Brainstem and Cranial Nerves Flashcards
(152 cards)
1
Q
What are the three main parts of the brainstem?
A
Midbrain, pons, and medulla oblongata.
2
Q
True or False: The brainstem is responsible for basic life functions.
A
True.
3
Q
Fill in the blank: The _____ is the uppermost part of the brainstem.
A
Midbrain.
4
Q
What cranial nerve is associated with the midbrain?
A
Cranial Nerve III (Oculomotor Nerve).
5
Q
Which part of the brainstem contains the respiratory centers?
A
Pons.
6
Q
What is the primary function of the medulla oblongata?
A
Regulation of vital functions such as heart rate and breathing.
7
Q
Multiple Choice: Which cranial nerve is responsible for hearing and balance?
A
Cranial Nerve VIII (Vestibulocochlear Nerve).
8
Q
True or False: The brainstem is involved in motor control.
A
True.
9
Q
What are the surface features of the brainstem?
A
The surface features include the cerebral peduncles, pons, and olive.
10
Q
Which cranial nerves originate from the medulla oblongata?
A
Cranial Nerves IX (Glossopharyngeal), X (Vagus), XI (Accessory), and XII (Hypoglossal).
11
Q
Fill in the blank: The _____ connects the cerebellum to the brainstem.
A
Pons.
12
Q
What is the role of the reticular formation in the brainstem?
A
It regulates wakefulness and sleep-wake transitions.
13
Q
Multiple Choice: Which of the following is NOT a function of the brainstem?
A
Higher cognitive functions.
14
Q
What is the clinical significance of the brainstem?
A
It is crucial for assessing brain death and neurological functions.
15
Q
True or False: The brainstem does not influence the autonomic nervous system.
A
False.
16
Q
What are the longitudinal sections of the brainstem called?
A
Motor and sensory pathways.
17
Q
Which cranial nerve is responsible for taste sensation?
A
Cranial Nerve VII (Facial Nerve).
18
Q
Fill in the blank: The _____ is involved in the control of eye movements.
A
Midbrain.
19
Q
What is the function of the vestibular nuclei located in the brainstem?
A
They are involved in balance and spatial orientation.
20
Q
Multiple Choice: Which structure is located anteriorly in the brainstem?
A
Cerebral peduncles.
21
Q
What is the function of the solitary nucleus in the brainstem?
A
It processes sensory information from the visceral organs.
22
Q
True or False: The brainstem contains nuclei for cranial nerves involved in facial sensations.
A
True.
23
Q
What is the role of the red nucleus in the midbrain?
A
It is involved in motor coordination.
24
Q
Fill in the blank: The _____ connects the brain to the spinal cord.
A
Medulla oblongata.
25
What cranial nerve is responsible for eye movement and pupil constriction?
Cranial Nerve III (Oculomotor Nerve).
26
Multiple Choice: Which cranial nerve is primarily responsible for the sense of smell?
Cranial Nerve I (Olfactory Nerve).
27
What structure in the brainstem is involved in the control of blood pressure?
Nucleus tractus solitarius.
28
True or False: The brainstem can be affected by strokes leading to specific deficits.
True.
29
What is the function of the pontine nuclei?
They relay signals from the cerebral cortex to the cerebellum.
30
Fill in the blank: The _____ is involved in regulating sleep and arousal.
Reticular formation.
31
What cranial nerve is involved in swallowing and salivation?
Cranial Nerve IX (Glossopharyngeal Nerve).
32
Multiple Choice: Which part of the brainstem is the largest?
Pons.
33
What is the reflex center for vomiting located in the brainstem?
Chemoreceptor trigger zone.
34
True or False: The brainstem is not involved in auditory processing.
False.
35
What cranial nerve is responsible for the movement of the shoulder and neck?
Cranial Nerve XI (Accessory Nerve).
36
Fill in the blank: The _____ regulates involuntary functions.
Brainstem.
37
What is the primary role of the superior colliculus?
