiation
Melanocytes
lack of melanin may result to?
Albinism
a yellow-red or brown-black pigment that contributes to skin color and absorbs damaging UV light
Melanin
star-shaped cells arising from red bone marrow that migrate to epidermis
Langerhan cells (Intraepidermal macrophages)
involved in immune responses, help other cells of the immune system recognize an invading microbe and destroy it
Langerhan cells (Intraepidermal macrophages)
T or F
Langerhan cells are resistant to UV light
FAlSE
Langerhan cells are easily damaged by UV lights
Cell for sensation of touch along with the adjacent tactile discs
Merkel Cells (Tactile epithelial cells)
least numerous of the epidermal cells
Merkel Cells (Tactile epithelial cells)
Cell that is located in the deepest layer of the epidermis, where they contact the flattened process of a sensory neuron (nerve cell)
Merkel Cells
Major types of skin (2)Where to find them
Thin (hairy) skin
- covers all body regions except the palms, palmar surfaces of digits and sole
- exposure to friction is greatest such as in the fingertips, palms, and sole
Thick (hairless) skin
- covers the palms, palmar surfaces of digits, and soles
Layers of the Epidermis (in order, outermost to inner)
S. Corneum
S. Lucidum
S. Glomerulus
S. Stratum
S. Basale
a.k.a Stratum germinativum
Stratum basale
composed of a single row of cuboidal or columnar keratinocytes
- deepest layer and is attached to the dermis
Stratum basale
where continuous cell division occurs, which produces all the other layers
- contains mostly columnar keratinocytes
- some cells are stem cells that undergo cell division to continually produce keratinocytes
Stratum basale
a.k.a spiny layer
Stratum spinosum
8-10 layers of keratinocytes
- melanin granules and Langerhans’ cell predominate
Stratum spinosum
have the same organelles as cells of the stratum basale
- each spine-like projection, bundles of keratin intermediate filaments insert into desmosomes, which tightly joins the cells to one another, it provides both strength and flexibility to the
skin
Stratum spinosum
contains 3-5 rows of flattened keratinocytes that are undergoing apoptosis
Stratum granulosum
includes keratohyalin (darkly staining granules) and lamellar granules (fuse the plasma membrane and release a lipid-rich
secretion)
Stratum granulosum
lamellated granules secrete glycolipids into extracellular spaces to slow water loss in the epidermis
Stratum granulosum
Layer that is present only in the thick skin area such as fingertips, palms, and soles
Stratum lucidum
provides an additional level of toughness in this region of thick skin
Stratum lucidum
four to six layers of dead keratinocytes that contain large amount of keratin and thickened plasma membranes
Stratum lucidum
Layer where cells are extremely thin, flat, plasma-membrane enclosed packages of keratin that no longer contain any internal organelles
Stratum corneum
- a.k.a Horny layer
What is the final product of the keratinocytes differentiation process
Stratum corneum
- a.k.a Horny layer
What causes Callus?
constant friction can stimulate formation of a callus (abnormal thickening of stratum corneum) because of the increased cell and keratin production-
composed of many sublayers of flat, dead, keratinocytes called corneocytes or squames that continuously shed and replaced by cells from deeper strata
Stratum corneum
- a.k.a Horny layer
the accumulation of more and more protective keratin, occurs as cells move from the deepest layer to the surface layer
Keratinization
T or F
Rate of cell division in stratum basale increases when the outer layer of the epidermis are stripped away (burns and abrasion)
TRUE
What is Dandruff?
Dandruff: an excess of keratinized cells shed from the scalp
Abnormal skin colors:
- Erythema =
- Pallor =
- Jaundice =
- Bruises/black and blue marks
Abnormal skin colors:
- Erythema = redness
- Pallor = blanching
- Jaundice = yellow cast
- Bruises/black and blue marks
What can appear if the skin is stretch too much?
Striae or stretch marks
It reflect contours of the underlying dermal papillae and form the basis for fingerprints and footprints
Epidermal ridges
Function of Epidermal ridges
their function is to increase firmness of grip by increasing friction
increase in surface area, increases the number of corpuscles of touch = increase tactile sensitivity
What is the study of the pattern of epidermal ridges?
