Key Concepts from Burn Patient Care and Cell Biology

Risks When Working with Burn Patients

• Major Concerns
  • Infection
  • The skin acts as a barrier protecting against microorganisms.
  • Extensive burns result in the loss of this barrier, significantly increasing infection risk.
  • Dehydration
  • The skin also prevents water loss.
  • Damaged skin leads to considerable fluid loss, risking dehydration.

Functions of the Skin

• Protection
  • Protects against dehydration and infection.
• Healing Process
  • Upon injury, cellular responses include:
  • Cells detach from the basement membrane.
  • Increased cell motility to migrate and cover the wound.
  • Enhanced cell division to replace lost or damaged cells.

Growth Factors and Wound Healing

• Role of Growth Factors
  • Produced by damaged cells and present in blood plasma.
  • Bind to cell receptors and activate intracellular signaling pathways.
• Signal Transduction
  • The binding of growth factors activates pathways like G-proteins and cyclic AMP, leading to:
  • Activation of transcription factors.
  • Changes in gene expression, leading to cellular responses critical for healing.

Abnormal Cell Behavior: Cancer

• Similarities with Healing Responses
  • Behaviors like increased motility, division, and changes in signaling in wound healing can also lead to cancer if persistent.
  • Mutations in DNA repair pathways can cause:
  • Cancer cells to produce their own growth factors.
  • Constant activation of signaling pathways, leading to uncontrolled growth.
• Cell Cycle Checkpoints
  • Normal cells have checkpoints during mitosis to prevent uncontrollable division.
  • If a checkpoint fails and repairs cannot be made, normal cells undergo apoptosis, unlike cancer cells.

Types of Cancer

• Basal Cell Carcinoma
  • The least dangerous skin cancer, typically does not metastasize.
• Melanoma
  • A highly dangerous skin cancer due to its ability to metastasize.
  • Noted for affecting organs like the lungs once spread occurs.

Tumors and Neoplasms

• Definitions
  • Tumors refer to abnormal growths, while neoplasms encompass cancers (both sarcomas and carcinomas).
  • Carcinomas: Cancers originating from epithelial tissues.
  • Sarcomas: Cancers of muscle or connective tissue.

Functions of Eccrine and Apocrine Sweat Glands

• Eccrine Glands
  • Function in thermoregulation (cooling the body).
• Apocrine Glands
  • Activated by emotional stress or nervousness.

Skin Texture and Healing

• Dermis Composition
  • Mostly dense irregular connective tissue for strength and elasticity.
• Importance of Collagen and Elastic Fibers
  • Collagen: Provides strength.
  • Elastic Fibers: Allow for stretch and recoil.

The Role of Melanin and Keratin

• Melanin
  • Protects against ultraviolet radiation.
• Keratin
  • Provides toughness to the skin, especially in areas experiencing abrasion.

Vitamin D and Its Health Effects

• Production and regulation of calcium homeostasis.
• Recent studies suggest additional roles, including potential cancer prevention.

Feedback Mechanisms in the Body

• Negative Feedback Loop
  • Essential for maintaining homeostasis, such as regulating blood glucose levels.
• Positive Feedback Loop
  • Amplifies a process or increases output, e.g., during childbirth.

Exam Preparation Tips

• Expect a variety of question formats (more writing than multiple choice).
• Be familiar with organ systems and definitions.
• Understand examples and functionalities of biological systems to aid in practical applications.