There are times when the physician desires to affect the amount of blood in the tissues of the head.  There may be congestion of the nasal, pharyngeal and laryngeal mucosa, as during a hard "cold."  After manipulating to relax the muscles- of the neck and overcome any effects these may have had on the position of the cervical vertebrae, it is well to try to cause vaso-constrictor action by stimulating nerve endings.  Fig. 251 illustrates a method of stimulating deeply under the zygoma in the sigmoid notch of the inferior maxillary bone.  When the patient opens his mouth, the physician places his finger over the depression below the zygoma and presses inward, at the same time making a vibratory movement of the finger.  This affects the branches of Meckel's Ganglion and, through it, the nasal mucosa.  It is a painful treatment, but the blood will often surge from the mucous tissues to the skin as a result of it.

    About the same effect is secured by using the movement illustrated in Fig. 252.  While the patient's mouth is open, the physician places his thumbs on the bridge of the nose, and his fingers at the angles of the jaw.  The tips of the little and ring fingers are pressed into the depression caused by the forward movement of the condyle of the jaw on the eminentia articularis.  The physician forces the mouth shut while the patient opposes.  The position of the tips of the little and ring fingers prevents the easy slipping of the condyles into the glenoid fossa.

    The sensory fibers around the condyle are intensely stimulated and frequently manifest it by spreading a flood of color over the face in front of the ear.  This is also a painful stimulation.  It is highly probable that all movements of this character which are painful secure results by causing activity of the dilator nerves to blood vessels in superficial tissues, thus depleting the blood in the congested area.  A sharp pain may cause a sudden blanching, but it is followed by vaso-dilation.

    If it is difficult for the patient to breathe through the nostrils, press on the nasal bones, first on the right side, then left, then make a heavy pressure over the junction of the nasal and frontal bone with one thumb above the other.  This movement is very pleasant to the patient, ordinarily.  To carry off the venous blood, make a stroke from the inner canthus of the eye downward over the junction of the masseter muscle with the lower jaw, thence to the supraclavicular fossae.

    The Fifth Cranial Nerve. - The fifth cranial nerve can be treated at its points of exit through the bones of the face.  Fig. 253 illustrates the position of these points.  A vibratory pressure over these points causes a dull but increasing pain.  If the movement is made quickly and vigorously, there will be evidence of a reaction in a flushed appearance.

    Inhibition of Suboccipital. - When there is a high blood pressure in the head and the patient is suffering with headache it is possible to give great relief by steadily inhibiting in the suboccipital fossae and temples, as illustrated by Fig. 254.  All nervous conditions are greatly reduced by this movement.  The inhibition reduces the number of sensory impressions, and lessens the tension of blood vessels all over the body.  This inhibitory movement should be used in cases of epilepsy and delirium tremens during the excitable stages.  Have an assistant inhibit in the splanchnic area, thus causing a general reduction of blood pressure in the superficial and deep tissues of the body and extremities.  The blood is thus drawn away from the head, and the patient becomes quiet.

    To inhibit the transmission of impulses to the diaphragm by the phrenic nerves, pressure should be made as in Pig. 255.  The physician's fingers compress the phrenic nerve against the scalenus antictis.

    The phrenic, pudic and pneumogastric are the only nerve trunks distributed in the body which can be easily compressed through soft tissue.  Fig. 256 illustrates stimulation of the pneumogastric.  The physician's fingers roll over the nerve trunk where it lies along the inner edge of the sterno-cleido-mastoid.

    The general tendency of an osteopathic treatment, which aims to relax the extensor muscles of the neck and trunk, is to reduce blood pressure.  Cases which are characterized by high blood pressure are greatly benefited by relaxation of muscle tension, by means of gentle leverage.  The use of heavy pressure movements is contraindicated, because they might occasion involuntary resistance by the patient and thus suddenly raise blood pressure to a dangerous degree.  It is very probable that the extension and counter pressure movements we use to reduce subluxations, act also as factors in changing blood pressure in localized visceral areas.

    Vasomotor effects can be secured by various forms of stimulation applied to spinal areas.  Counter irritation, cupping, heat or cold, concussion, or sudden pressure to the point of producing a "click" in an arthrodial joint, all produce vasomotor effects of various degrees.  They all serve a useful purpose and tend to reinforce each other in some cases.