1.
Which of the following structure of the bony labyrinth (inner ear) that converts mechanical energy into electrical energy?
Correct Answer
B. Cochlea
Explanation
The cochlea is the correct answer because it is a structure in the bony labyrinth of the inner ear that is responsible for converting mechanical energy into electrical energy. It contains specialized hair cells that vibrate in response to sound waves, which then generate electrical signals that are sent to the brain for interpretation. The other options mentioned, such as the vestibule, semicircular canals, and chorda tympani, have different functions within the inner ear and do not directly convert mechanical energy into electrical energy.
2.
In the Cochlea, the Scala vestibule ends at?
Correct Answer
C. Oval window
Explanation
The Scala vestibule is a part of the cochlea, which is located in the inner ear. It is one of the three fluid-filled chambers in the cochlea. The Scala vestibule extends from the oval window, which is a membrane-covered opening that connects the middle ear to the inner ear. This opening allows sound vibrations to enter the fluid-filled cochlea and stimulate the sensory cells in the organ of Corti, which is responsible for converting sound waves into electrical signals that can be interpreted by the brain. Therefore, the correct answer is Oval window.
3.
Which step of the following is not in its order regarding the mechanism of hearing?
Correct Answer
C. Electrical signal sent up the Cochlear nerve to the brain.
Explanation
The correct answer is "Electrical signal sent up the Cochlear nerve to the brain." This step is not in its order regarding the mechanism of hearing because it occurs after the sound waves enter the outer ear, the ear drum vibrates with the incoming sound, and the stapes move in and out of the oval window of the cochlea. The electrical signal sent up the Cochlear nerve to the brain is the final step in the process, where the auditory information is transmitted to the brain for interpretation.
4.
A 24 years old man lifting a 20kg dumbbells, what type of contraction firstly begins? And choose the tensions state.
Correct Answer
B. Isometric, increases.
Explanation
When a person lifts a 20kg dumbbell, the type of contraction that first begins is isometric contraction. Isometric contraction refers to the muscle generating tension without any change in length. In this case, the man is lifting the dumbbell, but the muscle length remains constant. Additionally, the tension in the muscle increases as the man lifts the dumbbell, which is why the correct answer is "Isometric, increases."
5.
4- Ali is facing a difficulty in moving his foot towards the plantar surface, which direction is he having problem with:
Correct Answer
B. Plantar flexion.
Explanation
Ali is experiencing difficulty in moving his foot towards the plantar surface, indicating a problem with plantar flexion. Plantar flexion refers to the movement of the foot in which the toes are pointed downward, away from the body. This movement is important for activities such as walking, running, and standing on tiptoes. If Ali is having difficulty with plantar flexion, it means he is unable to properly perform these movements, suggesting an issue with the muscles, tendons, or nerves involved in this motion.
6.
The cells that tear down and remodel the bone are the….?
Correct Answer
C. Osteoclasts
Explanation
Osteoclasts are cells that are responsible for breaking down and remodeling bone. They play a crucial role in bone development, growth, and repair. Osteoclasts are able to resorb bone tissue by secreting enzymes and acids that break down the mineralized matrix. This process is important for maintaining bone homeostasis and allows for the removal of damaged or old bone tissue. Osteoblasts, on the other hand, are responsible for bone formation, while osteocytes are mature bone cells that help regulate bone remodeling. Macrophages are immune cells that play a role in the immune response, but they are not directly involved in bone remodeling.
7.
In regard to bone cell development which of the following sequences is correct?
Correct Answer
D. Osteogenic-osteoblasts-osteocyte
Explanation
Osteogenic cells are the precursor cells that differentiate into osteoblasts, which are responsible for bone formation. Osteoblasts then become osteocytes, which are mature bone cells that maintain the bone tissue. Therefore, the correct sequence for bone cell development is osteogenic-osteoblasts-osteocyte.
8.
A developmental disorder in which pituitary produces excess growth hormone and the patients grows abnormally large is known as?
Correct Answer
C. Acromegaly
Explanation
Acromegaly is a developmental disorder characterized by the excessive production of growth hormone by the pituitary gland, leading to abnormal growth and enlargement of certain body parts. Unlike dwarfism, which is characterized by overall short stature, individuals with acromegaly experience disproportionate growth, particularly in the hands, feet, and facial features. Achondroplasia is a specific type of dwarfism caused by a genetic mutation, while osteogenesis imperfecta is a condition characterized by brittle bones. Therefore, the correct answer for the given question is Acromegaly.
9.
Permanent maxillary molars have _____ roots.
Correct Answer
A. A. Three
Explanation
Permanent maxillary molars have three roots. This is because the maxillary molars are large and have a complex root structure to provide stability and support for the tooth. The three roots are known as the mesiobuccal, distobuccal, and palatal roots. Each root serves a specific purpose in anchoring the tooth in the upper jaw and ensuring proper function during chewing and biting.
