Integumentary System Flashcards
Which vitamin is produced in the integumentary system?
vitamin D
What are seven functions of the integumentary system?
protection, sensation, temperature regulation, vitamin D production, excretion, immunity
What are four structures that are part of the integument?
skin, hair, nails, glands
What are the three layers of the skin?
epidermis, dermis, subcutaneous tissue
What is the most superficial skin layer?
epidermis
Which layer of the skin is technically not part of the skin but connects skin to underlying structures so is classified with them?
subcutaneous tissue
Which skin layer lends structural strength to the skin?
dermis
Which skin layer, dermis or epidermis, is vascular?
dermis
How do cells in the epidermis get the nourishment they need for metabolism?
nutrients must diffuse from capillaries in the dermis, through the basement membrane, and into epidermis cells (epidermis cells farther from dermis less metabolically active)
What are four types of cells in the epidermis?
keratinocytes, melanocytes, Langerhans’ cells, Merkel’s cells
Which epidermal cells are specialized for sensation?
Merkel’s cells
Is thick skin always literally thicker than thin skin?
No, thick or thin just refers to the number of layers
How many epidermal cell layers are in thick skin and where are two places it is found?
five layers, found in palms, bottom of feet
How many epidermal layers are in thin skin?
four
What does it mean to say that epidermal cells desquamate?
they fall (slough) off
It is usually not the _____ of melanocytes but the _______ of melanocytes that varies among people and leads to different skin shades.
number, metabolic production
What are two pigments that contribute to skin color?
melanin, carotene
_______ of melanin in the upper skin cells leads to pigmentation
endocytosis
Which skin pigment is fat-soluble?
carotene
What are ten structures found within the dermis skin layer?
fibers, fibroblasts, macrophages, adipocytes (some), blood vessels, nerves, hair follicles, smooth muscles, glands, lymphatic vessels
What are the two layers of the dermis?
papillary, reticular
What is the superficial layer of the dermis, filled with touch receptors and free nerve endings sensing pain?
papillary layer
Many of the functional structures of the dermis (follicles, nerves, glands, ducts, etc) are in which layer of the dermis?
reticular
The ______ dermis layer has a lot of areolar connective tissue with lots of elastic fibers, while the ______ dermis layer has dense irregular connective tissue with collagen and elastic fibers.
papillary, reticular
What type of connective tissue is found in the subcutaneous tissue?
loose connective tissue with collagen and elastic fibers
What are two other names for the subcutaneous tissue?
hypodermis, superficial fascia
About half the body’s adipose tissue is found in the _______ tissue
subcutaneous
What kind of blood supply goes into the hair bulb?
arterioles and venules
What are the 3 concentric layers of the hair?
medulla (center), cortex (bulk), cuticle (surface)
What is the average rate of hair growth per day?
0.3 mm
What is the arrector pili muscle?
smooth muscle whose contraction cause the hair to “stand on end”
Where do most of the skin’s sebaceous glands empty?
into the hair follicle
What is the purpose of the oily sebaceous gland secretions?
prevents drying, may inhibit bacteria
What are the two types of sweat glands?
merocrine (eccrine), apocrine
Which sweat gland is the most common type?
merocrine (eccrine)
______ sweat glands are active at puberty, secrete organic compounds that when broken down by bacteria lead to BO
apocrine
______ sweat glands are compound coiled tubular glands that usually secrete into the hair follicle above the sebaceous gland opening
apocrine
______ sweat glands are simple coiled tubular glands that open directly onto the surface of the skin and have their own pores.
merocrine (eccrine)
The final sweat product produced by merocrine glands is…
hyposmotic
Where are ceruminous glands found and what do they secrete?
found in the external auditory meatus, secrete earwax (cerumen)
Ceruminous glands are modified _______ sweat glands, while mammary glands are modified _____ sweat glands.
merocrine, apocrine
Temperature regulation in the skin relies on what kind of feedback mechanism?
negative
Vitamin D is a hormone called what?
calcitriol
What is the effect of vitamin D?
increases the amount of Ca2+ (calcium) in blood
What are 3 ways vitamin D (calcitriol) stimulates increased blood calcium levels?
stimulates Ca2+ (and PO42-) uptake from intestines, promotes Ca2+ (and PO42-) release from bones, reduces Ca2+ loss from kidneys
