In this article we will discuss about the extent and relations of cervical sympathetic trunk. Extent of Cervical Sympathetic Trunk: From base of skull to the neck of first rib. Preganglionic fibres arise from upper thoracic part of spinal cord - lateral horn cells (T1-T5). Relations of Cervical Sympathetic Trunk: Anterior: Carotid sheath with its content. Posterior: Prevertebral muscles and [...]
Waldeyer’s ring is a collection of lymphoid tissue or follicles in the upper part of digestive system. This ring is formed by: Superiorly- Pharyngeal tonsils or Adenoids. Inferiorly- Lingual tonsil. Laterally- Palatine tonsils and tubal tonsils. I. Pharyngeal Tonsil: Lie postero superiorly under the mucous membrane of the roof and adjoining posterior wall of nasopharynx. II. Lingual Tonsil: This is [...]
In this article we will discuss about the meaning, parts and surfaces of frontal bone which belongs to human skull. Meaning and Parts of Frontal Bone: This is a membrane bone, forms forehead and lodges frontal air sinus, i.e., pneumatic bone. Parts: Three parts are: 1. Squamous part 2. Orbital plates are on either side 3. Nasal part. I. Squamous [...]