Anatomy Infratemporal Fossa & Prevertebral Region

1. The lesser petrosal nerve carries preganglionic parasympathetic fibers to the:

Geniculate ganglion

Otic ganglion

Submandibular ganglion

Ciliary ganglion

The lesser petrosal nerve is a branch of the glossopharyngeal nerve (CN IX). The lesser petrosal nerve carries presynaptic parasympathetic fibers to the otic ganglion. These fibers synapse in the otic ganglion, and the postsynaptic fibers travel on the auriculotemporal nerve to innervate the parotid gland. The geniculate ganglion is the sensory ganglion of the facial nerve--it holds the cell bodies of the neurons that carry taste sensations from the anterior 2/3 of the tongue.

Explanation

The lesser petrosal nerve is a branch of the glossopharyngeal nerve (CN IX). The lesser petrosal nerve carries presynaptic parasympathetic fibers to the otic ganglion. These fibers synapse in the otic ganglion, and the postsynaptic fibers travel on the auriculotemporal nerve to innervate the parotid gland. The geniculate ganglion is the sensory ganglion of the facial nerve--it holds the cell bodies of the neurons that carry taste sensations from the anterior 2/3 of the tongue.

2. What is the function of the temporalis muscle?

Elevates and protrudes the mandible‬‬‬‬‬‬‬

Elevates and retracts the mandible

Depresses and protrudes mandible‬‬‬‬‬‬‬

Depresses and retracts mandible

The temporalis muscle is responsible for elevating and retracting the mandible. It is one of the main muscles involved in chewing and closing the mouth. When the temporalis muscle contracts, it pulls the mandible upwards (elevation) and backwards (retraction), allowing for the closing of the mouth and the grinding of food.

Explanation

The temporalis muscle is responsible for elevating and retracting the mandible. It is one of the main muscles involved in chewing and closing the mouth. When the temporalis muscle contracts, it pulls the mandible upwards (elevation) and backwards (retraction), allowing for the closing of the mouth and the grinding of food.

3. Mr. Chotas, a budding medical student, underwent surgery for his impacted mandibular third molar. As a good doctor, the surgeon warns Mr. Chotas about the possible lasting numbness in the tip of his tongue. This loss of general sensation is due to the damage of what nerve?

Auriculotemporal nerve

Chorda tympani

Lingual nerve

Mental nerve

Nerve to mylohyoid

The lingual nerve is a branch of V3 that conveys sensation to the anterior two-thirds of the tongue. It enters the oral cavity by passing just under the mandibular third molar between the medial pterygoid muscle and the mandibular ramus. Don't get this confused with the chorda tympani that does travel with the lingual, but carries taste from the anterior two-third of the tongue

Explanation

The lingual nerve is a branch of V3 that conveys sensation to the anterior two-thirds of the tongue. It enters the oral cavity by passing just under the mandibular third molar between the medial pterygoid muscle and the mandibular ramus. Don't get this confused with the chorda tympani that does travel with the lingual, but carries taste from the anterior two-third of the tongue

4. A 55-year-old man undergoes surgery on his parotid gland. When presenting for a follow-up visit one month later, he reports feeling his skin damp over his surgical site when he eats. The surgeon replies that this is likely a consequence of his surgery. He explains that this is likely because of incorrect regeneration of which of the following nerves?

Lesser petrosal nerve

Greater petrosal nerve

Auriculotemporal nerve

Inferior alveolar nerve

Superficial temporal nerve

This is a description of Frey’s Syndrome, where fibers of the auriculotemporal branch of the trigeminal nerve regenerate incorrectly; there is crossover between the sympathetic fibers supplying sweat glands of the scalp and parasympathetic fibers supplying parotid gland salivation, causing sweating over the parotid while eating. Lesions of the remainder of these nerves would not create this clinical picture.

Explanation

This is a description of Frey’s Syndrome, where fibers of the auriculotemporal branch of the trigeminal nerve regenerate incorrectly; there is crossover between the sympathetic fibers supplying sweat glands of the scalp and parasympathetic fibers supplying parotid gland salivation, causing sweating over the parotid while eating. Lesions of the remainder of these nerves would not create this clinical picture.

5. A physician takes a small feather and touches the anterior portion of his patients tongue. The patient asks what does that test? Thinking back to your anatomy you reply?

