Ch 1 A & P Flashcards
Generates the physical force to make the body structures move
Arranged in bundles
Contractile cells that provide the ability to move the body in three dimensions
Well supplied with blood vessels (lots of energy and waste requirements)
Muscle Tissue
Detects changes inside/outside the body
Initiates and transmits nerve impulses that coordinate body activities and help maintain homeostasis
Nervous Tissue
Integumentary system is comprised of:
Skin, Hair, Nails
Accessory structures
Covers body surfaces; lines body cavities, hollow organs, and ducts; and forms glands
Epithelial Tissue
Medical term for skin and main portion of the integumentary system
Epithelium
Protects and supports the body and its organs
- Binds organs together
- Stores energy reserves as fat
- Provides immunity
Connective tissue
Provide contact or adhesion between neighboring cells or between a cell and extracellular matrix
Maintain paracellular barrier of epithelia and control transport of materials or signals between cells
Cell Junctions
Cell junctions are dense in _______ tissues because the needs to maintain both strength and integrity in a wide variety of conditions
Epithelial
Form a barrier against water and antigens passing between individual epithelial cells
Tight Junctions
Cell-to-cell adhesions continuously assembled and disassembled so cells can respond to changes in their microenvironment
Adherens Junctions
Form stable adhesion junctions between cells
Desmosomes
Allows various molecules and electrical signals to pass freely between cells
Gap junctions
Facilitate the stable adhesion of basal epithelial cells to the underlying basement membrane
Hemidesmosomes
Two broad categories of epithelial tissue
Covering & Lining epithelium
Glandular epithelium
Covers external surfaces of the body and some internal organs
Lines body cavities, blood vessels, and ducts
Lines interior of respiratory, GI, urinary and reproductive systems
Integral part of sense organs for hearing, vision and touch
Covering and lining epithelium
Secreting portion of the glands, such as sweat glands
Glandular epithelium
Most superficial layer of cells
Apical layer
Deepest layer of the cell
Basal layer
Thin extracellular structure composed mostly of protein fibers
Located between the epithelium and underlying connective tissue layer
Helps to bind and support the epithelium
Basement membrane
Two ways of classifying epithelial tissue
Morphology
Stratification
Classification of epithelial cells based on shape
Morphology
Classification of epithelial cells based on number of layers
Stratification
Thin, flat shape allows rapid passage of substances through them
Can be keratinized or non-keratinized; wet or dry depending on their location
Squamous epithelium
Found in areas such as the lining of the esophagus, mouth and cervix
Squamous Epithelium
Tall as they are wide and shaped like cubes or hexagons
Frequently have microvilli at apical surface
Function in either secretion of absorption
Cuboidal epithelium
Found in areas such as the salivary glands and thyroid follicles
Cuboidal epithelium
Taller than they are wide
Protect underlying tissues
Apical surfaces may have cilia or microvilli
Often specialized for secretion and absorption
Columnar epithelium
Lines most organs of the GI tract, respiratory tract, and fallopian tubes
Columnar epithelium
Able to change shape from flat to cuboidal and back depending on tension and distention of tissue
Useful for organs such as the urinary bladder, when it is stretching (distend) to a larger size and as it collapses to a smaller size
Transitional epithelium
A single layer of cells that functions in a diffusion, osmosis, filtration, secretion and absorption
Simple epithelium
Simple epithelium that appears to be stratified because the nuclei lie at different levels and not all cells reach the apical surface
Pseudostratified epithelium
Specialized type of pseudostratified cells that secrete mucus and are an integral part of mucous membranes
Goblet cells
Cilia provide two forms of locomotion depending on the cell
Movement of the cell itself
Movement of particles or substance across or around the cell
Increase the surface area of a cell by multiplying the area from 2 dimensions to 3 dimensions
Enable the absorption and secretion of far more nutrients/material
Microvilli
Help anchor sperm to the egg and allow for easier fertilization
Act as an anchoring point and aid in the migration of WBCs
May sweep unwanted materials toward an absorptive area of the cell
Microvilli
Highly-insoluble fibrous protein with water proofing qualities and high friction resistance
Keratin
Epithelial cells infused with keratin in the stratum basale of the epidermis
Keratinocytes
Lose their nucleus and organelles to make room for keratin; they are no longer living cells
Keratinocytes
Found on wet/interior surfaces exposed to considerable wear and tear
Lining of mouth cavity, tongue, pharynx, esophagus, and vagina
Non-keratinized epithelium
Found on dry/outer surfaces where resistance to both friction and water is needed
Outer epidermis consists of keratinocytes that provide protection against water, friction, abrasion, and microorganisms
Keratinized stratified epithelium
Supports and physically connects other tissues/cells together to form the organs of the body
Connective tissue
More cells; Less extracellular space
Epithelial tissue
Less cells; More extracellular space
Connective Tissues
Three components of connective tissue
Resident cells
Extracellular Matrix
Protein fibers
Extracellular material produced by the connective tissue cells embedded within it.
