Tissue Repair - Integumentary System Flashcards
occurs during wound healing, which is the process by which the skin or any injured organ restores itself after an injury.
tissue repair
The main objectives of wound healing are to prevent further damage, clean and seal the wound to prevent infection, and restore tissue strength and function if possible.
tissue repair
The damaged tissue is replaced by the same type of cells. The new tissue completely restores the damaged area to its normal state.
Regeneration
two mechanisms of tissue repair
regeneration and fibrosis
The damaged tissue is replaced with dense fibrous connective tissue or scar tissue. This can interfere with or inhibit the normal function and architecture of the underlying organ or tissue. Examples include fibrosis in the lungs, liver, brain, and heart.
Fibrosis
Epithelial Tissues, fibrous tissues, bone tissues, blood vessels, and some muscle tissues.
Regenerative tissue
Cardiac tissues and nervous tissues in the brain and spinal cord
Non-regenerative tissue
two types of severity of injury
Shallow wounds, deep wounds
Affect only the epidermis; dermis remains intact.
Shallow wound
Damage the dermis. Clean cuts heal more successfully than ragged tears.
Deep wounds
prevent further injury
inflammation
■ Damaged cells release inflammatory chemicals, increasing capillary permeability
■ White blood cells (WBCs) and clotting proteins seep into the injured area.
■ Platelets migrate to form a fibrin clot, which seals the wound and prevent blood loss
■ Immune cells (neutrophils and macrophages) accumulate to remove debris and bacteria
■ Symptoms include swelling,redness, pain, and heat
Inflammation
Supply cells and nutrients for remodeling.
Granulation tissue forms
Events of tissue repair
inflammation, granulation tissue forms, surface epithelium regeneration
■ New blood vessels form around the wound, creating ___________—delicate pink tissue with new capillaries.
■ Connective tissue cells (fibroblasts) produce collagen fibers and extracellular matrix.
■ __________- facilitates wound closure as fibroblasts synthesize collagen.
■ Myofibroblasts pull the wound edges together.
Granulation tissue
Regenerate surface epithelium and finalize wound closure.
Surface epithelium regenerates
■ ___________, thickens, and makes its way between granulation tissue and the scab.
■ The scab eventually detaches, leaving behind a scar.
■ The fibrous tissue matures to form a scar, which may be visible or invisible depending on the severity of the wound.
■ During remodeling, the new tissue matures to more closely resemble the surrounding mature tissue.
Surface epithelium regenerates
What is the regenerative capacity? Skin epidermis, mucous membranes, fibrous connective tissues, blood tissues, bones.
High
What is the regenerative capacity? Smooth muscles, tendons, ligaments
moderate
What is the regenerative capacity? Skeletal muscles, cartilage.
Weak
Repair of superficial wounds or clean surgical incisions approximated by surgical supports. Involves inflammation, granulation, and maturation stages.
Primary union (first intention)
What is the regenerative capacity? Cardiac muscles, nervous tissues in the brain and spinal cord.
Virtually no
Repair of large wounds, abscesses, ulcerations, or necrosis. Involves both regeneration and scarring, with more intense inflammation, abundant granulation tissue, extracellular matrix accumulation, and large scar formation.
Secondary union (second intention)
→ Cause: Fungal infection
→ Symptoms: Itchy, red peeling skin
between the toes
Athlete’s foot
→ Cause: Inflammation of hair follicles
→ Symptoms: Painful, swollen bumps
Boils (furuncles)
→ Cause: Herpes Simplex Virus 1
→ Symptoms: Fluid-filled blisters
around lips and mouth, itching, and stinging
Cold sores (fever blisters)
→ Cause: Clusters of boils, often due to
Staphylococcus aureus
→ Symptoms:Multipleinterconnected boils
Carbuncles
→ Cause: Staphylococcus or
Streptococcus bacteria
→ Symptoms: Pink fluid-filled lesions
with yellow crusts, primarily around mouth and nose.
Impetigo
→ Cause: Exposure to chemicals (e.g., poison ivy)
→ Symptoms: Itching, redness, swelling, possibly blistering
Contact dermatitis
→ Autoimmune disorder
→ Rapid skin cell production,
resulting in red lesions covered with dry, silvery scales; triggered by trauma, infection, hormonal changes, or stress
Psoriasis
Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals
Burns
Result in loss of body fluids and infection from the invasion of bacteria
Burn
→ Only epidermis is damaged
→ Skin is red and swollen
→ Heals in 2-3 days
First-degree burn (superficial burn)
→ Epidermis and superficial part of dermis are damage
→ Skin is red, painful, and blistered
→ May result in scarring
→ Regrowth of the epithelium can occur
→ Caused by hot water, flames, chemicals, or electricity.
