Integumentary System Flashcards
- A network of features that forms
the covering of an organism. - Delimits the body of the
organism, separating it from the
environment and protecting it
from foreign matter. - At the same time, it gives
communication with the outside,
enabling an organism to live in a
particular environment.
Integumentary System
Species that has epidermis provides all the basic
features of an integument.
Cnidarians
What do corals release through their epidermis
Calcareous skeleton
What species that are protected by shell, which is made up of calcium carbonate secreted by the mantle
Mollusks
What species such as flukes and tapeworms have a body covering known as tegument.
Platyhelminths
What do bacteria have that helps them maintain the shape
and turgidity of the cell and
affords protection
Cell Wall
In nematodes, it provides all the basic features of an integument
Epidermis
Nematodes has a thick outer _____
Cuticle
Largest organ of the body
Skin
Skin is also known as the
Cutaneous membrane
Main components of the skin
Epidermis and Dermis
It refers to the Keratinized
stratified epithelium
Epidermis
Loose connective
and dense irregular tissue
Dermis
also known
as superficial fascia/
subcutaneous tissue
Hypodermis
5 Skin Function
Protection
Excretion
Vitamin D Synthesis
Thermoregulation
Sensation
What happens to the blood vessels of the skin when cold
Blood vessels constrict which allows more heat carrying blood to circulate to the muscles and organs
What happens to the blood vessels of the skin when hot
The blood vessels in the skin dilate that brings more blood to the surface for cooling by radiation
sensitive to
stimuli from external environment
Exteroceptors
sensitive to
stimuli from internal environmen
Interoceptors
sensitive to both external and internal stimuli and are responsible for relaying information about our body’s spatial position to the brain
(muscle length and tension, limb
position)
Proprioceptors
Types of receptors according to
source (location) of stimulus
Exteroceptors
Interoceptors
Proprioceptors
Type of Stimulus detected
Mechanoreceptors
Thermoreceptors
Nociceptor
Photoreceptors
Chemoreceptors
Osmoreceptors
Baroreceptors
Detect deformation of the receptor or adjacent cell; provides a sensation of touch, pressure, vibration, proprioception, hearing, equilibrium, blood pressure, and stretching of internal organs
Mechanoreceptors
Detects change in temperature
Thermoreceptors
Respond to stimuli resulting from physical or chemical damage to tissue
Nociceptor
Detect the light that strikes the retina of the eye
Photoreceptors
Detect chemicals in the mouth (taste), nose (smell), and body fluids
Chemoreceptors
Sense the osmotic pressure of body fluids
Osmoreceptors
Sensitive to pressure changes and considered as mechanoreceptors
Baroreceptors
Enumerate the Cutaneous receptors
Free nerve endings
Meissner’s corpuscle (tactile corpuscle)
Ruffini endings
Root hair plexus
Pacinian Corpuscle
Krause end bulbs
Merkel’s disks
sensitive to heat, cold or pain
(thermoreceptors, nociceptors and mechanoreceptors).
Free nerve ending
respond to
touch and low-frequency vibration.
Meissner’s corpuscles (tactile corpuscles)
detect stretch, deformation withinjoints,
and warmth (sensitive to pressure).
Ruffini ending
very sensitive mechanoreceptor for
touch that is located at the base of the hair.
Root hair plexus
the largest skin receptor, very quick to
adapt to skin displacement (sensitive to pressure).
Pacinian corpuscle
mechanoreceptors, sensitive to cold,
more superficially located than Ruffini endings
Krause end bulbs
located superficially in the dermis,react slowly to pressure (sustained pressure)
Merkel’s Disks
- Make up 95% of cells in the
epidermis - Strengthens epidermis,
makes it resistant to
mechanical trauma - Joined by desmosomes
- Arranged into “strata
(layers)”
Keratinocytes
Strata/Layers of the epidermis
Stratum corneum
Stratum lucidum
Stratum granolosum
Stratum spinosum
Stratum germinativum (Stratum bassale or bassal bottom)
the outermost strata of the epidermis. It is mostly dead cells, filled with a protein substance called keratin. It is thicker on the soles of the feet
than on the eyelids…where there is less pressure.
Stratum corneum
a
translucent layer lying directly beneath the
corneum. It may not even exist in thinner skin.Cells in this layer are also dead or are in the process
of dying.
Stratum lucidum
one or more layers of cells starting to die and become hard. They are in the process of
keratinization becoming
fibrous protein similar to that in hair and nails.
