ICSE Class 9 Answered

1. They secrete turbid fluid containing water, proteins, lipids and odour precursors. They also secrete moisturizing factors such as lactate, urea, sodium and potassium to maintain skin hydration

 

2. The inner lining of the ileum shows the presence of a large number of tiny finger-like projections called villi. Each villus is covered by a single-cell thick epithelium. It consists of an artery, a vein, inter-connecting blood capillaries and a lymph vessel called lacteal. The villi enormously increase the inner surface area of the intestines, which facilitate absorption of digested food.There are small holes between the villi, through which intestinal juice is secreted.