Integumentary System

Cards (90)

  • General Characteristic of Integumentary System:
    • Integument/ Cutaneous layer
    • Largest single organ of the body
    • 15-20% of total body weight
  • Functions of skin:
    • Protection
    • Sensory
    • Thermoregulatory
    • Metabolic
    • Sexual signaling
  • It covers the palms and soles (400 to 1400 micrometer)
    Thick skin
  • It covers the whole body except palms and soles (varies from 75 to 150 micrometer)
    Thin skin
  • Characteristics of Epidermis:
    • Stratified squamous keratinized epithelium
    • lack vasculature
    • receive nutrients from the dermis
  • Keratinocyte
    • Primary cells
    • Located at the epidermis
    • Originate the stratum basale and move up to the final barrier of the skin, stratum corneum
  • Melanocyte:
    • Located at the basal epidermis
    • Neutral crest derived
    • Pale-staining, rounded cell bodies
    • Synthesizes dark melanin pigment in melanosomes
    • Protects nuclear DNA from UV damage
    • Disease related to melanocyte: Albinism and vitiligo
  • It is brown or black pigment; found in hair follicle
    Eumelanin
  • Termed as red hair
    Pheomelanin
  • A condition wherein the less melanin than usual in the body; condition that leads to having very light skin, hair and eyes.
    Albinism
  • It is due to defect in the enzyme tyrosinase
    Albinism
  • A disorder that cause patches of skin to lose pigment or color; happens when melanocyte are attaked and destroyed
    Vitiligo
  • Three general layers of the skin:
    Epidermis
    Dermis
    Hypodermis (subcutaneous layer)
  • What are the cells present in epidermis?
    Keratinocyte
    Melanocyte
    Langerhans
    Merkel cell
  • Responsible for sensing gentle touch?
    Merkel cell
  • What is the pigment that produced by melanocyte?
    melanin
  • It is decrease activity of melanocyte
    Vitiligo
  • Where does the langerhans cell located?
    Stratum spinosum
  • Langerhan cells:
    • Antigenic presenting cell
    • 2-8% of cells in epidermis
    • Bind, process and present antigen to T-lymphocytes
  • Aka Epithelial Tactile Cells
    Merkel cells
  • Merkel cells:
    • Mechanoreceptors for light touch
    • Abundant in fingertips and bases of some hair follicles
    • Small, golgi-derived dense-core neurosecretory granules containing peptides
  • Where does the melanocyte is located?
    basal epidermis or stratum basale
  • Neural crest derived
    Melanocyte
  • Layers of the Epidermis:
    All layers have thick and thin skin except Stratum lucidum which has thick skin only.
  • Enumerate the layers of the epidermis:
    1. Stratum corneum
    2. Stratum lucidum
    3. Stratum granulosum
    4. Stratum spinosum
    5. Stratum basale
  • It is keratin-filled keratinocyte
    squames
  • Stratum corneum:
    • 15-20 layer of dead, flattened, anucleate, keratin-filled called squames
    • Layer of dead keratinocytes
    • Bound by hydrophobic lipid-rich segment which provides protection against water loss and friction
  • What are the layers of skin that have function of protection of Water loss?
    Stratum corneum and Stratum granulosum
  • What are the functions of squames?
    Protection for friction and water loss
  • How many layers of anucleate dead cells in stratum lucidum?
    2-3 layers
  • Stratum granulosum:
    • 3-5 layers of keratinocyte
    • Contains kerato-hyaline granules
    • intensely basophilic
    • Contains lamellar granules which produces lipid-rich impermeable for barrier against water loss
  • It is lipid-rich impermeable layer around the cells forming a major part of the skin's barrier against water loss
    lamellar granules
  • Considered as thickest layer among stratums
    Stratum spinosum
  • Stratum spinosum:
    • Thickest layer
    • Consists polyhedral cells having central nuclei with nucleoli and cytoplasm actively synthesizing keratins
    • Several layers of keratinocyte all joined by desmosomes
    • Contains tonofibrils, prickle cells
    • Cells may still divide
    • Contains Stratum germinativum
  • It binds to our desmosomes thus forming spines between keratinocytes in the stratum spinosum
    tonofibrils
  • Structure present in the stratum spinosum that causes keratin or prickle
    tonofibrils
  • Keratinocytes in our stratum spinosum
    Prickle cell
  • Where does mitosis occurs?
    Stratum basale
  • Stratum basale:
    • Single layer of cuboidal to low columnar cells in contact with basement membrane
    • Mitosis occurs
    • Melanocytes and Merkel cell also present
  • Where does merkel and melanocyte are present?
    Stratum basale