Dermatoglyphics:
What are patches of discolored skin caused by benign tumor of dermal blood capillaries some disappear in childhood – others last for life
Hemangiomas (birthmarks)
The layer od the skin that is the inner, thicker connective tissue portion containing collagen and elastic fibers
- vascular; if the cut penetrates to the dermis there Is bleeding
Dermis
Difference between the Papillary and Reticular Region of the Epidermis
Papillary Region
- consists of loose areolar connective tissue
- with thin collagen and elastic fibers, with dermal papillae (including capillary loops), corpuscles of touch and free nerve endings
- Reticular Region
- consists of dense irregular connective tissue, attached to subcutaneous layer
- the collagen fibers are arranged in a net-like manner
- with collagen and elastic fibers adipose cells, hair follicles, nerves, sebaceous (oil) glands, and sudoriferous (sweat) glands
- combination of collagen and elastic fibers which provides skin with strength, extensibility, and elasticity
T or F
Hypodermis is a part of the skin
FAlSE
Hypodermis is not part of the skin
This layer consists of areolar and adipose tissue
- it attaches the skin to the underlying tissues and organs
Hypodermis
Function of the Hypodermis?
thermal regulator, storage depot for fat and contains large blood vessels
The hypodermis contains what?
contains lamellated (Pacinian) corpuscles which detect external pressure applied to the skin
Accessory Structures of the Skin
Hair
Glands
Nails
fine, unpigmented hair that appears on the fetus in the last three months of development
Lanugo:
fine, pale hair that replaces lanugo by time of birth
Vellus hair:
Terminal hair is?
longer, coarser, and usually more heavily pigmented
T or F
Hirsutism: the partial or complete lack of hair
Alopecia: excessive hairiness, increased androgens
FALSE
Hirsutism: excessive hairiness, increased androgens
Alopecia: the partial or complete lack of hair
Gland/s that secrete an oily substance called sebum which prevents dehydration of hair and skin, and inhibits growth of certain bacteria
Sebaceous (oil) glands
Sudoriferous (sweat) glands has 2 types:
Eccrine (merocrine) sweat glands
Apocrine sweat glands
Difference between the Eccrine and Apocrine sweat gland
Eccrine (merocrine) sweat glands
- helps to cool the body by evaporating, and also eliminates
small amounts of wastes
- found in palms and soles of feet
- sweating regulated by sympathetic nervous system
- gland responsible for emotional sweating and thermoregulation
Apocrine sweat glands
- excretory ducts open into hair follicles
- secreted during emotional stress and sexual excitement
- present after puberty
It is formed when the trapped sebum and bacteria stay below the skin surface
Whitehead
It is formed when the trapped sebum and bacteria partially open to the surface and turn black due to melanin. It can last for a long time because the contents very slowly drain to the surface.
Blackhead
modified sweat glands located in the ear canal
That secretes what?
Ceruminous glands
Secretes cerumen (earwax)
It is composed of hard, keratinized epidermal cells located over the dorsal surfaces of the ends of fingers and toes
Nails
Receptor for deep pressure, fast vibration and stretch
Pacinian (lamellated) corpuscles
Meissner’s (tactile) corpuscles are receptors for?
▪ light touch, vibration and discriminative touch
▪ nociceptors and thermoreceptors, dendrites that lack any apparent structural specialization. give rise to the sensation of warmth, coolness, pain, tickling, and itching
Free (naked) nerve endings
Receptors for deep pressure and heat
Ruffini’s corpuscles
In Deep wound healing, a phase where extensive growth of epithelial cells beneath the scab, deposition by fibroblasts of collagen fibers in random patterns, and continued growth of blood vessels
Proliferative phase:
In Deep wound healing, the phrase where the clot becomes a scab, and epithelial cells migrate beneath the scab to bridge the wound, granulation tissue fills the wound
Migratory phase:
In Deep wound healing,the phase where extensive growth of
epithelial cells beneath the scab, deposition by fibroblasts of collagen fibers in random patterns, and continued growth of blood vessels
Proliferative phase
T or F
Fibrosis: the process of scar tissue formation
- Hypertrophic scar: scar remains within the boundaries of the original wound
- Keloid scar: extends beyond the boundaries into normal surrounding tissue
FALSE
In Deep wound healing, a phase where the scan sloughs off once the epidermis has been restored to normal thickness
Maturation phase:
tissue damage caused by excessive heat, electricity, radioactivity, or corrosive chemicals that denature proteins in the skin
Burns
Burn severities are?
provide deccription
Superficial (1st degree)
▪ epidermis only
▪ pain, redness, swelling
Partial-thickness (2nd degree)
▪ epidermis and dermis
▪ pain, redness, swelling, edema, blisters
Full-thickness (3rd degree)
▪ all layers of skin and often underlying structures
▪ skin appears charred
▪ burned region is numb
▪ always requires medical attention, skin grafting
A 25 year old female patient has sustained burns to the back of the right arm, posterior trunk, front of the left leg, anterior head and neck, and perineum. Using the Rule of Nines, calculate the total body surface area percentage that is burned?
37%
A 68 year old male patient has partial thickness burns to the front and back of the right and left leg, front of right arm, and anterior trunk. Using the Rule of Nines, calculate the total body surface area percentage that is burned?
58.5%
A 35 year old male patient has full thickness burns to the anterior and posterior head and neck, front of left leg, and perineum. Using the Rule of Nines, calculate the total body surface area percentage that is burned?
19%
known as decubitus ulcers of bedsores
- caused by a constant deficiency of blood flow to tissues
Pressure ulcers
