Chapter 5 Flashcards
What is skin’s main function?
Protection
What is another name for skin?
Integument
What are the 2 distinct regions for the integument?
- Epidermis
- Dermis
What is the epidermis?
The superficial region
Epithelial tissue
What is the dermis?
Underlies epidermis
Mostly consist of connective tissue
Strong and flexible
What is the hypodermis?
- subcutaneous layer deep to the skin
- not part of the skin
- mostly muscles and adipose tissue
What are the 4 cells of the epidermis?
- Keratinocytes
- Melanocytes
- Dendritic cell
- Tactile cells
Keratinocytes
- Produce keratin - fibrous protein
- most cells of epidermis
- tightly connected by desmosomes
Melanocytes
- 10-25% of cells in deepest epidermis
- produce melanin → packaged into melanosomes → responsible for skin color
Dendritic cells (langerhans)
- Immune cell
- macrophages - key activators of immune system
Tactile cells (merkel)
- Sensory touch receptors
What are the layers of the epidermis (superficial to deep?)
- Stratum corneum
* stratum lucidium ( only in thick skin e.g. Palms of hand or soles of feet) - Stratum granulosum
- Stratum spinosum
- Stratum basale
Stratum basale
- Deepest epidermal layer
- actively mitotic:
• produces 2 daughter cells - melanocytes compose 10-25% of this layer
Stratum spinosum
- Aka prickly layer
- several layers thick
-Present melanosomes and dendritic cells
Stratum granlosum
- 4-6 cell layers
- keratinization begins
- cells apical to this layer die
Stratum lucidium
- Clear layer
- Only in thick skin
- few rows of dead keratinocytes
Stratum Corneum
- 20-30 rows of dead, flat, anuclecte, keratinized sacs
- although dead, functions to protect deeper cell
What are the two layers of the dermis?
- Papillary
- Reticular
What is the papillae layer composed of?
- areolar connective tissue
- collagen fibers
- elastic fibers
- blood vessels
What is the dermal papillae?
- peglike projections
What is a fingerprint ridge called?
Friction ridges
This layer is deep to the papillary layer.
Reticular layer
What composes the reticular layer?
- Dense fibrous connective tissue
- elastic fibers
- collagen filers
• cleavage line
What are the dark lines an our fingers and hands?
Flexure lines
What are stretch marks known as?
Striae ( silvery white scars)
In striae what does the stretching cause?
Dermal tears
What is a blister?
Fluid filled pocket that separates the dermis and epidermis
What are the 3 pigments that contribute to skin color?
- Melanin
- Carotene
- Hemoglobin
What color das hemoglobin give off?
Pinkish fair skin
What color does carotene give off? Where does it accumulate?
-Yellow to orange
- stratum corneum and hypodermis
What color does melanin give off?
- Reddish-yellow
- brownish - black
What can stimulate melanin production?
Sun exposure
If diagnosed with cyanosis, what color wold the skin be and why?
Blue and due to low oxygen of hemoglobin
If diagnosed with erythema, what color would the skin be and why?
Red and due to : fever, hypertension, inflammation, allergy
If diagnosed with jaundice, what color would the skin be and why?
Yellow and liver disorder
If I detected bruising on the skin, what is happening?
Clothed blood beneath the skin
If I detected the bronzing of someone’s skin , what would be the issue?
Inadequate steroid hormones in addison’s disease
What are the derivatives of the epidermis?
- Hairs and hair follicles
- Nails
- Sweat glands
- Sebaceous glands
What is hair and its function?
Dead keratinized cells; protection, sensation, and warmth
What do hair pigments consist of?
Melanins & trichossiderin
The main regions of the hair follicles are?
Shaft& root
What is the function of the hair matrix?
Dividing area; mitotically active cells that produce hair
What is the function of the hair matrix?
Dividing area; mitotically active cells that produce hair
Arrector pilli
Smooth muscle attached to follicle
hair papilla
dermal tissue- blood supply
2 types of hair
Vellus and Terminal
What is vellus hair?
