Topic 7: Tissue Level of Organization (Histology) Flashcards
1
Q
What is histology?
A
- the study of tissues
2
Q
What are tissues?
A
- A group of cells with similar structure and function
3
Q
What are the four main tissue types?
A
- Epithelial
- connective
- Muscle
- nervous
4
Q
What is epithelial tissue?
A
lining tissue
5
Q
What is connective tissue?
A
- connecting tissue
6
Q
What is muscle tissue?
A
- contractile tissue
7
Q
What is nervous tissue?
A
- signalling tissue
8
Q
What are cell junctions? (2)
A
- Points of contact between adjacent cells
- seen in epithelial tissue, some nervous and muscle cells
9
Q
How are cell junctions formed?
A
- formed by cell membrane proteins
10
Q
What are three examples of cell junctions?
A
- Tight junctions
- Anchoring junctions
- Gap junctions
11
Q
What are tight junctions? (3)
A
- are a partial fusion of specific proteins on the lateral surface of the cell membrane
- form a ring-like tight seal (like the plastic that holds a 6 pack)
- the seal prevents leakage between cells
12
Q
What are anchoring junctions?
A
- proteins that fasten cells to each other, and/or to extracellular material
- “rivets” cells together
ex. desmosomes
13
Q
What are the proteins anchored by the cell in anchoring junctions? (2)
A
- glycoprotein = cadherin
- intermediate filaments = keratin
14
Q
What are gap junctions?
A
- open channels (formed by proteins - connexins) through the adjacent cell membranes interconnecting the cytosols of the cells
15
Q
What is the function of gap junctions?
A
- allows ions/small molecules to pass from one cell to another