It is involved in visual reflexes.
38
Multiple Choice: Which cranial nerve is known for its long pathway throughout the body?
Cranial Nerve X (Vagus Nerve).
39
What part of the brainstem contains the fourth ventricle?
Medulla oblongata and pons.
40
True or False: The medulla oblongata contains centers for autonomic functions.
True.
41
What is the function of the inferior colliculus?
It is involved in auditory processing.
42
Fill in the blank: The _____ is the site for the crossover of motor fibers.
Medulla oblongata.
43
What cranial nerve is responsible for facial expressions?
Cranial Nerve VII (Facial Nerve).
44
Multiple Choice: Which structure in the brainstem is involved in the regulation of breathing?
Pneumotaxic center.
45
What is the function of the locus coeruleus?
It is involved in the regulation of arousal and stress responses.
46
True or False: The pons contains nuclei that relay signals to the cerebellum.
True.
47
What cranial nerve is involved in the sense of taste from the anterior two-thirds of the tongue?
Cranial Nerve VII (Facial Nerve).
48
Fill in the blank: The _____ is a major pathway for motor control.
Corticospinal tract.
49
What is the role of the medial lemniscus in the brainstem?
It carries sensory information regarding touch and proprioception.
50
Multiple Choice: Which cranial nerve is involved in the movement of the tongue?
Cranial Nerve XII (Hypoglossal Nerve).
51
True or False: The brainstem is part of the central nervous system.
True.
52
What is the function of the trigeminal nerve?
It is responsible for sensation in the face and motor functions such as biting and chewing.
53
Fill in the blank: The _____ is the lowest part of the brainstem.
Medulla oblongata.
54
What cranial nerve is involved in the control of the diaphragm?
Cranial Nerve X (Vagus Nerve).
55
Multiple Choice: Which cranial nerve is not involved in eye movement?
Cranial Nerve IV (Trochlear Nerve).
56
What is the role of the periaqueductal gray matter?
It is involved in pain modulation and defensive behavior.
57
True or False: The brainstem has a role in the coordination of motor control.
True.
58
What cranial nerve supplies the muscles of mastication?
Cranial Nerve V (Trigeminal Nerve).
59
Fill in the blank: The _____ is responsible for reflexive head movements.
Tectum.
60
What is the function of the medullary pyramids?
They contain the corticospinal tract fibers.
61
Multiple Choice: Which cranial nerve is involved in the sensation of the throat?
Cranial Nerve IX (Glossopharyngeal Nerve).
62
True or False: The brainstem is involved in the processing of visual information.
True.
63
What is the role of the pontine respiratory group?
It helps regulate the rhythm of breathing.
64
Fill in the blank: The _____ integrates sensory information from the inner ear.
Vestibular nuclei.
65
What cranial nerve is responsible for the sense of taste from the posterior one-third of the tongue?
Cranial Nerve IX (Glossopharyngeal Nerve).
66
Multiple Choice: Which part of the brainstem is responsible for regulating cardiovascular functions?
Medulla oblongata.
67
True or False: The brainstem is involved in the coordination of eye movements.
True.
68
What is the function of the abducens nerve?
It controls lateral eye movement.
69
Fill in the blank: The _____ is involved in the modulation of pain.
Periaqueductal gray.
70
What cranial nerve is primarily responsible for the sense of sight?
Cranial Nerve II (Optic Nerve).
71
Multiple Choice: Which cranial nerve is involved in motor control of the facial muscles?
Cranial Nerve VII (Facial Nerve).
72
True or False: The brainstem contains centers for reflexes such as coughing and sneezing.
True.
73
What is the role of the nucleus ambiguus?
It controls muscles involved in swallowing and phonation.
74
Fill in the blank: The _____ connects the cerebellum with the brainstem.
Cerebellar peduncles.
75
What cranial nerve is responsible for the sense of taste and visceral sensations?
Cranial Nerve X (Vagus Nerve).
76
What is the location and function of the inferior colliculus?
