Exam 2: Integumentary System Flashcards
T/F: Skin is the largest organ of the body
T
Name the layers of thin skin from most superficial to deep.
Stratum corneum, stratum granulosum, stratum spinosum, stratum basale
Name the layers of thick skin from most superficial to deep.
Stratum corneum, stratum LUCIDUM, stratum granulosum, stratum spinosum, stratum basale
Describe the stratum corneum.
Dead cells; flat membranous sacs filled with KERATIN; GLYCOLIPIDS in extracellular space
Describe the stratum granulosum.
flattened cells with deteriorating organelles; cytoplasm full of LAMELLATED GRANULES and KERATOHYALIN GRANULES
Describe the stratum spinosum.
Cells contain thick bundles of intermediate filaments made of pre-keratin. Langerhan cells.
Describe the stratum basale.
Cells are actively mitotic stem cells; some newly formed cells become part of the more superficial layers.
What is the stratum basale also known as?
Stratum germinativum
Where are melanocytes found and what is their function?
Found on superficial surface of keratinocytes in the stratum basale; melanocytes produce melanin which chemically protects the nuclei of keratinocytes from UV radiation of sunlight.
What happens when you go out into the sun?
Melanocytes produce more melanin for protection.
What is albinism?
A condition in which melanin is not produced (melanocytes present but do not produce melanin.
Why are albinos more prone to skin cancer?
The lack of protection from UV radiation due to no production of melanin increases the risk of skin cancer.
What does the stratum basale consist of?
A SINGLE layer of cells including keratinocytes, melanocytes, and merkel cells.
Where are Merkel cells?
In the stratum basale, at the junction of epidermis and dermis
What do Merkel cells form?
Merkel discs that act as touch receptors as Merkel cells associate with free nerve endings.
What are cells connected by in the skin?
Desmosomes
Where are tonofilaments located?
Stratum spinosum
Where are Langerhan Cells located?
Stratum spinosum
What specialized particles are in the stratum spinosum?
Tonofilaments and Langerhan cells.
What do tonofilaments do?
They are intermediate filaments that resist tension placed on the skin.
What do Langerhan cells function as?
Epidermal dendritic cells; they engulf and degrade pathogens in the skin as the epidermis is not vascularized.
How many layers of cells are in each strata of the epidermis?
Basale: Single layer
spinosum: several layers
Granulosum; 3-5 layers
Corneum: 20-30 layers
What can you find in the stratum granulosum?
Two types of granules
1. Lamellated granules: contain glycolipids which give the skin the ability to be waterproof
2. Keratohyalin granules: contain tough protein, keratin, that helps the skin resist abrasions
What are lamellated granules?
granules located in the stratum granulosum that contain glycolipids, helping the skin be water proof
What are keratohyalin granules?
Granules located in the stratum granulosum that contain keratin, allowing the skin to resist abrasions
What is the function of the stratum lucidum?
Thicken the epidermis in THICK SKIN only, located in palms of hands and soles of feet
How is the stratum corneum formed?
Cornification: dead cells that contain glycolipids and keratin to provide a tough, durable, and waterproof coat.
What are the layers of the dermis?
- superficial papillary layer
- deep reticular layer
Explain the basis for fingerprints in individuals.
Epidermal ridges are located between the papillary layer and epidermis, These ridges form impressions on the epidermal surface and act to increase friction and grip ability in thick skin. Patterns are genetically determined and thus unique to individuals.
What type of tissue is the papillary layer composed of?
areolar connective tissue
What type of tissue is the reticular layer made of?
dense irregular connective tissue
What are Pacinian corpuscles?
contain touch receptors for deep pressure; located in reticular layer of dermis
Where are the touch receptors for deep pressure located?
Pacinian corpuscles in the dermis (reticular layer)
Where are Merkel discs and what are they?
Epidermal-dermal junction; light touch receptors
Describe Meissner’s corpuscles.
touch receptors in papillary layer of dermis
Describe root hair plexus
wrapped around the base of a hair follicle called the hair bulb and it’s stimulated when the hairs bend; act as touch
Where are all accessory structures of the skin derived from?
