integumentary system Flashcards
what is the integumentary system is composed of:
-Skin
-Hair
-Nails
-sweat glands
-Sebaceous glands
-Mammary glands
what are the functions of the skin?
- Thermoregulation
- Blood reservoir
- Protection
- Cutaneous sensations
- Excretion and absorption
- Synthesis of vitamin D
what is gross anatomy of te integumanetary systen
- large organ composed of all 4 tissues
- 22 sq feet
- 0.5 mm - 5.0 mm thick
- thicker on feet and palms - weights approximately 10 LBS
what are the two layers of the skin?
- epidermis is epithelial tissue only (can see)
- dermis is a layer of connective tissue, never & muscle
what is subcutaneous tissue?
- Sub Q, hypodermis is a layer of adipose and areolar tissue
what is the cutaneous membrane made out of?
- epidermis (thin)
- dermis
what are the accessory structures?
- hair follicles
- exocrine glands
- nails
what is the overall structure of the integumentary system
- cutaneous membrane
- epidermis
- superficial epithelium - Dermis
- underlying connective tissue
- deep to fermis is the hypodermis
- also known as sub q - hypodermis
what is the function of the epidermis
- Protects dermis from
trauma, chemicals - Sensory receptors
detect touch, pressure,
pain, and temperature - Synthesizes vitamin D
- Prevents entry of
pathogens - Controls skin
permeability, and
prevents water loss
What is the function of the hair follicles?
- Produce hairs that
provide delicate
touch sensations
on general body
surface - produce hairs that protect the skull
what is the function of exocrine glands?
- assists in thermoregulation
- excrete waste
- lubricates epidermis
What is the function of the nails?
- protect and supports tips and fingers and toes
overview of epidermis?
- Stratified squamous epithelium
- Contains no blood vessels
- 4 types of cells
- 5 distinct strata (layers) of cells
what are the layers of the epidermis
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
-Stratum basale
COME
LETS
GET
SUN
BAKED
what are the cells of the epidermis
- Keratinocytes–90%
- produce keratin - Melanocytes—–8 %
- produces melanin pigment
- melanin transferred to other cells with long cell processes - Langerhan cells
- from bone marrow
- provide immunity - Merkel cells
- in deepest layer
- form touch receptor with sensory neuron
what does the stratum Basale
- Deepest single layer of cells
- Called stratum germinativum
- Combination of merkel cells, melanocytes, keratinocytes & stem cells that divide repeatedly
- Cells attached to each other & to basement membrane by desmosomes & hemidesmosomes
what’s in the second layered the Stratum spinosum
- 8 to 10 cell layers held together by desmosomes
- During slide preparation, cells shrink and look spiny
- Melanin taken in by phagocytosis from nearby melanocytes
what’s in the stratum grandulosum
- 3 - 5 layers of flat dying cells
- Show nuclear degeneration
- Contain dark-staining keratohyalin granules
- Contain lamellar granules that release lipid that repels water
what’s in the stratum lucidum
- Seen in thick skin on palms & soles of feet
- Three to five layers of clear, flat, dead cells
- Contains precursor of keratin
what’s in the Stratum Corneum?
- 25 to 30 layers of flat dead cells filled with keratin and surrounded by lipids
- Continuously shed
- Barrier to light, heat, water, chemicals & bacteria
- Friction stimulates callus formation
what is the process of keratinzation & epidermal growth
- Stem cells divide to produce keratinocytes
- As keratinocytes are pushed up towards the surface, they fill with keratin
- 4 week journey unless outer layers removed in abrasion
- Hormone EGF (epidermal growth factor) can speed up process
what are skin grafts?
- New skin can not regenerate if stratum basale and its stem cells are destroyed
- Skin graft is covering of wound with piece of healthy skin
- autograft from self
- isograft from twin
- autologous skin
- transplantation of patients skin grown in culture
what layer of skin cannot regenerate if damaged?
- stratum Basale
- & it’s stem cells
what are the two major regions of the dermis?
- papillary region
- reticular region
what is the dermis composed of?
- Connective tissue layer composed of collagen & elastic fibers, fibroblasts, macrophages & fat cells
- Contains hair follicles, glands, nerves & blood vessels
what is the papillary region composed of?
