anatomy review for NMBE Flashcards
blinking - what nerve?
facial nerve
The oculomotor nerve innervates the muscles moving the eyeball, except the rectus lateralis muscle, which is supplied by the abducens nerve. The supraorbital nerve and the lacrimal nerve are branches of the trigeminus nerve.
The optic nerve is part of a reflex protecting the cornea from visual danger but not at all involved in the process of blinking.
In the forearm, the lateral antebrachial cutaneous nerve arises from the
musculacutaneous
Which nerve arises from the medial cord and if injured results in numbness of the medial aspect of the forearm?
The medial antebrachial cutaneous nerve (medial cutaneous nerve of the forearm) arises from the medial cord of the brachial plexus. It lies between the axillary artery and vein, and descends medial to the brachial artery. Below the middle of the arm it pierces the fascia, becomes subcutaneous and divides into anterior and ulnar branches. The anterior branch supplies the skin on the anterior and medial side of the forearm and the ulnar branch supplies the skin on the medial and posteromedial aspects of the forearm.
The middle meningeal artery descends through which foramen?
F. spinosum
severe facial injuries; there is marked ptosis of her left eye. The left pupil is dilated, but the right eye is normal.
ciliary ganglion
Question Highlights
What muscle’s denervation is responsible for the blurred vision in this case?
Pupilloconstrictor
Correct Answer: Pupilloconstrictor
The correct response is the pupilloconstrictor. Injury to this muscle causes mydriasis and results in blurry vision and light sensitivity.
The clinical picture is suggestive of injury to the oculomotor nerve, which is the third cranial nerve. It innervates the following muscles:
Superior rectus Inferior rectus Medial rectus Inferior oblique Pupilloconstrictor Levator palpebrae superioris The superior rectus causes elevation of the eye with adduction.
The inferior rectus causes depression of the eye with adduction.
The medial rectus causes adduction of the eye.
The levator palpebrae superioris causes elevation of the eyelid.
Causes of third cranial nerve palsy include:
Intracranial and intraorbital lesions (e.g., neoplasms)
Head and orbital trauma
Ocular myopathies
Cerebral aneurysms
Transtentorial herniation
The valve of Thebesius
Is a semicircular fold of the lining membrane of the right atrium, protecting the orifice of the coronary sinus. It prevents the regurgitation of blood into the sinus during the contraction of the auricle. This valve is occasionally double
ankle jerk is a reflex twitch of the triceps surae (gastrocnemius and soleus) induced by tapping the tendo calcaneus (Achilles tendon). Where is the reflex center?
first or 2nd sacral spine
Which one of the following cranial nerves passes through the stylomastoid foramen
facial nerve
How does the lumbar spine differ from the cervical and thoracic vertebrae?
There is an absence of costal facets in the lumbar and sacral spine
?
Anterior to the trachea, anterior and medial to the vagus nerve, posterior and medial to the sternothyroid muscle, and medial to the jugular veins
The lower posterior part of the acetabulum is contributed by
the ischeum
The etiology of facial paralysis is multiple. If a patient has bilateral function of the frontalis and the orbicularis oculi but only unilateral function of the rest of the muscles of facial expression, the lesion is most likely to be at which level? Answer Choices Ico-marker Ico-abct 1 Stylomastoid foramen Ico-marker Ico-abct 2 Facial nucleus in the pons Ico-marker Ico-abct 3 Supranuclear level Ico-marker Ico-abct 4 Middle ear Ico-marker Ico-abct 5 Facial cana
Supranuclear level
Show Explanation
Which of the following ligaments arises from the floor of the acetabular fossa and attaches to the fovea capitus of the femur?
Ligament of the head of the femur
The temporalis muscle is innervated by which nerve?
Mandibular branch of the trigeminal nerve
A patient is not only unable to turn the eyeball laterally, but the eyeball seems to be pulled medially also. This problem indicates damage to the
If this nerve is damaged, not only will the patient be unable to turn the eyeball laterally, but because of the lack of muscle tonus to the lateral rectus muscle, the eyeball will be pulled medially.
Abducent nerve
The small abducent nerve (CN-VI) originates from a nucleus within the pons and emerges from the lower portion of the pons and the anterior border of the medulla oblongata. It is a mixed nerve that transverses the superior orbital fissure of the orbit to innervate the lateral rectus eye muscle. If this nerve is damaged, not only will the patient be unable to turn the eyeball laterally, but because of the lack of muscle tonus to the lateral rectus muscle, the eyeball will be pulled medially.
Damage to the trochlear nerve (CN-IV) impairs movement in the direction permitted by the superior oblique eye muscle. A person whose oculomotor nerve (CN-III) is damaged may have a drooping upper eyelid or a dilated pupil or be unable to move the eyeball in the directions permitted by the four extrinsic muscles innervated by this nerve. Trauma to the facial nerve (CN-VII) results in inability to contract facial muscles on the affected side of the face and distorts taste perception, particularly of sweets. Damage to both vagal nerves (CN-X) will cause death. The injury of one nerve causes vocal impairment, difficulty in swallowing, or other visceral disturbances.
The central perineal tendon
a mass of tissue present in central area in front of the anus and behind the perineal membrane.
All four mastication muscles are supplied by which of the following?
Mandibular division of the trigeminal nerve
Which one of the following muscles of the pharynx has its origin in the lower part of the stylohyoid ligament and from the lesser and greater cornua of the hyoid bone?
Middle Constrictor muscle
The ischiopubic or conjoint ramus is formed when the ischial ramus joins which of the following structures?
Inferior pubic ramus
Branches of the maxillary artery gain entrance to the pterygopalatine fossa via which of the following structures?
Pterygomaxillary fissure
A 42-year-old man sees his physician because of hearing loss and a sensation of the room spinning while he is standing. A lesion to which cranial nerve would most likely result in these symptoms?
CN VIII
A 14-year-old girl arrives at the dentist’s office to have a cavity in her lower right incisor filled. Which nerve will the dentist most likely block before beginning the procedure?
CN V-3
Sweat glands within the S2 dermatome along the posterior region of the thigh most likely receive innervation via preganglionic sympathetic neurons originating from which of the following central nervous system levels?
L2 spinal cord level
Radiographic imaging reveals puss building up around the ear ossicles. Which of the following is the most likely location of the puss?
middle ear