Microscopic Anatomy modulejjjiuuuuujiiiu

Hh

1. Microscopic Anatomy Introduction of the cell

2. What is a cell? A cell is the basic structural and functional unit of all living organisms. Interestingly, cells can exist as single units, like bacteria, or as part of a larger organism.

3. There are two main types of cells: Prokaryotes and Eukaryotes

4. Prokaryotic cell lack nucleus and include organism like bacteria Eukaryotic cell have nucleus and membrane bound organelles like plants and animal.

5. THE basic structure are : • The cell membrane- which act as a protective barrier. • The cytoplasm is jelly-like substance that holds the cells components. • The nucleus- is the control center in the eukaryotic cell. • Organelles- specialized structures that perform specific functions like energy production or protein synthesis.

6. Cells perform a variety of functions essential for life, including : • Providing structure and support to organisms. •Facilitating growth through processes like mitosis. •Transporting nutrients and eliminating waste. •Carrying out metabolic activities and enabling reproduction. These functions highlight the importance of cells in maintaining life.

7. Cells perform a variety of functions essential for life, including: • Providing structure and support to organisms. • Facilitating growth through processes like mitosis. • Transporting nutrients and eliminating waste. • Carrying out metabolic activities and enabling reproduction. These functions highlight the importance of cells in maintaining life.

8. Membrane transport Membrane transport refers to the movement of substances across the cell membrane. The cell membrane is selectively permeable, meaning it controls what enters and exits the cell. This regulation ensures that essential molecules like nutrients and oxygen get in while waste products are removed.

9. There are two main types of membrane transport: Passive Transport, which does not require energy. Active Transport, which requires energy in the form of ATP.

10. Passive transport. Passive transport is driven by the natural movement of molecules from areas of high concentration to low concentration. There are three main types: Diffusion – Movement of small molecules like oxygen and carbon dioxide directly through the membrane. Facilitated Diffusion – Uses protein channels or carriers to move larger or charged molecules, such as glucose or ions. Facilitated diffusion is specific and saturable: mediated by carrier proteins. It implies a conformational change of the protein. 3. Osmosis – The movement of water molecules through a semipermeable membrane, from a region of low solute concentration to high solute concentration."

11. Active transport Active transport moves substances against the concentration gradient, from areas of low concentration to high concentration. This process requires ATP. An example is the sodium-potassium pump, which helps maintain the electrochemical gradient essential for nerve impulses and muscle contractions."

12. Functions of sodium and potassium Provides energy for the 2nd transport of other molecules Nerve and muscle cells use the k+Na + gradient to produce electrical impulses Active Na+ output is important to maintain cellular osmatic balance Diffusion of Na+ into the cell (down the gradient) provides for movement of another molecule against the gradient .

13. Symport: the other molecule moves in the same direction as Na+ Antiport: in the opposite direction

14. Microscopic Anatomy Cytoplasm, Cytoskeleton and Organelles

15. Cytoplasm and Cytoskeleton The cytoplasm is the cellular content found between the plasma membrane and the nucleus. It is the site for all intracellular (inside) activities occurs except the nucleus. The Cytoskeleton is a network of protein filaments that provides shape, support, and movement for the cell.

16. Cytoskeleton Protein filaments Actin/ Microfilament Thin and flexible. Intermediate are combinations of protein and Microtubules they are huge hallow components they aid in cell shapes, support, movements and organization.

17. Organelles Organelles are specialized structures with characteristic shapes and specific functions in the cellular processes. Such as the Nucleus, Mitochondria, Ribosomes, Endoplasmic Reticulum (ER), Golgi Apparatus Lysosome ….

18. Cell division

19. Microscopic Anatomy Introduction to Tissues

20. Tissue Tissues are group of similar cells that perform specific function. They are four main types of tissues: 1. Epithelial tissue 2. Connective tissue 3 . Muscular tissue 4 .Nervous Tissue

21. Epithelial tissue Characteristics 1. Cellularity – Composed mostly of tightly packed cells with little or no extracellular matrix. 2. Polarity – Has an apical (free) surface and a basal surface attached to the basement membrane. 3. Avascular – Lacks blood vessels and relies on diffusion for nutrients. 4. Regeneration – Capable of rapid cell division and renewal.

22. Types of Epithelial Tissue Epithelial tissues are classified based on the number of layers and the shape of cells: Based on Layers 1 . Simple Epithelium – Single layer of cells; functions in absorption, secretion, and filtration. 2. Stratified Epithelium – Multiple layers of cells; provides protection against wear and tear. 3. Pseudostratified Epithelium – Appears multilayered but is a single layer with varying cell heights.

23. Based on Cell Shape 1. Squamous – Flat, thin cells; found in areas of diffusion (e.g., lungs, blood vessels). 2. Cuboidal – Cube-shaped cells; involved in secretion and absorption (e.g., kidney tubules). 3. Columnar – Tall, column-like cells; found in the digestive tract for absorption.

24. Connective Tissue Definition Connective tissue is a type of tissue that supports, binds, and protects other tissues and organs. It has a large amount of extracellular matrix, which distinguishes it from epithelial tissue. Characteristics 1. Extracellular Matrix – Contains fibers (collagen, elastin) and ground substance. 2. Vascularity – Varies; some connective tissues (e.g., bone) are highly vascular, while others (e.g., cartilage) are avascular. 3. Widely Spaced Cells – Unlike epithelial tissue, connective tissue has fewer cells embedded in the matrix.

25. Differences Between Epithelial and Connective Tissue Conclusion Epithelial and connective tissues are fundamental components of the human body, each playing a crucial role in maintaining homeostasis. While epithelial tissue primarily covers and protects, connective tissue supports and binds structures together. Their structural differences enable them to perform their respective functions effectively. Understanding these tissues is essential in fields like medicine and biology, as they form the foundation of organ systems.