Histology Flashcards
How do cells stick together?
- ECM
- Anchoring junctions
What is ECM made out of?
- Fibrous components (collagen and elastin)
- Amorphous component (proteoglycans - made of protein and carbohydrates called GAG)
What are desmosomes?
-Connect cells via their cytoskeleton. They have intracellular and transmembrane (adhesion proteins) domains.
What is pemphigus disease?
Autoantibodies are produced against the adhesion proteins causing them to change shape and dissociate from the intracellular part.
This means adjacent cells are no longer connected to each other via cytoskeleton and the cells split
What are the connective tissues?
4 types of connective tissue:
- ordinary connective tissue (type 1, 2, 3, 4)
- fat
- bone
- cartilage (ordinary connective tissue type 2)
What is basal lamina?
Type IV ordinary connective tissue and laminin
Why is vitamin C important?
Collagen synthesis - it prevents the autoinactivation of enzymes
What is the structure of elastin?
Elastin fibres cross-link. They are relaxed at a low energy state; stretched at a high energy state.
What is cartilage?
Cartilage has no vessels or nerves.
There are 3 types of cartilage:
- hyaline (tracheal rings, articular surfaces)
- elastic (external ear)
- fibrous (IV discs)
What are key facts about epithelium?
- Tightly packed (little ECM)
- Have secure attachment due to anchoring junctions, tight junctions, desmosomes, hemidesmosomes
- They lie on connective tissue (basement membrane)
What are ducts and glands made from?
- Cuboidal epithelium
- Subunit of a multicellular gland = acinus
What is special about urinary epithelium?
- Transitional epithelium
- Cells on the apical surface are squamous when stretched, cuboidal when relaxed.
-Capping cells produce uroplakin to protect from high toxicity.
What does Ruffini corpuscle do?
Detect stretch
What does Pacinian corpuscle do?
Detect vibration and pressure
What does Meissner’s corpuscle do?
Detect stretch
