Anatomy and Physiology Part 2 Flashcards
What are the derm specific glands?
- Endocrine glands
- Exocrine glands
- Derm specific exocrine glands
What are the two derm specific exocrine glands?
- Sebaceous
- Sudoriferous (sweat glands)
What is the function of sebaceous glands?
- Opens into a hair follicle and secretes oily/waxy sebum
- Found in all areas except palms of hand and soles of feet
- Secretion works in conjunction with apocrine glands in thermoregulation
What are some general facts about eccrine sudoriferous glands?
- Cover nearly entire body
- Empty directly onto skin surface
- Major thermoregulator
- Dilute electrolyte solution (H2O, NaCl)
What are the two types of sudoriferous glands?
- Eccrine
- Apocrine
What is the function of apocrine sudoriferous glands?
- Largely confined to axillae, perineum, and concentrated in hairy areas
- Attached to hair follicle
- Apocrine sweat is cloudy, viscous, and initially odorless
- Do not become functional until puberty
What are the different parts of the nail?
- Free edge
- Nail body(plate)
- Lunula
- Cuticle
- Nail bed
- Nail root
- Nail matrix
What is the function of nails?
- Protect distal phalanxes and surrounding soft tissue
- Enhance precise and delicate finger movements
- Enables “extended precision grip”
What is nail growth dependent on?
- Age
- Sex
- Season
- Exercise level
- Diet
Fingernail/toenail growth time?
- Finger: 3.5 mm/month and 3-6 months for full regrowth
- Toes: 1.6 mm/month and 12-18 months for full regrowth
What will make skin appear blueish or cyanotic?
Lack of oxygen
What will make the skin appear yellow?
Jaundice
- Due to buildup of yellow pigment bilirubin, indicated liver disease
What makes the skin appear red/Erythema?
Engorgement of capillaries in the dermis with blood
- Due to skin injury, exposure to heat, inflammation, or allergic reaction
What will make the skin appear pale/pallor?
Shock and anemia
What are the three main pigments that influence skin pigmentation?
- Melanin (epidermis)
- Carotene (dermis)
- Hemoglobin (RBC’s within capillaries of dermis)
What does a high melanin rate do to skin tone?
Darker brown to black skin tones
What does a high carotene rate do to skin tone?
Yellow to reddish skin tones
What does a high hemoglobin rate do to skin tone?
Red to pinkish tones
What number are the same regardless of skin tone?
Melanocytes
What are some facts about melanin?
- Primary determinant of skin, hair, and eye color
- High levels of melanin = darker skin
- Low levels of melanin = lighter skin
- Causes skin to very from pale yellow to reddish-brown to black
What are carotenoids?
Yellow colored, lipid soluble compounds found in red, orange, yellow, and green vegetables and fruit
What is carotenemia?
Yellow-orange discoloration of skin from consuming large quantities of carotenoids
What are some facts about hemoglobin?
- Iron containing oxygen transport protein in RBC’s (erythrocytes)
- Sudden drop in oxygenation causes pallor
What are some facts about UV light and skin color?
- UV light exposure stimulates melanin production
- Increase of melanin is adaptive protective function
- UV overexposure is predisposing factor for skin cancer
What is albinism?
- Genetic condition characterized by little or no melanin pigment in eyes, skin, or hair
What are the main health concerns in albinism?
- Sunburns easily during UV exposure
- Increased risk for skin cancer
What is vitiligo?
- Acquired depigmentation of the skin characterized by loss of melanocytes
- Autoimmune disorders
What are the functions of the skin?
- Temperature regulation
- High Protection
- Cutaneous Sensation
- Excretion/Absorption/Synthesis
How does the skin function in terms of temperature regulation?
- Homeostatic temperature regulation occurs through sweating (evaporation) or flow of blood (radiation)
How does keratin (protein) in the skin help with protection?
Protects against microbes, abrasion, heat, water loss, and chemicals
How does lipids (fat) in the skin help with protection?
Inhibit the evaporation of water from the skin surface and prevents dehydration
How does melanin (pigmentation) in the skin help with protection?
Provides protection against damaging effects of UV lights
How does sebum (Fat, wax esters, and fatty acids) in the skin help with protection?
Prevent hair from drying out, are mildly bactericidal and have acidic pH
What are the three cutaneous sensations?
- Tactile (exteroceptors)
- Thermal sensations
- Pain
What are the three different types of exteroceptors (tactile sensations)?
- Touch (mechanoreceptors)
- Pressure (baroreceptors)
- Vibration (Meissner corpuscles)
What are the two different types of thermoreceptors (thermal sensations)?