Stratum granulosum
composed of daughter keratinocytes and dendritic cells, which fight infections in the body
Stratum spinosum
Stratum spinosum is shiny in appearance due to protruding structures called
Desmosomes
is composed of several
layers of living cells capable of cell division. It is the innermost layer of the epidermis, and contains melanin -
the pigment that gives color to the skin. The more abundant the melanin the darker the skin color. Damage to this layer,
such as in severe burns, requires skin grafts. Helps to
synthesize vitamin D
Stratum germinativum (Stratum bassale or bassal bottom)
compose mostly of superficial layer of
the epidermis and several layers of dead,
flattened keratinocytes; sheds dead
keratinocytes
stratum corneum
found deep to the Stratum Corneum; found
in thick skin; and compose of clear layer of
dead keratinocytes
stratum lucidum
the middle layer of the epidermis named
for prominent granules; with 3-5 rows of cells;
and excretes a lipid-based substance
Stratum granulosum
Deep to the Stratum Basale; the thickest
stratum of the epidermis named due to its spiky
appearing cells; with cells that are metabolically
active (undergo mitosis): help to synthesize
vitamin D
Stratum Spinosum
the deepest layer of the epidermis; consists of a
single layer of stem cells; contains melanin; rich in blood supply; with cells that are mostly metabolically active (undergo mitosis); helps to synthesize vitamin D
stratum germinativum
Enumerate Keratinocyte Life Cycle
- Begins in the Stratum Spinosum
- Can shed from environmental
and physical stress - Shed cells are replaced by mitosis
- Cells primarily divide at
night - Stratum corneum sheds
dead keratinocytes )
Found in the Stratum Spinosum
Contain Phagocytes of the immune system
Protects the skin and underlying tissue from pathogens
Dendritic (Langerhans) Cells
- Oval cells found in the Stratum Basale
- Contain sensory receptors that detect light touch, shapes, and textures
- Also found in the fingertips, lips, and base of hair
Merkel Cells
Found in the Stratum Basale
Produces melanin, a protein that gives pigment to skin
Melanocytes (melan-black)
a protein that gives pigment to skin
Melanin
When exposed to extra pressure, both thick and thin skin will develop extra layers of the Stratum Corneum
Callus
- Anchors epidermis in place
- It contains the lymphatics,
nerves, nerve endings, blood
vessels, sebaceous and sweat
glands, elastic fibers, and hair
follicles.
Dermis
2 layers of the Dermis
Papillary layer and Reticular layer
It is the uppermost layer of the
dermis and is composed of
loose areolar conective tissue
Papillary layer
It is composed of dense irregular
connective tissue.
Reticular layer
- Found on the surface of the
papillary layer - Houses tiny blood vessels
called capillaries and Tactile
(Meissner) corpuscles
Dermal Papillae
- The most superficial layer of the
dermis and onsists of loose
connective tissue - Contains collagen fibers that
anchor dermis and epidermis
together
Papillary Layer
- Elastic fibers that allow skin to
revert after stretching - Contains proteoglycans that hydrate
the skin - Contains blood vessels and
accessory structures (hair, sweat
glands, sebaceous glands) - Contains sensory receptors, such
as Pacinian (lamellated) corpuscles
that respond to changes in pressure
and vibration
Reticular layer
It is composed of adipose
tissue. It supports, nourishes, insulates, and cushions the skin.
Subcutaneous tissue or Hypodermis
Interactions between the dermis and
epidermis are shown on the skin as small
lines
Skin marking
Thick collagen fibers arrange the
dermal papillae into
Dermal ridges
The epidermis will blend in with the dermal
papillae that lies underneath, creating?
Epidermal ridges
Tiny sweat pores open along the ridges to
form a thin film called a ?
Fingerprint
Gaps found in between bundles of
collagen will indent to form cleavage
lines, also known as
Tension lines
are produced when a high number of melanocytes are proliferated in one spot.
Moles
are produced when pigment is concentrated in one spot from a high amount of melanin production.
Freckles
It is when melanocytes fail to produce the tyrosinase enzyme. This lack of skin pigmentation can increase the risk of DNA damage of keratinocytes.
Albinism
- Gives yellow-orange pigment
- Lipid-soluble molecule
- Usually ingested in diet from yellow and
orange foods - Accumulates in stratum corneum
Carotene
- Gives skin a pinkish hue
- Protein found in red blood cells that binds and
transports oxygen - Turns a bright-orange red color when oxidized
Hemoglobin
Part of the hair that projects from the
surface of the skin.
Shaft
Part of the hair that is embedded in
the dermis of the skin.
Root
Indentation at the base of the hair bulb that contains blood vessels.
Hair Papilla
Structure at the deep end of the
hair follicle
Hair Bulb
Structure at the base of hair
bulb that produces new hairs via
mitosis.
Hair Matrix
Infolding surrounding the hair root
Hair follicle
Two parts of the Epithelial Root Sheath
Outer and Inner component
Anchors hair follicle to the dermis
Outer component
Anchors tightly to the root
Inner component
Supports the hair follicle and separates it from the dermis
Dermal Root Sheath
It is a threadlike structure formed by a group of cells that develop within a hair follicle or socket
Hair
is attached to the side of each
follicle. It is stimulated by skin irritants, emotional arousal, or cold temperatures, and reacts by contracting.
Arrector pili muscle
It is transparent and covers the hair shaft like shingles on a roof, protecting it from the elements and chemicals, and from losing moisture.
