Ch.5 Intguentary System Flashcards
List the components of the integumentary system
-Skin
-hair
-nails
- sweat glands
- oil glands
Functions of the integumentary system
Protection
Thermoregulation
Cutaneous sensation
Metabolic functions
Blood reservoir
Excretion
Name the two distinct regions of the skin
-epidermis
• superficial
-epithelial
-dermis
•underlies epidermis
-mostly fibrous connective tissue, vascularized
4 cell types make up the epidermis?
•Keratinocytes
•Melanocytes
•Dendritic (Langerhans) cells
•Tactile (Merkel) cells
What type of tissue makes up the epidermis?
Keratinized stratified squamous epithelium, consisting of 4-5 layers of cells each with different characteristics
Keratinocytes
-the most common epidermal cell
-Produce fibrous protein keratin that gives the epidermis its protective properties
-Tightly connected to one another
Melanocytes
-are found in the deepest layers of the epidermis
-Produce pigment melanin
• which is transferred to the keratinocytes and protect the apical surface of those cells from UV damage
Dendritic (Langerhans) cells
-arise from the bone marrow and migrate to the epidermis
-They function as macrophages and are key activators of the immune system
Tactile (Merkel) cells
-Sensory touch receptors; each cell associates with the nerve ending
-Not very abundant
4-5 Layers of the epidermis
From deep to superficial
-stratum basal
-stratum spinosum
-stratum granulosm
-stratum lucidum (only thick skin)
-stratum corneum
Where “ thick skin” located
Thick skin covers area subject to abrasions; palms of the hand, soles of the feet and fingertips
Thin skin
Covers the rest of the body. The stratum lucidum is an absent, and the other layers are thinner.
Stratum basale (base layer)
-deepest epidermal layer from the attached to the dermis
-single roll of stem cells,actively miotic
-occasional tactile cells
-dermal papilla
Stratum spinosum (prickly layer)
-several layers thick
-System of intermediate pre-keratin filaments attached to cell junctions
-Abundant monocytes and dendritic cells
-Langerhan cells which function as macrophage by engulfing bacteria, foreign particles, and damage cells
Stratum granulosum (granular layer)
-4-6 cell deep layer
-cells flatten
-Nuclei and organelles disintegrate
-The cells accumulate two types of granules
•keratohyaline granules, which keep form keratin and upper layers
•lamellar granules who release water resistant glycolipids into the extra cellular space (slows water loss)
-Sales of this layer have thickened plasma membranes to form a waterproof barrier
-All cells above this lay dead. They are too far from capillaries.
Stratum lucidum (clear layer)
-found in only thick skin
-thin translucent band
-2 to 3 rows of flat dead cells, aide in making skin waterproof
• found in Palms, soles of feet and fingertips
Stratum corneum (horny layer)
•20-30 rows of dead flat membraneous sacs
•3/4 epidermal thickness
• Keratin and thicken plasma protects the skin against abrasion
• glycolipids (waterproof) protect from abrasion and penetration barrier against biological chemical, physical assaults
What are the two layers of the dermis?
-papillary
-reticular
Dermis
-the second layer of the skin is the dermis a layer of strong, flexible, connective tissue
-the cells found in the dermis are typical of connective tissue proper (dense irregular, areolar and connective tissue)
• fibroblast, microphages, and occasionally mass cells and white blood cells
-rich supply of nerve fibers, blood, and lymphatic vessels
-Contains epidermal hair follicles; oil and sweat glands
Dermis
Papillary layer
-the proper layer is areolar connective tissue with a fine interlacing of collagen and elastic fibers.
-many small blood vessels.
-loose tissue, which allows for phagocytes and other defense cells to patrol for microorganisms
-superficial peg like projections called dermal papillae, contain capillary loops, nerve endings (pain) or or touch receptors (meissners corpuscles)
Dermal Papillae
-thick skin, capillary loops, dermal ridges that caused epidermal ridges
-Collectively these ridges are called friction ridges
• enhance gripping ability
• contribute to sense of touch
• pattern is fingerprints
• nerve endings
Dermis
Reticular layer
-the reticular is composed of dense, irregular connective tissue
-This layer is nourished by a network of blood vessels
-elastic fiber provide stretch-recoil
-the collagen fiber run in many directions but most run parallel to the skin surface
-separation or less dense regions between the collagen bundles form cleavages lines in the skin
Dermis
Flexure lines
-are dermal folds that occur or near joints and our places where the dermis is tightly secured to deeper structures
-Since skin cannot slide easily for joint movement
-Visible on hands hands, wrists, fingers and soles and toes
Appendages of the skin
-hair and hair follicles
-Nails
-sweat glands
-sebaceous (oil) glands
List the two type of sweat glands
Eccrine
Apocrine
- Both types of sweat glands contain myoepithelial cells which contract upon nervous system stimulation to force sweat into ducts and onto the skin surface
Dermal papillae
-dermis
-superficial peglike projections, which indent the overlying epidermis, many contain capillary, loops, nerve endings (pain receptors), or touch receptors
Kertainocytes
-epidermis
-the most common epidermal cell produce fibrous protein keratin that gives it epidermis It’s protective properties.
Melanocytes
Epidermis
-melanocytes produce pigment melanin
-transferred to the keratinocytes and protect cells from UV damage
tactile (Merkel) cells
-epidermis
-Tactile cells are sensory touch receptors each cell associates with a nerve ending
Dendritic cells
-epidermis
-Dendritic cells are a type of white blood cell. They function as macrophages and are key activators of immune system. (stimulate a sort of memory of the invader to be informed so it can be recognized again)
Sudeiriferous (sweat) glands
-dermis
-sweat glands are distributed over the entire skin surface
-two main types of sweat glands
•Eccrine (Merocrine) sweat glands
•Apocrine sweat glands
-both types of sweat glands contain myoepithelial cells
*contract upon nervous systems stimulation to force sweat into the ducks and onto the skin surface
Eccrine (Merocrine) gland
-dermis
-function; thermal regulation.
-it can also be induced by emotions (I.e. “ nervous sweating”).
-regulated by the sympathetic nervous system the system responsible for “ flight or flight” responses
-ducts empty onto skin surface
Approcrine glands
Apocrine sweat glands are confined to axillary and anogenital areas - their ducts empty into hair follicles.
-function unknown, but may act as sexual scent gland
Arrector pili muscle
-dermis
-arrector pili-muscles are a bundle of smooth muscle cells associated with each hair follicle. Responsible for ”goosebumps”
Sebaceous glands
-dermis
-sebaceous or glands are found all over the body except for the thick skin of palms and soles. Most develop as outgrowth from hair follicle and secrete directly into the hair follicle.
-sebaceous glands secrete sebum an oily Holocrine secretion, which is bactericidal, and also also serves to soften her and skin
The dermis is rich in blood vessels and nerve fibers
True
Eccrine sweat glands, the most numerous are found in the greatest numbers on the palms soles of your feet and forehead
True
Most sebaceous glands secrete their products directly onto the skin surface via ducts
False
Apocrine sweat, gland, ducts, empty their products into hair follicles
True
Lines in our skin, such as fingerprints and flexure lines are shaped by the epidermis
False
The epidermis contains 4 - 5 layers of cells; each layer different in structure, and function
True
The layers of the epidermis from deepest to most superficial are stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale
False
Listed as superficial to deep
Label the following structures
