24. The muscles and nerves that are responsible for adducting the eyeball (rotating the cornea medially) include the following except which?
A. the superior rectus
B. the medial rectus
C. the oculomotor nerve
D. the inferior obliquus
E. the inferior rectus
25. The outermost layer of the optic nerve sheath is a continuation of the.
A. arachnoid membrane
B. meningeal dura
C. periosteal dura
D. pia mater
26. The inner lining of the eyelid is called the.
A. orbital septum
B. palpebral conjunctiva
E. tarsal plate
27. The ducts of the lacrimal gland open into the.
A. superior fornix of the conjunctiva
B. inferior fornix of the conjunctiva
C. lacrimal puncta
D. lacrimal canaliculi
E. lacrimal lake
28. Starting from a position gazing straight ahead, to direct the gaze downward, the inferior rectus muscle must be active along with the.
A. superior obliquus
B. inferior obliquus
C. medial rectus
D. lateral rectus
E. superior rectus
1. 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?
2. What would the examining physician notice in the eye of a person who has taken a sympathetic blocking agent?
A. exophthalmos and dilated iris
B. enophthalmos and dry eye
C. dry eye and inability to accommodate for reading
D. wide open eyelids and loss of depth perception
E.ptosis and miosis (pin-point iris)
3. A patient complains of loss of hearing in the fight ear. Examination reveals ankylosis (otoselerosis) of the footplate of the stapes to the surrounding bone. Which part of the bony labyrinth is involved?
A. aditus and antrum
B. cochlear (round) window
C. cochlear duct
D. internal acoustic meatus
E. vestibular (oval) window
4. You have a patient with a drooping fight eyelid. You suspect Homer's syndrome. Which of the following signs on the fight side would confirm this diagnosis?
A. constricted pupil
B. dry eye (lack of tears)
D. pale, blanched face
E. sweaty face
5. Following endarterectomy on the fight common carotid, a patient is found to be blind in the fight eye. It appears that a small thrombus embolized during surgery and lodged in the artery supplying the optic nerve. What artery would be blocked?
A. central artery of the retina
6. You are asked to check the integrity of the trochlear nerve in the right eye Of a patient. Starting with the eyes directed straight ahead, you would have the patient look.
A. inward, toward the nose and downward
B. inward, toward the nose and upward
C. toward the nose in a horizontal plane
D. laterally in a horizontal plane
E. outward, away from the nose and downward
7. An elderly patient with chronic otitis media (middle ear infection) might have all the following complications except:
A. inability to chew food due to injury to the mandibular division of the trigeminal nerve (CN V)
B. loss of taste in the anterior part of the tongue due to injury to the chorda tympani nerve
D. paralysis of facial muscles due an injury to the facial nerve (CN VII)
E. some degree of deafness due to damage to the ossicles
8. An adolescent boy suffers from severe acne. As is often the case he frequently squeezed the pimples on his face. He subsequently develops a fever and deteriorates into a confused mental state and drowsiness. He is taken to his physician and after several tests a diagnosis of cavernous sinus infection and thrombosis is made. The route of entry to the cavernous sinus from the face was most likely the
5. The entry of bacteria through which space could lead to an infection in the mastoid air cells?
6. The spiral organ lies in.
True or False Questions
1. The central artery of the retina runs in the substance of the optic nerve and enters the eyeball at the center of the optic disc. Here, it divides into branches, which may be studied in a patient through an ophthalmoscope. The branches are end arteries. ( )
2. The optic nerve enters the orbit from the middle cranial fossa by passing through the superior orbital fissure. ( )
3. The transparent cornea is largely responsible for the refraction of the light entering the eye. It is in contact posteriorly with the aqueous humor. ( )
4. The lens is situated behind the iris and in front of the vitreous body and is encircled by the ciliary processes. ( )
5. To accommodate the eye for close objects, the ciliary muscle relaxes and let the ciliary body forward and inward so that the radiating fibers of the suspensory ligament are relaxed. ( )
6. The internal acoustic meatus in the skull is located in the body of the sphenoid bone. ( )
7. The middle ear communicates in front through the auditory tube with the nasopharynx and behind with the mastoid antrum. ( )
8. The bony labyrinth consists of three parts, the vestibule, the semicircular canals, and the cochlea. They are lined by endosteum and contain a clear fluid, the endolymph. ( )
1. How many tissue layers (tunics) comprise the wall of eyeball and how are the tunics arranged?
2. What important structures are located on the inner surface of the posterior retinal wall?
3. What substances are contained within the space anterior to the lens and within the space posterior to the lens respectively?
4. How does the lens focus light?
5. Give a simple description of the middle ear.
6. What is the structural feature and the function of the auditory tube?
7. What is the difference, if any, between a semicircular canal and semicircular duct?
Multiple Choice Questions
1. D 2. E 3. B 4. B 5. A 6. B 7. A 8. B 9. E 10. A
11. D 12. A 13. C 14. E 15. D 16. B 17. D 18. C 19. B 20. E
21. E 22. C 23. A 24. D 25. B 26. B 27. A 28. A
1. E 2. E 3. E 4. A . A 6. E 7. A 8. D
1. E 2. A 3. C 4. D 5. A 6. B
True or False Questions
1. T 2. F 3. T 4. T 5. F 6. F 7. T 8. F
Explanation of Terms
1. The transparent tissue constituting the anterior sixth of the outer wall of the eye, with a 7.7-mm radius of curvature as contrasted with the 13. 5 mm of the sclera.
