Class 1/2 - Integumentary System Flashcards
What are the main functions of the integumentary system?
- synthesis of vitamin D
- temperature regulation
- protection from external environment
- sensation perception
- blood reservoir
- excretion + absorption
What percentage of total blood volume is stored in the integumentary system?
8-10%
What percentage of total body weight is the skin?
7%
What four types of cells make up the epidermis?
keratinocytes
melanocytes
intraepidermal macrophages (Langerhans)
tactile epithelial cells (Merkel)
What percentage of epidermal cells are keratinocytes?
90%
Which cell of the epidermis produces lamellar granules?
keratinocytes
Thin skin has _ layers, thick skin has _. Which is missing from thin skin?
4, 5
stratum lucidum
Langerhans cells are also called ____ and come from _____.
Intraepidermal macrophages
from bone marrow
What is the function of Langerhans cells?
recognize invading organisms (immune response)
What is the function of Merkel/tactile epithelial cells?
detect touch sensations and relay that information to flattened processes of sensory neurons in the deepest layer of the epidermis
Compare and contrast thick vs. thin skin?
thick skin
- hairless
- regions of high mechanical stress
- 5 epidermal layers
- stratum lucidum
- dermal ridges present
- no sebaceous glands
- more sudoriferous glands
thin skin
- hairy
- occurs in most regions of the body
- 4 epidermal layers
- no stratum lucidum
- no dermal ridges
- fewer sudoriferous glands
In what order of areas does sweating start for thermoregulation, vs. for emotional sweating?
thermoregulatory:
- forehead and scalp
- rest of body
- palms and soles
emotional:
- palms, soles, axilla
- other areas of the body
Where are appocrine sweat glands found?
axilla, groin, areola, bearded regions
Describe the consistency of appocrine gland sweat
contains lipids and proteins, appears milky/yellowish, creates BO
Hair follicles are found in which layer of the dermis?
reticular
The stratum basale is composed of…
a single row of keratinocytes
stem cells
melanocytes
Merkel cells
Which layer of the epidermis is transitional between active and dead keratinocytes?
stratum granulosum
What creates fingerprints?
downward projections of the epidermis between dermal papillae
The growth stage of the hair cycle is called…
anagen
The resting stage of the hair cycle is called…
telogen
List the places sebaceous glands are NOT associated with a hair follicle
lips, eyelids, glans penis, labia minora
What part(s) of the body do not have sebaceous glands?
palms, soles
Eccrine glands are most numerous in…
the forehead, palms, and soles
Deep wound healing involves 4 phases, which are…
inflammatory
migratory
proliferative, and
maturation
The ABCD of melanoma exams (moles) are…
a - asymmetry
b - border irregularity
c - colour
d - diameter
Which layer of the skin are langerhans cells found?
stratum spinosum of the epidermis
Mammary glands are specialized…
apocrine (sweat) glands
What are the 3 main types of skin cancer?
basal cell carcinoma
squamous cell carcinoma
malignant melanoma
Who is at highest risk of malignant melanomas?
people who are fair skinned, burn easily, don’t tan, have freckles and red hair
Three things that fingerprints enable the increase of:
- surface area/friction
- number of tactile receptors
- contact with blood vessels
Where is carotene stored?
stratum corneum + fat cells
Nails grow from the…
matrix
Which layer of the skin has 25-30 layers of dead keratinocytes?
stratum corneum
Which layer of the skin is transitional between active and dead keratinocytes?
stratum granulosum
Which layer of the skin houses the Langerhans cells?
stratum spinosum
Which layer of the skin is composed of a single layer of keratinocytes and contains stem cells?
stratum basale/germinativum
What is found in the papillary layer of the dermis?
blood vessels, Meissner’s corpuscles, free nerve endings
What is found in the reticular layer of the dermis?
collagen fibres, coarse elastic fibres
fibroblasts, adipose cells
hair follicles, nerves, glands
At any given time, most hairs on your head are in which stage?
anagen
Eccrine sweat glands are active in ____
thermoregulation
Eccrine sweat glands are NOT found in…
lips, nail beds, glans penis/clitoris, labia minora, or the tympanic membrane
