Histology

Componente of cytoplasme

Definition of histology and histopathology

• Histology is : Studding of normal structures or normal

tissues .• Histopathology is : Studding of abnormal structures or abnormal

tissues (disease) tissues

Types of the tisseus

• Cells work together in functionally related groups called tissues

• Types of tissues:1. Epithelial – lining and covering2. Connective – support 3. Muscle – movement4. Nervous – control

Definition of the eukaryotic cell

• Eukaryote : mean group of organisms whose cells have defined nucleus surrounded by nucleus membrane

• So the cell its real cell content real nucleus or defined nucleus

• In general the cell it’s the functional unite of the body .

• In contrast of prokaryote cell

Component of the cell

• Each real cell consiste of two main structures• Cytoplasm• Nucleus• Each real cell surrounded by lipid membrane

called plasma membrane or plasmalema (pm)

Componente of cytoplasme

Content the following organeles and inclusion :

• Plasma membrane• Mitochondria• Ruogh endoplasmic

reticulum• Smooth endoplasmic

reticulum• Golgi apparatus• phagocytosis

• Lysosomes • centrosome• Cellular pigments• Glycogen• Lipid• Cytoskeleton• Microfliments• Intermediate filiments

and microtubules

Plasma Membrane

composed of : double layer phospholipids, cholesterol,

proteins, and chains of oligosaccharides covalently linked to phospholipids and protein molecules.

functions as a selective barrier that regulates the passage of certain materials into and out of the cell and facilitates the transport of specific molecules.

Plasma Membrane

Function of mitochondrium

• Each Mitochondrium is bounded by two membranes:

1 - smooth outer one,2- and an inner one which

is thrown into folds called cristae.

• The mitochondrium provides the energy for the cell .

Function Rough-endoplasmic reticulum - rER

• The outer membrane of the rER is studded with ribosomes.

• The rER plays a major role in protein synthesis.

Function Smooth-endoplasmic reticulum

• The lining of the smooth endoplasmic reticulum is smooth .

• has no ribosomes.• has branched tubules.• It plays a major role in

lipid biosynthesis (makes lipids and steroids)

• and in detoxification mechanisms.

Function of Golgi-apparatus

• is usually found close to the cell nucleus and consists of one or more stacks of membrane-bound cisternae (sacs).

• The Golgi receives synthetic products from the ER, modifies them, and exports them to a variety of destinations.

• It also produces enzymes that are sorted into lysosomes, to degrade proteins and organelles. It also plays a role in retrieving and recycling proteins.

Function of Lysosomes

• Primary lysosomes are produced by the Golgi apparatus.

• Lysosomes fuse with the organelles to form secondary lysosomes.

• They contain around 40 different types of hydrolytic enzymes,

• phagocytosis and require digesting, or organelles that require degrading

• Lysosomes are important for breaking down proteins.

Cytoskeleton

• Cells have three types of filaments

1- microfilaments - actin filaments (red in the diagram)

2- intermediate filaments (blue in the diagram)

3- microtubules (green in the diagram).

Collectively, these are known as the cytoskeleton.

Functions of Cytoskeleton

• are important in cell shape and cell motility.

• also important in mitosis, and are important constitutents of cilia

• Also in cell – cell junction

Method of visulization

• To study cells, biologists use microscopes and the tools of biochemistry

• Scientists use microscopes to visualize cells that are too small with the naked eye

• Light microscopes (LM.s)– Pass visible light through a specimen– Magnify cellular structures with lenses

• Electron microscopes (EM.s)– Focus a beam of electrons through a specimen (TEM) or

onto its surface (SEM)

THE END

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