Second-degree burn (partial-thickness burn)
→ Destroys epidermis and dermis; burned area is painless
→ Requires skin grafts, as regeneration is not possible
→ Burned area is blanched (gray-white) or black
Third-degree burn (full-thickness burn)
→ Extends into deeper tissues (bone, muscle, tendons)
→ Appears dry and leathery
→ Requires surgery and grafting
→ May require amputation
Fourth-degree burn (full-thickness burn)
Most common types of skin cancer
○ Basal cell carcinoma
○ Squamous cell carcinoma
○ Malignant melanoma
→ Least malignant and most common type of skin cancer
→ Arises from cells in stratum basale that are altered so that they can no
longer make keratin
→ Lesions appear as shiny, dome-shaped nodules that develop a central ulcer
Basal cell carcinoma
→ Believed to be induced by UV Exposure
→ Arises from cells of stratum spinosum
→ Lesions appear as scaly, reddened papules that gradually form shallow ulcers
→ Early removal allows a good chance of cure
→ Metastasizes to lymph nodes if not removed
Squamous cell carcinoma
The ABCDE of malignant melanoma
○ A: Asymmetry
○ B: Border irregularity
○ C: Color variation
○ D: Diameter > 6mm
○ E: Evolution or change in characteristics
Most deadly of skin cancers, but accounts for only 5 percent of skin cancers
→ Arises from melanocytes
→ Metastasizes rapidly to lymph and blood vessels
→ Detection uses ABCDE rule for recognizing melanoma
Malignant melanoma
Downy hair covering body by 5th or 6th month, disappears by birth
Lanugo
Oily substance protecting skin at birth
Vernix Caseosa
Small white spots on nose and forehead, are at common at birth and disappear by 3rd week
Milia
Due to activated sebaceous glands
Acne
Thick, resilient, well-hydrated skin
Youth
○ Decreased elasticity
○ Drier skin, prone to bruising
○ Formation of bags under eyes
○ Hair thinning and graying
○ Balding (alopecia) and graying due to decreased melanin and hair follicles
○ Accelerated by smoking and sun exposure
Aging effects
○ Avoid smoking and excessive sun exposure
○ Maintain good nutrition and hydration
Protection measure
→ Yellowish, reddish brown, or black pigment produced by melanocytes.
→ Increased melanin production due to sunlight exposure leads to tanning.
→ Higher melanin levels result in darker
skin, while lower levels lead to lighter skin.
Melanin
→ Orange-yellow pigment from some vegetables
→ High carotene intake can give the skin a yellow-orange hue.
Carotene
→ Red coloring from blood cells in dermal capillaries
→ Oxygen content determines the extent of red coloring
Hemoglobin
Reddened skin from embarrassment, inflammation, hypertension, fever, or allergy
Redness (erythema)
→ Low oxygen levels in the blood cause the lips, fingers and toes look blue
→ Poorly oxygenated hemoglobin can cause a bluish tint in the skin, known as cyanosis.
Cyanosis
Pale skin due to emotional stress (such as fear), anemia, low blood pressure, impaired blood flow to an area
Pallor (blanching)
Yellow skin tone indicates liver disorders with excess bile pigments in the blood.
Jaundice (yellow cast)
Cutaneous glands are all ____ glands
exocrine
→ Black and blue marks from blood escaping circulation and clotted in tissues, called hematomas.
→ Frequent bruising may indicate vitamin C deficiency or hemophilia.
Bruises (black and blue marks)
Caused by blocked sebaceous
glands.
Acne
→ Located all over the skin except for palms and soles. These glands are most numerous on the face.
→ Produce sebum (oil) which helps lubricate the skin and hair. Makes skin soft and moist
→ Prevents hair from becoming brittle
→ Kills bacteria
→ Most have ducts that empty into hair follicles; others open directly onto the skin surface
→ Glands are activated at puberty
Sebaceous (oil) glands
_____ result from oxidized, dried sebum;
blackheads
→ Produce sweat
→ Widely distributed in skin
Sweat (sudoriferous) glands
_____- are from non-oxidized sebum.
whiteheads
two types of sweat glands
eccrine and apocrine glands
→ Located in the axilla and perineum.
→ Ducts empty into hair follicles in the armpit and genitals
→ Begin to function at puberty
→ Release sweat that also contains fatty acids and proteins (milky or yellowish color), which can develop an odor when bacteria decompose it
→ Play a minimal role in body temperature regulation
Apocrine glands
→ Open via duct to sweat pores on the skin’s surface
→ Produce acidic sweat
→ Water, salt, vitamin c ,traces of metabolic waste
→ Function in body temperature regulation
Eccrine glands
Produced by melanin granules deposited by melanocytes.
