1. The fourth layer or loose areolar tissue is called "dangerous area" of scalp.

2. Facial muscles are derived from mesoderm of second brachial arch and are supplied by facial nerve.

3. Chief artery of the face is facial artery. It also receives blood supply by transverse facial artery which is a branch of superficial temporal artery.

4. Facial vein is the chief vein of face. Its connections are:

a)  Joins anterior division of retromandibular vein to form common facial vein which drains into the internal jugular vein.

b)  Deep connection between supraorbital and superior ophthalmic vein.

c)  It communicates with the pterygoid plexus through the deep facial vein. Through this connection, it communicates with cavernous sinus.

5. The following glands are present in the eyelids or palpebra

        a) Sebaceous glands of cilia- Zeiss glands

        b) Sweat glands of cilia- Moil's glands

        c) Sebaceous glands of tarsi- tarsal glands or meibomian glands.

6. Carotid sheath is a condensation of fibroareolar tissue. The contents of it include:

a) Common and internal carotid artery

b) Internal Jugular vein

c) Vagus nerve

7. Sternocleidomastoid muscle is called the muscle of neck. It divides neck into anterior and posterior triangles.

 8. Anterior triangle is subdivided by the digastric and superior belly of omohyoid into:

a) Submental

b) Digastric

c) Carotid

d) Muscular triangle

 9. The contents of parotid gland are ECA, retromandibular vein, facial nerve, 

10. Branches of external carotid artery (ECA)

Anterior branches: Superior thyroid, lingual and facial

Posterior branches: Occipital and posterior auricular

Medial branch: Ascending pharyngeal

Terminal branches: Maxillary and superficial temporal

11. Tonsil is the only lymphoid tissue of body which is lined by squamous epithelium

12. Sympathetic ganglion of neck

Superior cervical ganglion: Largest of all formed by C₁, C₂, C₃, C₄.

Middle cervical ganglion: Fusion of C₅ and C₆.

Inferior cervical ganglion: Known as thoracocervical (stellate) ganglion formed by fusion of C₇, C₈ and T₁.

 13. Brain is covered by (D.A.P)

a) Dura mater: Outermost and thickest of all the layers. It encloses cranial venous sinuses. It has distinct blood supply and so also the nerve supply.

b) Arachnoid: Middle layer arachnoid is separated from dura mater by subdural space, subarachnoid space contains CSF and it separates arachnoid and pia mater.

c) Pia mater: Innermost layer of brain.

14. The different folds of dura mater are

a) Falx cerebri: Sickle shaped fold of dura mater encloses straight sinus and inferior sagittal sinus in its posterior 2/3 rd.

b) Tentorium cerebelli: Tent shaped fold of dura mater encloses transverse and superior petrosal sinus. It also forms the trigeminal/Meckel's cave in which trigeminal or gasserian ganglion is present.

c) Falx cerebelli: Sickle shaped encloses occipital sinus.

d) Diaphragm sellae: Forms the roof of hypophyseal fossa.

 15. Cavernous sinus

a) Large venous sinus in middle cranial fossa one on either side of body of the sphenoid bone.

b) The structures which pass through the cavernous sinus are:

Oculomotor, trochlear, ophthalmic and maxillary nerves in the lateral wall

ICA, and abducent nerve in the centre of sinus: (3,4,5,6 - nerves)

16. Length of trachea is 10-15 cm and width is 3 mm at 1 year of age and corresponds to the age in years during childhood with maximum of 12 mm in adults. Tracheostomy is an emergency operation done at retrothyroid region by cutting the isthmus of thyroid gland. A suprathyroid tracheostomy is liable to structure and infrathyroid is difficult due to depth of trachea and dangerous as numerous vessels lie anterior to it.

 17. Spinal cord gives rise to 31 pairs of spinal nerves, 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal.

 18. The cranial cavity contains brain and meninges. The meninges are:

• Outer - Dura mater
• Middle - Arachnoid mater
• Inner - Pia mater

 Dura mater has outer endosteal and inner meningeal layers. The two layers are fused to each other at all places except where the cranial venous sinuses are enclosed between them. Dura mater is separated from arachnoid membrane by subdural space. The arachnoid is separated from pia mater by subarachnoid space. That is filled with cerebrospinal fluid (CSF).

 19. Free nerve endings - pain

• End bulbs of Krause - cold
• Organs of Ruffini - warmth
• Organs of Golgi Mazzone -heat.

 20. Cervical parts of right and left sympathetic trunks are situated one on each side of the cervical part of the vertebral column.

 Origin: From fibres of T1 to T4 of spinal cord that ascend into the neck. Due to fusion of three ganglia superior, middle, inferior branches of superior ganglia:

a) To ventral rami of upper four cervical nerves

b) Plexus around internal carotid artery. A part of this plexus supplies to dilator pupillae.

c) Plexus around external carotid artery.

d) Pharyngeal branches form pharyngeal plexus.

e) Left superior cervical cardiac goes to superficial cardiac plexus while the right goes

deep cardiac plexus.

 Middle cervical ganglion: Formed by 5th & 6th cervical ganglia

Branches: Branches to ventral rami of 5th & 6th cervical nerves, thyroid, parathyroid, tracheal, oesophageal and to deep cardiac plexus.

 Inferior cervical ganglia: Formed by fusion with first thoracic ganglion and 7 and 8 cervical ganglions is called stellate ganglion.

 Branches: To ventral rami of C7 & C8 plexus around vertebral artery and Subclavian artery deep cardiac plexus.

 21. Facial vein is the largest vein of face. It begins as angular vein by the union of supratrochlear and supraorbital vein and continues as facial vein that joins the retro mandibular vein which drains into Internal jugular vein.

Facial vein communicates to the cavernous sinus through pterygoid, plexus (to which it is connected by deep facial vein) and supraorbital and superior ophthalmic vein.