Cell Systems Flashcards
What is the Hierarchy of Atoms to Organism?
Atoms –> Molecules –> Macromolecules –> Internal Cell Structures –> Cells –> Tissues –> Organs –> Organ Systems –> Organism
What is Histology?
The study of the microscopic structures of tissues.
What are the five stages of Histology?
1) Fixation
2) Embedding
3) Sectioning
4) Staining
5) Visualize
How do Light Microscopes work?
By passing light through a sample, or reflecting it off the sample (dissection microscope). Glass lenses magnify the image. Has a limited resolution - light scatters away from the focal plane.
What are the three different types of light microscopy?
- Brightfield
- Darkfield
- Phase contrast
What are Fluorescence Microscopes?
They are microscopes with a higher resolution than light microscopes. Using the energy of excitation light to get an electron to jump from its ground state to an excited state on a fluorescent tag. As the electron goes back to its ground state, it releases a photon. The photon is what is detected with the fluorescent atom. The excitation light needs a very specific wavelength which is achieved using a laser. They cost more and require more specific training.
What is the resolution of an Electron Microscope?
Vastly higher resolution compared to light microscopy (10,000,000 X). Using a beam of electrons rather than light. Instead of using a lens it uses electromagnetism to filter and direct the electrons into the required path (electrostatics control this). Heavy metals are used to stain the samples.
What does SDS_PAGE stain?
It linearizes the protein so that its in its primary structure. Done through heat but linear shape kept by SDS (gives protein a net negative charge). It is a protein specific stain within the gel, but stains ALL proteins. For specific staining you can do a process called Western blotting.
What are the four basic tissue types?
1) Epithelium
2) Connective tissue
3) Muscle
4) Neural
What are the characteristics of Simple squamous tissue?
- Epithelium tissue
- In a single layer (permeable e.g. gas diffusion, filtration, delicate, low friction)
- Built on a basal lamina
- Lines capillaries, alveoli and glomeruli
What are the characteristics of Stratified squamous tissue?
- Epithelium
- Cells are in layers
- Built on a basal membrane
- Non-keratinised (can’t dry out) found in mouth, eyes, internal membranes
- Keratinised (dry and impermeable) found in skin, especially palms and soles, gums, top of mouth, tongue
What are the characteristics of Simple cuboidal tissues?
- Epithelium
- Single layer on a basal lamina
- Cube shape means nucleus is not squished between two sides of the cell
- Common secretive tissues (passive or active release of materials)
- Found in kidneys, thyroid gland, eyes, salivary glands, ovaries, testes
What are the characteristics of Simple columnar tissue?
- Epithelium
- Line digestive tract (stomach, small and large intestine)
- More space for nucleus and for machinery for protein production or secretion
What are the characteristics of Stratified columnar tissue?
- Epithelium
- Layered
- Found in places with much higher levels of mechanical stress, but still need to be secreting things
- Found in salivary glands, conjunctiva (eyes), pharynx (back of throat), anus and male urethra
What are the characteristics of Pseudostratified and Ciliated tissues?
- Epithelium
- Ciliates columnar cells (similar to little hairs) move mucus and other liquids in respiratory tract, airways, Fallopian tubes, uterus and central spinal cord
- Pseudostratified = contain more than 1 cell type so looks like multiple layers, but is a single layer
General connections between structure and function of cells
Flat = Absorption Tall = Secretion Layers = Stress resistance
There will always be exceptions
What is the Glandular epithelium?
Epithelial tissue that secretes a substance. Can be a single cell or a complex organ. Can be arranged into complex structures (endocrine and exocrine glands).
What is the Endocrine Gland?
Secrete into extracellular space, circulated in the blood.
- e.g. pineal gland, pituitary gland, pancreas, thyroid
What is the Exocrine Gland?
Secrete into a duct, taken directly to another organ or the surface of an epithelium.
- e.g. sweat, saliva, ceruminous gland
What are simple exocrine gland types?
- Tubular (intestine)
- Branched Tubular (oesophagus)
- Coiled Tubular (sweat glands)
- Branched Alveolar (spacious glands e.g. skin)
What are Exocrine Gland compound types?
- Tubular
- Alveolar
- Tubuloalveolar
What are “proper” Connective tissues?
- Extracellular fibers
Can be dense (tendons) or loose (adipose). The type of proper connective tissue it is depends on the number of cell types, fiber density and the base solution. - mainly made from collagen fibres
What are Supporting Connective tissues?
- Densely packed fibers
- Uniform cell types
- Example of these is cartilage and bone
What are Fluid Connective tissues?
- Cells suspended in fluid
- Example is blood and lymph