Auditory sensation, commonly called hearing, involves the transformation of sonic waves into neural impulses facilitated by the structures of the auditory organ. The prominent, flesh-like structure on the side of the head, called the auricle, directs sound waves towards the auditory canal. The auricle is often mislabeled as the pinna, a term more aligned with mobile structures like a feline's external ear. The auditory canal penetrates the cranium via the external auditory meatus of the...

A tracheostomy is a surgical procedure that creates an artificial opening into the trachea, typically at the second or third cartilaginous ring level. This opening allows the insertion of a tracheostomy tube, which can replace an endotracheal tube, provide mechanical ventilation, bypass an upper airway obstruction, or remove accumulated tracheobronchial secretions.
Tracheostomy tubes can be made of semiflexible plastic (polyurethane or silicone), rigid plastic, or metal, and they come in...

The auditory ossicles of the middle ear transmit sounds from the air as vibrations to the fluid-filled cochlea. The auditory ossicles consist of two malleus (hammer) bones, two incus (anvil) bones, and two stapes (stirrups), one on each side. These bones develop during the fetal stage and are the ones to ossify first. They are fully mature at birth and do not grow afterward.
The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...

Chondrocytes form a temporary cartilaginous model by dividing and secreting a thick gel-like extracellular matrix. Once the chondrocytes undergo programmed cell death, osteoblasts enter the site of the cartilaginous model. The process of replacing the temporary cartilaginous model with bone in an ordered manner is called endochondral ossification. In endochondral ossification, not all of the cartilage is replaced by bone tissue. Some cartilage that performs a protective and supportive function...

Tracheostomy care is an essential nursing skill that involves cleaning and maintaining a tracheostomy tube to prevent infection and other complications. Here's a step-by-step guide explaining each procedure with its rationale. Note that disposable gloves are to be worn at all times and changed as often as needed to maintain a sterile work environment, and to protect both patient and healthcare worker.
Step 1: Perform hand hygiene, and put on personal protective equipment: gown, gloves, mask and...