Interesting Facts about Scalp, Temple and Face
Because of the abundance of sebaceous glands, the scalp is a common site for sebaceous cysts.
Since the blood supply of scalp of a scalp and the superficial temporal region is very rich; avulsed portions need not be cut away. They can be replaced in position and stitched: they usually take up nd heal well.c
Wounds of the scalp bleed profusely because the vessels are prevented from retracting by the fibrous fascia. Bleeding can be arrested by applying pressure against the bone.
Because of the density of fascia, subcutaneous haemorrhages are nerve extensive, and the inflammations in this layer cause little swelling but mush pain.
The layer of loose areolar tissue is known as the dangerous area of the scalp because the emissary’s veins, which open here may transmit infection from the scalp to the cranial venous sinuses.
A collection of blood in the layer of loose connective tissue causes generalised swelling of the scalp. The blood may extend anteriorly into the root of the nose and into the eyelids, causing the black eye. The posterior limit of such haemorrhage is not seen. If bleeding is due to local injury, the posterior limit of haemorrhage is seen.
Wounds of the scalp do not gap unless the epicranial aponeurosis is divided transversely.
Because the pericranium is adherent to sutures, the collection of fluid deep to the pericranium known as cephalhaematoma take the shape of the bone concerned.
The facial nerve is examined by testing the following facial muscles,
Frontalis : Ask the patient to look upwards without moving his head, and look for normal horizontal wrinkles of the forehead.
Dilators of mouth : Showing the teeth.
Orbicular oculi : Tight closure of the eyes.
Buccinator : Puffing the mouth and then blowing forcibly as in whistling.
Platysma : Forcible pulling off the angles of the mouth downwards and backwards forming prominent vertical folds of skin on the side of the neck. The platysma contracts along with the risorius.
In intranuclear lesions of the facial nerve, known as Bell’s palsy, the whole of the face of the same side gets paralysed. The face becomes asymmetrical and is drawn up to the normal side. The affected side is motionless. Wrinkles disappear from the forehead. The eye can not be closed. Any attempt to smile draws the mouth to the normal side. During mastication, food accumulates between the teeth and the cheek. Articulation of labials is impaired.
In supranuclear lesions of the facial nerve; usually, a part of hemiplegia, only the lower part of the opposite side of the face is paralysed. The upper part with the frontalis and orbicular oculi escapes due to its bilateral representation in the cerebral cortex.
The sensory distribution of the trigeminal nerve explains why a headache is a uniformly common symptom in involvements of the nose (common, cold, boils,) the paranasal air sinuses (sinusitis) infections and inflammations of teeth and gums, refractive errors of the eyes, and infection of the meanings as in meningitis.
Trigeminal neuralgia may involve one or more of the three divisions of the trigeminal nerve. It causes attacks of very severe burning and scalding pain along the distribution of the affected nerve. Pain is relieved either: (a) by injecting 90% alcohol into the affected division of the trigeminal ganglion or (b) by sectioning the affected nerve which is situated superficially in the medulla. The procedure is called medullary tractotomy.
The facial veins and its deep connecting veins are devoid of valves, making an uninterrupted passage of blood to the cavernous sinus. Squeezing the pustules or pimples in the area of the upper lip or side of the nose or even the cheeks may cause infection which may be carried to the cavernous sinus leading to its thrombosis. So the cheek area may also be included as the dangerous area.
The Muller’s muscle or involuntary part of levator palpebrae superioris is supplied by sympathetic fibres from the superior cervical ganglion. Paralysis of this muscle leads to partial ptosis in Horner’s syndrome.
The palpebral conjunctiva is examined for anaemia and for conjunctivitis; the bulbar conjunctiva for jaundice.
Foreign bodies are often lodged in a groove situated 2 mm from the edge of each eyelid.
A chalazion is inflammation of a tarsal gland, causing a localised swelling pointing inwards.
Ectropion is due to eversion of the lower lacrimal punctum. It usually occurs in old age due to laxity of skin.
Conjunctivitis is one of the commonest diseases of the eye. It may be caused by infection or by allergy.
Trachoma is a contagious granular conjunctivitis caused by the trachoma virus. It is regarded as the commonest cause of blindness.
Stye or hordeolum is a suppurative inflammation of one of the whole of the lid is oedematous. The plus points near the base of one of the cilia.
Blepharitis is inflammation of the eyelids, especially of the margin.
The ducts of lacrimal gland open through its palpebral part into the conjunctival sac. Because of this orbital part as well.
Excessive secretion of lacrimal fluid , i.e tears is mostly due to emotional reasons. The tears not only flow on the cheeks but also flow out through the nasal cavity, due to stimulation of pterygopalatine ganglion.
Excessive secretion of the lacrimal fluid overflowing on the cheeks is called Epiphora. Epiphora may result due to obstruction in the lacrimal fliud pathway, either at the level of punctum or canaliculi or nasolacrimal duct