Skin 2 Flashcards
skin may be considered as what type of organ?
Sensory
Order of skin receptors from most superficial
Meissners corpuscles Merkles corpuscles Free nerve ending Lamellated / pacinian corpsuscle Ruffini corpuscle
What does meissners corpuscle sense?
Light touch
What does merkles corpuscle sense?
Touch
What do free nerve endings sense?
Pain
What do lamellated/ pacinians corpuscles sense?
Deep pressure
What do ruffini corpuscles sense?
Tensile force
What glands are widely distributed in the skin?
Sweat glands
Where are sweat glands situated?
Deeper dermis / hypodermis
What are sweat glands aka?
Sudoriferous glands
What do sweat glands respond to?
Body temp
What are the two types of sweat glands?
Merocrine and apocrine
Characteristics of merocrine glands
• Open via duct to pore on skin
surface
• Most common
• Numerous in palms and soles
Characteristics of apocrine glands
- Ducts empty into hair follicles
- Found in axillae, genitalia, around anus
- viscid milky fluid
Why are apocrine glands known as scent glands?
Bc they develop a scent as the secretion is metabolized by bacteria
When are apocrine glands activated?
After puberty
Where are apocrine glands located?
in arm pit, groin, and around nipples, and bearded areas of face in adult males.
What are Apocrine ceruminous (wax), & mammary (milk) glands ?
types of apocrine glands that secrete cellular product and portion of the free ends of cells
When merocrine gland secretes ..
Cell remains intact
When apocrine gland secretes..
Small portion of gland secreted
When holocrine gland secretes..
Secretion and entire cell secreted in lumen
Apocrine sweat glands are found primarily in …. And may also be found in …
Found primarily in the axillary, pubic, and anal regions of the body.
• Also found in the facial region in men only.
Which type of sweat gland is larger apocrine or merocrine?
Apocrine
Where do apocrine sweat glands empty?
Hair follicles
Why is apocrine sweat thicker than merocrine sweat?
Because it contains more lipids and proteins
When does apocrine sweat release a foul ofor?
When its degraded by epidermal bacteria
When do apocrine glands secrete sweat?
during times of pain, stress, and
sexual activity
Apocrine sweat glands may have a __________ function
Pheromone-like
True or false. Apocrine sweat glands play a role in thermoregulation.
False they play no role.
Glands are derivatives of what?
Epithelial tissue
Where are sebaceous glands found?
All over except palms and soles of feet
What are functions of sebaceous glands?
• Produce oil (Sebum)
• Lubricant for skin and
hair
• Kills bacteria
What are sebaceous glands most associated with?
Most associated with ducts that empty into hair follicles
What are holocrine glands ?
Glands that disintegrate cell and its contents for
secretion (SEBUM)
When are holocrine glands activated?
Puberty
What causes acne?
excess sebum production and active infection of sebaceous glands
Sebaceous glands help…
keep skin and hair soft, pliable, and waterproof (prevents excessive evaporation also
What are ceruminous glands?
Modified sweat glands
What do ceruminous glands secrete?
waxy substance called cerumen
Where are ceruminous glands located?
located in external ear canal
What are mammary glands?
Modified sweat glands that secrete milk
Where des hair originiate from?
Hair follicle
What is a hair made up of ?
Root
Shaft
Medulla cortex cuticle
What is a root surrounded by?
root hair plexus
Whats the function of the root hair plexus?
Nourishment and nerve supply of hair
What is the hair follicle associated eith?
sebaceous glands that secrete sebum
arrector pili- cold and fright
What are the sebaceous glands associated with the hair follicle stimulated by?
Sex hormones
What are conditions or infections associated with open pores?
Blackheads
Pimples
Hair follicles
organs from which hairs develop and are surrounded by dense fibrous connective tissue that are from dermis
Glassy membrane
a thickened basement membrane that separates the dermis from the epithelium of the hair follicle.
Hair root
the expanded terminus of the hair follicle and its indented
What together are known as the hair bulb?
Hair root and dermal papilla
What does the dermal papilla contain?
Rich supply of capillaries
What does Structure of Hair contain?
Hair root Glassy membrane Dermal papilla Cortex Medulla Cuticle
Medulla
the innermost region consisting of large cells and air spaces.
Cortex
surrounds the medulla and consists of flattened keratinized cells
Cuticle
outer layer of flat keratinized cells that overlap like shingles with their free edges pointing upward.
hair root plexus
Network of sensory nerve endings wrapped around bulb of follicle
What does the hair plexus allow?
Hairs to serve a sensory function
Whats attached to each hair?
bundle of smooth muscle known as an arrector pili muscle.
Whats the function of arrector pili?
In times of fright or cold, these muscles contract and cause the hair to stand on end – and produces goose bumps.
Increases airflow in mammals with significant hair (i.e., not humans) and increases the apparent size of an animal with significant hair. Vestigial in humans.
Structures of nail
Nail plate Nail bed Cuticle ( eponychium) Distal phalanx Nail matrix Collagen fibers Epidermis Hyponychium
What is the cuticle/ eponychium?
Layer above the nail plate
Where is the nail bed located?
Under nail plate
What part of the nail is rich in blood supply?
Nail matrix
What is the nail plate?
Nail you look at
Whats the hypochonium?
Attachment of nail
Area of transition between nail and nail bed
What are examples of viral infections to the skin?
Small poxs
Chicken pox
Measles
Herpes simplex
What are bacterial infections that affect the skin?
• Pimples • Acne • Chancre- gonorrhea and syphilis (STDs)
What are allergic reactions that affect the skin?
- Eczema
- Psoriasis
- Urticaria
What are allergic reactions that affect the skin?
- Eczema
- Psoriasis
- Urticaria
Why is the hair root concave?
the concavity conforms to the shape of the dermal papilla occupying it.
