Histologie 2 et 6

Histologie 2

• Cellule: The basic structural and functional unit of living organisms.
• In the human body, there are approximately 100 trillion cells.
• There are around 200 different cell types.
• Average cell size: 200 micrometers.
• Tissues: There are four main types of tissues.
  • Epithelial tissue: Covers surfaces and secretes substances.
  • Muscle tissue: Provides movement.
  • Connective tissue: Supports and connects other tissues.
  • Nervous tissue: Regulates and coordinates body functions.
• Tissue Level: Cells sharing the same morphology and function are grouped together.
• Microscopy Techniques:
  • Macroscopic observations: Visible to the naked eye (e.g., human, chicken).
  • Microscopic observation: Using a microscope (e.g., light microscope).

Histologie 6

• Hormones act at a distance: Endocrine glands release hormones into the bloodstream, affecting target cells.
• Hormones action: Act on cells via receptors on the cell surface or in the cytoplasm.
• Hormone secretion:
  • Solid clusters: Cells grouping together in round shapes.
  • Cordons: Cells forming rows or bands, usually surrounded by capillaries.
  • Follicles: Cells arranged in a circle around a cavity. The follicle contains a fluid.
• Amphicrine glands: Perform both endocrine (into the blood) and exocrine (via ducts) functions. Examples include the pancreas (insulin, glucagon, digestive enzymes).
• Pancreas: Functions as both an endocrine and exocrine gland.
• Blood sugar regulation: The pancreas helps maintain blood sugar levels by releasing glucagon, which raises blood sugar, and insulin, which lowers it.
• Hypoglycemia/Hyperglycemia: Imbalance of blood sugar levels, with factors like diet.

Histologie 1

• Levels of organization:
  • Chemical level (atoms, molecules, macromolecules).
  • Cellular level (organelles, cells).
  • Tissue level
  • Organ level
  • Organ system level
  • Organism level
• Biomolecules:
  • Organic: Carbohydrates, Lipids, Proteins, Nucleic acids.
  • Inorganic: Water, Salt, Acids/Bases.
• Organelles: Specialized structures within cells performing specific functions (mitochondria, endoplasmic reticulum, etc.).

Histologie 3

• Epithelium: Tightly packed cells forming layers.
• Basement membrane: Separating the epithelium from underlying tissues.
• Epithelial classifications:
  • Simple, stratified, pseudostratified according to layering.
  • Squamous, cuboidal, columnar based on cell shape.
• Uni-stratified: A single layer of simple cells.
• Pseudo-stratified: A single layer of irregularly shaped cells, appearing layered.
• Stratified: Multiple layers of cells with deeper layers dividing.

Histologie 8

• Glandular epithelium: Cells specialized in secretion.
• Exocrine glands: Secrete substances into a duct (e.g., salivary glands).
• Endocrine glands: Secrete substances into the bloodstream (e.g., thyroid, pituitary).
• Modes of secretion: Merocrine, apocrine, holocrine.
• Functional classifications: Serous, mucous.

Histologie 7

• Wound Healing: The dynamic process of tissue repair after injury.
• Types of wounds (1, 2, 3, 4 degree)
• Wound characteristics: Appearance, depth, pain, affected areas
• Wound healing stages

Histologie 10

• Bone Tissue:
  • Formation pathways (Intramembranous, Endochondral).
  • Ossification process.
  • Compact and spongy bone structure.
  • Repair and remodelling.

Histologie 9

• Connective Tissue types:
• Specialized and Non-Specialized connective tissues
• Connective tissue composition
• Extracellular matrix
• Composition of the cells

Histologie 11

• Nervous tissue: Made up of neurons and glial cells.
• Nervous system components: Central and peripheral systems.
• Brain tumors (gliomas): Diagnosis and Imaging methods.