ILS-3 histology Flashcards
Cell Biology (Cytology)
Studies the cell’s– structure, composition, metabolism, cycle, function, behavior, and communication
first two scientists to discover cells under the microscope
Robert Hooke , Antoni van Leeuwenhoek
how are cells studied
Study of cells through– cell culture, microscopy techniques, cytometry, and cell fractionation
Histology
study microscopic structure of normal biological cells and tissues
using light and electron microscope
main uses of Histology and Histopathology:
- show changes in tissues that occur at cellular level
ii) Medicine– identification of normal and abnormal tissue, diagnosis, and analysis of effects of treatment
iii) Autopsies and forensic investigations– for identifying the cause of death from microscopic
tissue examination
how are tissues prepared
Tissue (sample) preparation and processing– selection, sectioning, trimming, embedding in a harder medium, and chemical fixation
with what are tissues stained
Tissue staining– Hematoxylin stains cell nuclei blue, and
Eosin stains the cytoplasm and other tissues in pink
Hematoxylin
Hematoxylin stains cell nuclei blue, and
Eosin
Eosin stains the cytoplasm and other tissues in pink
tissue examples
group of cells with a similar structure that have a definite and unique function
– include epithelial tissue, connective tissue, nerve tissue, and muscle tissue
cell
Cell– basic microscopic building block of human body
– smallest and basic structural and functional unit of various organs essential for sustaining life
Plasma membrane
Plasma membrane– lipid bilayer (phospholipid, cholesterol, hydrophilic head, hydrophobic tail)
-passive and active transport
- cell adhesion, ion conductivity, and cell signaling
-provide attachment surface for several extracellular structures and intracellular network of cytoskeleton
-lipid-soluble substances (e.g, oxygen, carbondioxide, and nitrogen,
-water-soluble substances (e.g, ions, glucose, aminoacids, and water,
cytosol (cytoplasm)
Sodium is the major cation in extracellular fluid (ecf)
– Potassium is the major cation in intracellular fluid (icf)
– Calcium, Chloride, and Bicarbonate are present in relatively more concentration in ecf
– Magnesium, and Proteins are present in relatively more concentration in icf
nucleus
Nucleus– surrounded by nuclear membrane (nuclear pores), contain genetic information (DNA/chromosomes/chromatin), controls cell growth and multiplication by regulating gene expression, initiating cellular reproduction, site for DNA replication and RNA synthesis using DNA as template (Transcription), contain nucleolus (rRNA is made)
Ribosomes-
protein synthesis (translation– During translation, ribosomes synthesize polypeptide chains from mRNA template molecules),
Rough endoplasmic reticulum (RER)
synthesizes proteins in sacks called cisternae
compromised structure and functions of RER can lead to these diseases
diabetes, inflammation, and neurodegenerative disorders including Alzheimer’s disease, Parkinson’s disease, and bipolar disorder
Smooth endoplasmic reticulum functions
– carry out synthesis of lipids (e.g, cholesterol) and phospholipids and secretion of steroid hormones
store and release of calcium ions (e,g, in muscles– sarcoplasmic reticulum
detoxification of natural metabolic products, alcohol, and drugs
Golgi apparatus/body/complex:
sorts new proteins made on RER, perform post-translational modifications (e.g, glycosylation, etc) in newly synthesized proteins, packages proteins and carbohydrates into membrane-bound transport vesicles for export from the cell