The lumen of the trachea is lined by pseudostratified columnar epithelium. Note that all the surface cells have cilia at their free (apical) surface. (What function do these cilia serve in the trachea?) Mucus-secreting unicellular gland cells (goblet cells) are interspersed among the ciliated cells.
Donât think you need to be able to do the modified version perfectly before you try theseâyou just need to feel brave enough to go upside down. To complete a handstand push up: 1  Face a wall in a standing position.  Kick your feet up so youâre in a handstand position against a wall.
These are known as planche push-ups. To do this variation, the body's center of gravity must be kept over the hands while performing the push-up by leaning forward while the legs are elevated in the air, which requires great strength and a high level of balance. The entire body weight is lifted in this variation.