Dentosphere : World of Dentistry

 # Select the incorrect statement about the carotid sinus: A. It is a dilatation near the beginning of the internal carotid artery B. It is innervated by the glossopharyngeal nerve C. It acts as a chemoreceptor D. Its wall has thick tunica adventitia The correct answer is C. It acts as a chemoreceptor; which is incorrect because carotid sinus is a baroreceptor.  Carotid Sinus : The termination of the common carotid artery, or the beginning of the internal carotid artery shows a slight dilatation, known as the carotid sinus which receives a rich innervation from the glossopharyngeal and sympathetic nerves. The carotid sinus acts as a baroreceptor or pressure receptor and regulates blood pressure. Carotid Body: Carotid body is a small, oval reddish-brown structure situated behind the bifurcation of the common carotid artery. It receives a rich nerve supply mainly from the glossopharyngeal nerve, but also from the vagus and sympathetic nerves. It acts as a chemoreceptor and respo...

# The base of the submental triangle is formed by: A. Chin B. Anterior belly of digastric C. Posterior belly of digastric D. Hyoid bone The correct answer is D. Hyoid bone. Submental triangle is a median triangle. On each side, there is the anterior belly of the corresponding digastric muscles. Its base is formed by the body of the hyoid bone. Its apex lies at the chin. The floor of the triangle is formed by the right and left mylohyoid muscles and the median raphe uniting them. CLICK HERE FOR MORE MCQs

 # All of the infrahyoid muscles are supplied by ansa cervicalis EXCEPT: A. Thyrohyoid B. Sternohyoid C. Sternothyroid D. Inferior belly of omohyoid The correcct answer is A. Thyrohyoid. Infrahyoid muscles are sternohyoid, sternothyroid, thyrohyoid and omohyoid present in the superficial plane of the anterior triangle of neck. Sternohyoid, sternothyroid, omohyoid are supplied by ansa cervicalis EXCEPT thyrohyoid which is supplied by the first cervical nerve through hypoglossal nerve. CLICK HERE FOR MORE MCQs

 # All of the following belongs to suprahyoid group of muscles EXCEPT: A. Omohyoid B. Mylohyoid C. Stylohyoid D. Geniohyoid The correct answer is A. Omohyoid.  Suprahyoid Muscles are: Digastric, Stylohyoid, Mylohyoid, Geniohyoid   @ Super Stylish Getho and Mylo Di.  Infrahyoid muscles: Sternohyoid, Sternothyroid, Thyrohyoid, Omohyoid  (SH, ST, TH, OH) CLICK HERE FOR MORE MCQs

 # Torticollis or Wry Neck is the result of spasm of which of the following muscles? A. Omohyoid and sternohyoid B. Trapezius and Sternocleidomastoid C. Platysma and mentalis D. Scaleneus anterior and scaleneus posterior The correct answer is B. Trapezius and Sternocleidomastoid Torticollis or Wry neck is a deformity in which the head is bent to one side and the chin points to the other side. This is a result of spasm or contracture of the muscles supplied by the spinal accessory nerve, these being the sternocleidomastoid and the trapezius. CLICK HERE FOR MORE MCQs

 # Which of the following are called as ‘Signal nodes’? A. Supraclavicular nodes B. Jugulo-omohyoid C. Jugulodigastric D. Submandibular The correct answer is A. Supraclavicular nodes The left supraclavicular nodes or Virchow's or scalene nodes are also involved in malignant growths of distant organs, e.g. the stomach, the testis and other abdominal organs. Therefore, they are known as signal nodes. Scalene node biopsy is very helpful in the early diagnosis of such malignancies.  CLICK HERE FOR MORE MCQs

 # The origin of clavicular head of sternocleidomastoid muscle is from the: A. Medial one third of the inferior surface of the clavicle B. Lateral one third of the inferior surface of the clavicle C. Medial one third of the superior surface of the clavicle D. Lateral one third of the superior surface of the clavicle The correct answer is C. Medial one third of the superior surface of the clavicle. Origin of Sternocleidomastoid Muscle 1. The sternal head is tendinous and arises from the superolateral part of the front of the manubrium sterni. 2. The clavicular head is musculotendinous and arises from the medial one third of the superior surface of the clavicle. Insertion of Sternocleidomastoid Muscle It is inserted  a) by a thick tendon into the lateral  surface of the mastoid process from its tip to its superior border, and  b) by a thin aponeurosis into the lateral half of the superior nuchal line of the occipital bone. Nerve Supply of Sternocleidomastoid The spinal...