
THE NERVES NERVES OF THE FACE AND NECK BLOOD SUPPLY ARTERIES VEINS CAPILLARIES
We can distinguish heat, cold and pain as well as differences between light and deep preasure.
Motor nerve endings supply the muscles which produced facial expressions and move the eyes. Neck and lower job.
NERVES OF THE FACE AND NECK
Nerves arising from the brain are called cranial nerves. There are 12 pairs of cranial nerves, some of which are sensory, some motor and some mixed. The main cranial nerves supplying the face and neck are the trigeminal, Facial and accessory nerves.
5th cranial (trigeminal) nerve
This has 3 main branches:
Ophthalmic branch, which is sensory and supplies the upper part of the orbital cavity and also the skin of the nose, forehead and scalp
Maxillary branch, which is sensory and supplies the upper teeth, part of the nose and cheeks and part of the eye orbit.
Mandibular branch, which is motor and supplies the lower teeth, lower jaw and the muscles of mastication (chewing)
7th premier (facial) nerve this is responsible for facial expressions and branches to various muscles:
Temporal branch supplies the muscles of the forehead and eyebrows.
Zygomatic branch supplies the muscles of the eyes and nose.
Buccal branch supplies the muscles of the cheeks, upper lip and sides of face.
Mandibular branch supplies the muscles of the lower lip and chin.
Cervical branch supplies the platysma muscle of the neck.
The 11th cranial (accessory) nerve is a motor nerve which supplies the sternomastoid and trapezius muscles.
BLOOD SUPPLY
Blood carries food, oxygen and water to the bodies tissues and takes up there waste products for exretion by the kidneys, lungs and skin. The heart is the pump which derives the blood through the circulation. Blood circulates around the body in different types of blood vessles.
ARTERIES
Arteries carry oxygenated blood (red) from the heart to the tissues, large artries are elastic and pulsate with the heart beat. They drive the blood on through the system. Arteries sub-divide into arterioles.
VEINS
Veins carry de-oxygenated blood (blue) from the tissues to the heart. Thinner then arteries, they have valves to keep the blood flowing in the right direction. Veins sub-divide venules.
CAPILLARIES
The walls of these tiny vessels are thin and porous. They consists only of a single layer of cells. Capillaries join arterioles with venules. The gaps between the blood capillaries and the cells contains tissue fluid. The interchange of nutrients and waste products takes place through tissue fluids.
Fluids leaks out of the capillary walls and bathes the tissues. The nutrients contain in the fluid penetrate the walls of the cells. Waste products leave through the walls of the cells and enter the tissue fluid before passing into the capillary network and then on to a large vein.
Although some of the tissues fluid containing waste products returns to the blood capillaries, much of it is collected up by a second set of vessels which form lymphatic system.
BLOOD SUPPLY TO THE FACE AND NECK
The external carotid artery is the main vessels supplying blood to the upper part of the neck and face. It sub-divides into branches which supply different areas. These include the following arteries and veins.
FACIAL ARTERY
The facial artery lies between the supper ficial and deeper muscles and supplies the upper and lower lips and facial muscles.
OCCIPITAL ARTERY
The occipital artery supplies the upper part of the neck and back of the scalp.
SUPER FICIAL TEMPORAL ARTERY
The super ficial temporal artery supplies the face by its transverse facial branch.
INTERNAL JUGULAR VEIN
This vein is the main vessel draining blood from the face and neck. Blood is supplied to it by smaller veins which drain different areas.
These include:
The facial vein, which drains the front of the scalp and the super ficial structures of the face.
The retromandibular vein, which drain the face below the jaw and the back of the scalp.
LYMPHATIC VESSELS
Lymphatic vessels are present in the tissue spaces as blind-ended tubes which removes proteins and surplus fluid from the tissue spaces in this way, swelling is prevented. The vessels contain lymph, a fluid made up of cells (mainly lymphocytes) and plasma (a watery fluid containing some proteins). Lymphocytes are special cells which fight of infection.
The lymphatic vessels create a network through a tissue spaces in very close proximity to the blood vessels.
Lymphatic glands or nodes are found at intervals along the path of these vessels. The lymph nodes "filter" foreign bodies and quickly lymphatic vessels empty there contents back into the blood circulation .
DIRECTION OF LYMPH DRAINAGE
CHIN -> SUBMENTAL NODES
MIDDLE PART OF FACE AND CHEEKS -> SUBMANDIBULAR NODES
SIDES OF CHEEKS AND FOREHEAD -> PAROTID NODES
Lymphatic circulation:
Lymph from the left side of the head and neck eventually passes through the thrthoracic duct and empties into the left subclavian vein.








