integumentary system

• What are the two major categories of body membranes?

  Epithelial and connective tissue
• What are the three types of epithelial membranes mentioned?

  Cutaneous membrane, mucous membranes, and serous membranes
• Why is it misleading to call cutaneous, mucous, and serous membranes purely epithelial?

  They always contain an underlying layer of connective tissue
• What is the cutaneous membrane commonly known as?

  Skin
• What type of epithelium composes the superficial epidermis of the cutaneous membrane?

  Keratinizing stratified squamous epithelium
• What type of connective tissue primarily makes up the underlying dermis of the cutaneous membrane?

  Dense fibrous connective tissue
• What is a characteristic of the cutaneous membrane compared to other epithelial membranes?

  It is exposed to air and is a dry membrane
• What does a mucous membrane line?

  All body cavities that open to the exterior
• What is the term used to refer to the loose connective tissue membrane associated with mucous membranes?

  Lamina propria
• What types of epithelial tissue are most mucosae composed of?

  Stratified squamous epithelium or simple columnar epithelium
• Why are mucous membranes considered "wet"?

  They are almost continuously bathed in secretions
• What is the primary function of the epithelium of mucosae?

  Adapted for absorption, secretion, and/or replacement
• What is a serous membrane also known as?

  Serosa
• What type of epithelium composes a serous membrane?

  Simple squamous epithelium
• How do serous membranes differ from mucous membranes in terms of location?

  Serous membranes line closed body cavities, while mucous membranes line open cavities
• What are the two layers of serous membranes called?

  Parietal layer and visceral layer
• What does the serous fluid do?

  It allows organs to slide easily against each other
• What is the primary function of the integumentary system?

  To protect the body
• What are some functions of the skin?

  Protects from water damage, mechanical damage, and chemical damage
• What is the outermost layer of the skin called?

  Stratum corneum
• What is the primary component of the epidermis?

  Stratified squamous epithelium
• What happens to epidermal cells as they move away from the dermis?

  They become keratinized and eventually die
• What is the role of keratin in the skin?

  It toughens the cells and provides a protective layer
• What is the significance of the stratum basale?

  It contains the only epidermal cells that receive adequate nourishment
• How does the skin regulate heat loss?

  By activating sweat glands and allowing blood to flush into skin capillary beds
• What is the function of the subcutaneous tissue?

  It anchors the skin to underlying organs and serves as a shock absorber
• What are the five layers of the epidermis called?

  Stratum basale, spinosum, granulosum, lucidum, and corneum
• Why can a man shave daily without bleeding?

  The epidermis is avascular and has no blood supply of its own
• What is the role of melanocytes in the skin?

  They produce melanin, which offers protection from UV radiation
• What happens to the cells in the stratum corneum?

  They are dead and filled with keratin
• What is the common saying related to the stratum corneum?

  "Beauty is only skin deep"
• What are the two superficial layers of the epidermis mentioned in the text?

  Stratum spinosum and stratum granulosum
• What happens to epidermal cells as they move away from the dermis?

  They become flat, increasingly full of keratin, and eventually die
• Where does the stratum corneum occur, and what is its significance?

  It occurs only on hairless and extra thick skin, like the soles of hands and feet
• Why are stratum corneum cells unable to get adequate nutrients and oxygen?

  Because they are far from the blood supply in the dermis
• How thick is the stratum corneum?

  20 to 30 cell layers thick
• What are corneocytes?

  Dead cell remnants in the stratum corneum filled with keratin
• What does the saying "Beauty is only skin deep" imply in the context of skin structure?

  It highlights that what we see is mostly dead keratin
• What protective functions does the stratum corneum serve?

  It protects deeper cells from germs, water loss, and physical assaults
• How often do we have a completely new epidermis?

  Every 25 to 45 days