Major component is ground substance crisscrossed by protein fibers
Matrix
Most common cells in connective tissue
Produce and maintain most of the tissue’s extracellular components
Synthesizes and secretes collagen and elastin
Fibroblasts
Fat cells or adipose cells or adipose tissue
Specialized for cytoplasmic storage of lipid as neutral fats, or less commonly for production of heat
Large population serves to cushion and insulate the skin and other organs
Adipocytes
Components of loose connective tissues, often located near blood vessels in the skin
Function in localized release of compounds important to inflammatory response, innate immunity, and tissue repair
Mast Cells
Most abundant protein in the body (25% of all protein)
Very strong and resistant to shear forces
Key element of all connective tissues, as well as epithelial basement membranes
Collagen fibers
Composed of elastin
Strength and elasticity
Have rubberlike properties that allow tissue containing these fibers to be stretched or distended and return to their original shape
Elastic fibers
Where are elastic fibers found?
Stroma of the lungs
Composed of glycogen and glycoprotein
Provide strength and support in the walls of small blood vessels
Supporting framework of many soft organs; most notably the immune system, liver, endocrine glands, spleen and lymph nodes
Reticular fibers
Lines entire GI, respiratory, reproductive, and much of the urinary system
Epithelial layer secretes mucous via goblet cells
- Prevents cavities from drying out
- Traps particles in the respiratory tract
- Lubricates and absorbs food as it moves through the tract, secretes digestive enzymes
- Helps bind the epithelium to underlying structures
Mucous membranes
Lines body cavity that doesn’t open directly to exterior and covers organs that lie within the cavity
Includes parietal, visceral, mesothelium, pleura, pericardium, peritoneum
Serous membranes
Lines joints
Composed of areolar connective tissue and adipose tissue with collagen fibers
No epithelial layer
Synovial membranes
Reduces frictions, lubricates and nourishes cartilage, and removes microbes/debris from the joint
Synovial fluid
Surface layer
Comprised of epithelial tissue
Epidermis
Lies inferior/deep to the epidermis
Comprised of connective tissue
Dermis
Lies inferior/deep to the dermis
Not part of the skin
Subcutaneous
Epidermis primarily consists of:
Continually regenerating keratinocytes
Lifecycle of keratinocytes
30 days
Thickness of eyelids
75-150 micrometers
Thickness of palms and soles
0.4 to 1.5 mm
Epidermis lacks any vascular structures and obtains all nutrients from the dermal vasculature by ________
Diffusion
Epidermis Layer
- Cells consist mostly of keratin
- Cells are shed and replaced from below
Stratum Corneum
Epidermis Layer
-Found only in palms and soles of hands and feet
Stratum Lucidum
Epidermis Layer
- Losing cell organelles and nuclei
- Infusion of waterproofing lipids
Stratum Granulosum
Epidermis Layer
-Cells beginning to flatten
Stratum Spinosum
Epidermis Layer
-Stem cell layer, new cells arise here
Stratum Basale
Layer of skin located between the epidermis and subcutaneous tissues
Dense irregular connective tissue and functions to cushion the body from stress and strain
Dermis
What always occurs between the stratum basale of the epidermis and dermis?
