Ch. 6 - Skin & Its Appendages Flashcards
What is the body’s largest organ?
Skin
What is the integumentary system?
Skin & its appendages (hair, nails & skin glands)
Skin is classified as ___________ membrane
cutaneous
List 2 primary layers of the skin
- epidermis
2. dermis
What layer does the hypodermis lie beneath?
Dermis
There are 2 types of skin - thick & thin. What does these types cover?
thin - covers most of body’s surfaces
thick - covers soles and palms
List the 4 types of epidermal cells
- keratinocytes
- melanocytes
- epidermal dendritic cells
- tactile epithelial cells
skin cell that is the principal structural element of the outer skin
keratinocyte
skin cell that constitues 90% of cells present
keratinocyte
skin cell that is sometimes called corneocytes after it is fully keratinized
keratinocyte
skin cell that contains melanin?
melanocyte
skin cell that produces pigment
melanocyte
skin cell that filters UV light
melanocyte
skin cell that plays a role in immune response
epidermal dendritic cells
skin cell that is also called langerhan cells
epidermal dendritic cells
skin cell that are branched antigen-presenting cells
epidermal dendritic cells
skin cell that attach to sensory nerve endings to form ‘light touch’ receptors
tactile epithelial cells
skin cell that are also called Merkel cells
tactile epithelial cells
list the 5 cell layers in epidermis (from deepest to superficial)
- stratum basale (base layer)
- stratum spinosum (spiny layer)
- stratum granulosum (granular layer)
- stratum lucidum (clear layer)
- stratum corneum (horny layer)
this epidermal layer contains single layer of columnar cells that undergoes mitosis - after which the cells migrate through the other layers until they are shed
stratum basale
epidermal layer that is rich in RNA
stratum spinosum
epidermal layer that is arranged in 8 to 10 layers with desmosomes that pull cells into spiny shapes
stratum spinosum
epidermal layer that can initiate protein synthesis for production of keratin
stratum spinosum
epidermal layer where cells are arranged in 2-4 layers and filled with keratohyalin granules
stratum granulosum
epidermal layer that contains high levels of lysosomal enzymes
stratum granulosum
epidermal layer where cells are filled with keratin precursor called eleidin
stratum lucidum
epidermal layer absent in thin skin
stratum lucidum
epidermal layer composed of dead cells filled with keratin known as the barrier area
stratum corneum
the time required for epidermal cells to form in the stratum basale and migrate to the skin surface is known as this:
turnover or regeneration time
what is the approximate length of regeneration time
35 days
what does epidermal growth factor regulate?
epidermal growth and repair
a shortened turnover time increases the thickness of stratus corneum and results in this:
callus formation
each group of 8-10 basal cells in mitosis with their vertical columns of migrating keratinocytes is called this:
epidermal proliferating unit
this epidermal component is a partial barrier to the passage of some cells and large molecules
dermoepidermal junction
this epidermal component is a basement membrane with a polysaccharide gel ‘glue’ that connects the epidermis to the dermis below
dermoepidermal junction
this is sometimes called the ‘true skin’
dermis
true or false.
the dermis is much thicker than the epidermis and lies beneath it
true
this gives strength to skin
dermis
this serves as a reservoir storage area for water and electrolytes
dermis
5 structures that are found in the dermis
- arrector pili muscles
- hair follicles
- sensory receptors
- glands (sweat and sebaceous)
- blood vessels
rich vascular supply plays a critical role in _____________ regulation
temperature
different receptors in the skin detect ________ & _____________
pain, pressure
2 layers of the dermis
- papillary layer
2. reticular layer
which dermal layer forms a unique pattern that gives finger prints?
papillary layer
which dermal layer is tough yet stretchable and produces leather
reticular layer
true or false.
The dermal layer continually sheds and regenerates itself just like the epidermal layer
false - it does not
what structures form scars during wound healing
fibroblasts
what are cleavage lines also known as?
langer’s lines
what is also called the subcutaneous layer or superficial fascia?
hypodermis
what connects skin to muscles below?
hypodermis
true or false.
hypodermis is part of the skin
false
2 types of melanin
- eumelanin
2. pheomelanin
what determines skin colour?
quantity, type & distribution of melanin
what releases melanin in packets called melanosomes?
melanocytes
type of injection that enters the skin at a 15 degree angle into the subcutaneous tissue
intradermal (ID)
type of injection that enters the skin at a 45 degree angle and goes beneath the subcutaneous tissue
subcutaneous (SQ)
congenital absence of melanin
albinism
produced by the cumulative effects of UV ray exposure
age spots
what determines the amount of melanin in the skin?
