Cell. Human anatomy for med students .pptx

O comprehensive overview of cell , tissue

1. The Cell Diversity

2. Outline Definition of Cell Structure of the Human Cell Function of Cell

3. Objectives of studying Cell diversity To know the cells of human body structure, shape and sizes. Explain those cells and structure how to related to our body. To describe the function of cell our body.

4. Definition of Cell “A cell is defined as the smallest, basic unit of life that is responsible for all of life's processes.” Cells are the structural, functional, and biological units of all living beings. A  cell  is the structural, functional, and biological unit of all  organisms . For example: Plant, Animals and Humans. So, I want to talk about the human cell.

5. Cell Diversity Describe how human cells differ in size and shape The size of cell Cells have a diverse range of sizes and shapes, and they are characterized by their microscopic nature. Body of Human adult is composed nearly 100 trillion cells. All cells can be classified into 200 different cell types. For instance human sperm cells are only about 0.0002 inch long and 0.00012 inch wide or human ova or egg cell more than 20 times bigger with a diameter of 100hmeter. The size of cells are measured in unit is called micrometer. 1hmeter = 10 -6 meter The largest cell a single oocyte has a diameter above 140hmeter visible to an aided eye. Red blood cell has a diameter of 8hmeter The cell in the body range from 8hmeter to 140hmeter in size.

6. Shape of cell Shape of cell can also vary considerably they are: Round shape Oval shape Flat shape Cube shape Columen shape Elongated shape Star shape Cylindrical shape Disk shape

7. Cont… The cell shape is related to its function in the body Example 1:- Sperm cell – has a low whiplike tail or flagellum that is used for locomotion. Example 2:- The disk shape of red blood cell gives it a large surface area that enhances its ability to pass oxygen to other cell. Example 3:- The long spindle shape of a relaxed smooth muscle cells shortness as it contracts

8. Components of the Cell Cells have 3 main part Cell membrane Protoplasm Nucleus  

9. 1. Cell membrane Also called Plasma membrane or Plasmalemma . About 7.5-10nm thick. Freely permeable to small and nonpolar lipid soluble molecules , but impermeable to charged ions .

10. Cell membrane Cell membrane made by the following components Lipids Proteins Carbohydrates

11. Functions of the cell membrane Selective permeability Endocytosis Is bulk uptake of materials across the plasma membrane that involves folding and fusion of the membrane to form vesicles (vacuoles). Phagocytosis ("cell eating") Pinocytosis ("cell drinking") 3. Exocytosis Secretion or excretion

12. 2. Protoplasm Cytoplasm ( cytosol ) Organelles Inclusions

13. Protoplasm Organelles. Metabolically active structures performing distinct functions. Divided into: Membrane bound organelles. Non-membrane bound organelles .

14. Membranous organelles Endoplasmic reticulum Golgi complex (bodies or apparatus) Lysosomes Peroxisomes ( microbodies ) Mitochondria

15. Endoplasmic Reticulum Network of anastomsing membrane channels ( cisternae ) that may be elongated, flattened, round or tubular . There are two types of endoplasmic reticulum Rough or granular endoplasmic reticulum (RER) Smooth or agranular endoplasmic reticulum (SER)

16. Rough or granular endoplasmic reticulum (RER) With attached ribosomes via protein called ribophorins . Show continuity at various points with the outer nuclear membrane Synthesize proteins For export out of the cell For integral proteins of the plasma membrane . Lysosomes .

17. Smooth or agranular endoplasmic reticulum (SER) Irregular network of anastomosing channels that have more tubular or vesicular cisteranae than the RER, and with no ribosomal attachments. Functions in: Synthesis of steroid hormones Lipid metabolism Glycogen breakdown Detoxification Store and release calcium ions in the striated muscle cells

18. Golgi complex (bodies or apparatus) Functions in: Synthesis of polysaccharides Modifications of secretory products Packaging of secretory products received from the RER for exocytosis . Ex:- Lysosomes are also packaged here. Concentration and storage of secretory products prior to secretion Made by: Stalk of 3-10 discrete flattened and slightly curved bag-like channels or cisternae . Located usually near the nucleus and centrioles

19. Lysosomes A lysosome is a membrane-bound cell organelle that contains digestive enzymes. Lysosomes are involved with various cell processes. Function of lysosomes Hetrophagy of foreign organisms Autophagy of nonfunctional organelles or excess cytoplasmic structures autolysis in cause of programmed cell death.

20. Peroxisomes Are like the lysosmes , but larger in diameter Produce hydrogen peroxide (H 2 O 2 ) to kill microorganisms and detoxifies toxic agent Main function of peroxisomes The main function of peroxisome is the lipid metabolism and the processing of reactive oxygen species. Other peroxisome functions include: They take part in various oxidative processes.

21. Mitochondria Spherical, filamentous or rod-shaped Are the largest organelles, 2-7 μm long and 0.2 μm wide Has double membranes Outer smooth membrane Forming a continuous porous covering b. Inner membrane - Are less porous - Makes cristae

22. Cont… Functions include Generate and store ATP Synthesize DNA and proteins .

23. Non membranous organelles Ribosomes Cytoskeleton - Microtubule - Microfilaments - Intermediate filaments - Centrioles

24. 1. Ribosomes Measure 12 by 25 nm Intensely basophilic: sites of protein synthesis. • In glandular cells ( ergastoplasm ). • In neurons ( Nissl bodies). • Other cells (basophilic bodies).

25. 2. Cytoskeleton A complex network of protein filaments involved in: Gel-like consistency of cytoplasm Maintenance of cell shape Structural framework Movements of organelles, vesicles and entire cells.

26. Protoplasm Inclusions Are accumulations of metabolically inactive materials made by: Metabolic by products Storage forms of various nutrients Inert crystals and pigments  

27. The Nucleus Oval, elongated or flattened in shape. 5-10 µm in diameter Usually one in number per cells, but may be two or multiple in some cells. May be located centrally, basally or eccentrically in different cells.

28. Nucleus Composed of: Nuclear envelope Chromatin Nucleolus Nucleoplasm

29. Nuclear envelope Double membrane that run parallel to each other . Show perinuclear cisterna of 30-50 nm in diameter Nuclear pores . Nuclear pores Up to several thousands and 80-100 nm in diameter. Make the nuclear pore complex along with a nonmebranous glycoproteins known as nucleoporins fitted into the pores.

30. Chromatin Is composed of DNA and associated histone and nonhistone proteins that undergo a super helical coiling to give repeating structural units called nucleosomes

31. Nucleolus Round basophilic non-membrane bound region usually located eccentrically within the nucleus. Is site of rRNA synthesis and assembly of ribosomes .

32. Reference Principle of anatomy and physiology volume 1 pg64 & pg103 and John Wiley & Sons. Inc International student version The Human body how its work cell tissue and skill Donna M. Bozzone . PhD. And Douglasb Light PhD. (Third Edition) Cell Biology: Basic Research and Application book Molecular Biology of The cell - NCBI bookshelf from National institute of Health https://www.drnaitiktrivedi.com/

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