The guttural pouch has close association with many major structures including several [[Cranial Nerves - Anatomy & Physiology|cranial nerves]] (glossopharyngeal, vagus, accessory, hypoglossal), the sympathetic trunk and the external and internal carotid arteries. The pouch directly covers the temporohyoid joint. The pouch has an extremely thin wall which is lined by [[Respiratory Epithelium - Anatomy & Physiology|respiratory epithelium]] which secretes mucus. This normally drains into the pharynx when the horse is grazing. | The guttural pouch has close association with many major structures including several [[Cranial Nerves - Anatomy & Physiology|cranial nerves]] (glossopharyngeal, vagus, accessory, hypoglossal), the sympathetic trunk and the external and internal carotid arteries. The pouch directly covers the temporohyoid joint. The pouch has an extremely thin wall which is lined by [[Respiratory Epithelium - Anatomy & Physiology|respiratory epithelium]] which secretes mucus. This normally drains into the pharynx when the horse is grazing. |