where can I buy a rectal tube for pediatrics
Rectal polyps are commonly found by sigmoidoscopy (visual inspection with an instrument consisting of a tube and a light) or colonoscopy
Ear canal
maybe trachea??
You are describing the "ear canal".
The ear canal is the part of the outer ear that is a tube lined with tiny hair like features. The ear canal leads into the ear from the bottom of the auricular and is what conducts the vibrations.
An ascon is a cavity, in the form of a bag or tube, lined with choanocytes, which forms the structure of sponges.
The uterine tube is lined with cilia. These small hair-like projections sweep the egg toward the uterus.
Your fallopian tubes are lined with tiny hair-like structures called cilia which are constantly swaying back and forth to help guide the egg and push it along to the uterus :)
rectal sparing
alveoli
A bilateral animal has a lined gut cavity. On the other hand, animals like roundworms have a gut cavity but it is only partially lined.