ANAPHY PRELIMS WEEK 4

INTEGUMENTARY SYSTEM

-            It consists of the skin and its appendages such as the hair, glands, and nails.

-            Functions:

Component	Function
Protection	Shields the body from physical damage, pathogens, and harmful substances.
Sensation	Detects touch, pressure, pain, and temperature through nerve receptors.
Vitamin D Production	Synthesizes vitamin D when the skin is exposed to sunlight.
Temperature Regulation	Maintains body temperature through sweat production and blood flow control.
Excretion	Eliminates waste products like salts and urea through sweat.

PROTECTION

Shields the body from physical damage, pathogens, and harmful substances.

SENSATION

Detects touch, pressure, pain, and temperature through nerve receptors.

VITAMIN D PRODUCTION

Synthesizes vitamin D when the skin is exposed to sunlight. Active form of Vitamin D: Cholecalciferol

TEMPERATURE REGULATION

Maintains body temperature through sweat production and blood flow control.

EXCRETION

Eliminates waste products like salts and urea through sweat.

EPIDERMIS

-            Most superficial layer of the skin

-            Stratified squamous epithelium

-            Thickness ≤ 0.12 mm

-            Contains:

o   Keratinocytes: most abundant skin cells that produce keratin, a protein that strengthens the skin.

o   Melanocytes: produce melanin, the pigment responsible for skin color and protection against UV radiation.

o   Langerhans Cells: Immune cells that help detect and fight off pathogens in the skin.

o   Merkel Cells: Sensory cells that help detect touch and pressure.

KERATINOCYTES

o   most abundant skin cells that produce keratin, a protein that strengthens the skin.
-            Process where epithelial cells change shape and chemical composition.

-            Becomes more rigid and durable.

MELANOCYTES

o   produce melanin, the pigment responsible for skin color and protection against UV radiation.

LANGERHAN CELLS

o   Immune cells that help detect and fight off pathogens in the skin.

MERKEL CELLS

o   Sensory cells that help detect touch and pressure.

LAYERS OF EPIDERMIS

Inner to Outer:

1. Stratum Basale

2. Stratum Spinosum

3. Stratum Granulosum

4. Stratum Lucidum

5. Stratum Corneum

STRATUM CORNEUM

-            Most superficial layer of the epidermis

-            Also called the “horny layer”

-            Composed of dead squamous cells filled with keratin

-            Provides structural strength

-            Coated and surrounded by lipids released from lamellar bodies

-            Acts as a “waterproofing” material

-            Contains 25 or more layers of dead squamous cells joined by desmosomes.

STRATUM LUCIDUM

-            Thin, clear zone between the stratum granulosum and stratum corneum

-            Contains no nuclei or organelles

-            Known as the “clear layer” – because id doesn’t contain nuclei or organelles.

-            Contains droplets of eleidin.

o   Thick Skin: stratum lucidum is present

o   Thin Skin: stratum lucidum is absent.

STRATUM GRANULOSUM

-            Flat and diamond-shaped cells

-            Accumulates more keratin and releases the contents of lamellar bodies into the extracellular space

-            Contains keratohyalin granules, which is why it’s called the Granular Layer

-            Has a “grainy appearance”

-            Consists of 3-5 layers of flattened cells.

STRATUM SPINOSUM

-            Cells have a flattened appearance and accumulate lipid-filled vesicles called lamellar bodies

-            Contains lamellar bodies, which are rich in lipids

-            Known as the “spiny” or “prickle layer”

-            Consists of 8–10 layers

STRATUM BASALE

-            Deepest layer of the epidermis

-            Composed of cuboidal or columnar cells that undergo mitotic division approximately every 19 days

-            Anchored by hemidesmosomes and desmosomes

-            Forms epidermal ridges, which create fingerprints

STRATUM GERMINATIVUM

• Stratum Basale and Stratum Spinosum

• It is primarily responsible for producing new skin cells through mitosis, the process of cell division.

• Growth Layer

SKIN COLOR

Factor	Brief Definition
Melanin production	Pigment that gives skin its color and protects from UV rays.
Blood circulation	Blood flow affecting skin color and warmth.
Diet	Nutrients intake influencing skin health and appearance.
Biochemical imbalance	Changes in body chemicals that can affect skin tone or condition.

SKIN CONDITIONS

Term	Brief Definition
Albinism	Inability to produce tyrosinase, leading to lack of skin pigment.
Erythema	Reddening of the skin due to increased blood flow.
Cyanosis	Bluish skin color caused by decreased blood flow or oxygen.
Jaundice	Yellowing of the skin and mucous membranes due to excess bilirubin.

ALBINISM

Inability to produce tyrosinase, leading to lack of skin pigment.

ERYTHEMA

Reddening of the skin due to increased blood flow.

CYANOSIS

Bluish skin color caused by decreased blood flow or oxygen.

JAUNDICE

Yellowing of the skin and mucous membranes due to excess bilirubin—a yellowish fluid in bile, a fluid produce in liver that aids digestion.