genes
a group of yellowish pigments from food that can also contribute to skin colour
beta-carotene
colour changes also occur as a result in blood flow because of this:
hemoglobin
bluish colour caused by darkening of hemoglobin
cyanosis
if liver is unable to remove bile colour pigment the skin starts to look yellow and is known as ____________
jaundice
the yellow breakdown product when red blood cells are destroyed that is associated with jaundice
bilirubin
what are the 8 functions of the skin
- protection
- sensation
- flexibility
- excretion
- hormone production
- immunity
- temperature regulation
- surface film
vitamin d is produced by which function of the skin
endocrine
4 sensations of the skin
- pain
- heat and cold
- pressure
- touch
somatic sensory receptors are a mechanism of what function of the skin
sensation
surface film/mechanical barrier, keratin, melanin, and tissue strength are a mechanism of what function of the skin
protection
elastic and recoil properties of skin and subcutaneous tissue are a mechanism of what function of the skin
movement and growth
activation of precursor compound in skin cells by UV light is a mechanism of what function of the skin
endocrine
regulation of sweat volume and content are a mechanism of what function of the skin
excretion
phagocyte cells and epidermal dendritic cells are a mechanism of what function of the skin
immunity
regulation of blood flow to the skin and evaporation of sweat are a mechanism of what function of the skin
temp. regulation
what is the control centre for temperature?
hypothalamus
homeostasis of body temperature is an example of what kind of feedback loop?
negative
what is the name of fine soft hair present before birth
lanuga
what is coarse pubic and axillary hair that develops at puberty called
terminal hair
where do hair follicles and hair develop from
epidermis
5 parts of hair:
- papilla
- root
- shaft
- medulla
- cortex
(cluster of capillaries under germinal matrix related to hair)
papilla
(part of hair embedded in follicle in dermis)
root
(visible part of hair)
shaft
(inner core of hair)
medulla
(outer portion of hair)
cortex
the colour of hair is a result of different amounts of _______ in the cortex of hair
melanin
hair grows an average of _______ per year
5 inches
_________ glands attach to and secrete sebum into follicle
sebaceous
what is sebum
skin oil
what is androgenic alopecia
male pattern baldness
androgenic alopecia is a result of 2 things:
- genetic tendency
2. male sex hormones
5 parts of the nail
- nail body
- root
- lanula
- nail bed
- cuticle
2 types of sweat glands
- eccrine glands
2. apocrine glands
these glands are the most numerous sweat glands, distributed over total body surface, function throughout life, and secrete perspiration
eccrine glands
these sweat glands are located deep in subcutaneous layer, limited distribution, large, begin to function at puberty
apocrine glands
2 types of skin glands:
- sebaceous
2. ceruminous
the glands secrete sebum, are found in the dermis, may lead to formation of pimples and blackheads
sebaceous glands
these glands are modified apocrine sweat glands, empty contents into external ear canal, produce ear wax
ceruminous glands
skin is classified as a __________ membrane
cutaneous
this function of the skin is described as an emulsified protective barrier formed by mixing of residue and secretions of sweat and sebaceous glands with sloughed epithelial cells from skin surface
surface film
shedding of epithelial elements is called:
desquamation
skin act as a sophisticated _________ organ
sense
somatic sensory ___________ detect stimuli that permit us to detect pressure, touch, temperature, pain and other general senses
receptors
skin is supple and _________, thus permitting change in body contours without injury
elastic
2 products excreted by the skin
- water
2. urea/ammonia/uric acid
epidermal dendritic cells trigger helpful immune reaction working with “helper ___ cells”
T
to maintain homeostasis of body temperature, heat production must equal _______ ______
heat loss
chief determinant of heat production is the amount of ________ work being performed
muscular
in heat loss approximately 80% of heat loss occurs through the ________, and 20% occurs through the __________ of the respiratory, digestive and urinary tracts
skin, mucosa
this method of heat loss is especially important at high environmental temperatures when it is the only method by which heat can be lost from the skin
evaporation
transfer of heat from one object to another without actual contact
radiation
important method of heat loss in cool environmental temperatures
radiation
transfer of heat to any substance actually in contact with the body and accounts for relatively small amounts of heat loss
conduction
transfer of heat away from a surface by movement of air; usually small amounts
convection
receptors in the _____________ monitor the body’s internal temperature
hypothalamus
layer of epithelium under nail body that contains abundant blood vessels
nail bed
separation of nail from the nail bed is called:
onycholysis
nails grow by mitosis of cells in the stratum _________ beneath the lanula
basale
average growth of ________ is .55 mm per week, 1 inch per year
nails
lipid components have _____________ activity in sebaceous glands
anti-fungal
glands found in dermis except the palms and soles
sebaceous
function of the ceruminous glands are to protect areas from ___________
dehydration
skin that is smooth, unwrinkled, and characterized by elasticity and flexibility, rapid healing, and is few sweat glands is typical in ______________
children
skin that has development and activation of sebaceous and sweat glands, increased sweat production, body odour, and acne due to increased sebum production is typical in ______________
adults
skin that has decreased sebaceous and sweat gland activity, wrinkling, and decreased ability to cool the body is typical in ______________
old age
skin is a major component of the body’s ____________ framework
structural
skin defines the ___________ environment of the body
internal
primary functions of skin are _______________ and __________________
support and protection
Identify the two main or primary layers of skin. What tissue type dominates each layer?
