Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
Integumentary system
|
composed of the skin and its derivatives: hair, nails, sweat, oil, and mammary glands
covers the entire body surface, even the eyes and ear drums |
|
|
Tissues found in the skin
|
all four tissue types are found within the integument
-epithelium -connective tissue -smooth muscle -nerves |
|
|
Functions of the skin
|
protection
regulation of body temperature retards water loss houses sensory organs synthesizes chemicals excretes waste |
|
|
Composition of the skin
|
composed of an epidermis and a dermis; separated by a basement membrane
|
|
|
Cell types found in epidermis
|
keratinocytes
melanocytes Merkel cells Langerhans cells |
|
|
Keratinocytes
|
most abundant epithelial cells
|
|
|
Melanocytes
|
pigment producing cells
|
|
|
Merkel cells
|
have a role in detecting sensations
|
|
|
Langerhans cells
|
phagocytic cells
|
|
|
What kind of epithelium make up the epidermis?
|
stratified squamous epithelium
|
|
|
Layers in thick skin
|
stratum germinativum
stratum spinosum stratum granulosum stratum lucidum stratum corneum |
|
|
Layers in thin skin
|
stratum germinativum
stratum spinosum stratum granulosum stratum corneum |
|
|
Stratum germinativum
|
Stratum basale
-mitotic layer -innermost, basal layer -attached to basal lamina -stem cells or basal cells dominate. The division of stem cells replace the more superficial keratinocytes that are lost at epithelial surface -contain epidermal stem cells, melanocytes, Merkel cells |
|
|
Stratum spinosum
|
-each time a stem cell divides, a daughter cell is pushed into stratum spinosum
-cells being to differentiate into keratinocytes -several cells thick -keratinocytes are bound together by desmosomes attached to tono fibrils of the cytoskeleton -Langerhans cells and melanocytes are often present |
|
|
Stratum granulosum
|
-consists of keratinocytes displaced from the stratum spinosum
-keratinocytes produce keratohyalin and keratin -keratin fibers develop as cells become thinner and flatter -gradually the cell membranes thicken, the organelles disintegrate, and the cells die |
|
|
Stratum lucidum
|
appears as glassy layer in thick skin only
|
|
|
Stratum corneum
|
-multiple layers of flattened, dead, interlocking keratinocytes
-typically relatively dry -water resistant, but not waterproof -permits slow water loss by insensible perspiration -keritinization |
|
|
Finger prints?
|
stratum germinativum layer of epidermis forms epidermal ridges that extend into the dermis, increasing the area of contact between the two regions. Projections from the dermis toward the epidermis, called dermal papillae, extend between adjacent ridges
|
|
|
Why is thick skin thicker?
|
Thicker because MORE LAYERS of cells in the stratified squamous epithelium (NOT just because of the presence of hte stratum lucidum)
|
|
|
Most of the body is covered by what kind of skin?
|
Most of the body is covered by THIN skin
-only 4 layers present |
|
|
Skin color is due to:
|
-Dermal blood supply
-Pigments -Environment, physiological factors, genes -Thickness of stratum corneum |
|
|
Carotene
|
orange-yellow pigment
|
|
|
Melanin
|
black, yellow-brown, or brown pigment
|
|
|
Dermis
|
-supply the blood, regulate body temperature
-nervous tissue scattered in dermis -binds epidermis to underlying tissue |
|
|
What nervouys tissue is found is dermis?
|
-sensory receptors
-Motor fibers |
|
|
Layers of dermis?
|
-Reticular layer
-Papillary layer |
|
|
Reticular layer
|
-deeper layer of dermis
-dense irregular connective tissue that surrounds blood vessels, hair follicles, nerves, sweat glands, sebaceous glands -tough collagen and elastic fibers surrounded by ground substance |
|
|
Papillary layer
|
-superficial layer of dermis
-loose connective tissue -contains capillaries supplying the epidermis and the axons of sensory neurons that monitor receptors in the papillary layer and the epidermis |
|
|
Superficial fascia
|
hypodermis or subcutaneous layer
-lies beneath the dermis (no sharp boundary is present) -loose connective and adipose tissue -adipose tissue serves as an insulator |
|
|
Accessory organs of the skin
|
-hair follicles
-sebaceous glands -nails--keratinzed epithelial cells -ceruminous glands -sweat glands |