DERMIS

-            Dense collagenous connective tissue containing fibroblasts, adipocytes, and macrophages

-            Contains nerves, hair follicles, smooth muscles, glands, and lymphatic vessels

-            Composed of collagen and elastic fibers

-            Has cleavage lines (tension lines)

-            Can develop stretch marks

LAYERS OF DERMIS

• Papillary Layer

• Reticular Layer

PAPILLARY LAYER

-            Named for finger-like projections called “dermal papillae”

-            Made of loose connective tissue with thin, loosely arranged fibers

-            Contains blood vessels

RETICULAR LAYER

-            Composed of dense irregular connective tissue

-            Main layer of the dermis – makes up the 80% of the dermis.

-            Continuous with subcutaneous tissue

-            Forms a mat of irregularly arranged fibers resistant to stretching in many directions

HAIR

	Description	Timing/Location
Lanugo	Delicate, unpigmented hair	Develops at 5th or 6th month of fetal development
Terminal Hair	Long, coarse, and pigmented hair	Appears near birth; replaces lanugo on scalp, eyelids, and eyebrows
Vellus Hair	Short, fine, and usually unpigmented hair	Replaces lanugo on the rest of the body

-            The hair is made up of three layers arranged concentrically.

LANUGO

Description	Timing/Location
Delicate, unpigmented hair	Develops at 5th or 6th month of fetal development

TERMINAL HAIR

Description	Timing/Location
Long, coarse, and pigmented hair	Appears near birth; replaces lanugo on scalp, eyelids, and eyebrows

VELLUS HAIR

Description	Timing/Location
Short, fine, and usually unpigmented hair	Replaces lanugo on the rest of the body

PARTS OF THE HAIR

Part	Definition
Follicle	Tube-like invagination of the epidermis that extends into the dermis.
Bulb	Base of the hair root where growth occurs.
Papilla	Dermal projection into the hair bulb that supplies nutrients.
Root	Portion of the hair below the skin surface, inside the follicle.
Shaft	Visible part of the hair that extends above the skin surface.
Medulla	Central core of the hair shaft, often soft and flexible.
Growth	Process of hair development involving cell division in the bulb.
Sebaceous Gland	Oil gland connected to the hair follicle that lubricates hair and skin.

FOLLICLE

Tube-like invagination of the epidermis that extends into the dermis.

BULB

Base of the hair root where growth occurs.

PAPILLA

Dermal projection into the hair bulb that supplies nutrients.

ROOT

Portion of the hair below the skin surface, inside the follicle.

SHAFT

Visible part of the hair that extends above the skin surface.

MEDULLA

Central core of the hair shaft, often soft and flexible.

GROWTH

Process of hair development involving cell division in the bulb.

SEBACEOUS GLAND

Oil gland connected to the hair follicle that lubricates hair and skin.

NAILS

-            A thin plate consisting of layers of dead stratum corneum cells that contain a very hard type of keratin

-            Growth: 0.5–1.2 mm per day

-            Parts of the Nails:

Nail Part	Definition
Nail root	Proximal end of the nail, covered by skin
Nail body	Distal, visible portion of the nail
Nail fold	Skin covering the proximal and lateral edges of the nail
Nail matrix	Tissue under the nail root where new nail cells are produced
Nail bed	Skin beneath the nail body
Lunula	Whitish, crescent-shaped area at the base of the nail

NAIL ROOT

Proximal end of the nail, covered by skin

NAIL BODY

Distal, visible portion of the nail

NAIL FOLD

Skin covering the proximal and lateral edges of the nail

NAIL MATRIX

Tissue under the nail root where new nail cells are produced

NAIL BED

Skin beneath the nail body

LUNULA

Whitish, crescent-shaped area at the base of the nail

SWEAT GLANDS

-            Sudoriferous glands.

-            2 Types:

Gland Type	Description
Eccrine Sweat Glands	-         Most common type -         Simple, coiled, tubular glands opening directly onto skin surface via sweat pores -         Distributed over most of the body, especially palms and soles -         Absent on lip margins, labia minora, and tips of penis and clitoris
Apocrine Sweat Glands	-         Simple, coiled, tubular glands opening into hair follicles near sebaceous glands -         Located in axillae, genitalia (scrotum and labia majora), and around the anus -         Do not regulate temperature in humans  -         Secrete 3-methyl 2-hexenoic acid

ECCRINE SWEAT GLANDS

-         Most common type -         Simple, coiled, tubular glands opening directly onto skin surface via sweat pores -         Distributed over most of the body, especially palms and soles -         Absent on lip margins, labia minora, and tips of penis and clitoris

APPOCRINE SWEAT GLANDS

-         Simple, coiled, tubular glands opening into hair follicles near sebaceous glands -         Located in axillae, genitalia (scrotum and labia majora), and around the anus -         Do not regulate temperature in humans  -         Secrete 3-methyl 2-hexenoic acid — HUMAN BODY ODOR

INFECTIONS AND ALLERGIES

1. Athlete’s Foot

2. Boils (Furuncles/Carbuncles)

3. Cold Sores (Fever Blisters)

4. Contact Dermatitis

5. Impetigo

6. Psoriasis

ATHLETE’S FOOT

-        Itchy, red, peeling condition of the skin between the toes

-        Caused by a fungal infection

-        A type of ringworm infection

BOILS (FURUNCLES/CARBUNCLES)