Cuticle
provides most of the hair’s weight. It contains melanin which provides color to the hair,
stores oils, provides flexibility and elasticity and adds shape to the hair.
Cortex
is an inner hollow core that runs the length of the
shaft. Found in thick hairs only and contains soft keratin
Medulla
- Mitosis occurs in the matrix of the root
- As cells divide, cells above are pushed upward from blood supply
- Cells keratinize and die
Hair Growth
- Cells in matrix stop dividing and begin to die
- The follicle shortens
- Hair is pushed upward and remains dormant for a few months
Resting Stage
Length of average hair growth per month
1 cm - 1.5 cm
is a type of thin hair that has no pigment. It grows on the skin of a fetus,
and usually falls out by the time the baby is born.
Lanugo
is thinner than terminal hair, and is nonpigmented. It is found around various places of the body
Vellus hair
is thick, coarse, and pigmented. It is found on the scalp and around the eyes (eyelashes,eyebrows).
Terminal hair
Released through sweat pores. Produces sweat that contains antimicrobial compounds to prevent the growth of pathogens. Also functions in thermoregulation.
Eccrine sweat glands
Sweat released into hair pores. Only in certain parts of the body such as armpits, areolas, and the anal area. Sweat metabolized by bacteria which produces an odor.
Apocrine sweat glands
Secretes a thick fluid called cerumen (earwax) into hair follicles. Cerumen lines the ears and functions to lubricate the eardrum. Traps particles before they reach the eardrum
Ceruminous Glands
Produces a sweat called milk. Milk contains, proteins, lipids, sugars, and immune cells to nourish a newborn.
Mammary glands
are oil glands. They have tiny
ducts that open into each hair follicle
Sebaceous
secrete a mixture of salt, urea, and water, which microorganisms on the skin convert to odorous products.
Apocrine glands
release watery secretions in
evaporative cooling
Eccrine glands
Sweat glands produce
Sweat or perspiration
they are active only on the pads of the paws or along the lip margins and may be entirely
absent over the rest of the body; such animals often depend on panting for effective temperature control
Sudoriferous Glands
Are involved in skin problems such as acne and keratosis pilaris. A blocked sebaceous gland can
result in a sebaceouscyst
Ceruminous glands
Are the organs that, in the female
mammal, produce milk for the
sustenance of the young. These
exocrine glands are enlarged and
modified sweat glands and are the
characteristic of mammals which
gave the class its name
Mammary glands
are hard structures located at the end of our digits that contain hard keratin
Nails
Part of the nail that rests on top of the
epidermal nail bed.
Nail Plate
Deep to the nail plate, nourishes and
protects the nail
Nail bed
Visible part of the nail
Nail body
Lies under the skin
Nail root
Part of the nail with living, dividing cells.
Supplies oxygen to the nail, sight of nail growth
Nail matrix
Covers the edge of the root
Proximal nail fold
Also known as the “cuticle”, found at the
base of the nail, protects matrix from infection
Eponychium
Overlapping of skin that borders the nail
laterally and medially
Nail folds
Skin that lies under the free edge of the
nail
Hyponychium
Crescent shaped area where keratin
accumulates
Lunula
The nail root is also called as what
germinal matrix
An ingrown toenail happens when the corner
or edge of your toenail curves and grows into
the surrounding skin
Ingrown toenail
- Modification of the epidermis
- Flat, horny plates (fingers and toes in
primates) - Claws (in reptiles, birds, and
mammals) and hooves (in ungulates,
are exaggerated nails) - Horns in sheep, goats and cattle (not
to be confused with antler, made of
bone; not formed in the epidermis) - Baleen plates in whales
Nail
Bird’s skin is divided into
(1) feathered skin
(2) scale
covered skin on the lower legs and feet
(3) hard, horny
areas of the beak and toenails
(4) pad of the foot (or plantar); and skin of the comb and wattles
The integumentary system of a chicken consists of
the feathers, and the appendages (beaks and claw)
The areas where feathered skin grows
pterylae
The areas where feathered skin does not grow
apteria
color bearing cells that give many lizards and snakes their colorful hues
chromatophores
- Skin that excrete pheromones that function in sex recognition and defense
- Skin has no respiratory function
Reptile skin
Molting process is also known as
ecdysis
concentric ridges-milkfish
Cycloid scales
w/spines or ctenii
Ctenoid scales
rhomboid shape
Ganoid scales
spines directed caudally-sharks,skates
Placoid scales
- Skin is permeable and functions in gas exchange
- Epidermis also has mucous glands (prevents
bacterial and fungal infections, as well as reduc
friction when the fish swims) and granular gland
(secrete an irritating / poisonous alkaloid)
Bony fish
Skins of bony fish contains what scales
cycloid, ctenoid, and ganoid
The skin is covered in placoid scales
(bony, spiny projections with an enamel-like covering), or dermal denticles, tooth-like
scales different from the flat scales found on bony fish. The dermal denticles is structurally homologous with vertebrate teeth.
Cartilaginous Fish
