【英语时差8,16】耳石是什么？

 Ear rocks, also known as “otoliths,” are tiny pebbles¹ of calcium² carbonate in our inner ear that help keep us balanced. They’re located deep inside the inner ear in a small pouch³ called a utricle. When we move our heads, the tiny rocks move around and bump into nerve cells. These nerve cells send signals to our brain that tell it which way the head is oriented. It’s one way we know up from down. But problems with ear rocks can be a cause of chronic⁴ dizziness or vertigo⁵. Occasionally the little pebbles fall out of the utricle and can get into another part of the inner ear canals. When this happens, the brain senses that we’re moving much more than we really are, resulting in sensations of unsteadiness or dizziness.

1 pebbles   

[复数]鹅卵石； 沙砾； 卵石，小圆石( pebble的名词复数 )

参考例句：

• The pebbles of the drive crunched under his feet. 汽车道上的小石子在他脚底下喀嚓作响。
• Line the pots with pebbles to ensure good drainage. 在罐子里铺一层鹅卵石，以确保排水良好。

2 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

3 pouch   

n.小袋，小包，囊状袋；vt.装...入袋中，用袋运输；vi.用袋送信件

参考例句：

• He was going to make a tobacco pouch out of them. 他要用它们缝制一个烟草袋。
• The old man is always carrying a tobacco pouch with him.这老汉总是随身带着烟袋。

4 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

5 vertigo   

n.眩晕

参考例句：

• He had a dreadful attack of vertigo.他忽然头晕得厉害。
• If you have vertigo it seems as if the whole room is spinning round you.如果你头晕，就会觉得整个房间都旋转起来