Taste of Anterior 2/3 of tongue via CN VII

Taste of Anterior 2/3 of tongue via CN IX

General sensation of Anterior 2/3 of tongue via CN VII

General sensation of Anterior 2/3 of tongue via CN V division 3

Remember general sensation and taste follow two different cranial nerves on the anterior 2/3 of the tongue. Taste is mediated via CN 7 while sensation follows the V3 of Trigeminal nerve. The posterior 1/3rd of the tongue is innervated through CN 9 for sensation and taste.

Explanation

Remember general sensation and taste follow two different cranial nerves on the anterior 2/3 of the tongue. Taste is mediated via CN 7 while sensation follows the V3 of Trigeminal nerve. The posterior 1/3rd of the tongue is innervated through CN 9 for sensation and taste.

6. A 28-year old lady is involved in a motor accident. After the accident, she presents to your clinic because she has difficulty in opening her mouth, but has no difficulty in closing it. Which of the following muscles was MOST LIKELY damaged?

Medial pterygoid

Masseter

Lateral pterygoid

Temporalis

Orbicularis oris

the lateral pterygoids are the only muscles of mastication that open the mouth.

Explanation

the lateral pterygoids are the only muscles of mastication that open the mouth.

7. A 65-year-old man has difficulty swallowing and frequently aspirates fluids while drinking. MRI scan reveals that he has a tumor near the jugular foramen. Involvement of which structure is responsible for the presenting symptoms?

Ansa cervicalis

Vagus Nerve

Cervical sympathetic trunk

Accessory nerve

Hypoglossal nerve

The vagus nerve (CN X), which exits the skull through the jugular foramen, is the motor nerve to the pharynx and allows for swallowing.

Explanation

The vagus nerve (CN X), which exits the skull through the jugular foramen, is the motor nerve to the pharynx and allows for swallowing.

8. A 56 year old male comes into the clinic and is diagnosed with Horner's Syndrome. Which one of the following will he not suffer from?

Miosis

Mydriasis

Ptosis

Anhidrosis

A patient with Horner's syndrome will have a problem with his sympathetic nervous system. This will result in miosis (pupillary constriction), ptosis (drooping eyelid), and anhidrosis (decreased sweatng on face). Mydriasis is pupillary dilation, which will not be seen in Horner's syndrome.

Explanation

A patient with Horner's syndrome will have a problem with his sympathetic nervous system. This will result in miosis (pupillary constriction), ptosis (drooping eyelid), and anhidrosis (decreased sweatng on face). Mydriasis is pupillary dilation, which will not be seen in Horner's syndrome.

9. The parotid gland is innervated by CN , via the ganglion. Once the gland is stimulated it secretes fluid through the duct.

VII, PPG, serous, Wharton

IX, Otic, mucinous, Wharton

VII, PPG, mucinous, Stensens

IX, Otic, serous, Stensens

The parotid gland is innervated by CN IX, via the Otic ganglion and the auriculotemporal nerve (V3). Once the gland is stimulated it secretes serous fluid through the Stensens duct. The submandibular and sublingual glands are innervated by CN VII and secrete mucinous fluid through the Whartons and sublingual ducts, respectively.

Explanation

The parotid gland is innervated by CN IX, via the Otic ganglion and the auriculotemporal nerve (V3). Once the gland is stimulated it secretes serous fluid through the Stensens duct. The submandibular and sublingual glands are innervated by CN VII and secrete mucinous fluid through the Whartons and sublingual ducts, respectively.

10. The parasympathetic innervation of the parotid gland involves the glossopharyngeal nerve to hitch hike onto other nerves. What is the correct sequence from the tympanic plexus to the parotid gland?

Tympanic nerve → Otic ganglion → Auriculotemporal nerve of V3 → to parotid gland

Greater petrosal nerve → Otic ganglion → Auriculotemporal nerve of V3 → to parotid gland

Lesser petrosal nerve → Otic ganglion → Auriculotemporal nerve of V3 → to parotid gland

Lesser petrosal nerve → Tympanic ganglion → Auriculotemporal nerve of V2 → to parotid gland

from the medulla, fibers from CN IX hitch hike onto the tympanic nerve to the tympanic plexus, then becomes lesser petrosal nerve to the Otic ganglion. After the otic ganglion, post-ganglionic fibers hitch hike onto auriculotemporal to the parotid gland.

