MIDTERM Integumentary Flashcards
Give the 5 functions of the Skin
- Resistance to trauma and infection
- Other barrier functions
- Vitamin D synthesis
- Sensation
- Thermoregulation
an epithelial tissue in the form of keratinized stratified squamous epithelium
Epidermis
a connective tissue layer in the form of dense fibrous irregular connective tissue
Dermis
loose connective tissue containing fat or adipose tissue
Hypodermis or subcutaneous
3 layers of the skin
- Epidermis
- Dermis
- Hypodermis or subcutaneous
Epithelial tissue which is composed of 4 different types of cells:
- Keratinocytes
- Melanocytes
- Langerhans cells / dendritic cells
- Merkel cells
most numerous and most prominent; these cells that are transformed into keratin
Keratinocytes
produce skin pigment or skin color
Melanocytes
defense cells; antigen-presenting cells (APC)
Langerhans cells / dendritic cells
for tactile/touch sensation
Merkel cell
The keratinocytes form five distinct layers of the epidermis:
- stratum basale / germinativum
- stratum spinosum.
- stratum granulosum / granular layer
- stratum lucidum / clear cell layer
- stratum corneum.
consists of 15 - 20 layers of flattened keratinized cells- cytoplasm is filled with keratin; surface cells continuously shed off
Stratum Corneum
seen only in thick skin; flattened clear cells devoid of nuclei and organelles
Stratum Lucidum / clear cell layer
3-5 layers of flattened polygonal cells whose cytoplasm is filled with darkly basophilic granules called keratohyaline granules
Stratum Granulosum / granular layer
single layer of columnar or cuboidal cells which undergo intense mitosis for constant production of epidermal cells
Stratum Basale / germinativum
thickest layer; consist of polyhedral cells
Stratum Spinosum
upward projections of the dermis, called…
Dermal Papillae
interdigitate with evaginations of the epidermis are calledl
Epidermal Ridges
dense fibrous irregular tissue that supports the epidermis and binds it to the underlying hypodermis
Dermis
2 Layers of the Dermis
- Papillary layer
- Reticular Layer
superficial layer containing dermal papilla
Papillary Layer
thicker deeper layer containing skin appendages
Reticular Layer
found all over the body EXCEPT for palms of hands and soles of feet.
Sebaceous Glands
mucus glands associated with hairs
Sebaceous Glands
In Sebaceous Glands it secrete an oily substance called…
Serum
elongated keratinized structures derived from the hair follicle.
Hair / Hair Follicle
Skin Appendages consist of these 4:
- Sebaceous glands
- Hair and Hair follicle
- Arrector Pili muscle
- Sweat glands
3 Types of Hair
- Vellus hairs
- Terminal hairs
- Lanugo
soft, fine, short and pale
Vellus Hair
hard, large, coarse, long and dark hairs of the scalp and eyebrows
Terminal Hair
fine hair present on the fetus
Lanugo
band of smooth muscle fiber attached to the hair follicle
Arrector Pili Muscle
upon its contraction, forms tiny “goose bumps” on the skin surface
Arrector Pili Muscle
serous glands; secretory portions are coiled
Sweat Glands
2 types of Sweat Glands
- Eccrine (merocrine) sweat glands
- Apocrine (holocrine) sweat glands
largely confined to the axillary and the anogenital regions
Apocrine (holocrine) sweat glands
abundant on palms of hands, soles of feet and the forehead.
Eccrine (merocrine) sweat glands