Pale and fine body hair of children and adult females
What is terminal hair?
-coarse. long hair of eyebrows & scalp that occur at puberty
What is the nail
protective cover for distal, dorsal surface of fingers and toes
What are sweat glands called?
Sudoriferous glands
Where are sudoriferous glands located?
all skin surfaces except nipples and external genitalia
About how many sudoriferous glands are present within the body?
3 million
What are two types of sudoriferous glands?
- Eccrine (merocrine)
2.Apocrine
Eccrine are the most ____ sweat glands
numerous
What are eccrine glands made up of?
99% water, salts, vitamin C, antibodies, dermcidin, and metabolic wastes
What is dermcidin?
antimicrobial agent
Where are eccrine glands commonly found?
Palms, soles, and forehead
Classification of eccrine glands would be:
active sweating
Apocrine glands are confined to which locations?
Axillary and anogenital areas
What are apocrine glands composed of?
Sweat, fatty substances, and proteins
Which sudoriferous gland causing odor?
Apocrine
Which sudoriferous gland is larger?
Apocrine
When does the apocrine gland begin functioning?
At puberty
What are two types of apocrine glands?
ceruminous and mammary
Where is the ceruminous gland? What does it produce/secrete?
lining of external ear canal; cerumen
Where is the mammary gland? What does is produce/secrete?
The breast/mammary area; milk
Where are sebaceous glands located? What do they produce/secrete?
Develop from hair follicles; secrete oily holocrine /bactericidal into hair follicles
What is the function of a sebaceous gland?
softens hair and skin
What gland also is not active until puberty?
Sebaceous glands
What stimulates sebaceous glands?
hormones and androgens
What are the functions of the Integumentary System?
1.Protection
2. Body temp regulation
3.Cutaneous sensation
4.Metabolic functions
5. Blood reservoir
6. Excretion
What are the 3 barriers in protection?
- Chemical
- Physical
- Biological
What is the function of chemical barriers?
To detour pathogens
What is melanin’s function?
Defense against UV radiation damage
What do biological barriers do?
Cells that actively defend
What are 2 biological barriers
dendritic cells to the epidermis
macrophages to dermis
What is another biological barrier having to do with genetic material?
DNA: electrons absorb UV rays
Rays convert to heat
What is normal body temperature classified as?
Insensible perspiration
If your body temperature increases, what is that due to and What is it called when the body is being cooled down?
- Dilation of dermal vessels and increased sweat glands
- sensible perspiration
What is the function of the cutaneous sensation?
Sensory receptor that detects temperature, touch, and pain
What is the metabolic function?
Synthesis of Vitamin D
What are the steps of Vitamin D synthesis?
Sunlight → cholesterol molecules converted to Vitamin D precursor → transported by blood
What element is the metabolic function essential for?
Calcium
How much of the body’s blood volume is stored in the blood reservoir?
5%
What is excretion?
Nitrogenous waste and salt in sweat
A (blank) causes tissue damage by what?
Burn; heat, electricity, radiation, certain chemicals
A burn is a homeostatic imbalance (T/F)
True
What is the immediate threat a burn causes?
Dehydration and electrolyte imbalance
How are burns evaluated?
- Body divided into 9’s
Burn classifications by severity
- First degree
- Second degree
- Third degree
What are the 2 burns that are partial thickness burns?
First and Second degree
What burn is classified as full thickness burn?
Third degree
What part of the skin does the first degree damage? Examples?
Epidermis; redness, edema, pain
What part of the skin does the second degree damage? Examples?
Epidermis and some dermis damage; blisters
What part of the skin does the third degree damage? Examples?
The entire dermis and epidermis; skin gray white, chewy red, or blackened; no swelling
When is a burn classified as critical?
- 25% of body has second degree burns
- Third degree burns present
What are different treatments for burns?
- Debridement
- Antibiotics
- temporary covering
- skin grafts