Explanation

from the medulla, fibers from CN IX hitch hike onto the tympanic nerve to the tympanic plexus, then becomes lesser petrosal nerve to the Otic ganglion. After the otic ganglion, post-ganglionic fibers hitch hike onto auriculotemporal to the parotid gland.

11. During thyroidectomy, the surgeon ligates the most inferior vessel supplying blood to the gland. Trace the vessel back to its origin.

Inferior thyroid A. → Costocervical trunk → Subclavian A. → Aorta

Inferior thyroid A. → Costocervical trunk → Brachiocephalic trunk → Aorta

Inferior thyroid A. → Thyrocervical trunk → Subclavian A. → Aorta

Inferior thyroid A. → Thyrocervical trunk → Common Carotid A. → Aorta

The inferior thyroid artery supplies the posteroinferior portion of the thyroid gland and originates off of the thyrocervical trunk. The thyrocervical trunk is a branch of the subclavian artery which originates off of the aorta on the left side and off of the brachiocephalic trunk on the right side.

Explanation

The inferior thyroid artery supplies the posteroinferior portion of the thyroid gland and originates off of the thyrocervical trunk. The thyrocervical trunk is a branch of the subclavian artery which originates off of the aorta on the left side and off of the brachiocephalic trunk on the right side.

12. The external and internal laryngeal nerves are branches of the superior laryngeal nerve (which is a branch of the vagus nerve). Which of the following is correct?

External laryngeal provides sensory innervation to the larynx above the vocal cords

The internal laryngeal provides motor innervation to the larynx

The internal laryngeal provides sensory innervation to the larynx above the vocal cords.

The internal laryngeal provides sensory innervation to the vocal cords.

The internal laryngeal nerve provides sensory innervation to the larynx above the vocal cords. This nerve punctures the thyrohyoid membrane and travels with the superior laryngeal artery(branch of external carotid artery). The internal laryngeal nerve travels through the piriform recess. The external laryngeal nerve supplies motor innervation to the cricothyroid muscle and some innervation to the inferior constrictors.

Explanation

The internal laryngeal nerve provides sensory innervation to the larynx above the vocal cords. This nerve punctures the thyrohyoid membrane and travels with the superior laryngeal artery(branch of external carotid artery). The internal laryngeal nerve travels through the piriform recess. The external laryngeal nerve supplies motor innervation to the cricothyroid muscle and some innervation to the inferior constrictors.

13. A 54 year old female undergoes thyroidectomy. While ligating the superior thyroid artery, the surgeon accidentally severs a nearby nerve. Which of the following muscles is denervated as a result of this injury?

Thyroarytenoid

Lateral cricoarytenoid

Posterior cricoarytenoid

Cricothyroid

Aryepiglotticus

the superior thyroid artery, superior thyroid vein, and external branch of the superior laryngeal nerve run together in a neurovascular triad that originates superior to the thyroid gland and lateral to the thyroid cartilage. Because the external branch of the superior laryngeal nerve courses just deep to the superior thyroid artery, it is at risk of injury during thyroidectomy. The cricothyroid muscle is the only muscle innervated by this nerve. The remaining laryngeal muscles are innervated by the recurrent laryngeal nerves, and also provide sensory innervation to the larynx below the vocal folds. a), b), c), and e) are all innervated by the recurrent laryngeal nerve.

Explanation

the superior thyroid artery, superior thyroid vein, and external branch of the superior laryngeal nerve run together in a neurovascular triad that originates superior to the thyroid gland and lateral to the thyroid cartilage. Because the external branch of the superior laryngeal nerve courses just deep to the superior thyroid artery, it is at risk of injury during thyroidectomy. The cricothyroid muscle is the only muscle innervated by this nerve. The remaining laryngeal muscles are innervated by the recurrent laryngeal nerves, and also provide sensory innervation to the larynx below the vocal folds. a), b), c), and e) are all innervated by the recurrent laryngeal nerve.