Stratum basale; BUT –> they extend and reside in the dermis for nutrients as the epidermis is avascular
What are the accessory structures of the skin?
- Hair
- Nails
- Sweat glands
- Oil glands
What are sweat glands?
Simple (coiled) tubular multicellular exocrine glands;
What are the two types of sweat glands?
Eccrine and Apocrine
What do eccrine glands do?
Secrete SWEAT for thermoregulation when body temperature rises
What mode of secretion do the sweat glands use?
Merocrine
What is another name for eccrine sweat glands?
Merocrine sweat glands
What is another name for apocrine sweat glands?
Odoriferous glands
What is sweat composed of?
- 99% water!!1!
- hypotonic filtrate of blood
- Antibodies
- Vitamin C
- NaCl
- Metabolic wastes
- Dermcidin!!!!
What is the acidic mantle?
the phenomena of the acidic sweat and dermcidin to act and prevent bacteria from living in the skin
T/F: Apocrine glands are active from birth
F; they become activated by sex hormones after puberty
What are the two specialized sweat glands?
- Ceruminous glands that secrete cerumen (earwax) to prevent foreign objects entering ear canal
- Mammary glands that secrete milk
What type of gland is a sebaceous gland?
Simple branched alveolar multicellular exocrine glands
T/F: Sebaceous glands use the merocrine mode of secretion.
F: Holocrine mode (whole cells)
Where is hair produced?
Hair matrix
What are the two regions of of hair?
Hair root (enclosed in skin) , Hair shaft (extended outside of skin and exposed)
Name a thermoregulatory function of hair.
Protection from the cold by contraction of arrector pili muscles causing goosebumps (provides insulation)
What part of the skin is affected by first-degree burns?
Damage only to the epidermis, assosciated redness,swelling, and pain. heals in 3 days, no medical intervention needed
What part of the skin is affected by second-degree burns
damage to the entire epidermis and the papillary layer of the dermis. associated blisters due to fluid collection at the epidermal-dermal junction, swelling, redness, pain, heals in 3-4 weeks bar infection
What part of the skin is affected by third-degree burns?
damage the entire skin (entire epidermis and dermis including all nerve endings). No pain, subject to infections and fluid loss, grafting, fluid, protein and ion replacement as treatments
Why do we get whiteheads?
sebum accumulates in the ducts of sebaceous glands
Why do we get blackheads?
popped whiteheads that result in oxidation and darkening
Why do we get acne?
inflammation of sebaceous glands caused by bacteria
T/F: Cells are loosely packed in the epidermis and densely packed in the dermis.
F; the opposite is true
touch receptors for deep pressure that are located in the reticular layer of the dermis are known as ____
Pacinian corpuscles
What are cleavage lines?
Areas of the reticular layer with less collagen bundles
Name the three main types of skin cancer.
- Basal Cell Carcinoma
- Squamous Cell Carcinoma
- Melanoma
Describe basal cell carcinoma.
cancer of cells in the stratum basale layer. least malignant but most common; grows slowly
Describe squamous cell carcinoma.
cancer of cells in the stratum spinosum. 2nd most common behind basal cell carcinoma; grows rapidly
Describe melanoma.
cancer in melanocytes, most aggressive but least common out of the 3 discussed, highly metastatic and resistant to chemotherapy,
What is a burn?
Tissue damage from intense heat, radiation, electricity, and acids
How do wrinkles form?
Loss of elasticity and thinning of the skin and lack of moisture
How does botox help prevent wrinkles?
Botox blocks the transmission oof signals from nerves to muscles by hindering production of the neurotransmitter
What happens as we age and wrinkles form/
With age, skin loses moisture and elasticity and becomes susceptible to muscle tension. Begins to adhere to muscle tissue, creates valleys, lines, or deep wrinkles over time.
If a patient burns the anterior and posterior parts of their trunk, how much of their body would have been burned?
36%
How does the skin provide physical, biological and chemical protection?
Physical: Keratin provides tough nails and protects the digits
Biological: Langerhan cells in the stratum spinosum act as epidermal dendritic cells too remove pathogens
Chemical: Melanocytes provide protection in the form of melanin protecting skin from UV rays
Which sweat glands provide a thermoregulatory function?
Eccrine