Unit III Flashcards
The skin and its accessory skin structures make up the ___
integumentary system
The Functions of the Skin
- Organ of Protection
- The skin is an organ of regulation
- The skin is an organ of sensation
- Skin reduces water loss
- Excretes wastes
- The Skin serves as immune-competent system
Skin provides protection from mechanical impact and pressure, temperature variations, microorganisms, radiation and chemicals
Organ of Protection
___ is the precursor of vitamin D, which plays an essential role in the control of calcium and phosphorus metabolism
Cholesterol
___ produces 7-dehydrocholesterol (Cholesterol precursor)
Dermal Vitamin Synthesis
___ absorb calcium and promote bone growth, another name for Vitamin D3
Cholecalciferol (Vitamin D3)
___ binds in the kidney with Vitamin D binding protein for body utilization
Calcitriol
A steroid hormone its important role in regulating body levels of calcium and phosphorus, and in mineralization of bone
Calcitriol
senses heat or cold
thermoreceptor
senses “touch”
Meissner’s corpuscle
senses pain
nociceptor
senses “pressure”
pacinian corpuscle
Adhere cells to each other and to form a protective layer on the outside of the skin
keratin
Inform immune system for any microbes gaining entrance into the body
Langerhans cells
Detects, engulfs and destroys pathogens and apoptotic cells (cells that are no longer needed or are a threat to the organism)
Macrophage-like antigen of the epidermis
Found in the basal layer (stratum basale) of the skin, Responsible for forming tight junctions with the nerves of the skin
Keratinocytes
___ line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs
Epithelial cells
Layers of the skin
Epidermis
Dermis
Hypodermis
Upper most layer of the skin, A stratified epithelium, which protects like oropharynx that undergo wear-&-tear
Epidermis
Levels of the Epidermis
Stratum Basale
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum
Stratum Corneum
Forms a strong bond between epidermis and dermis, A single layer of cells which grow & divide
Stratum Basale
forms epidermal ridges like the
fingerprints
Stratum basale
___ is produced within the skin in cells called melanocytes and it is the main determinant of the skin color of darker-skinned humans
Melanin
The epidermis contains three specialized cells:
Melanocytes
Langerhans cells
Merkel cells
___ are melanin-producing neural crest-derived cells located in the bottom layer (stratum basale) of epidermis
Melanocytes
two types of melanin
Eumelanin
Pheomelanin
Types of eumelanin
Brown eumelanin
Black eumelanin
___ is a dark pigment that predominates in black and brunette hair
Eumelanin
Small amount of ___ in the absence of other pigments apparently causes blond hair
brown eumelanin
The more ___ in your skin, the darker your skin will be.
eumelanin
___ is a lighter pigment found in red hair, and is concentrated in the redder areas of the skin such as the lips
Pheomelanin
___ progressive destruction of melanocytes
Vitiligo
___ is the inability to produce melanocytes
Albinism
Help protect by keeping microbes from entering the body. They are like the air traffic controllers of the immune system
Langerhans cells
Produced by division of stratum basale, Contain dentritic
(Langerhans) cells for immune response
Stratum spinosum “Spiny”
Essential for light touch sensation
Merkel cells
Cells shrink until cytoskeleton (microfilaments,
intermediate filaments, and microtubules) stick out.
Stratum spinosum “Spiny”
Composed of keratin & keratohyalin (protein structure found in granules in the stratum granulosum of the epidermis)
Stratum granulosum “grainy”
Keratin fibers creates a tightly interlocked layer of cells during dehydration and surrounded by keratohyalin
Stratum granulosum “grainy”
Found in the thickened skin of the palms and soles, Contains cells that are clear and lack any internal structures and functions
Stratum lucidum “clear”
The exposed surface of the skin, Layers of dead cells that flattened and no longer have a nucleus
Stratum corneum “horn”
How long does it take for stratum corneum to shed and replace itself?