2. Delicate fibers that pass from the equator of the lens to the ciliary body, collectively known as the ciliary zonule.
3. The serrated extremity of the optic part of the retina, located a little behind the ciliary body and marking the limits of the percipient portion of the membrane.
4. A depression in the center of the macula lutea containing only cones and lacking blood vessels.
5. An oval area of the ocular fundus devoid of light receptors where the axons of the retinal ganglion cell converge to form the optic nerve head.
6. The vascular structure encircling the anterior chamber of the eye and through which the aqueous is returned to the blood circulation.
7. A triangular area at the anterior inferior part of .the tympanic membrane, extending from the umbo to the periphery, where there is a reflection of light.
8. An oval opening on the medial wall of the tympanic cavity leading into the vestibule, closed in life by the foot of the stapes.
9. An opening on the medial wall of the middle ear leading into the cochlea, closed in life by the secondary tympanic membrane.
10. The prominence on the medial wall of the tympanic cavity above the vestibular window produced by the presence of the facial canal.
11. A prominent ridge of highly specialized epithelium in the floor of the cochlear duct overlying the basilar membrane of cochlea, containing one inner row and three outer rows of hair cells, or cells of Corti (the auditory receptor cells innervated by the cochlear nerve) supported by various columnar cells.
12. The macula sacculi is placed vertically on the medial wall of the saccule. The hair cells in the macula are innervated by fibers of the vestibular division of the vestibulocochlear nerve. It is primarily static organs for signaling of the position of the head in space, and also responds to quick tilting movement and to liner acceleration and deceleration.
13. An elevation on the inner surface of the ampulla of each semicircular duct; filaments of the vestibular nerve pass through the crista to reach hair cells on its surface; the hair ceils are capped by the cupula, a gelatinous protein-polysaccharide mass.
Answer the Following Questions
1. The wall of the eyeball has three tunics. The most external tunic, the fibrous tunic, consists of the posterior sclera and the anterior cornea. The middle tunic, vascular tunic, consists of the choroid, the ciliary body and the iris anteroposteriorly. The inner tunic, sensory tunic, consists of an outer pigmented layer and an inner nervous layer.
2. Two important spots can be found on the posterior retinal wall. (1) the macula lutea with its central fovea which is the area of highest visual acuity; (2) the optic disc, called blind spot, which is the place where axons of ganglion cells form the optic nerve.
3. Within the space anterior to the lens aqueous humor is contained in both anterior and posterior chambers, and the gel-like vitreous humor is contained within the space posterior to the lens.
4. The biconvex lens helps to focus light. It is suspended in the eye by the suspensory ligament (zonule) attached to the ciliary body. Tension in the zonule resists the lens' natural tendency to round up. A resting eye, with its lens stretched flat by tension in the suspensory ligament, is set to focus the almost parallel rays from distant points. However the diverging rays from nearby points must be bent more sharply if they are to focus on the retina, and this is accomplished by releasing the tension on the suspensory ligament and rounding of the lens.
5. The middle ear is a small chamber within the temporal hone. Its boundaries are the eardrum laterally, the bony wall of the inner ear medially, a bony roof superiorly, a posterior wall that opens into the mastoid antrum, and an anterior wall that opens into the auditory tube.
6. The auditory tube consists of posterolateral bony part and inferomedial cartilaginous part. It connects the tympanic cavity to the pharynx and equalizes air pressure across the eardrum.
7. The three semicircular canals are bony structures, but the semicircular ducts are membranous structures. The special receptors that measure rotational acceleration of the head are located in some particular area called membranous ampulla of semicircular duct.
(Dai Jibin, Pan Feng) Multiple Choice Questions
1. The human nervous system can be subdivided into.
A. autonomic nervous system (ANS) and central nervous system (CNS)
B. autonomic nervous system (ANS) and peripheral nervous system (PNS)
C. central nervous system (CNS) and peripheral nervous system (PNS)
D. somatic nervous system and central nervous system (CNS)
E. somatic nervous system and peripheral nervous system (PNS)
2. The brain has a tiered structure and, from a gross point of view, can be subdivided into.
A. the cerebrum, the brain stem, and the cerebellum
B. diencephalon, the brain stem, and the cerebellum
C. midbrain, pons, and medulla oblongata
D. telencephalon, diencephalon, and the cerebellum
E. diencephalon, pons, and medulla oblongata
3. Which is the basic structural and functional unit of the nervous system?
C. Nissl bodies
D. nerve fiber
4. Which nerves convey stimuli from the skin, mucous membranes, and deeper structures?
A. sympathetic nerves
B. parasympathetic nerves
C. motor nerves
D. sensory nerves
E. efferent nerves
5. What consists of rough endoplasmic reticulum and associated ribosomes?