Midterms | Integumentary System Flashcards
Compositions of the integumentary system
Skin
Hair
Oil and sweat glands
Nails
Sensory receptors
Medical specialty that deals with the structure, function and disorders of the integumentary system
Dermatology
Dermatology is a medical specialty that deals with the (1), (2) and (3) of the integumentary system
- structure
- function
- disorders
Functions of the integumentary system
- Regulates body temperature
- Stores blood
- Protects body from external environment
- Detects cutaneous sensations
- Excretes and absorbs substances
- Synthesizes VITAMIN D
Other term for the skin
Cutaneous membrane
Largest organ of body in weight
Skin
Measurement, weight, and percentage of the skin in adults
Skin covers 2 square meters and weighs 4.5-5 kg (7% of the total body weight)
Thickness of the skin in diff body parts
0.5 mm (eyelids)
4 mm (heels)
1-2 mm (most of the body)
Superficial parts of the skin
Epidermis
Dermis
Storage depot for fat and contains blood vessels that supply the skin
Subcutaneous
What tissues does the hypodermis contain?
consists of areolar and adipose tissue
What type of epithelial tissue is the epidermis made up of?
Made up of keratinized stratified squamous epithelium
4 principal types of cells of the epidermis
- Keratinocytes
- Melanocytes
- Intraedpidermal Macrophanges/ Langerhans Cells
- Tactile Epithelial Cells/ Merkel Disc
Functions of each cells of the epidermis
- Keratinocytes: produces keratin
- Melanocytes: produces melanin
- Intraedpidermal Macrophanges/ Langerhans Cells: participate in immune response, help other cells of the immune system recognize an invading microbe and destroy it
- Tactile Epithelial Cells/ Merkel Disc: detect touch sensations
Helps protect the skin and underlying tissue from abrasion, heat, microbes, and chemicals
Keratin
What does keratin protect the skin and underlying tissue from?
Abrasion
Heat
Microbes
Chemicals
Function of melanin
Contributes to skin color and absorbs damaging UV light
Color range which the melanin contribute
Yellowish - red
Black - brown
One responsible for producing vitamin D
Skin
Advantage of vitamin D
Helps maintain protective barrier against sun damage
Nerve endings sensitive to pressure
Lamellated corpuscles
Where do intraepidermal macrophanges arise from?
Red bone marrow
Where is the tactile epithelial cell located?
Deepest layer of the epidermis (Stratum basale; along with melanocytes)
Principal layers/ strata of cells
- Stratum Basale
- Stratum Spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
Describe stratum basale
▪ Deepest layer
▪ Single row of cuboidal or columnar keratinocytes
▪ Contains KERATIN INTERMEDIATE FILAMENTS
Other term for stratum basale
Stratum germinativum
Protects deeper layer from injury
Keratin
Where is keratin attached to (in diff parts of the skin)
- Desmosomes (Stratum spinosum)
- Hemidesmosomes (Epidermis and Dermis)
Describe stratum spinosum
▪ Superficial to stratum basale
▪ With coarse bundles of keratin in intermediate filaments
▪ Cells shrink and pull apart appearing like thornlike spines
Function of thornlike spines of stratum spinosum
Provides strength and flexibility of skin
Describe stratum granulosum
▪ Middle of epidermis
▪ With 3-5 layers of keratinocytes undergoing APOPTOSIS
Assembles keratin intermediate filaments to keratin
Keratohyalin
Fuses plasma membrane and release lipid-rich secretion
Lamellar granules
Water-repellent sealant
Lipid-rich secretion
Function of lipid-rich secretion released by lamellar granules
Manage entry and exit of water and foreign substances
Describe stratum lucidum
▪ Present only in the thick skin (fingertips, palms and soles
▪ 4-5 layers of flattened, clear and dead keratinocytes (with thick plasma membranes)
Provides an additional level of toughness in this region of the skin
Stratum lucidum (Needs tp be thick for it is prone to friction)
Describe stratum corneum
▪ Cells are extremely thick, flat, plasma membrane-enclosed packages of keratin
▪ Final product of the process of keratinocytes
▪ Cells overlap one another like the scales on the skin of a snake
Constant exposure of skin to friction (increased cell and keratin production)
Callus
Abnormal thickening of stratum corneum
Callus
Describe the dermis
● Composition: Dense irregular connective tissue containing collagen and elastic fibers
● Has the ability to stretch and recoil easily
● Blood vessels, nerves, glands and hair follicle
Regions of the dermis
- Papillary region (superficial region)
- Reticular region (deeper region)
Small, nipple-shaped structures that project into the undersurface of the epidermis (with capillary loops/blood
vessels)
Dermal Papillae
Nerve endings sensitive to touch (warmth, coolness, pain, tickling and itching)
Corpuscles Of Touch/ Meissner Corpuscles
Contains bundles of thick collagen fibers, scattered fibroblasts and various wandering cells
Reticular region
What does the reticular region contain?
