Tissues, Organs And Systems Flashcards
What holds cells together?
Cell-cell adhesion molecules, extracellular matrix proteins, internal-external scaffolding and close proximity (pressure effects).
What’s the role of tight junctions?
To prevent movement of larger molecules through the outer layer into the deeper tissue layers of the organ.
Role of desmosomes and where they are found.
To provide mechanical strength and prevent tissue destruction. Found in tissues that experience intense mechanical strength (e.g. cardiac muscle) and is the only cell-cell adhesion found in upper epidermal cells.
Function of gap junctions.
To quickly communicate changes in intercellular molecular composition, e.g. electrolyte and energy changes. Important in smooth muscle contraction.
Location and role of hemi-desmosome.
Only found on basal surface of epithelial cells. It’s role is to anchor epithelial cells to the basal lamina and prevent loss to external surface.
Describe adherence of epithelial cells.
Adhere to epithelial cells through cell surface proteins, adhere to basal lamina through cellular adhesion molecules, adhere to muscle cells through connective tissue fibres.
What is a mucosal membrane?
The moist, inner lining of some organs and body cavities.
What are the functions of the mucosal membrane?
Stops pathogens from entering the body, prevents bodily tissues from becoming dehydrated, lubricate the surface.
Function of mucosa in the GI tract.
To absorb substances from the lumen, prevent ingress of pathogens, move contents and expel waste.