- Top 20% of dermis
- Composed of loose CT & elastic fibers
- Finger like projections called dermal papillae
what is the function of the papillary region?
Functions:
- anchors epidermis to dermis
- contains capillaries that feed epidermis
- contains Meissner’s corpuscles (touch) & free nerve endings (pain and temperature)
what is the reticular region composed of?
- Dense irregular connective tissue
- Contains interlacing collagen and elastic fibers
- Packed with oil glands, sweat gland ducts, fat & hair follicles
- Provides strength, extensibility & elasticity to skin
- stretch marks are dermal tears from extreme stretching
- Epidermal ridges form in fetus as epidermis conforms to dermal papillae
- fingerprints are left by sweat glands open on ridges
- incase grip of hand
How do wrinkles occur?
- The interwoven collagen fibers provide tensile strength
- The elastic fibers allow the skin to stretch and recoil
Skin wrinkles are due to:
- Age
- Change in hormone levels
- UV light
what makes stretch makers occur?
- Extensive stretching during pregnancy (or excessive weight gain) can cause reticular fibers to break
- The skin does not recoil
- The skin wrinkles and creases, resulting in stretch marks
what are tension lines? and where are they located
- they are located in the dermis
- Collagen and elastic fibers have a tendency to organize themselves in a parallel pattern
- In certain areas of the body, there is a pattern of cleavage lines due to stress or a specific type of movement
- To reduce scar formation (extensive damage to the fibers), surgeons try to cut parallel to the lines of cleavage
How is melanin produced in the epidermis?
- Melanin produced in epidermis by melanocytes
- same number of melanocytes in everyone, but differing amounts of pigment produced
- results vary from pale yellow to red to tan to black
- melanocytes convert tyrosine to melanin
- UV in sunlight increases melanin production
what is the function of carotene in the dermis?
- yellow-orange pigment (precursor of vitamin A)
- found in stratum corneum & dermis
what is the function of hemoglobin in the dermis?
- red, oxygen-carrying pigment in blood cells
- if other pigments are not present, epidermis is translucent so pinkness will be evident
why do patients turn jaundice
- yellowish color to skin and whites of eyes
- buildup of yellow bilirubin in blood from liver disease
why do patients turn cyanotic?
- bluish color to nail beds and skin
- hemoglobin depleted of oxygen looks purple-blue
what is erythema
- redness of skin due to enlargement of capillaries in dermis
- during inflammation, infection, allergy or burns
what are accessory structures of the skin?
- Epidermal derivatives
- Cells sink inward during development to form:
- hair
- oil glands
- sweat glands
- nails
What is the structure of the hair?
- Shaft – visible
- Root – below the surface
- Follicle surrounds root
- external root sheath
- internal root sheath
- base of follicle is bulb
- blood vessels
- germinal cell layer
what is the arrector pili in the hair?
- smooth muscle in dermis contracts with cold or fear.
forms goosebumps as hair is pulled vertically
what is the hair root plexus?
- detect hair movement
what is the cycle of hair growth?
- Growth cycle = growth stage & resting stage
- Growth stage :
- lasts for 2 to 6 years
- matrix cells at base of hair root producing length
Resting stage:
- lasts for 3 months
-matrix cells inactive & follicle atrophies
- Old hair falls out as growth stage begins again
- normal hair loss is 70 to 100 hairs per day
What is hair color produce from?
- Result of melanin produced in melanocytes in hair bulb
- Dark hair contains true melanin
- Blond and red hair contain melanin with iron and sulfur added
- Graying hair is result of decline in melanin production
- White hair has air bubbles in the medullary shaft
What are the function of the hair?
- Prevents heat loss
- Decreases sunburn
- Eyelashes help protect eyes
- Touch receptors (hair root plexus) senses light touch
what are the glands of the skin:
- Specialized exocrine glands found in dermis
- Sebaceous (oil) glands
- Sudiferous (sweat) glands
- Ceruminous (wax) glands
- Mammary (milk) glands
what is the function of sebaceous gland?
