BIOLOGICAL SCIENCES

By:

MARIA KRISIA FAE DELOS REYES DE ASIS, BSN-RN

INTEGUMENTARY SYSTEM-Made up of skin and its accessory structures (hair, nails, glands, muscles, nerves)-Protects the body, helps maintain a constant body temperature, and provides sensory information about the surrounding environment-Easily inspected and exposed to infection, disease, and injury-Can also reflect emotions (frowning, blushing) and normal physiology (sweating)

INTEGUMENTARY SYSTEM+ DERMATOLOGY – medical specialty that deals with the diagnosis and treatment of integumentary system disorders

SKIN-Or CUTANEOUS MEMBRANE-Largest organ of the body in area and weight- Area = 22 square feet- Weight = 4.5-5 kg

INTEGUMENTARY SYSTEM-Thinnest = eyelids- Thickest = heel- 2 main parts:EPIDERMIS – epithelial tissueDERMIS – connective tissue

+ SUBCUTANEOUS LAYER -Or HYPODERMIS- consists of areolar and adipose tissue- serve as a storage for fat and contains blood vessels

INTEGUMENTARY SYSTEM-Contains nerve endings called lamellated (Pacinian) corpuscles that are sensitive to pressure.

EPIDERMIS-Composed of keratinized stratified squamous epithelium-Four types of cells: KERATINOCYTES, MELANOCYTES, LANGERHANS CELLS, and MERKEL CELLS.

INTEGUMENTARY SYSTEMKERATINOCYTES-90% of epidermal cells-Arranged in four or five layers and produce the protein keratin-Produce lamellar granules, which release a water-repellant sealant that decreases water entry and loss and inhibits the entry of foreign materials

INTEGUMENTARY SYSTEMMELANOCYTES-8% of epidermal cells-Produce the pigment melanin-Long and slender projections extend between the keratinocytes and transfer melanin granules to them

+ MELANIN – a yellow-red or brown-black pigment that contributes to skin color and absorbs damaging UV light

INTEGUMENTARY SYSTEMLANGERHANS CELLS-Arise from red bone marrow and migrate to the epidermis, where they constitute a small fraction of the epidermal cells-The participate in immune responses mounted against microbes that invade the skin

INTEGUMENTARY SYSTEMMERKEL CELLS-Least numerous of the epidermal cells-Located in the deepest layer of the epidermis, where they contact a structure called a tactile or Merkel disc which detect touch sensations

INTEGUMENTARY SYSTEMDERMIS-Deeper part of the skin-Composed mainly of connective tissue-Blood vessels, nerves, glands, and hair follicles are embedded in it-2 regions:PAPILLARY – superficial portion of the dermis (1/5) which consists of areolar connective tissue with elastic fibers

INTEGUMENTARY SYSTEMPAPILLARY – also consists dermal papillae that contain capillaries, nerves of touch, and free nerve endings

RETICULAR – deeper portion of the dermis (4/5) which consists of dense irregular connective tissue with bundles of collagen and some coarse elastic fibers. Spaces b/n fibers contain adipose cells, hair follicles, nerves, sebaceous glands.

INTEGUMENTARY SYSTEMSkin color:3 pigments:1. Melanin2. Hemoglobin3. Carotene

+ Albinism – inherited inability to produce melanin

+ Vitiligo – partial loss of melanocytes from patches of skin producing white irregular spots

INTEGUMENTARY SYSTEMSkin color:

CYANOTIC – bluish; decreased oxygen in tissuesJAUNDICE – yellow; buildup of bilirubin in the skin (liver disease)ERYTHEMA - redness; engorgement of capillaries in the skinPALLOR – paleness; shock, anemia

INTEGUMENTARY SYSTEM+ TATTOOING-Permanent coloration of the skin in which a foreign pigment is deposited with a needle into the dermis

+ ACNE- Inflammation of sebaceous glands that usually begins at puberty, when the sebaceous glands grow in size and increase in production of sebum

INTEGUMENTARY SYSTEMFUNCTIONS OF THE SKIN:

1. Thermoregulation2. Blood reservoir3. Protection4. Cutaneous sensations5. Excretion and Absorption6. Synthesis of Vitamin D

INTEGUMENTARY SYSTEM+ Calcitriol-Most active form of Vitamin D-Hormone that aids in the absorption of calcium in foods from the Gastrointestinal Tract into the blood

TACTILE SENSATIONS:1. Crude touch – Ruffini corpuscles2. Fine touch – Merkel discs3. Pressure and Vibration –

Lamellated or Pacinian corpuscles

Please bring out any piece of paper and prepare for a quiz..

GOOD LUCK!

QUESTION:

1. This protects the body, helps maintain a constant body temperature, and provides sensory information about the surrounding environment

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2. This is a group of tissues performing specific functions

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3. This is a group of organs performing specific functions

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4. This is the inherited inability to produce melanin

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5. This is the deeper part of the skin that is mainly composed of connective tissue

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6. These arise from red bone marrow and migrate to the epidermis, where they constitute a small fraction of the epidermal cells

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7. This is a yellow-red or brown-black pigment that contributes to skin color and absorbs damaging UV light

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8. This is the medical specialty that deals with the diagnosis and treatment of integumentary system disorders

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9. These are nerve endings that are sensitive to pressure and vibration

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10. This is the superficial portion of the dermis (1/5) which consists of areolar connective tissue with elastic fibers

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11. Yellowish color of the skin which indicates liver disease

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12. This is the permanent coloration of the skin in which a foreign pigment is deposited with a needle into the dermis

QUESTION:

13. This is the most active form of Vitamin D?

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14. These are the least numerous of the epidermal cells

QUESTION:

15. These are the most numerous epidermal cells