Bundles of thick collagen fibers,
scattered fibroblasts, and
various wandering cells
Arranged in a netlike manner (helps the skin resist stretching)
Collagen fibers
Arrangement of collagen fibers, and why?
Netlike manner. Helps the skin resist stretching
Provides strength, extensibility, ability to stretch, and elasticity
Collagen fibers and elastic fibers
Ability of substances to stretch and go back to its original shape
Elasticity
Dead, keratinized epidermal cells
Hair
Other term for hair
Pili
Anatomy of the hair
A. Shaft
B. Root
Describe the shaft of the hair
- Superficial portion
- Projects above the skin
Describe the root of the hair
- Hair deep to the shaft
- Penetrates dermis, sometimes the subcutaneous layer
3 concentric layers of the hair root
- Inner medulla
- Middle cortex
- Cuticle of the hair
Lacking in thinner hair
Inner medulla
Small amounts of pigment granules in gray hair
Inner medulla
Lack of pigment granules and presence of air bubbles in white hair
Inner medulla
What are absent and present in white hair?
Lacks pigment granules
There is presence of air bubbles
Major shaft of hair root
Middle cortex
Outermost layer of hair root
Cuticle of the Hair
Cuticle cells on the shaft are arranged like —
Arranged like shingles, with their free edges pointing toward the end of the hair
Surrounding of the root of the hair
Hair follicle
Parts of the hair follicle
- Internal root sheath
- External root sheath
Together, the external and internal root sheath are referred to as the —
epithelial root sheath
Produced at the matrix, and forms a cellular tubular sheath
of epithelium between the external root sheath and the hair
Internal root sheath
Downward continuation of the epidermis
External root sheath
Base of the hair follicle
Bulb
Contains connective tissue and many BV that nourishes the growing hair follicle
Papilla of the hair
Arise from the stratum basale (site of cell division)
Hair matrix
Germinal layer of cells
Hair matrix
Function of the hair matrix
Responsible for the growth of existing hairs and produces new hair when old hairs shed
Smooth muscle that extends from the superficial dermis of the skin to the dermal root sheath around the side of the hair follicle.
Arrector Pili
Arrector pili is a (1) that extends from the (2) of the skin to the (3) around the side of the hair follicle.
- smooth muscle
- superficial dermis
- dermal root sheath
Generate nerve impulses if hair shafts are moved
Hair root plexus (Dendrites of neurons)
Normal growth of hair
90 degrees angle
Other term for goosebumps
Gooseflesh
Goosebumps/ Gooseflesh
Under (1) or (2) (cold/fright), autonomic nerve endings stimulate the (3) to contract,
which pulls the (4) perpendicular to the skin surface
- psychological
- emotional stress
- arrector pili muscles
- hair shafts
Skin glands
- Sebaceous (Oil) Glands
- Sudoriferous (Sweat) Glands
- Ceruinous Glands
Description (appearance) of sebaceous glands
Simple, branched, acinar (rounded) glands
Where are sebaceous glands present?
Lips
Glans penis
Labia minora
Tarsal glands of the eyelids
What do sebacous glands secrete?
Sebum
Coats surface of hair and helps them from drying and becoming brittle.
Sebum
Prevents excessive evaporation of water from the skin, making it soft and pliable
Sebum
What do sudoriferous glands release?
Sweat/ perspiration
Classifications of sudoriferous glands
- Eccrine sweat glands
- Apocrine sweat glands
Differentiate eccrine and apocrine sweat glands in terms of WHEN it occurs in a person
Eccrine sweat glands are present at birth while apocrine sweat glands occurs once patient reaches puberty
Differentiate eccrine and apocrine sweat glands in terms of WHERE (part of body) it occurs
Eccrine: Forehead, palms and soles
Apocrine: Axilla, groin, areola of breasts, bearded regions around
the face of adult males.
Helps regulate body temperature through evaporation (large quantities of heat leave the body).