Hair color
Heavily keratinized, scale-like modifications of the epidermis
Nail
The visible, attached portion of the nail.
body
The tip of the nail that extends beyond the finger or toe.
free edge
The portion of the nail embedded in the skin.
root nail
Skin folds that overlap the borders of the nail.
Nail folds
The thick proximal nail fold, also known as the eponychium, that covers the base of the nail.
Cuticle
The stratum basale of the epidermis extends beneath the nail, responsible for nail growth.
Nail bed
The thick, proximal area beneath the cuticle where nail growth occurs.
Nail matrix
Can be cutaneous (skin), mucous, or serous membranes.
Epithelial membranes
Example includes the synovial membrane.
Connective tissue membranes
→ Are considered as simple organs
→ Also called covering or lining membranes
Epithelial membranes
→ A dry membrane
→ Covers the body surface
→ Outer most protective boundary
Cutaneous membrane
Composed of keratinized stratified squamous epithelium.
Epidermis
A protein in the epidermis that makes skin water-resistant.
Keratin
Includes dense regular and dense irregular connective tissue.
Dense connective tissue
Primarily dense fibrous connective tissue.
Dermis
→ Moist membranes
→ Line all body cavities that open to the exterior body surface
Mucous membrane
Line open body cavities that are closed to the exterior of the body
Serous membrane
→ Loose areolar connective tissue only
(no epithelial tissue)
→ Line fibrous capsules surrounding joints
Synovial membrane
Lubricates joints and reduces friction during movement.
Synovial fluid
4 roles of the integumentary
protection, temperature regulation, excretion, vitamin d production
→ The outer most layer of the skin, composed of epithelial cells.
→ Made up of keratinized stratified squamous epithelium.
Epidermis
Deepest layer of epidermis
Stratum Basale
Cells become increasingly flatter and more keratinized. Provides strength and flexibility to the skin
Stratum spinosum
Cells start to die and form a granular layer.
Stratum granulosum
Found only in hairless skin areas like the palms and soles.
Stratum Lucidum
Outer most layer of epidermis with shingle-like dead cells filled with keratin. Provides a protective barrier and prevents water loss
Stratum corneum
○ Pigment produced by melanocytes, which gives skin its color (ranging from yellow to brown to black).
○ Located primarily in the stratum basale.
○ Accumulates in melanosomes
Melanin
○ Alert and activate immune cells to a threat (bacterial or viral invasion)
○ Found in the stratum spinosum.
Epidermal dendric cells (Langerhans cells)
○ Associated with sensory nerve endings and function as touch receptors
○ Located in the stratum basale.
Merkel cells
→ Located below the epidermis, this layer consists of irregular connective tissue. It supports and nourishes the epidermis.
Dermis
Two regions of dermis
Papillary layer (areolar), and reticular layer (dense irregular connective tissue)
→ Blood vessels, sweat and oil glands
→ Deeper layer of the dermis.
→ Composed of dense connective tissue.
→ Houses deeper pressure receptors like Lamellar corpuscles.
→ Contains structures such as sweat and oil glands.
Reticular layer
→ Upper dermal region; Indent the epidermis above
→ Contains loose connective tissue with collagen and elastic fibers.
→ Forms dermal papillae, which create fingerprints
Papillary layer
Found in the dermis; help regulate body temperature through sweating. May appear as round structures in cross-sections of the skin.
Sweat glands
Provides strength and structure to the skin.
Collagen
Allows the skin to return to its original shape after stretching.
Elastin
Engulf and destroy pathogens.
Phagocytes
Supply nutrients to the skin and help regulate body temperature.
Blood vessels
are sensitive to rapid changes in pressure or vibration. Detects deep pressure and vibrations (located in the reticular layer).
Pacinian Corpuscles
Detect light touch and low-frequency vibrations (located in the papillary layer).
Meissner’s corpuscles
Response to sustained pressure and perceives shapes and edges (located in the stratum basale).
Merkel discs
Respond to sustained pressure and stretching of the skin (located in the reticular layer).
Ruffini Corpuscles
Detect pain and temperature (distributed throughout the dermis).
Free nerve endings
→ Also known as the subcutaneous tissue, it is located below the dermis.
→ Composed of adipose (fat) tissue.
Hypodermis
Mechanical stimuli as the input to our sense of touch or tactile sensations.
Sensory input
Mechanoreceptors detect and respond to mechanical stimuli.
Process