14. Which of the following structures is formed by branching while in the infratemporal fossa?

Chorda tympani branching from the lingual nerve

Chorda tympani branching from the facial nerve

Nerve to mylohyoid branching from the lingual nerve

Nerve to mylohyoid branching from the facial nerve

Middle meningeal artery branching from the superficial temporal artery

Middle meningeal artery branching from the maxillary artery

Lingual artery branching from the external carotid artery

Lingual artery branching from the maxillary artery

Several of the answers have incorrect pairs, while others are correct pairings but do not branch in the infratemporal region. Answer A is incorrect because chorda tympani does not branch from the lingual nerve. Rather, it joins a branch of V3 to form the lingual nerve. Chorda tympani is actually a branch of the facial nerve, but the process branching occurs will in the middle ear, not infratemporal fossa. Therefore, answer B is incorrect. The nerve to the mylohyoid does branch in the infratemporal fossa, but not from the lingual or facial nerves. It is a branch of V3 (trigeminal). Therefore, answers C and D are incorrect. The middle meningeal artery is a branch of the maxillary artery and this occurs in the infratemporal fossa. Therefore answer F is correct and E is incorrect. Lastly, the lingual artery is a branch of the external carotid artery, but this occurs more caudally (in the neck), making both G and H incorrect.

Explanation

Several of the answers have incorrect pairs, while others are correct pairings but do not branch in the infratemporal region. Answer A is incorrect because chorda tympani does not branch from the lingual nerve. Rather, it joins a branch of V3 to form the lingual nerve. Chorda tympani is actually a branch of the facial nerve, but the process branching occurs will in the middle ear, not infratemporal fossa. Therefore, answer B is incorrect. The nerve to the mylohyoid does branch in the infratemporal fossa, but not from the lingual or facial nerves. It is a branch of V3 (trigeminal). Therefore, answers C and D are incorrect. The middle meningeal artery is a branch of the maxillary artery and this occurs in the infratemporal fossa. Therefore answer F is correct and E is incorrect. Lastly, the lingual artery is a branch of the external carotid artery, but this occurs more caudally (in the neck), making both G and H incorrect.

15. A patient undergoes removal of a parotid adenoma, resulting in removal of her left parotid gland. Which of the following can be a likely complication resulting from parotid gland surgery?

Loss of pain and temperature on the left side of her face

Loss of light touch and proprioception on the left side of her face

Drooping of her left face

Hoarseness

Drooping of her left shoulder

Drooping of the left side of her face. The facial nerve (VII) runs through the parotid gland and is easily injured in parotid gland surgery. The facial nerve is responsible for innervating the muscles of facial expression, and damage to this nerve results in drooping of the face, Bell’s palsy (left side in the case). (a) and (b) would result from damage to the trigeminal nerve. The trigeminal nerve branches before exiting the skull and neither branch runs through the parotid gland, and is not easily injured in surgery of the parotid gland. (d) would result from damage to the vagus nerve, which does is not run through the parotid gland. IT exits the skull via the jugular foramen and runs through the carotid sheath. (e) this presentation is consistent with damage to the spinal accessory nerve, which is not located near the parotid gland and highly unlikely to be damaged in parotid gland surgery.

Explanation

Drooping of the left side of her face. The facial nerve (VII) runs through the parotid gland and is easily injured in parotid gland surgery. The facial nerve is responsible for innervating the muscles of facial expression, and damage to this nerve results in drooping of the face, Bell’s palsy (left side in the case). (a) and (b) would result from damage to the trigeminal nerve. The trigeminal nerve branches before exiting the skull and neither branch runs through the parotid gland, and is not easily injured in surgery of the parotid gland. (d) would result from damage to the vagus nerve, which does is not run through the parotid gland. IT exits the skull via the jugular foramen and runs through the carotid sheath. (e) this presentation is consistent with damage to the spinal accessory nerve, which is not located near the parotid gland and highly unlikely to be damaged in parotid gland surgery.

16. The internal laryngeal nerve branches directly off which nerve?

Vagus nerve‬

Recurrent laryngeal nerve‬‬‬‬‬‬

External laryngeal nerve

Superior laryngeal nerve

Inferior laryngeal nerve‬‬‬‬‬‬

The internal laryngeal nerve branches directly off the superior laryngeal nerve to supply sensory sensation to the larynx above the vocal cords. The second branch of the superior laryngeal nerve is the external laryngeal nerve, which provides motor innervation to the cricothyroid muscle. Below the vocal cords, sensation is provided by the recurrent laryngeal nerve. ‬‬‬‬

Explanation

The internal laryngeal nerve branches directly off the superior laryngeal nerve to supply sensory sensation to the larynx above the vocal cords. The second branch of the superior laryngeal nerve is the external laryngeal nerve, which provides motor innervation to the cricothyroid muscle. Below the vocal cords, sensation is provided by the recurrent laryngeal nerve. ‬‬‬‬

17. A 56-year-old woman undergoes a partial thyroidectomy for a malignant tumor. During the operation the internal laryngeal nerve was damaged. Which of the following structures will lose sensation?