10.
A 38-year-old patient complained of acute dental pain. The attending dentist found penetrating dental caries (dental decay) affecting one of the mandibular molar teeth. Which nerve would the dentist need to anesthetize to work on that tooth?
Correct Answer
B. Inferior alveolar
Explanation
The dentist would need to anesthetize the inferior alveolar nerve to work on the tooth with penetrating dental caries. The inferior alveolar nerve supplies sensory innervation to the mandibular teeth and their surrounding tissues. By anesthetizing this nerve, the dentist can ensure that the patient does not feel any pain during the dental procedure.
11.
Incapacity to protrude the mandible indicates a dysfunction of which muscle?
Correct Answer
C. Lateral pterygoid
Explanation
The lateral pterygoid muscle is responsible for protruding the mandible. If there is an incapacity to protrude the mandible, it indicates a dysfunction of the lateral pterygoid muscle.
12.
The largest cusp in the occlusal surface of lower 1st permanent molar is:
Correct Answer
A. Mesiobuccal cusp
Explanation
The mesiobuccal cusp is the largest cusp in the occlusal surface of the lower 1st permanent molar. This cusp is located towards the front and outer side of the tooth, making it larger and more prominent compared to the other cusps. It plays a crucial role in the chewing and grinding of food, as it is the first cusp to come into contact with the opposing tooth during occlusion.
13.
The geometrical form of the occlusal surface of lower 1st permanent molar is:
Correct Answer
D. Hexagonal
Explanation
The occlusal surface of the lower 1st permanent molar is hexagonal in shape. This means that it has six sides or angles. The hexagonal shape allows for proper alignment and distribution of forces during chewing and biting, ensuring efficient function of the tooth. Additionally, the hexagonal shape provides stability and prevents excessive wear and tear on the tooth, promoting longevity.
14.
Lower 3rd molar may be similar to the 1st permanent molar, but differ than the 1st permanent molar in:
Correct Answer
A. It has supplemental grooves and no distal contact area.
Explanation
The lower 3rd molar differs from the 1st permanent molar in that it has supplemental grooves and no distal contact area.
15.
The permanent 1st molar is the key of occlusion because of all the following reasons except:
Correct Answer
A. It is the last permanent tooth to develop and erupt.
Explanation
The permanent 1st molar is the key of occlusion because it is the largest permanent tooth, its eruption is guided to its correct position just distal to the deciduous molars, and its eruption can never be disturbed since it has no predecessor. However, it is not the last permanent tooth to develop and erupt, which means that this reason does not contribute to its importance as the key of occlusion.
16.
When upper 8 is heart-shaped, which cusp is the smallest-or even absent?
Correct Answer
D. Distolingual
Explanation
When the upper 8 is heart-shaped, the distolingual cusp is the smallest or even absent.
17.
When the eye is the neutral position, this muscle is responsible just for adduction.
Correct Answer
E. Medial rectus muscle
Explanation
The medial rectus muscle is responsible for adduction of the eye when it is in the neutral position. Adduction refers to the movement of the eye towards the midline of the body. The medial rectus muscle is located on the inner side of the eye and contracts to move the eye inward. This muscle works in conjunction with the other muscles of the eye to control eye movements and maintain proper alignment and coordination.
18.
The following are the action of superior oblique muscle:
Correct Answer
B. Depression
Explanation
The superior oblique muscle is responsible for depression of the eye. Depression refers to the downward movement of the eye, allowing it to move in a downward direction. This action is important for various visual tasks such as looking down or reading. The superior oblique muscle works in conjunction with other eye muscles to control eye movement and maintain proper alignment.
19.
You are testing the extraocular muscles and their innervation in a patient who periodically experiences double vision. When you ask him to turn his right eye inward toward his nose and look downward he is able to look inward, but not down. Which nerve is most likely involved?
Correct Answer
E. Trochlear
Explanation
The trochlear nerve is responsible for innervating the superior oblique muscle, which is responsible for moving the eye downward and inward. In this case, the patient is able to look inward, indicating that the abducent nerve (innervating the lateral rectus muscle) is functioning properly. However, the patient is unable to look downward, suggesting that the trochlear nerve is likely involved.
20.
The cranial nerves that innervate the extrinsic ocular (eye) muscles include the:
Correct Answer
A. Occulomotor, abducent, trochlear nerves
Explanation
The correct answer is Occulomotor, abducent, trochlear nerves. These are the cranial nerves that innervate the extrinsic ocular muscles. The occulomotor nerve controls most of the eye muscles, including the levator palpebrae superioris, which raises the eyelid, and the superior, inferior, and medial rectus muscles, which move the eye in different directions. The abducent nerve controls the lateral rectus muscle, which moves the eye laterally. The trochlear nerve controls the superior oblique muscle, which moves the eye downward and laterally.