What structures are formed by the apical membranes of adjacent hepatocytes surrounding bile canaliculi?

What structures are formed by the apical membranes of adjacent hepatocytes surrounding bile canaliculi?

• A. Bile canaliculi formed by apical membranes of adjacent hepatocytes and connected by tight junctions.
• B. Desmosomes on basolateral surfaces.
• C. Gap junctions between hepatocytes.
• D. Hemidesmosomes anchoring hepatocytes to basement membrane.

Answer: (A)

Bile canaliculi form where the apical membranes of neighboring hepatocytes come together and are sealed by tight junctions. This creates a small, continuous space (the canaliculus) that bile is secreted into and that directs flow into the bile ducts. The apical surface is specialized for secretion toward this lumen, while the tight junctions keep bile confined and prevent leakage into the surrounding tissue. Desmosomes on the basolateral surfaces provide strong cell adhesion but don’t create a lumen. Gap junctions between hepatocytes allow small molecules to pass directly between cells but don’t enclose a channel. Hemidesmosomes anchor the basal surface to the basement membrane. So the canaliculi are specifically formed by apical membranes joined by tight junctions.

Bile canaliculi form where the apical membranes of neighboring hepatocytes come together and are sealed by tight junctions. This creates a small, continuous space (the canaliculus) that bile is secreted into and that directs flow into the bile ducts. The apical surface is specialized for secretion toward this lumen, while the tight junctions keep bile confined and prevent leakage into the surrounding tissue.

Desmosomes on the basolateral surfaces provide strong cell adhesion but don’t create a lumen. Gap junctions between hepatocytes allow small molecules to pass directly between cells but don’t enclose a channel. Hemidesmosomes anchor the basal surface to the basement membrane. So the canaliculi are specifically formed by apical membranes joined by tight junctions.