Over the epiglottis only

The larynx below the vocal cord

The ventricle of the larynx

The larynx above the vocal cord

The saccule of the larynx only

the internal laryngeal nerve (branch of the superior laryngeal) provides sensory innervation above the vocal cords while the inferior laryngeal nerve (branch of the recurrent laryngeal) provides sensory innervation below the vocal cords.

Explanation

the internal laryngeal nerve (branch of the superior laryngeal) provides sensory innervation above the vocal cords while the inferior laryngeal nerve (branch of the recurrent laryngeal) provides sensory innervation below the vocal cords.

18. A 25 year old man comes into the ER after getting into a street brawl late Friday night, the right side of his face is extremely swollen, he also complains of dry mouth and an x-ray is taken. Results show a fracture of the neck of the mandible, what is the origin of the parasympathetic nerve you suspect to be damaged?

Glossopharyngeal

Facial

Trigeminal

Lingual

The Auriculotemporal nerve is commonly damaged in fractures of the neck of the mandible, which carries parasympathetic fibers to supply the partoid gland from the Lesser petrosal branch of cranial nerve IX.

Explanation

The Auriculotemporal nerve is commonly damaged in fractures of the neck of the mandible, which carries parasympathetic fibers to supply the partoid gland from the Lesser petrosal branch of cranial nerve IX.

19. A 65-yo, female presents to your primary care clinic after undergoing extensive facial plastic surgery in Beverly Hills. The surgery was uneventful, and the patient is very satisfied with the results. However, lately she has been complaining of difficulty swallowing her food. She says that she feels like she always has to take a drink of water when chewing and swallowing meals. Furthermore, the patient describes polydipsia and consequently polyuria but no trouble expressing facial emotions. As a knowledgeable physician, you begin exploring possible differentials given the patient's presentation and history and you suspect that the surgeon may have cut a nerve contributing to your patient's symptoms. Which nerve and respective modality was MOST LIKELY injured in this patient?

Facial n.; GSE

Facial n.; GVE

Glossopharyngeal n.; GSE

Facial n.; GSA

Glossopharyngeal n.; GVE

Cranial nerve IX, glossopharyngeal innervates the parotid gland not V3 mandibular branch of the trigeminal nerve. Yes CN IX does "hand" over the signal/fibers to V3 to reach the parotid gland, but CN IX still gets credit

Explanation

Cranial nerve IX, glossopharyngeal innervates the parotid gland not V3 mandibular branch of the trigeminal nerve. Yes CN IX does "hand" over the signal/fibers to V3 to reach the parotid gland, but CN IX still gets credit

20. Mr. Jones presents to your office 3 days after completing a partial thyroidectomy due to a follicular thyroid carcinoma involving the right and left lateral thyroid lobes. The patient is complaining of hoarseness in his voice and just not feeling "right" lately. Furthermore, EKG and lab results indicate that Mr. Jones has a slight cardiac arrhythmia that which you suspect may be related to his abnormally low serum calcium levels. You begin to worry that the surgeon may have mistakenly removed the parathyroid glands and injured a nerve in close proximity to the thyroid gland. Which artery runs in close proximity with the nerve that was MOST likely damaged in this patient?

Subclavian a.

Superior thyroid a

Internal Carotid a.

Inferior thyroid a.

External Carotid a.

The inferior thyroid artery and vein run in close proximity with the recurrent laryngeal nerve. The patient is presenting with hoarseness of voice. This should be a clear indication that the nerve which the surgeon most likely cut was a branch of the vagus nerve; more specifically the recurrent laryngeal nerve. Remember, be able to trace back your nerve roots to the original source. It's not enough to memorize the endings. This is a fair option some professors may choose when providing answer choices for mini questions (i.e., vagus n. ----> superior laryngeal n.-----> external and internal laryngeal n. etc.) The parathyroid gland is responsible for maintaining normal calcium levels in the body. These glands are small and may sometimes be mistaken for parts of the thyroid. In other words, it was a red herring in the question and you should learn to filter this type of information in question stems.

