Integumentary system Flashcards
Stratum corneum
The outermost layer of the epidermis, consisting of dead, flattened cells that form a protective barrier. The barrier that prevents unwanted materials from entering, and excessive loss of water from exiting the body
Stratum lucidum
A thin layer of dead cells between the stratum granulosum and stratum corneum of the epidermis.
Reduces friction between the two mentioned layers.
Stratum granulosum
The middle layer of the epidermis, containing granules of keratin and other proteins.
Stratum spinosum
The layer of the epidermis between the stratum granulosum and stratum basale, containing multiple layers of spiny cells. This layer also helps to make your skin flexible and strong.
Stratum basale
The deepest layer of the epidermis, containing stem cells that divide and differentiate to form the other layers of the epidermis. Produces new cells
Keratinocytes
produce keratin, which protects and
keeps the skin waterproof
Melanocytes
produce melanin, one of the major
pigments responsible for skin colour, also protects
the skin from UV rays
Papillary region
Outer most layer just below epidermis
forms finger-like projections into epidermal layer
forms a firm & flexible junction
made up of loose connective tissue with elastin, contains some sensory structures (touch, pressure etc.)
contains small blood vessels
Reticular region
Deeper layer of the dermis
made up of dense connective tissue with
lots of elastin & collagen
this region provides skin with most of its
strength & flexibility
contains various glands, nerve endings,
blood vessels, hair follicles
Hair
sensation (touch)
protection (dust & insects)
temperature regulation
each hair is made of dead, keratinized cells
produced in a hair follicle located
in the dermis of the skin
Sebaceous glands
Secrete oily substance that keeps hair from drying out or becoming brittle. Aids in keeping skin pliable and hydrated. Oil has some anti-microbial properties
Sudoriferous glands(Apocrine)
Produce sweat but also some fat & protein
(gives this sweat a yellowish colour)
these are usually located in armpits, and groin area Pheromones
Sudoriferous glands (Eccrine)
produce sweat and are distributed
throughout the skin in most regions of the
body
Ceruminous glands
secrets cerumen – a wax
located in the ear canal
wax protects ear against dust, insects
has some anti-microbial properties
Nails
Derived from the epidermis
made up of compacted, keratin filled
dead epithelial cells.
Protect the tips of fingers & toes
aid in ability to manipulate & grasp objects
scratching / digging
defense
Functions of the skin (Excretion)
(removal of waste)
various components in sweat also excreted
Functions of the skin (Protection)
Covers the body so protecting internal structures
Mechanical barrier to bacteria etc.
Prevents dehydration
Protects against UV radiation
Functions of the skin (Immunity to disease)
produces chemicals & antibodies
Functions of the skin (Sensation)
(linked to the nervous system)
Receptors in the skin detect various stimuli
(e.g. Temperature, pain, touch, pressure)
Functions of the skin (Temperature Regulation)
Heat loss from the surface of the skin
Perspiration (sweat) and evaporation, maximise heat loss
Direct gain of heat from environment
(linked to the circulatory & neural systems)
Epidermis
The epidermis is the outermost layer of the skin and is composed of cells that act as a protective barrier against the environment. The epidermis is made up of several layers of cells that are continually being replaced. It also contains cells called melanocytes that produce the pigment melanin, which gives our skin its color.
Dermis
The dermis is the layer of the skin located beneath the epidermis and hypodermis. It is composed of collagen and elastin fibers, which give the skin structure and strength. The dermis also contains sweat glands, hair follicles, and sebaceous glands, which produce oil to keep the skin moist and healthy. In addition, the dermis contains blood vessels, lymph vessels, and nerve endings that provide sensation.
Hypodermis
The hypodermis is the layer of the skin located below the epidermis. It is composed of fat cells and connective tissue, which helps to provide cushioning and insulation for the body. It also contains blood vessels, lymph vessels, and nerve endings that help regulate body temperature and provide sensation.
Outer Ear The auricle (pinna)
Shell-shaped Cartilage covered by thick skin. Collects and
transmits sound waves to middle ear, causing tympanic membrane to vibrate.
Outer Ear External auditory
canal
– Short, curved tube in temporal bone and filled with ceruminous glands Hairs and ear wax in external auditory canal prevent foreign materials entering ear. collects sound waves and channels them into the ear canal (external auditory meatus), where the sound is amplified.
Outer Ear Tympanic membrane
(eardrum)
Thin connective tissue membrane that vibrates in response to sound. Transfers sound energy to the middle ear ossicles
Boundary between outer and middle ears.
Structure of the middle ear
Small, air-filled cavity in the temporal bone. Tympanic membrane separates middle ear from external ear Ov.al and round windows separate middle ear from inner ear.
Functions of the middle ear
- Transmit vibrations from tympanic membrane to fluid in the cochlea (inner ear) via vibration of ossicles.
- Equalizes pressures on both sides of tympanic.
-Middle ear provides protection from large vibrations.
Ear Ossicles
- The tympanic cavity contains three small bones: the malleus (hammer), incus (anvil), and stapes (stirrup)
- Transmit vibratory motion of the eardrum to the oval window
The inner ear structure
- Bony labyrinth
- Canals hollowed out of the
temporal bone - Contains 3 areas: the semicircular canals(equilibrium), the vestibule (equilibrium), and the cochlea (hearing)
- Filled with perilymph (similar to CSF)
The cochlea
- A spiral, conical, bony
chamber that:
– Extends from the anterior
vestibule
– Contains the cochlear duct,
which ends at the cochlear
apex
– Contains the organ of Corti
(hearing receptor)
Scala vestibuli
the scala vestibuli is a cochlear duct that runs along the length of the cochlea and is filled with endolymph. It is where sound vibrations from the oval window enter the cochlea and travel through the organ of Corti. It also contains the vestibular membrane which helps to regulate the pressure of the endolymph.
Scala media
the scala media is the longest cochlear duct and is filled with perilymph. It contains the organ of Corti, which is made up of sensory hair cells that detect sound vibrations and send signals to the brain. These signals are then translated into meaningful auditory information.
Scala tympani
the scala tympani is the shortest cochlear duct and is also filled with perilymph. It contains the basilar membrane which vibrates in response to sound waves, and this vibration helps to amplify the sound waves traveling through the duct. It also contains the tectorial membrane which helps to convert the sound waves into electrical signals. The electrical signals are then sent to the brain and are interpreted as sound.
Vestibular apparatus
equilibrium receptors in the
semicircular ducts and vestibule
Maintain our orientation and balance in space
Organ of the corti
Structure in the cochlea in which hair cells transduce movements from sound waves into electrochemical signals.
