47.下列有關肝臟的功能性肝細胞小室（functional liver acini）的敘述，那些正確？①近門脈的肝細 胞為第一區，含有較多之細胞呼吸酵素（respiratory enzyme） ②近中央靜脈的肝細胞為第三 區，含有較多之細胞微粒體酵素（microsomal enzyme）或解毒酵素 ③第一區肝細胞易有膽汁 沉積 ④第三區肝細胞易發生營養及缺氧性病灶
(A)①②③
(B)①②④
(C)①③④
(D)②③④

Metabolic Zonation of Hepatic Lobules.

Functional organization of the liver. Both the lobule and the acinus are represented.

The lobule is a hexagonal unit with portal areas at the margin and a terminal hepatic vein (central vein) at the center.

The lobule is divided into the periportal, midzonal, and centrilobular areas.

The acinus is a diamond-shaped structure with the distributing branches of the vessels from the portal areas as the center of the structure and central veins at the extremities.

Zone 1 of the acinus is closest to the afferent blood supply, and zone 3 is at the tip of the diamond-shaped structure, closest to the terminal hepatic vein (central vein).

Zone 2 is in between zones 1 and 3.

Zone 3 receives the least oxygenated blood and is therefore more susceptible to hypoxia.

In addition, zone 3 has the greatest enzymatic activity (mixed function oxidases) capable of activating many compounds into toxic forms.  

膽汁不會沉積在肝細胞裡