Epidermis and dermis. Epithelium dominates the epidermal layer and connective tissue dominates the dermis.
The terms thin and thick skin refer to which primary layer of skin?
Most of the body surface is covered by thin skin.
How do thin and thick skin differ?
Skin covering the palms of the hands, soles of the feet, and other body areas subject to friction is classified as thick skin. In thin skin, the number of cell layers in each epidermal stratum is less than that in thick skin. Raised parallel ridges are not present in the dermis of thin skin.
Identify the 2 main types of cell types found in the epidermis.
Keratinocytes and melanocytes.
List the 5 layers or strata of the epidermis
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale.
What is the name of the gluelike layer separating the dermis from the epidermis?
Dermal-epidermal junction.
Which layer of the dermis forms the bumps that produces the ridges on the palms and soles?
Dermal papillae.
Which layer is vascular: the epidermis or dermis?
Dermis.
What is the main function of the hypodermis?
The hypodermis forms a connection between the skin and the underlying structures of the body.
What is the one means of heat production in the body? In what type of organs does the most heat production occur?
Metabolism of foods. Muscles and glands produce more heat than any other tissues.
Name three of the four physical process by which heat is lost from the body.
Evaporation, radiation, conduction, and convection.
Identify the pigment that determines hair colour.
Varying amounts of melanin.
List 7 functions of the skin
Protection, sensation, growth, synthesis of important chemicals and hormones, excretion, temperature regulation, and immunity
How does surface film contribute to the protective function of the skin
The surface film is produced by the mixing of residue and secretions from sweat and sebaceous glands, with the epithelial cells constantly being cast off from the epidermis.
List the appendages of the skin
Hair, nails, and skin glands.
What are 2 types of sweat glands. How do they differ?
Eccrine: the most numerous and widespread in the body. They are small and function throughout life to produce perspiration rich in salts, ammonia, uric acid, urea, and other wastes. Apocrine: located deep in the subcutaneous layer. They are much larger than eccrine glands and are connected with hair follicles. Apocrine glands enlarge and begin to function at puberty, producing a more viscous and colored secretion.
List 2 functions of sebum
Keeps the hair supple and the skin soft and pliant.
What substances make up the skin’s surface film?
Surface film is produced by the mixing of residue and secretions from sweat and sebaceous glands with epithelial cells.
The two main layers that compose the skin are the dermis and: A. superficial fascia. B. subcutaneous. C. epidermis. D. hypodermis.
C. epidermis.
The epidermis is composed of several types of epithelial cells. One type, called keratinocytes, become filled with a tough, fibrous protein called: A. melanin. B. keratin. C. stratum lucidum. D. eleidin.
B. keratin.
The dermis is composed of two layers, a thin papillary layer and a thick \_\_\_\_\_ layer. A. reticular B. epidermal C. muscle D. connective tissue
A. reticular
Each hair follicle has a small bundle of involuntary muscles attached to it called the: A. smooth muscle layer. B. microvilli. C. arrector pili muscles. D. dermal papillae.
C. arrector pili muscles.
The basic determinant of skin color is: A. keratin. B. mucus. C. melanin. D. tyrosine.
C. melanin.
Which of the following is not a function of the skin? A. Sensation B. Protection C. Temperature regulation D. Contraction
D. Contraction
The shedding of epithelial elements from the skin surface is called: A. hydration. B. buffering. C. lubrication. D. desquamation.
D. desquamation.
Around the sixth month of pregnancy, the developing fetus is almost entirely covered by a fine soft hair coat called the: A. lanugo. B. papilla. C. vellus. D. sebum.
A. lanugo.
The skin glands include three kinds of microscopic glands. They are the \_\_\_\_\_\_\_\_\_\_ glands. A. sweat, eccrine, and sebaceous B. sweat, sebaceous, and ceruminous C. sweat, eccrine, and ceruminous D. sebaceous, eccrine, and ceruminous
B. sweat, sebaceous, and ceruminous
The mixed secretions of sebaceous and ceruminous glands form a brown waxy substance called the: A. sebum. B. keratin. C. melanin. D. cerumen.
D. cerumen.
