hnL8 - blood and lymph of the head and neck

• describe the path of oxygenated blood from the heart to the head and neck:

  • oxygenated arterial blood travels to the head and neck from the left ventricle, via the aorta
  • aorta ascends from the heart and forms an arch, gives off branches to supply the head and upper limbs.
  • then descends behind the heart to supply the abdomen and lower limbs.
• describe the location of the branches on the carotid arteries:

  • left common carotid artery arises directly from the arch of the aorta.
  • right common carotid artery branches off the brachiocephalic artery (which arises from the arch of the aorta).
• describe the carotid sheath:

  • each carotid artery lies within a carotid sheath.
  • made of connective tissue and contains: internal jugular vein, vagus nerve.
  • associated with a chain of lymph nodes.
• branches of the external carotid has several branches in the neck including the lingual artery. where does it arise and what does it supply?

  arises at the level of the hyoid bone

  supplies the tongue
• describe the blood supply to the tongue:

  arterial:

  • lingual artery (tongue) (branch of external carotid)
  • tonsillar branch of facial artery (tonsils found at the back of the tongue)
  • ascending pharyngeal branch of external carotid.

  venous:

  • lingual vein (tongue) (feeds into internal jugular vein)
• [branches of the external carotid]

  describe the route taken and function of the facial artery:

  • arises just above the hyoid bone
  • travels forwards, crosses submandibular gland, hooks over lower border of the mandible at anterior border of masseter.
  • supplies chin, lips, cheek, side of nose.
• [branches of the external carotid]

  describe the route taken and function of the maxillary artery:

  • enters pterygopalatine fossa and splits into: branches that follow the branches of the maxillary division of the trigeminal nerve and the inferior alveolar artery.
  • inferior alveolar artery supplies the mandible.
• [branches of the external carotid]

  describe the route taken and function of the superficial temporal artery:


  • passes upwards in front of the ear.
  • to supply the frontal and temporal skin and scalp.
• describe the internal carotid artery:

  -no branches in the neck

  enters cranium via carotid canal

  supplies the orbit, forehead and brain
• describe vaguely the process of venous drainage of head and neck:

  • cavernous sinus in the skull collects deoxygenated venous blood from the cranium.
  • it drains through jugular foramen on the base of the skull into internal jugular vein.
• what is the function of the internal jugular vein?

  Drainage
• describe the route taken by the internal jugular vein:

  • descends through the neck in the carotid sheath
  • joins other veins and finally becomes the superior vena cava which empties into the right atrium of the heart.
• describe the structure and positioning if the lymph:

  • lymphatic system conveys (removes) excess tissue fluid back to the blood circulatory system.
  • consists of a series of tubes and filters.
  • tubes are blind-ended, contain many valves preventing lymph from flowing back to its tissue of origin.
  • vessels often closely associated with veins.
  • filters are called lymph nodes.
  • waste they filter includes bacteria and viruses.
  • lymph nodes found all over the body from the level of the maxilla down
  • lymph nodes also associated with major salivary glands.
• what is the waldeyer's ring and where is it located:

  this is an interrupter ring of lymph nodes around the upper end of the respiratory and alimentary tracts and includes:

  • lingual tonsil (posterior 1/3 of the tongue)
  • palatine tonsil ( between palatoglossal arch and the palatopharyngeal arch)
  • pharyngeal and tubal tonsils ( in the roof of the nose and next to the auditory tube).
• explain the route taken by the lymph associated with waldeyer's ring:

  • from the deep cervical group of nodes, lymph flows in lymph vessels associated with the carotid sheath.
  • eventually, it drain into the thoracic duct.
  • thoracic duct contains lymph from the rest of the body
  • drains into left brachiocephalic vein and lymph re-joins the circulatory system.