-        Inflammation of hair follicles and surrounding tissues, commonly on the dorsal neck

-        Appear as red, raised bumps with accumulation of pus

-        Cause Agent:

o   Staphylococcus Aurous

COLD SORES (FEVER BLISTERS)

-        Small fluid-filled blisters that itch and sting

-        Caused by HSV-1 (Herpes Simplex Virus type 1)

-        Virus localizes in a cutaneous nerve and remains dormant until triggered by emotional upset, fever, or UV radiation

-        Occur around the lips and mucosa of the mouth and nose

CONTACT DERMATITIS

-        Itching, redness, and swelling of the skin, progressing to blistering

-        Caused by exposure to chemicals (e.g., poison ivy) that trigger allergic responses in sensitive individuals

IMPETIGO

-        Pink, fluid-filled, raised lesions commonly around the mouth and nose

-        Lesions develop a yellow crust and eventually rupture, weeping fluid

-        Caused by Staphylococcus or Streptococcus infections

-        Cause Agent:

o   Bullous Type: Streptococcus

o   Non-Bullous Type: Staphylococcus

PSORIASIS

-        Reddened epidermal lesions covered with dry, silvery scales that itch, burn, crack, and sometimes bleed

-        A chronic condition

-        An autoimmune disorder

-        Triggered by trauma, infection, hormonal changes, or stress

BURNS

-        Injury to tissue caused by heat, cold, friction, chemicals, electricity, or radiation

-        Classified by surface area involved and burn depth

-        Critical Burn Conditions:

o   Over 30% of the body has second-degree burns

o   Over 10% has third- or fourth-degree burns

o   Burns on the face, hands, feet, or genitals (third- or fourth-degree)

o   Burns affecting the airway

o   Circumferential burns around the body or limb

TYPES OF BURNS

Burn Type	Description	Healing & Notes
1st-degree burn	Affects only the epidermis; causes redness, pain, and slight swelling	Caused by sunburn or brief hot/cold exposure; heals in about a week without scarring
2nd-degree burn	Damages epidermis and dermis; causes redness, pain, swelling, and blisters	Heals in about 2 weeks, usually without scarring
3rd-degree burn	Epidermis and dermis completely destroyed; may appear white, tan, brown, black, or deep red	Surrounded by 1st and 2nd-degree burns; skin regeneration only from edges; often requires skin grafts
4th-degree burn	Electrical Burn, Extends beyond skin into underlying tissues such as muscle, tendons, or bone; most severe	Requires extensive medical treatment; often results in loss of function or amputation

1ST DEGREE BURN

Affects only the epidermis; causes redness, pain, and slight swelling

Caused by sunburn or brief hot/cold exposure; heals in about a week without scarring

2ND DEGREE BURN

Damages epidermis and dermis; causes redness, pain, swelling, and blisters

Heals in about 2 weeks, usually without scarring

3RD DEGREE BURN

Epidermis and dermis completely destroyed; may appear white, tan, brown, black, or deep red

Surrounded by 1st and 2nd-degree burns; skin regeneration only from edges; often requires skin grafts

4TH DEGREE BURN

Electrical Burn, Extends beyond skin into underlying tissues such as muscle, tendons, or bone; most severe

Requires extensive medical treatment; often results in loss of function or amputation

RULE OF NINE

-        A method used to estimate the percentage of total body surface area (TBSA) affected by burns by dividing the body into sections, each approximately 9% (or multiples of 9%) of the total body surface. This helps guide treatment decisions.

SKIN CANCER

1. Basal Cell Carcinoma

2. Squamous Cell Carcinoma

3. Malignant Melanoma

BASAL CELL CARCINOMA

-        Least malignant and most common skin cancer

-        Occurs mainly on sun-exposed areas of the face

-        Appears as shiny, dome-shaped nodules that develop a central ulcer with a “pearly” beaded edge

-        Slow growing, with metastasis rarely occurring before detection

-        Has a 99% cure rate

SQUAMOUS CELL CARCINOMA

-        Arises from the cells of the stratum spinosum

-        Lesions appear as scaly, reddened papules that gradually form shallow ulcers with firm, raised borders

-        Commonly found on the scalp, ears, back of the hands, and lower lip, but can appear anywhere on the skin

-        Grows rapidly and can metastasize to nearby lymph nodes if not removed

-        Induced by UV exposure

MALIGNANT MELANOMA

-        Arises from accumulated DNA damage in skin cells

-        Usually appears as a spreading brown to black patch

-        Metastasizes rapidly to surrounding lymph and blood vessels

-        Has a 50% chance of survival

-        ABCDE Rule to Distinguish Melanoma from Mole:

Letter	Meaning	Description
A	Asymmetry	Two sides of the mole or spot do not match
B	Border irregularity	Borders are uneven, not smooth, with indentations
C	Color	Contains multiple colors such as black, brown, tan, blue, or red
D	Diameter	Larger than 6 mm (size of a pencil eraser)
E	Evolution	Changes or evolves in size, shape, or color over time