Basement membrane
Nutrients from keratinocytes diffuse into the avascular epidermis from the dermal vasculature through the _______ ________
Basement membrane
Layer of dermis directly underneath the epidermis
Papillary layer (loose areolar tissue)
Thicker than the overlying papillary dermis; comprised of a dense concentration of collagenous, elastic, and reticular fibers that weave throughout it
Reticular layer
Protein fibers of this layer give the dermis its strength, extensibility, and elasticity
Contains the roots of the hair sebaceous glands, sweat glands, receptors, nails, and blood vessels
Reticular layer
Specialized cells of the epidermis and hair follicle; primary function is synthesis and transfer of melanin to adjacent keratinocytes
Melanocytes
Melanin synthesis occurs in this specialized organelle
Melanosome
Melanocyte numbers are similar in individuals of different races.
Differences of pigmentation result from:
Amount and quality of melanin in the skin
Typically found in the stratum spinosum
Form a mobile and dense network of cells that samples any antigens that attempt to pass through the epidermis
These monocyte-derived cells represent a large part of the skin adaptive immunity
Dendritic Cells
Hair is comprised of ____ ______ cells surrounded by the hair follicle
Fused Keratinized
Largely determines pattern/distribution of hair
Genetic/Hormonal influences
Protection from the Scalp, Eyes, and Nostrils
Hair
Release secretions directly into the bloodstream
Endocrine glands
Release secretions onto an epithelial surface via a duct
Major role in Derm
Exocrine glands
Derm-specific glands:
Sebaceous
Sudoriferous (sweat glands)
An exocrine gland in the skin that opens into a hair follicle and secretes an oily/waxy sebum
Sebaceous Glands
Lubricates the hair in humans and other mammals
Sebum
Found in all areas of skin except the palms of hands and soles of feet
Sebaceous glands
Sebaceous secretions work in conjunction with ______ glands in thermoregulation
Apocrine
Helps emulsify the sweat produced by the eccrine glands and this produces a sheet of sweat that is not readily lost in drops of sweat
Sebum
In colder conditions sebum becomes more _____, coats the hair and skin and helps repel water
Lipid
Cover nearly the entire body surface; especially dense of the palms, soles, forehead, and upper limbs
Empty directly onto the skin surface, not from hair follicles
Eccrine Glands
Serves as major thermoregulation component of the integumentary system
Minimal odor from sweat
Eccrine Glands
Sweat is a dilute electrolyte solution comprised of:
H2O
NaCl
Minimal waste product
Different sudoriferous glands
Eccrine glands
Apocrine glands
Largely confined to the axillae, perineum, and concentrated in hairy areas
Attached to the hair follicle; sweat empties onto the skin via the follicle opening
Sweat is cloudy, viscous, and initially odorless. Serves as a nutrient source for microbes and has an odor.
