Chapter 3 - Cytology and Histology and Tissues Flashcards
What is cytology?
The study of cell structure and function
What is histology?
The study of tissue structure and function
What is the modern cell theory?
• All organisms composed of cells and cell products.
• Cell is the simplest structural and functional unit of life.
• Organism’s structure and functions are due to the activities of its cells (200 different types).
• Cells come only from preexisting cells.
• Cells of all species have many fundamental
similarities.
What are the different types of cell junctions?
- Gap Junctions
- Tight junctions
- Anchoring junctions
How do tight junctions have a protective function?
Force bacteria to go through cells and not in between = prevent infection
Where do tight junctions tend to be found (in regards to on the cell)?
On the apical side
Where can tight junctions be found?
Blood-brain barrier, skin, etc.
What proteins are used for tight junctions?
Claudins and occludins
How are anchoring junctions spaced out?
They are like buttons, so bacteria could still squeeze through
How do we get a blister?
Too much friction on the skin destroys the desmosomes, and now it gets filled with water
What is the difference between an Adherens junction and Desmosomes?
Adherens junction links actin filaments between cells. Desmosomes link to intermediate filaments (and are strongest type of junction)
What are hemidesmosomes?
They anchor the intermediate filaments of a cell to proteins in the matrix (strong!)
What types of proteins are used in anchoring junctions?
Cadherins - make cell-cell anchoring junctions
Integrins - make cell-matrix junctions
What are gap junctions for? What protein do they use?
Communication (electrical and chemical). They use connexins
What is epithelial tissue?
Tissue that protects surface of the body, lines hollow organs, and produces and secretes substances
