Integumentary System Flashcards
Define organ system
a group of 2 or more organs working together for a specific function/task
The integumentary system consists of 2 groups:
skin, and skin derivatives
What are the 4 skin derivatives?
hair, nails, glands, and sensory receptors
What are the 2 skin regions?
epidermis and dermis
What tissue type is found in the epidermis?
epithelial tissue
T/F: the epidermis is vascularized
False - avascular
What is the function of epidermis tissue?
protection
What type of tissue is found in dermis tissue?
fibrous connective tissue
T/F: the dermis is vascularized
True
What is the function of dermis tissue?
support, nourishment
T/F: the hypodermis is not considered a part of the skin portion
True
Where is the hypodermis located?
below the dermis
What type of tissue is found in the hypodermis?
mostly adipose tissue
What is the function of the hypodermis?
protective covering of the muscle
T/F: hypodermis thickens as you age
True; adipose cells grow in size with increased lipid concentration
What are the 4 types of cells found in the epidermis?
keratinocytes, melanocytes, Langerhans’s cells, Merkel cells/discs
T/F: keratinocytes make up the majority of the epidermis
True
Where did keratinocytes get their name?
they undergo keratinization
Describe the 4 steps of keratinization:
1.) produce protein called keratin
2.) keratin accumulates upward
3.) cells die
4.) dead cells are sloughed off
Why are keratinocytes important to the epidermis?
offer epidermal protection
T/F: melanocytes make up majority of the epidermis
False; make up small portion
How do melanocytes work?
stimulation causes them to produce the skin pigment melanin which gives skin its darkness
Pigment works as a _________ _____________
defense mechanism
Melanocytes are affected by:
genetics and sunlight/UV
What are Langerhan’s cells?
a derivative of bone marrow
What do Langerhan’s cells help to do?
prevent things from entering the skin
Where are Langerhan’s cells active?
the immune system
Where are Merkel cells found?
at the dermal - epidermis border, but on the epidermal side
What do Merkel cells help to do?
act as a sensory cell which detects light touch
What are the 4 layers of the epidermis (thin skin)?
stratum basale, stratus spinosum, stratus grandulosum, and stratus corneum
How many cell layers and living or dead for stratum basale?
1; living
How many cell layers and living or dead for stratum spinosum?
several; living
How many cell layers and living or dead for stratum gradulosum?
3 - 5; living
How many cell layers and living or dead for stratum corneum?
20 - 30; dead
Where is the stratum basale located in the epidermis?
bottom/deepest layer
What do the cells in the stratum basale do?
lots of germination/reproduction
Where is the stratum spinosum located in the epidermis?
in-between the stratum basale and the stratum grandulosum
What is a nickname for the stratum spinosum?
“prickly” layer
Why does the stratum spinosum appear “prickly?”
the cells in this layer are connected in a web-like system of intermediate filaments and desmosomes; when cells die, they shrivel up and leave the desmosomes behind, giving it a “prickly” appearance
Where is the stratum granulosum found in the epidermal layer?
in-between the stratum spinosum and the stratum corneum
What is another name for the stratum granulosum?
the grandular layer - it granules inside the cells
What are the 2 types of granules present inside the stratum granulosum?
keratohyalin granules and lamellated granules
What do keratohyalin granules contain?
keratin
What do lamellated granules contain?
glycolipids (help to “waterproof” the skin)
What are the 5 layers of the epidermal (thick skin)
stratum basale, stratus spinosum, stratum granulosum, stratum lucidum, and stratum corneum
What is the stratum lucidum?
a clear layer found only in very thick skin composed of dead cells
What are the 2 layers of the dermis?
papillary and reticular
Where is the papillary layer of the dermis found?
top layer of the dermis that connects to the irregularities of the epidermis (irregularity keeps two tissues from separating)
What is the function of the papillary layer?
thermoregulation and nourishment
Where is the reticular layer located?
deep/below the the papillary layer
What type of tissue makes up the reticular tissue of the dermis?
dense irregular connective tissue
What embryonic layers do the epidermis, dermis, and hypodermis come from?
epidermis (ectoderm), dermis (mesoderm), hypodermis (mesoderm)
Where does skin color come from? Why are different races different colors?
comes from a combination of different pigments; different ratios of the pigments result in racial differences
What are the 3 pigment types found in skin?
melanin, carotene, hemoglobin
Where in the skin is melanin found?
the epidermal layer
Where does melanin come from?
produced by melanocytes
What causes melanocytes to produce melanin?
UV exposure
What is tyrosincase?
an enzyme whose presence increases with increase in UV radiation exposure - leads to higher production of melanin in the skin
What is the function of melanin?
prevents rays of sun from being able to penetrate as easily by accumulating and dividing quickly - therefore tanning is a defense mechanism to keep the sun from damaging cells of active tissue
Where is the carotene pigment found?
the dermal layer
What color does the carotene pigment give off?
yellow/orange appearance
Where is the hemoglobin pigment found?
the dermal layer; specifically in the blood/capillaries of the dermis
What color does the hemoglobin pigment give off?
pinkish
What are the 2 types of surface features?
ridges and grooves
Where are ridges found on the body?
the fingers and toes
What layer of the skin are the ridges found in?
the dermal layer, but cause superficial layers in the epidermis
What is the function of ridges?
to provide extra grip or friction to grab onto things
T/F: ridges are unique to each person
True
What are grooves?
diamond-like shapes on the skin with many intersections; hair grows at these intersections
What is the explanation for why we have grooves “apparently?”
we were covered in scales
What do sudoriferous glands produce?
produce sweat
What are 4 types of sudoriferous glands?
eccrine, apocrine, ceruminous, mammary
T/F: there are not many eccrine glands found on our body
False; eccrine glands cover most of the body
How long do eccrine glands function in our body?
a lifetime
What is the function of an eccrine gland?
body temperature regulation
Does an eccrine gland function as a holocrine gland or a merocrine gland?
merocrine gland
Where are apocrine glands located? Give some examples
in the high friction areas of our bodies; armpits, groin
What is the function of apocrine glands?
prevent friction
How long do apocrine glands function in the body?
start functioning after puberty
Why does sweat smell?
the secretion itself is odorless, but is a food source for bacteria, which then produce the odor
What is a ceruminous gland? What does it secrete? What is its function?
a modified apocrine gland that secretes cerumen (wax); the wax helps to trap things from getting into the ears and protects the hearing membranes from loud noises
How long do ceruminous glands function in the body?
a lifetime
What is a mammary gland? What does it secrete? What is its function?
a modified apocrine gland that secretes milk (rich in proteins and fats); used for babies after birth
How long do mammary glands function?
not continuously-functioning - must be stimulated
T/F: a sebaceous gland is a type of sudoriferous gland
False; it is a separate type of gland in and of itself
What is secreted by a sebaceous gland? What is its function?
sebum (an oil/lipid); prevents water loss in the hair, softens and lubricates the hair, and can kill certain bacteria
T/F: sebaceous glands function as merocrine glands
True
Why are sebaceous glands and acne related?
sebaceous glands respond to hormonal secretions (testosterone)
