Lecture 2 Integument & Glands Flashcards
What are glands and what is their function?
- Down growth of epithelium that can be multicellular or unicellular
- specialized to produce and secrete substances that work on specific organs or tissues in the body
What are exocrine glands?
- Glands that secrete product directly onto a surface or into a duct
- classified by shape, product, and mechanism of secretion
What are endocrine glands?
secrete product into connective tissue or bloodstream
What are the types of products of exocrine glands?
Serous
- proteinaceous, watery, usually stains darkly
Mucous
-viscous, water-heavy, usually stains light
What are the mechanisms of secretion?
Merocrine (eccrine)
- vesicles of product released from cell
Apocrine
-vesicles coated in lipid membrane before release
Holocrine
-product builds in cytoplasm, cell dies and releases product and cellular debris
How are exocrine classified?
(Simple or compound duct) + (shape of secretory protein) + (serous or mucous product)
What are the different types of simple exocrine glands?
- Simple Tubular
- Simple Coiled Tubular
- Simple Acinar
- Simple Branched Acinar
What are the different types of compound exocrine glands?
- Compound Acinar
- Compound Tubular
- Compound Tubuloacinar
What are the functions of the skin?
Protection
- Trauma- heals quickly - Infection- physical and chemical barrier - Dehydration/ overhydration- prevents excess loss or absorption of water
Sensation
-several types of nerve endings react to temperature, pressure, vibrations, texture, and injury
Thermoregulation
-monitors the temperature of the body surface, and reacts to maintain appropriate response
Vitamin D
-initiates the synthesis of vitamin D
Communication
What are the general layers of the Integument and what are they made of ?
Epidermis
-stratified squamous keratinized epithelium
Dermis
- dense irregular CT - blood vessels, nerves, glands, and hair follicles
Hypodermis
-adipose tissue
What are the layers of the epidermis?
Stratum corneum
-stratum lucidem
Stratum granulosum
Stratum spinosum
Stratum BasaleWhat are characteristics of thick skin?
- They are found at the palms of hands and soles of feet
- eccrine sweat glands
- have a thicker stratum corneum
What are characteristics of thin skin?
everywhere except palms and soles
- has hair
- has sebaceous glands
- has eccrine sweat glands
- has thinner stratum corneum
What cells are found in the epidermis?
Keratinocytes
Melanocytes
Langerhans Cells
Merkel Cell
What is the predominant cell type in the epidermis?
Keratinocytes and they synthesize keratin
What cells secretes melanin?
melanocytes
Where are Langerhans cells found?
part of the immune system
What are merkel cells?
Sensory cells
What does eumelanin stain under a microscope?
brownish black
What does Phomelanin stain?
reddish yellow
What are color and intensity of pigmentation dependent on?
Dependent on type and distribution of melanin
What does blue skin color indicate?
- cyanosis
- lack of oxygen
What does red skin color indicate?
Erythema
-increased blood flow
What does pale/ashen skin indicate?
reduced blood flow
What does white skin color indicate?
- albinism
- genetic lack of melanin
What does yellow skin indicate?
Jaundice
- liver malfunction or excess bilirubin
What does black/green/blue skin color indicate?
- bruise
- broken blood vessel
What layers make up the papillary layer?
- Loose CT
- Blood vessels
- nerves
- immune cells
What makes up the reticular layer?
- Dense irregular connective tissue
- nerves
- blood vessels
- glands
What is the hypodermis made of?
Located below dermis
- adipose tissue
- energy storage
- thermal insulation
sometimes contains nerves, glands, other accessory structures
What are different skin markings and their characteristics?
Fingerprints
- ridges that increase sensitivity and ability to grasp things
Flexion lines-creases that occur near joints
Freckles- flat, melanized patches
Moles- raised melanized patches
Birthmarks (hemangiomas)- discolored skin in varying sizes and shapes
What are nerves specialized in as an accessory structure?
specialized sensory nervous tissue
What do glands specialize in?
specialized to help maintain body temperature, prevent dehydration, protect skin
What does hair specialize in?
specialized structures to maintain heat, protect from the sun
- not so much in human
What do nails specialize in?
specialized stratum corneum to protect ends of fingers and toes?
What are the specialized sensory structures?
Pacinian corpuscle and Meissner’s corpuscle
What glands are found in the integument?
eccrine, sebaceous and apocrine
what are characteristics of sebacceous glands?
attached to hair follicles
oily product
holocrine glands
What are characteristics of eccrine sweat glands?
- Merocrine secretion
- watery, serous product
- simple, coiled tubular gland
What are characteristics of apocrine glands?
- found in groin and axilla
- wide lumen, simple cuboidal epithelium
- lipid heavy product
What are characteristics of hair?
grows on thin skin
-filamentous tube of keratinized cells
What are the three types of hair?
Downy
- unpigmented hair of fetus
Vellus
-fine, unpigmented hair of children and adults
Terminal
-Coarse, pigmented hair of the scalp, eyebrows, axilla pubic, facial hair
What is the structure of hair?
- Follicle
- hair shaft
- root bulb
- associated glands
- sebaceous glands
- Piloerector muscle
What happens in the anagen stage of hair growth?
-early stage and mature stage
- growing phase, 6-8 years
stem cells multiply and follicle grows deeper into dermis
- hair matrix multiplies and keratinize, causing hair to grow upward; old club hair may persist temporarily alongside newly growing hair
What happens in the catagen stage of hair loss?
-hair growth ceases; hair bulb keratinizes and forms club hair, lower follicle degenerates
What happens in the telogen phase?
resting phase
- dermal papilla has ascended to the level of the bulge. club hair falls out, usually in telogen or next anagen
What are characteristics of nails?
derived from stratum corneum
- hardened, parallel rows of keratin
- protection of fingertips
- tools to aid manual manipulation
- increases the sensitivity of the fingertip
What are disorders of the integumentary System?
Acne Dermatitis Eczema Psoriasis Ringworm Rosacea Warts
What is Psoriasis?
Chronic, lifelong skin disease
common in adults
hereditary and auto-immune
characterized by thick, Silvery Scales
What is Eczema?
Condition is transient (come & goes)
Common in Infants & Children
Environmental Factors Aggravate It
Characterized by Red, Inflamed Skin
What are characteristics of Skin Cancer?
- induced by UV rays (both natural and tanning beds)
- elderly and fair skinned most common
- 3 types
- Basal cell carcinoma
- Squamous cell carcinoma
- Malignant melanoma
What are characteristics of Burn?
Leading cause of accidental death
-death primarily
- fluid loss
-infection
toxic effects of eschar (dead tissue)What are the various depth of burnt skin?
First degree - epidermis only
Second degree- epidermis and dermis
Third-degree- epidermis, dermis, and hypodermis