Do not become functional until puberty
Apocrine Glands
Distal margin of nail plate
Free edge
Portion of the nail that is visible; colored pink because of underlying capillaries
Surrounded by a soft tissue border known as the lateral and proximal nail folds
Nail body (plate)
Visible part of the matrix; whitish crescent at base of nail plate
Lunula
Semi-circular layer of epithelial cells (covering the proximal portion of nail plate
Cuticle
Thickened area of stratum carenum beneath the free edge that attaches the free edge to the fingertip
Nail bed
Portion of the nail that is not visible
Nail root
Proximal portion of the epithelium deep to the nail root where new nail cells are produced
Nail matrix
Nail functions
Protects
Enhances precise and delicate finger movements with counter-pressure
Extended precision grip
Nail growth rate is highly dependent on:
Age
Sex
Season
Exercise level
Diet
Other factors
Fingernails grow approx. ___ mm per month
Take ___ months to regrow completely
3.5 mm
3-6 months
Toenails grow approx. ___ mm per month
Require ___ months to regrow completely
1.6 mm
12-18 months
Pallor or paleness may occur in condition such as:
Shock
Anemia
Three main pigments that influence skin pigmentation
Melanin (epidermis)
Carotene (dermis)
Hemoglobin (red blood cells within capillaries of dermis)
High melanin rate =
Darker brown to black skin tones
High carotene rate =
Yellow to reddish tones
High hemoglobin rate =
Red to pinkish tone
Primary determinant of skin color, hair color and eye color
Melanin
Yellow colored, lipid-soluble compounds found in red, orange, yellow and green vegetables and fruit
Carotenoids
Excessive intake of foods that characterizes the skin to be yellow-orange
Carotenemia
Skin turned to yellow orange discoloration from Carotenemia can return to normal with:
Dietary Modifications
Sudden drop in oxygenation can change the skin color
initially: _______ and prolonged: _____
Pallor initially
Cyanotic prolonged
Stimulates melanin production; increasing both the amount and darkness of the melanin pigment imparted into the epidermis
UV Light Exposure
Protects the skin against UV radiation damage
Melanin
Predisposing factor for skin cancer
UV overexposure
A genetic (recessive-inherited) condition characterized by little or no melanin pigment in the eyes, skin or hair
Affects people of all races
Albinism
Main health complications for Albinism
Sunburns
Increased risk for cancer
Acquired depigmentation the skin characterized by loss of melanocytes
Affects 0.5-1.0%
Systemic autoimmune disorder in which antibodies attack the melanocytes
Vitiligo
Tattoos
Macrophages containing the pigment in the papillary dermis are trapped in the ______ matrix, forming a homogenized layer below the dermal/epidermal boundary
Collagen matrix
Homeostatic temperature regulation occurs by what two methods?
Transfer of heat via sweating (evaporation)
Maximizing or minimizing heat loss (radiation)
High environmental temperature
Dermal blood vessels _____
Dilate
Low Environment temperature
Dermal blood vessels _______
Constrict
Produced in the epidermis that protects from microbes, abrasion, heat, water loss, and chemicals
Keratin (protein)
Released by lamellar granules inhibit evaporation of water from the skin surface and prevent dehydration
Lipids (fats)
Provides protection against damaging effects of UV light
Melanin (pigment)
Prevent hair from drying out, are mildly bactericidal and have acidic pH
Sebum
Cutaneous sensation
-Tactile sensations
Exteroceptors
Cutaneous sensation
-Touch
Mechanoreceptors
Cutaneous Sensation
-Pressure
Baroreceptors
Cutaneous Sensation
-Vibration
Meissner Corpuscles
Thermal Sensation
-Warmth & Coolness
Thermoreceptors
Cutaneous sensation
-Pain (impending or actual tissue damage)
Nociceptors
Skin has a small role in _______
Has a big role in ______
Excretion
Absorption
Exposure of the skin to ultraviolet radiation activates:
Vitamin D
Vitamin D is converted to calcitriol which aids in the absorption of:
Calcium and phosphorus
Immunovascular response, without regard to the cause, to any potentially harmful stimuli
Generic response, it is not tailored to the specific stimuli
Inflammation
5 Signs of Inflammation
Localized Hyperthermia
Erythema
Localized Edema
Pain
Loss of Function
Aggregation of macrophages formed from chronic inflammation
Immune system attempts to isolate foreign substances that it cannot eliminate
Granulomatous inflammation (CYSTIC)
Characterized by the presence of an amorphous mass composed of active neutrophils, cellular debris and microbes
Generally caused by certain pyogenic bacteria (Staph) and forms an abscess
Suppurative Inflammation (ABSCESS)
Inflammation occurring near epithelium that results in necrotic loss of surface tissue that exposes lower layers
The subsequent excavation in the epithelium is known as an ulcer
Ulcerative inflammation (Ulcers)
The inevitable physiologic changes of the skin that occur with time and are influenced by genetic and hormonal factors
Not preventable and happens to everyone
Intrinsic Aging
The preventable structural and functional changes of the skin that occur with exposure to:
Environmental factors
Lifestyle (tobacco, ETOH, illicit drugs)
Social determinants
Elective Cosmetic surgeries
Most important source of preventable extrinsic aging is:
Ultraviolet radiation
Epidermal Aging starts between what ages?