The inferior colliculus is located just below the superior colliculus in the midbrain (dorsal aspect). It is involved in auditory processing and serves as part of the auditory pathway.
77
What is the superior medullary velum and where is it found?
The superior medullary velum is a thin sheet of white matter located in the midbrain. It forms part of the roof of the fourth ventricle.
78
Describe the inferior medullary velum and its location.
The inferior medullary velum is a white matter sheet found in the medulla. It forms the roof of the fourth ventricle and continues inferiorly as the arachnoid membrane.
79
Where are the cerebral peduncles located, and what is their function?
The cerebral peduncles are located in the midbrain (ventral aspect). They contain motor pathways (corticospinal tracts) that transmit signals from the cerebral cortex to the spinal cord.
80
What is the basilar groove and where is it located?
The basilar groove is located in the pons (ventral aspect). It serves as a channel for the basilar artery.
81
What is the ponto-medullary junction and where is it found?
The ponto-medullary junction is the area where the pons transitions into the medulla oblongata.
82
Where is the olive located and what is its function?
The olive is located in the medulla (lateral aspect) and plays a key role in motor coordination and cerebellar function.
83
What is the pyramid in the brainstem, and what is its function?
The pyramid is located in the medulla (ventral aspect). It contains the corticospinal tract fibers, where decussation (crossing) of motor pathways occurs.
84
Where is the superior cerebellar peduncle located, and what is its role?
The superior cerebellar peduncle is located in the upper pons and midbrain. It carries efferent fibers from the cerebellum to the thalamus and spinal cord.
85
What is the function of the middle cerebellar peduncle, and where is it located?
The middle cerebellar peduncle is located in the pons and carries afferent fibers from the pons to the cerebellum for coordination.
86
What is the function of the inferior cerebellar peduncle, and where is it located?
The inferior cerebellar peduncle is located in the medulla and carries afferent fibers to the cerebellum, involved in proprioception and motor control.
87
What is the cuneate tubercle and where is it located?
The cuneate tubercle is found in the medulla (posterior aspect) and contains the cuneate nucleus, involved in proprioception and fine touch from the upper body.
88
Where is the gracile tubercle located, and what is its function?
The gracile tubercle is located in the medulla (posterior aspect) below the cuneate tubercle. It contains the gracile nucleus, which processes proprioception and fine touch from the lower body.
89
Where is the facial colliculus located, and what structures does it represent?
The facial colliculus is located in the pons (posterior surface, near the fourth ventricle) and represents the motor fibers of the facial nerve (CN VII) and the abducens nerve (CN VI).
90
What is the function of the striae medullares, and where is it located?
The striae medullares are located in the medulla and are part of the acoustic pathway, involved in processing auditory information.
91
What are the corpora quadrigemina, and where are they located?
The corpora quadrigemina are located in the midbrain (dorsal surface) and consist of the superior and inferior colliculi, which are involved in visual and auditory reflexes.
92
How many cranial nerves are there, and what is their primary function?
There are 12 pairs of cranial nerves, which are responsible for sensory and motor functions related to the head and neck, including vision, hearing, movement, and facial sensations.
“Oh, Oh, Oh, To Touch And Feel Very Good, Velvet HA!”
93
Where do the cranial nerves attach to the brainstem?
Cranial nerves attach to different regions of the brainstem: CN I and II arise from the forebrain, CN III and IV from the midbrain, CN V–VIII from the pons, and CN IX–XII from the medulla.
94
What muscles are innervated by the oculomotor nerve, and what functions does it control?
The oculomotor nerve (CN III) innervates the medial rectus, superior rectus, inferior rectus, inferior oblique, and the levator palpebrae superioris muscles, controlling eye movement and pupil constriction.
95
What is the function of the olfactory nerve (CN I)?
The olfactory nerve is sensory and responsible for the sense of smell.
96
What is the function of the optic nerve (CN II)?
The optic nerve is sensory and responsible for vision.
97
What are the functions of the oculomotor nerve (CN III)?