Eccrine sweat glands
Differentiate eccrine and apocrine sweat glands in terms of their secretory (where sweat is produced) and excretory (where sweat will come out) portions
ECCRINE
Secretory: Dermis
Excretory: Epidermis
APOCRINE
Secretory: Deep dermis and upper subq layer
Excretory: Hair follicles
Homeostatic regulation of body temperature
Thermoregulation
Helps the body achieve thermoregulation
Thermoregulatory sweating
Under eccrine glnds, we have insensible and sensible perspiration. Differentiate the two
Insensible perspiration: Sweat that evaporates from the skin before it is perceived as moisture
Sensible perspiration: Sweat that is excreted in larger amounts and seen as moisture on the skin
Released sweat in response to emotional stress such as fear or embarrassment (palms, soles and axilla)
Emotional sweating/ Cold sweat
Where emotional sweating first occurs
Palms
Soles
Axilla
Simple, coiled, tubular glands
Apocrine sweat glands
Apocrine sweat glands appears (1) and (2) in color
- milky
- yellowish
Apocrine sweat interacts with (1), this metabolizes the components causing the (2) , thus called (3)
- bacteria
- MUSKY ODOR
- BODY ODOR
Modified sweat glands in the external ear
Ceruminous glands
Produces waxy lubricating secretion
Ceruminous glands
Secretory and excretory portion of ceruminous glands
Secretory: Subcutaneous layer
Excretory: Surface of EAM/ ducts of sebaceous glands
Other term for earwax
Cerumen
CERUMEN/EARWAX: yellowish combination of (1) and (2)
- ceruminous
- sebaceous sweat glands
Provides a sticky barrier to impede the entrance of foreign bodies and insects
Cerumen/ earwax
Waterproofs the canals and prevents bacteria and fungi to form
Cerumen/ earwax
Tightly packed, hard, dead, keratinized epidermal cells
Nails
Parts of the nails
- Nail body/ plate
- Free edge
- Nail root
- Lunula
- Hyponychium
- Nail bed
- Eponychium/ cuticle
- Nail matrix
Visible portion of the nail
Nail body/plate
Nail body that may extend past the distal end of the digits
Free edge
Nail that is buried in the fold of the skin
Nail root
Whitish, crescent area of the proximal end of the nail body
Lunula
Secures the nail to the fingertip
Hyponychium
Attaches nail to the skin
Hyponychium
Skin below the nail plate that extends from the lunula and hyponychium (lacks granulosum)
Nail bed
Occupies the proximal border of the nail and lacks corneum
Eponychium/ cuticle
Portion of the epithelium proximal to the nail root
Nail matrix
How long does the nail grow per week?
1mm per week
Functions of the nails
- Protection
- Touch sensation
- Grasp and manipulate small objects
Two kinds of wound-healing processes
- Epidermal wound healing
- Deep wound healing
Edges of the wound usually involve only slight damage to superficial epidermal cells
Epidermal wound healing
Common types of epidermal
wounds
Abrasion
Minor burns
A portion of skin has been scraped away
Abrasion
Process of epidermal wound healing
- Basal cells detach from basement membrane
- Cells enlarge
- Cells migrate as a sheet until advancing cells from opposite sides of the wound meet.
- Cells meet and stop migrating (Contact inhibition)
When do epidermal cells stop migrating?
Migration of the epidermal cells stops completely when each is finally in contact with other epidermal cells on all sides.
Stimulates basal cells to divide and replace the ones that have been moved into the wound
Epidermal growth factor
Injury extends to the dermis to the subcutaneous layer
Deep wound healing
Phases of deep wound healing
- Inflammatory
- Migratory
- Proliferative
- Maturation
Phase of deep wound healing
Blood clots forms in the wound and loosely unites the wound edges.
Inflammatory
Phase of deep wound healing
Neutrophils and monocytes develops into macrophages that
phagocytize microbes and mesenchymal cells and then develops to FIBROBLASTS.
Inflammatory
Phase of deep wound healing
Clot becomes scab
Migratory
Phase of deep wound healing
Epithelial cells migrate beneath the scab to build a bridge wound
Migratory
Phase of deep wound healing
Fibroblasts migrate, damaged BV regrows
Migratory
Phase of deep wound healing
Formation of GRANULATION TISSUE
Migratory
Phase of deep wound healing
Extensive growth of epithelial cells beneath the scab
Proliferative
Phase of deep wound healing
Continued growth of BV
Proliferative
Phase of deep wound healing
Scabs sloughs off once the epidermis has been restored to its normal thickness.
Maturation
Phase of deep wound healing
Collagen fibers become more organized, fibroblasts decrease in number, and blood vessels are restored to normal.
Maturation
Scar tissue formation
Fibrosis
Too much scar tissue is formed
during deep wound healing that a RAISED SCAR forms
Hyperthropic scar
Extends beyond the boundaries into normal surrounding tissues.
Keloid/ Cheloid scar