- Secretory portion in the dermis
- Most open onto hair shafts
- Sebum:
- combination of cholesterol, proteins, fats & salts - keeps hair and skin from soft & pliable - inhibits growth of bacteria & fungi(ringworm)
where does acne come from
Acne:
- bacterial inflammation of glands
- secretions stimulated by hormones at puberty
what is the faction ceruminous glands?
- Modified sweat glands produce waxy secretion in ear canal
- Cerumen contains secretions of oil and wax glands
- Helps form barrier for entrance of foreign bodies
- Impacted cerumen may reduce hearing
what are the function of nails?
- Tightly packed, keratinized cells
- Nail body is pink due to underlying capillaries
- Lunula appears white due to thickened stratum basale in that area
- Cuticle (eponychium) is stratum corneum
- Nail matrix deep to the nail root is the region from which the nail growth occurs
- Growth is 1mm per week–faster in summer & on most-used hand
what is the structure of nails?
- Tightly packed keratinized cells:
- Nail body
- visible portion pink due to underlying capillaries
- free edge appears white
Nail root:
- buried under skin layers
- lunula is white due to thickened stratum Basale
- Eponychium (cuticle)
- stratum corneum layer
how does nail grow?
- Nail matrix below nail root produces growth
- Cells transformed into tightly packed keratinized cells
- 1 mm per week
what are the 2 different types of skin?
- thin skin
- thick skin
what are the features of thin skin?
- covers most of body
- thin epidermis (.1 to .15 mm.) that lacks stratum lucidum
- lacks epidermal ridges, has fewer sweat glands and sensory receptors
what are the features of thick skin?
- only on palms and soles
- thick epidermis (.6 to 4.5 mm.) with distinct stratum lucidum & thick stratum corneum
- lacks hair follicles and sebaceous glands
what is the first degree burn like?
- it burned the epidermis
- ex: sunburn
what does a second degree burn look like?
- burned of the epidermis or dermis bc it has been split
- is composed of blisters
what does a tired degree burn look like?
- composed of burned tissue, epidermis, dermis, and subcutaneous tissue (muscle or bone)
- skin turns black
what are the rules of 9 for burns?
- anterior and posterior head and neck is 9%
- anterior and posterior shoulders, arms, forearms and hands is 18%
- anterior and posterior trunk 36%
- anterior and posterior thighs, legs, and feet are 36%
- peritoneum is 1%
what is a parenteral injections?
- Injected under the skin
Fastest route of administration
More blood supply, the faster the absorption
Faster in muscle than in fat
IM, ID, Sub-Q, IV
what is a Intramuscular Injections (IM) injections?
Given into the muscle when:
1) drugs irritate the SubQ,
2) need rapid absorption,
3)large volume of medication is injected
- Angle of insertion is 90 degrees
- 22-23 Gauge
- 1- 11/2 inches
- Usually hold 3 ml
- Aspirate
- Massage after withdraw
- Examples include Pcn, Demerol
what are some of the common IM sites?
- Vastus Lateralis (thigh- greater trochanter and patella)
- Dorsogluteal (gluteus- greater troachanter and posterior illiac spine—WATCH for sciatic!)
- Ventrogluteal (gluteus- greater trochanter, index finger pointed to anterior illiac spine and make triangle)
- Deltoid (arm – 2-3 fingers
below the acromion process)
what is the z- track pertaining to injections?
- IM injection that prevents leakage of medication into upper tissues
- Upper tissues are displaced laterally before introduction of the needle and meds- held for 10 sec. after the needle is removed, then release
- Use in gluteus
- ASPIRATE
- DO NOT MASSAGE!
What is a Subcutaneous (Sub Q) injection? and where is it injected into?
- Given below the skin into the adipose tissue
- Chosen when there is a slower required effect
- 25-26 Gauge
- 5/8 inch
- 3 ml
- Angle 45 degrees (except heparin & insulin=90)
- ASPIRATE!
- MASSAGE- except for heparin and insulin
- Given in deltoid, thigh, and abdomen
- Example is insulin
What is an intradermal (ID) injection?
- Given within the skin
- Small wheal is usually raised
- 27-28 Gauge
- 3/8 inch
- 1 ml
- Angle is 15 degrees (almost parallel to skin!)
- Do not ASPIRATE or MASSAGE!
- Forearm, upper arm, and upper back
- Examples are allergy skin tests and TB