Explanation

The inferior thyroid artery and vein run in close proximity with the recurrent laryngeal nerve. The patient is presenting with hoarseness of voice. This should be a clear indication that the nerve which the surgeon most likely cut was a branch of the vagus nerve; more specifically the recurrent laryngeal nerve. Remember, be able to trace back your nerve roots to the original source. It's not enough to memorize the endings. This is a fair option some professors may choose when providing answer choices for mini questions (i.e., vagus n. ----> superior laryngeal n.-----> external and internal laryngeal n. etc.) The parathyroid gland is responsible for maintaining normal calcium levels in the body. These glands are small and may sometimes be mistaken for parts of the thyroid. In other words, it was a red herring in the question and you should learn to filter this type of information in question stems.

21. A 37 year old female went to see her primary care physician complaining of sharp, burning and aching pain in the 4th and 5th digits in her left hand. The physician orders an MRI and the results reveal massive inflammation of her left anterior scalene muscle. Which of the following nerves innervates the anterior scalene muscle?

Dorsal ramus of C3 and C4

Ventral ramus of C3 and C4

Spinal accessory nerve

Dorsal ramus of C4 to C6

Ventral ramus of C4 to C6

The woman is complaining of pain due to thoracic outline syndrome involving her anterior scalene muscle.

Explanation

The woman is complaining of pain due to thoracic outline syndrome involving her anterior scalene muscle.

22. A 60-year-old man with a history significant for arteriosclerosis and hypertension presents with recent onset of periodic syncopal episodes. Upon performing an angiogram, the physician notes significant stenosis of the internal carotid artery; however, the patient's collateral arterial circulation is able to sustain blood flow to his brain. Which of the following vessels provide an anastamosis for the internal carotid artery as it enters the skull? ‪

Superficial temporal artery

Angular artery

Superior thyroid artery

Suprascapular artery

Ascending cervical artery

The angular and ophthalmic arteries provide the primary anastamosis for the ICA on the anterior head; posteriorly, this anastamosis may be provided by the occipital and meningeal arteries. None of the remainder of the answer choices provide any anastamosis with the as regarding blood supply to the brain.‬

Explanation

The angular and ophthalmic arteries provide the primary anastamosis for the ICA on the anterior head; posteriorly, this anastamosis may be provided by the occipital and meningeal arteries. None of the remainder of the answer choices provide any anastamosis with the as regarding blood supply to the brain.‬

23. During the winter, a patient comes to your office with chief complaints of unexpectedly sweaty skin on the left side of her face. On physical exam, her left pupil diameter is notably larger than the left. Which of the following best describes information involved with this case?

The patient has trigeminal neuralgia

The patient is showing signs of Horner's syndrome

The patient will need to be treated by stimulating one of the cervical chain ganglia

The patient will need to be treated by paralyzing the stellate ganglion

The patient has an early stage of a Pancoast tumor

The patient is showing signs and symptoms of Reynaud's disease, which is described by overstimulation of sympathetic nerve fibers leading to a widened pupil and increase activation of sweat glands. Treatment of this disease often involves surgically induced paralysis of the stellate ganglion in order to reduce the unpleasant symptoms. Trigeminal neuralgia (A) is mostly a sensory deficit involving increase sensitivity to touch stimuli. Horner's syndrome (B) is characterized by a lack of sweating and a miotic (constricted) pupil. Answer C is incorrect because you do not want to further stimulate the sympthathetic chain for Reynaud's. Early stage Pancoast tumors (E) effects the lung in its early stages.

Explanation

The patient is showing signs and symptoms of Reynaud's disease, which is described by overstimulation of sympathetic nerve fibers leading to a widened pupil and increase activation of sweat glands. Treatment of this disease often involves surgically induced paralysis of the stellate ganglion in order to reduce the unpleasant symptoms. Trigeminal neuralgia (A) is mostly a sensory deficit involving increase sensitivity to touch stimuli. Horner's syndrome (B) is characterized by a lack of sweating and a miotic (constricted) pupil. Answer C is incorrect because you do not want to further stimulate the sympthathetic chain for Reynaud's. Early stage Pancoast tumors (E) effects the lung in its early stages.