Page 104 - Atlas of Histology with Functional Correlations

Desmosomes anchor cells through extension of transmembrane proteins into

intercellular space between adjacent cells
Desmosomes bound to intermediate filaments
Hemidesmosomes are present at base of epithelial cells to prevent separation
from connective tissue layer, as in basal layer of skin
Gap junctions are spotlike structures with fluid channels called connexons

Ions and chemicals diffuse through connexons from cell to cell
Gap junctions allow rapid communications between cells for synchronized
action

Basal Regions of Cells

Infolded Basal Regions

Infolded basal and lateral cell membranes function in ionic transport

Found in kidney and salivary gland cells
+
+
Na /K ATPase (sodium pumps) embedded in infolded membranes
Numerous and long mitochondria in infoldings supply ATP for ion transport

Cilia

Motile apical surface modifications that are inserted into basal bodies
Line cells in the respiratory organs, uterine tubes, and efferent ducts in testes
Motility caused by sliding microtubule doublets
Motor protein dynein uses ATP to move cilia

Microvilli

Nonmotile apical surface modifications
Well developed in small intestines and kidney
Main function is absorption of nutrients from intestines and glomerular

filtrate

Review Questions

QUESTIONS

103