30 & 80
Aging
Epidermal turnover rate decreases by ___% which decreases wound repair capacity
30-50%
Epidermal Aging
Overall thinning of unexposed epidermis by ____% which makes it easier to cause injury to underlying tissues
10-50%
Epidermal Aging
Decrease in number and function of melanocytes by ___% per decade which causes an elevated risk of skin cancer in the elderly
20%
Epidermal Aging
Reduction in number and responsiveness of ________ cells cause weakened cutaneous immunity in the elderly
Langerhans cells
Reduction of collagen fiber production enhances rate and amount of UV exposure
Reduction of elastin fiber production
Decreased skin hydration and characteristic elderly xerosis (dry skin)
Dermal Aging
The restoration of tissue architecture after injury encompasses two separate processes:
Regeneration
Replacement
Damaged tissue is completely restored
Regeneration
Severely damaged or non-regenerable tissue is repaired by laying down connective tissue, resulting in scarring
Replacement
Most rapidly regenerating and repairing tissue and has capacity for continuous renewal
Epithelial Tissue
Adequate renewal capacity; slower than epithelial tissues and prone to hyperproliferation (scarring)
Connective Tissue
Relatively poor capacity for renewal. Tissue does not divide rapidly enough to replace extensively damaged fibers
Muscular Tissue
Poorest capacity for renewal because it does not undergo mitosis to replace damaged neurons
Nervous Tissue
Inflammatory phase occurs ___ days post injury
1-3 days
Serves mainly to clear bacteria and debris from the wound and to prepare wound environment for repair
Inflammatory phase
Forms in the injured space providing hemostasis and inducing both cellular and chemical inflammatory responses
Platelet and Fibrin clots
Release chemical mediators causing local capillary vasodilation increasing permeability and augmenting local blood flow and migration of inflammatory cells to the injury area
Mast Cells
Phagocytose cellular debris, bacteria, and foreign material, and release multiple factors that further the inflammatory reaction
After they are done, they are removed via physical sloughing or are phagocytosed themselves by macrophages
Neutrophils
Proliferative phase occurs ___ days post injury
2 to 10 days
Purpose is to construct granulation tissue to fill the defect caused by the wound
Fibroblasts are the major cellular agent in this phase and produce Type III collagen to provide structural integrity to the new tissue
Proliferative phase
Provides contractile force to minimize wound surface area during healing. Once enough extracellular matrix has been laid done most fibroblasts undergo apoptosis
Collagen
Healing “Early Remodeling” Phase occurs ___ weeks post injury
2-3 weeks
Healing “Late Remodeling” Phase occurs how long post injury?
Months to > 1 year
Late Remodeling Phase
The Type III collagen laid down by the fibroblasts is replaced with Type ___ collagen and collagen fibrils become more organized
Type I
Tensile strength of the wound at 3 weeks post injury
20%
Tensile strength of the wound at 6 weeks post injury
70-80%
Relies on dermal edges that are close together and easily approximated
Ex: Sutures, staples, dermal adhesive
Primary Intention
Relies on formation of granulation tissue to fill the space between the wound opening or edges
Secondary Intention