- Warmth
- Coolness
What is the pain sensation?
Impending or actual tissue damage
* Nociceptors *
How does the skin function in regards to Excretion/Absorption/Synthesis?
- Small role in excretion
- Can absorb a wide variety of substances readily
- Synthesis of vitamin D
How does the skin function in the synthesis of vitamin D?
- Exposure to UV light activates vitamin D
- Vitamin D is converted to calcitriol which aids in absorption of calcium and phosphorus
What are the 5 signs of inflammation?
- Localized hypothermia
- Erythema
- Localized edema
- Pain
- Loss of function
What are the three derm inflammation patterns?
- Granulomatous inflammation (cystic)
- Suppurative inflammation (abscesses)
- Ulcerative inflammation (ulcers)
What is granulomatous inflammation (cystic) characterized by?
Formation of granulomas and is common in certain diseases (Tuberculosis, leprosy, syphilis)
What is a granuloma?
- Aggregation of of macrophages form from chronic inflammation
- Immune system attempts to isolate foreign substances that it cannot eliminate
What is suppurative inflammation (abscesses) characterized by?
Presence of an amorphous mass (abscess) composed of active neutrophils, cellular debris, and microbes
- Generally caused by certain pyogenic bacteria (Staph)
What is ulcerative inflammation (ulcers) characterized by?
Occurs near the epithelium that results in necrotic loss of surface tissue that exposes lower layers
What is intrinsic aging?
Inevitable physiological changes of the skin that occur with time and are influenced by genetic and hormonal factors
What is extrinsic aging?
- Preventable structural and functional changes of skin that occur with exposure to:
- Environmental factors
- Lifestyle (tobacco, ETOH, illicit drugs)
- Social determinants
- Elective cosmetic surgeries
- Most important preventable source is UV radiation exposure
What happens with epidermal aging?
- Occurs between age 30-80
- Epidermal turnover rate decreases
- Overall thinning
- Decrease in number/function of melanocytes
- Reduction in number/responsiveness of langerhans cells
What happens with dermal aging?
- Reduction of collagen fiber production enhances rate/amount of UV exposure
- Reduction of elastin fiber decreases elastic recovery and resilience
What are the two separate processes of tissue repair?
- Regeneration
- Replacement
What is the regeneration process of tissue repair?
- Damaged tissue is completely restored
- Can happen continously
What is the replacement process of tissue repair?
Severely damaged or non-regenerable tissue is repaired by laying down connective tissue resulting in scaring
What is the epithelial tissue repair rate?
Most rapidly regenerating and repairing tissue and has capacity for continual renewal
What is connective tissue repair rate?
- Adequate renewal capacity
- Prone to hyperproliferation (scaring)
What is muscular tissue repair rate?
- Relatively poor capacity for renewal
- Tissue does not divide rapidly enough to replace extensively damaged muscle fibers
What is nervous tissue repair rate?
Poorest capacity for renewal because it does not undergo mitosis to replace damaged neurons
What happens during the inflammatory phase of skin healing?
- 1-3 days post injury
- Serves mainly to clear bacteria and debris from wound and to prepare wound environment for repair
- Platelet and fibrin clot forms in injured space
- Mast cells release chemical mediators causing local capillary vasodilation
What happens during the proliferating phase of skin healing?
- 2-10 days post injury
- Purpose: to construct granulation tissue to fill the defect
- Fibroblasts are major cellular agent
- Collagen provides contractile force to reduce surface area
What happens during the early remodeling phase of skin healing?
- 2-3 weeks post injury
- Tissue defect replaced with granulation tissue and new epithelial cells
What happens during the late remodeling phase of skin healing?
- months to >1 year
- Type III collagen replaced by type I collagen and collagen fibrils
- Over time collagen becomes scar
What is healing by primary intention?
- Relying on dermal edges that are close together and easily approximated
- Ex: sutures, staples, dermal adhesive
What are the pros of healing by primary intention?
Most often results in complete return to function with minimal scarring and loss of skin appendages
What are the cons of healing by primary intention?
- Requires relatively clean wounds
- Easily mismanaged
- Potential for scarring and poor cosmetic due to patient non-compliance
What is healing by secondary intention?
Relies on formation of granular tissue to fill space between wound edges or opening
What are the pros of healing by secondary intention?
- Decrease chance of wound infection by allowing exudate drainage from wound
- Closure of choice when dealing with large wound made by infection
What are the cons of healing by secondary intention?
- Wounds take much longer to heal
- Greater likelihood of scar formation
- Wounds must be regularly re-examined
