Chapter 5 - Integumentary System Flashcards
What mechanisms do sebaceous glands use to excrete their products?
holocrine excretion
What are the two types of sweat glands called?
eccrine (merocrine) and apocrine glands
First degree burns affect which layer of the skin?
Epidermis
What are the 7 functions of the integumentary system?
- protect tissues and organs, 2. excrete salts and organic waste, 3. thermoregulation via insulation and evaporative cooling, 4. UV protection melanin production, 5. Produces vitamin D, 6. Energy storage via dermal adipocyte, 7. sensory in put —nerves for temperature, pressure, pain, etc.
What are the 2 layers of cutaneous membrane?
Epidermis and dermis
How many layers are in the epidermis?
4 (5 on palms and soles)
What are the 5 strata of the epidermis?
stratum coronum, (lucidum–only in palms and soles), granulosum, spinosum, basale
What are the body’s most abundant epithelial cells?
keratinocytes
Keratinocytes are constandly produced by ______ cells in the stratum ___________.
stem; basale
Which of the strata is exposed to the environment?
stratum coronum
What is the lifespan of the cells in the stratum coronum?
2 weeks
Which strata is only found in “thick skin”?
stratum lucidum
The stratum granulosum is make up of 3-5 layers of _________.
keratinocytes
What phase of cell grown are keratinocytes in?
Go
In which layer does keratinization occur?
stratum granulosum
Langerhans cells are found in which layer of the epidermis?
stratum spinosum
what layer of the epidermis borders the dermis (i.e. what is the deepest layer of the epidermis)?
stratum basale
What sense are Merkel nerve cells responsible for?
touch
Separates the integument and the fascia of the deeper organs.
Hypodermis
These extend into the dermis and increase surface area.
Epidermal ridges
These project into the epidermis and work to tightly bind the layers.
Dermal papillae
What 2 things affect skin color?
Pigments and blood flow
A brown, yellow-brown, or black pigment
Melanin
Pigment producing cells ; found in the stratum basale
Melanocytes
Transport packets bringing melanin to keratinocytes
Melansomes
An orange-yellow pigment that accumulates in epidermal cells ; most apparent in the stratum corneum
Carotene
2 layers of the dermis
Papillary layer and reticular layer
Highly vascularized areolar tissue ; blood and lymphatic vessels are found here
Papillary layer
Dense layer of irregular connective tissue containing collagen and elastic fibers
Reticular layer
Touch sensitive ; between epidermal cells
Free nerve endings
Detect texture and steady pressure ; found deep in epidermis
Tactile discs
Detect delicate touch, pressure, and vibrations ; found in the papillary layer
Meissner’s corpuscles
Detects strong pressure/vibration ; found in both dermis and hypodermis
Lamellated (pacinian) corpuscles
Sensitive to pressure and stretching of the skin ; found in the reticular layer
Ruffini corpuscles
Erythma
Redness and inflammation of the skin
Why are second degree burns the most painful?
Because the entire epidermis and some of the dermis is afflicted
What are full-thickness burns? and what do they affect?
Third degree burns ; affects the entire epidermis, dermis, and some of the hypodermis
What is the rules of nines?
Provides a quick estimate for the surface area affected by burns ; different for children
What is the most common cancer? and why?
Skin cancer ; typically caused by over-exposure to UV radiation
4 phases of integument repair and regeneration
Inflammatory, migratory, proliferation, scarring
Injury triggers mast cells to initiate a response
Inflammatory phase
Several hours post-injury ; scab forms over the would ; acts as a temporary epidermis
Migratory phase
Granulation
Combination of blood clots, fibroblasts, and capillarization
1 week post injury ; epidermal cells undermine the scab
Proliferation phase
Several weeks post injury ; scab is gone ; epidermis complete
Scarring phase
Peptide growth factor ; produced in glands of the mouth and duodenum
Epidermal growth factor (EGF)
What does growth hormone do?
Stimulates fibroblasts and collagen synthesis, basal cell division, epidermal thickening
What do thyroid hormones do?
Maintain sub-papillary plexus blood flow
Cell division, epidermal thickness, dendritic cells that defend against cancer
Sex hormones
What is another name for cholecalciferol?
Vitamin D
What does calcitriol do?
Stimulates calcium and phosphate uptake in the intestines
Define/describe finger and toe nails.
Areas of dead, tightly packed (dense) keratin-filled cells
What portion of the nail is visibly seen?
the nail body
What is the source of nail growth?
Nail root
What is the name of the proximal extension of stratum corneum (cuticle)?
Eponychium
define: hyponychium
Thickened stratum corneum at the distal portion of the nail
Terminal hair
Large, coarse, typically dark ; found on scalp + armpits
Smaller, shorter, more delicate ; found on body surface
Vellus hair
Portion of the hair seen on the surface.
Hair shaft
Anchors hair in the skin
Hair root
Hair root plexus
Sensory nerves that surround the base of each follicle
Sebaceous gland
Produces secretions that coat the hair and surrounding skin
Comprised of matrix daughter cells ; has flexible keratin
Medulla
An intermediate layer of daughter cells underlying the cuticle
Cortex
Daughter cells produced at the edge of the matrix ; forms the surface of hair shaft
Cuticle
The oily mixture that the sebaceous glad secretes
Sebum
The muscle that squeezes the sebaceous glad
Arrector pilli muscles
The mechanism that is used in apocrine sweat glands
Merocrine secretion