2 weeks
layers of the dermis
papillary
reticular
The upper layer, contains a thin arrangement of collagen fibers, supplies nutrients to select layers of the epidermis and regulates temperature
papillary layer
___ is composed of bundles of collagen that strengthens the skin, provide structure and elasticity, It also supports other components of the skin, such as hair follicles, sweat glands, and sebaceous glands
reticular layer
Structures found in the dermis include:
Connective tissue (collagen and elastin)
Blood capillaries
Lymph vessels
Sweat glands
Nerve endings
Hair follicles
provides the skin with structure and strengthening bones
Collagen
___ is a highly elastic protein in connective tissue and allows many tissues in the body to resume their shape after stretching or contracting
Elastin
___ helps skin to return to its original position when it is poked or pinched
Elastin
___ is the most abundant protein in the body
Collagen
It is the major component of connective tissues that make up several body parts, including tendons, ligaments, skin and muscles
Collagen
___ are the smallest of blood vessels
Capillaries
___ a fluid containing infection-fighting white blood cells, throughout the body
Transport lymph
the functions of the sweat glands
thermoregulation
excretion
Types of sweat glands
Exocrine glands
Apocrine
Merocrine or eccrine glands
Holocrine glands
___ are found in the more odorous parts of the body,
including the armpits, scalp and genital region
Apocrine sweat glands
The salivary glands are an example of this
merocrine glands
___ have the highest numbers of merocrine glands
Palms and soles
___ cells accumulate a secretory product like the sebum or oil with remnants of dead cell
holocrine glands
The body contains close to how many hair follicles?
two million hair follicles
The deepest and innermost layer of the three layers of skin, Made up of fat, connective tissue and well supplied with blood vessels
Subcutaneous or Hypodermic
It acts as a cushion during fall or the person hits something with the body
Subcutaneous or Hypodermic
Act as a passage-way for the blood vessels and nerves from the dermis of the skin into the muscles
Subcutaneous or Hypodermic
areas of the skin that are supplied by a single spinal nerve
dermatomes
the area of the skin that provides sensory input to the dorsal roots of a pair of spinal nerves
dermatomes
name all the dermatome regions
8 cervical (C1 - C8)
12 thoracic (T1 - T12)
5 lumbar (L1 - L5)
5 sacral spine nerves (S1 - S5)
are useful in neurology for finding the site of damage to the spine
dermatomes
The Accessory Structures of the Skin
Hairs and hair follicles
Skin Glands
Nails
Types of skin glands
Sebaceous
Ceruminous
Sweat
Mammary
Glands located next to the hair follicles produce sebum (oil) which keeps the skin soft, pliable, and waterproof
Sebaceous glands
Responsible for releasing earwax into the external ear
Ceruminous glands
Found in the female that produces milk for infants
Mammary glands
___ is a soft tissue that protects the emerging nail plate
Proximal nail fold
___ is the thickened layer of skin surrounding fingernails and toenails
Eponychium
(from latin word, meaning ‘little moon’), is the crescent-shaped whitish area of the bed of a fingernail or toenail
lunula, or lunulae
___ is the visible part of the root of the nail
lunula
___ has the function of protecting the distal phalanx, the fingertip, and the surrounding soft tissues from injuries. It also serves to enhance precise delicate movements of the distal digits through counter-pressure exerted on the pulp of the finger
Nail
Factors affecting skin penetration
- Age
- Skin Condition
- Hydration
- Fat content
- Physiologic and pharmacologic factors
The normal adult body temperature:
37 degrees Celsius
To control heat loss the blood cells can be controlled by the following:
Vasoconstriction
Vasodilation
narrowing of the blood vessels
Vasoconstriction
when the hypothalamus senses that the body temperature is too high, it sends impulses that cause blood vessels supplying the capillaries in the skin to dilate
Vasodilation
Body responses to heat
Vasodilation
Sweating
Pilorelaxation
Stretching out
Body responses to cold
Vasoconstriction
Shivering
Piloerection
Curling up
heat gained by warm air rising from the ground
convection
heat gained by contact
conduction
Process of losing heat through physical contact with another object or body
For example, if you were to sit on a metal chair, the heat from your body would transfer to the cold metal chair
Conduction
Process of losing heat through evaporation of sweat
Evaporation
Process of losing heat through the move-ment of air or water molecules across the skin
Use of fan or cooling system
Convection
This involves the transfer of heat from one object to another, with no physical contact involved
The sun transfers heat to the earth
Radiation
The air inhale is warmed by the body and saturated with water vapor, when one exhale, heat is lost
Respiration
Conditions can be the result of extreme body temperature:
- Hyperthermia
- Hypothermia
cancer characterized by the uncontrolled growth of melanocytes
Melanoma
___ is a chronic skin condition that produces plaques of thickened, scaling skin
Psoriasis
___ is a scar that goes hypertropic
keloid
___ results in a red, blistered rash that may wrap around the torso or appear anywhere on the body.
Shingles virus (herpes zoster)
___ is a common skin disorder that presents as a red, flaky rash
Eczema
___ are infection in the top layer of skin, caused by viruses in the human papillomavirus
Warts
