History of the Microscope and SEM

Scanning Electron Microscope (SEM)

• SEM provides high-resolution images by using a focused beam of electrons.
• It is used for surface morphology and texture analysis of specimens.

History of the Microscope

• The development of microscopes has seen significant evolution over centuries.
• Early microscopes included the basic compound microscope, culminating in advanced types like electron microscopes.

Types of Electron Microscopes

• Transmission Electron Microscope (TEM) allows for viewing internal structures at extremely high magnification.
• Electron microscopes contrast structural details invisible to light microscopes, revealing cellular and sub-cellular features.

Themes of Anatomy and Physiology

• Anatomy studies the structure organs and body parts, while physiology examines their functions and interactions.
• Both fields are essential for understanding the complexity of living organisms.

Principles of Cell Theory

• All living organisms are composed of one or more cells.
• Cells are the basic unit of life and arise from pre-existing cells.

Prokaryotic vs. Eukaryotic Cells

• Prokaryotic cells lack a nucleus and membrane-bound organelles; they are generally smaller and simpler.
• Eukaryotic cells have a nucleus and are complex, with various organelles performing specific functions.

Key Cell Organelles

• Nucleus: Control center of the cell, containing genetic material.
• Ribosomes: Sites of protein synthesis, found in both prokaryotic and eukaryotic cells.
• Mitochondrion: Powerhouse of the cell, responsible for energy production.
• Cytoplasm: Jelly-like substance where organelles are located and cellular processes occur.
• Cytoskeleton: Provides structural support and helps in cell movement.
• Vacuole: Storage organelle; larger in plant cells for maintaining turgor pressure.
• Endoplasmic Reticulum: Site for protein and lipid synthesis; rough ER has ribosomes, smooth ER does not.
• Lysosomes: Contain digestive enzymes to break down waste materials and cellular debris.
• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion or use within the cell.
• Peroxisome: Breaks down fatty acids and detoxifies harmful substances.
• Vesicles: Small membrane-bound sacs that transport materials within the cell.

Differences Between Plant and Animal Cells

• Plant cells have a rigid cell wall and large central vacuoles, aiding in structure and storage.
• Animal cells lack cell walls and may contain small, temporary vacuoles.