The oculomotor nerve is motor and controls eye movement, pupil size, and lens accommodation.
98
What is the function of the trochlear nerve (CN IV)?
The trochlear nerve is motor and controls eye movement, specifically the superior oblique muscle.
99
What are the functions of the trigeminal nerve (CN V)?
The trigeminal nerve is both sensory and motor. It provides sensation to the face and controls muscles of mastication (chewing).
100
What is the function of the abducens nerve (CN VI)?
The abducens nerve is motor and controls the lateral rectus muscle, responsible for eye abduction (moving the eye outward).
101
What are the functions of the facial nerve (CN VII)?
The facial nerve is both sensory and motor. It is responsible for taste (anterior 2/3 of the tongue), facial expressions, and secretion of saliva and tears.
102
What is the function of the vestibulocochlear nerve (CN VIII)?
The vestibulocochlear nerve is sensory and responsible for balance (vestibular function) and hearing (cochlear function).
103
What are the functions of the glossopharyngeal nerve (CN IX)?
The glossopharyngeal nerve is both sensory and motor. It is responsible for taste (posterior 1/3 of the tongue), monitoring blood pressure and gases, swallowing, and secretion of saliva.
104
What are the functions of the vagus nerve (CN X)?
The vagus nerve is both sensory and motor. It provides taste, sensory input to the thoracic and abdominal viscera, and controls movement and secretion in the heart, lungs, and digestive system.
105
What is the function of the accessory nerve (CN XI)?
The accessory nerve is motor and controls movement of the pharynx, larynx, and neck (specifically the sternocleidomastoid and trapezius muscles).
106
What is the function of the hypoglossal nerve (CN XII)?
The hypoglossal nerve is motor and controls the movement of the tongue.
107
Which cranial nerves have parasympathetic functions?
The parasympathetic cranial nerves are CN III (Oculomotor), CN VII (Facial), CN IX (Glossopharyngeal), and CN X (Vagus).
108
Where does the decussation of the corticospinal tract occur?
The decussation of the corticospinal tract occurs in the medulla, at the level of the pyramids.
109
Where does the decussation of the sensory fibers from the posterior column tracts occur?
The decussation of the sensory fibers from the posterior column tracts occurs in the medulla, at the level of the sensory decussation.
110
What are the key structures to note within the cross-section of the medulla?
Key structures include the corticospinal tract, sensory tracts, cranial nerve nuclei, the pyramids (motor decussation), and the olive.
111
What arteries supply the medulla?
The medulla is supplied by branches of the vertebral artery, including the anterior spinal artery, posterior spinal arteries, and posterior inferior cerebellar arteries.
112
What are the key structures within the cross-section of the pons?
Key structures include the corticospinal tract, cranial nerve nuclei (V-VIII), the basilar pons, and the middle cerebellar peduncles.
113
What structures are found in the cross-section of the midbrain?
Key structures include the cerebral peduncles, substantia nigra, red nucleus, and the superior and inferior colliculi.
114
What are some clinically related conditions associated with lesions in the brainstem?
- Brainstem lesions can lead to symptoms like paralysis, sensory deficits, cranial nerve dysfunction, and issues with vital functions like respiration and heart rate regulation.
- Specific conditions include locked-in syndrome, Wallenberg syndrome, and brainstem strokes.
115
What are the symptoms of Lateral Medullary Syndrome (Wallenberg)?
Symptoms include:
- Vestibular symptoms (dizziness, vertigo)
- Ipsilateral cerebellar signs (ataxia)
- Ipsilateral loss of pain and temperature sensation in the face
- Contralateral loss of pain and temperature sensation in the trunk and limbs
- Ipsilateral laryngeal, pharyngeal, and palatal hemiparalysis
- Ipsilateral Horner’s syndrome
116
Dfin Vestibular Symptoms (Dizziness, Vertigo)
Symptoms originating from the vestibular system, indicating issues with balance and spatial orientation.
