The Pharynx
The pharynx or the throat is divided into three parts viz.
- the naso pharynx,
- the oro pharynx and
- the laryngo pharynx.
- Oropharynx and laryngopharynx are associated with the alimentary tract
- Food passes from the oral cavity to the pharynx and then into the oesophagus with which it is continuous.
The various layers of the Pharynx
- The lining membrane is stratified squomous epithelium
- The middle layer - fibrous tissue - contains blood and lymph vessles and nerves
- The outer layer - a number of involuntery constrictor muscles which are involved in swallowing.
Blood supply:
- Branches of the facial arteries
- Venous drainage : into the facial veins and the internal jugular veins
Nerve supply:
- Pharyngeal plexus and consists of parasmpathetic and sympathetic nerves
- parasympathetic : glossopharyngeal and vagus nerves
- Sympathetic from the cervical ganglia
Applied Anatomy
- Eustachian Tube opening into the nasopharynx gets inflamed : eustachian catarrh; the pressure equilibrium between the external and internal ears is disturbed and the ear gets a blocked sensation.
- Retropharyngeal abscess produces a swelling in the back of the throat