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.
As you bend at the elbows to lower yourself, keep your arms close to your body and tuck your elbows. The close-armed pushup should be as compact of a maneuver as possible â the opposite of a wide-armed pushup. Both wide-armed and close-armed pushups require good upper-body strength to perform. Don't feel discouraged if you can't do them the first few times. You can do both variations in an assisted position. An assisted pushup simply means your knees, not your feet, touch the ground.