The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.
 
        
                    
             
        
        
        
Answer:
lymphedema
Explanation:
Lymphedema - 
It refers to the medical condition , where the arms or legs swell up , is referred to as the condition of lymphedema . 
The condition arises due to the damage of the nodes of the lymph , which can usually occur during the treatment of cancer . 
The condition is very painful and restricts the flow of lymph in the lymphatic vessels . 
Hence , from the given information of the question , 
The correct answer is lymphedema . 
 
        
             
        
        
        
Answer: machinery and equipment developed from the application of scientific knowledge.