[Music] [Applause] scalp introduction the term scalp is applied to the soft tissues covering the Vault of skull the scalp is a part of the head that extends from the super celer arches or the eyebrows anteriorly to the external occipital protuberant and Superior nucal lines posteriorly laterally it continues inferiorly to the zygomatic Arch the scalp is a multi-layered structure with layers that can be defined by the word itself layers s for skin C for connective tissue which is dense a for aponeurotic layer l for loose connective tissue and P for pericranium examining the layers of the scalp reveals that the first three layers are tightly held together forming a single unit skin the skin of the scalp is thick and hairy except over the forehead it is firmly adherent to the epicranial eposis by dense connective tissue of superficial fascia as in Palms and Soles it is similar structurally to skin throughout the body with the exception that hair is present on a large amount of it being hairy it contains maximum number of hair follicles and Associated sebaceous glands as a result scalp is the commonest site of sebaceous cysts it also contains numerous sweat glands it has been estimated that there are about 120,000 or 1 L 120,000 hair on the scalp of an adult individual about 20 to 100 hair are lost daily and replaced concomitantly the baldness or loss of hair mainly affects males and few elderly females with high levels of androgenic hormones in their blood connective tissue dense also referred to as superficial fascia deep to the skin is dense connective tissue dense fibrous connective tissue that firmly binds the skin to the underlying oxipor frontalis and it's con eurosis fippa divide this layer into numerous small Pockets containing lobules of fat the blood vessels and nerves of the scalp lie in this layer clinical correlation this layer anchors the skin to the third layer and contains the arteries veins and nerves supplying the scalp when the scalp is cut the dense connective tissue surrounding the vessels tend to hold cut vessels open this results in profuse bleeding the bleeding however can be stopped by pressing against the underlying bone epine neurotic layer the deepest layer of the first three layers is the epine neurotic layer firmly attached to the skin by the dense connective tissue of the second layer this layer consists of the oxipor frontalis muscle which has a frontal belly anteriorly an occipital belly posteriorly and an aponeurotic tendon in the epicranial epon Neurosis also known as Gallia epon neurotica it is Latin Gallia means helmet connecting the two the frontal Belly of the oxipor frontalis begins anteriorly where it is attached to the skin of the eyebrows it passes upward across the forehead to become continuous with the epine neotic tendon posteriorly each occipital Belly of the occipital frontalis arises from the lateral part of the superior nucal line of the occipital bone it also passes superiorly to attached to the epino tendon the oxipor frontalis muscles move the scalp wrinkle the forehead and raise the eyebrows the frontal belly is innervated by temporal branches of the facial nerve which is the seventh cranial nerve and the posterior belly by the posterior oric Branch clinic correlation the wounds of the scalp do not gape unless epicranial epuris is cut transversely because the eposis is under tension in the Antero posterior Direction by the tone of oxy frontalis muscle loose connective tissue a layer of loose connective tissue separates the epino layer from the pericranium and facilitates movement of the scalp proper over the calvaria because of its consistency infections tend to localize and spread through the loose connective tissue this layer is traversed by Emissary veins connecting veins in the second layer of scalp with intracranial Dural Venus sinuses clinical aspect dangerous area of the scalp the layer of loose arol tissue is called Dangerous layer of scalp because blood and pus freely tend to collect in this layer if pus collects in this layer the infection May travel readily along Emissary veins into the intracranial Dural Venus sinuses leading to their thrombosis which may be fatal surgical layers of the scalp first three layers of the scalp that is the skin connective tissue layer and epino layer are firmly adhere to each other and cannot be separated from each other these layers are termed surgical layers of the scalp and form the scalp proper the layer of loose areolar tissue beneath the epino layer accounts for the free mobility of the scalp proper on the underlying bone additionally it provides an easy plane of cleavage an injury and a plane in which blood from severed blood vessels can spread for a long distance when the hairs are caught in Machinery the scalp proper is vul in this plane that surgeons mobilize scalp flaps black eye the blood and fluid collecting in the layer of loose areolar tissue following a blow on head tracks freely under the scalp producing generaliz swelling over the Dome of the skull but cannot pass into either occipital or Temple regions because of the Bony attachments of the occipital frontalis the blood and fluid can however track back forward into the eyelids because occipital frontalis has no bony attachment anteriorly this leads to formation of hematoma few hours after a head injury or cranial operation causing black discoloration of skin around the eyes a condition called black eye it is important to note that the commonest cause of black eye is local violence such as fist fight causing subcutaneous extravasation of blood into the eyelids pericranium the pericranium is the deepest layer of the scalp and is the periostium on the outer surface of the calvaria it is attached to the bones of the calvaria but is removable except in the area of the sutures it is Loosely attached to the bones and can be easily stripped but it sutures it is firmly attached to sutural membrane which in turn attaches it to the endocranium the periostium covering inner aspect of the skull bones clinical aspect safety valve hematoma seil hematoma and capid suidani fracture of cranial vault in children may be associated with the tearing of Dera matter and pericranium in such cases the blood from intracranial hemorrhage communicates with the sub urtic space of the scalp through the fracture lines the signs of cerebral compression did not develop until the sub EP neurotic space is fully filled with blood for this reason the collection of blood in the fourth layer is called a safety valve hematoma if cerebros spinal fluid collects in the sub urtic space the condition is called seil hydral seil hematoma is a sub periostal collection of blood since the periosteum of skull Loosely covers the bones of skull except at the sutal lines where it is firmly attached to the sutal membranes the hematoma is bound by suture lines and assumes the shape of related bones it is firm and its edges are well defined ail hematoma is commonly found in the parietal region capid suidani is a subcutaneous edema over the presenting part of the head at delivery it takes place during the passage of head through the birth canal due to interference of the Venus return it is the most common form of birth trauma of the scalp and usually occurs over the oxit and crosses the suture lines the affected parts of the scalp feel soft and margins are partly defined generally the edema subsides in a few days