117
Define Ipsilateral Cerebellar Signs (Ataxia)
Lack of voluntary coordination of muscle movements on the same side of the body as the lesion (ataxia).
118
Define Ipsilateral Loss of Pain and Temperature Sensation in the Face
Loss of sensation for pain and temperature on the same side of the face as the lesion.
119
Define Ipsilateral Laryngeal, Pharyngeal, and Palatal Hemiparalysis
Paralysis of the muscles controlling the larynx, pharynx, and palate on the same side as the lesion, affecting speech and swallowing.
120
Define Ipsilateral Horner’s Syndrome
Syndrome characterized by ptosis (drooping eyelid), miosis (constricted pupil), and anhidrosis (lack of sweating) on the same side as the lesion.
121
Which artery is usually blocked in Lateral Medullary Syndrome (Wallenberg)?
The Posterior Inferior Cerebellar Artery (PICA) is typically blocked in Lateral Medullary Syndrome (Wallenberg).
122
What clinical signs are associated with a blockage of the anterior spinal artery?
Symptoms include:
- Ipsilateral hypoglossal palsy (loss of tongue movement)
- Contralateral loss of proprioception, discriminative touch, and vibration sense
- Contralateral hemiplegia (paralysis)
123
What are the symptoms of Medial Medullary Syndrome?
Medial Medullary Syndrome results in:
Ipsilateral hypoglossal palsy
Contralateral hemiplegia
Contralateral loss of proprioception and discriminative touch
124
Describe the cause and effect of Ipsilateral Hypoglossal Palsy
Cause: Damage to the hypoglossal nerve (CN XII) or its nucleus, located in the medial medulla.
Effect: The tongue deviates toward the side of the lesion when protruded due to weakness or paralysis of the intrinsic and extrinsic muscles of the tongue (supplied by CN XII). This affects the ipsilateral side because cranial nerve nuclei and their fibers do not cross in the medulla.
125
Describe the cause and effect of Contralateral Hemiplegia
Cause: Damage to the corticospinal tract in the medial medulla. The corticospinal tract carries motor signals from the brain to the spinal cord, and fibers cross to the opposite side at the pyramidal decussation (in the lower medulla).
Effect: Paralysis occurs on the side opposite to the lesion in muscles below the level of the decussation (i.e., the contralateral side). This causes weakness or paralysis of voluntary motor function on the opposite side of the body
126
Explain how damage to the medulla can result in Contralateral Loss of Proprioception and Discriminative Touch
Damage to the medial lemniscus, which carries sensory information (proprioception, discriminative touch, and vibration) from the contralateral side of the body. These fibers originate in the posterior column nuclei (gracile and cuneate nuclei) and cross to the opposite side at the sensory decussation in the medulla.
Effect: Loss of proprioception and discriminative touch sensations is felt on the side opposite to the lesion.
127
What structures are present in the lower pons (through CN VII)?
Nucleus of the abducent nerve (CN VI)
Motor nucleus of the facial nerve (CN VII)
Facial nerve (CN VII)
Abducent nerve (CN VI)
128
What structures are present in the upper pons (through CN V)?
Sensory root of the trigeminal nerve (CN V)
Motor root of the trigeminal nerve (CN V)
Main sensory nucleus of the trigeminal nerve (CN V)
129
Which arteries supply the pons?
The pons is supplied by:
Pontine branches of the basilar artery
Anterior Inferior Cerebellar Artery (AICA)
Superior Cerebellar Artery
130
What is the corneal reflex?
A protective blink response to corneal stimulation (e.g., with a cotton wisp).
131
What are the nerves involved in the corneal reflex?
Sensory limb: CN V (Trigeminal nerve), specifically the ophthalmic division (V1).
Motor limb: CN VII (Facial nerve).
132
Describe the Pathway of the corneal reflex:
timulus at cornea → Trigeminal ganglion → Chief sensory nucleus of CN V → Interneurons to facial nucleus → CN VII → Orbicularis oculi muscle → Blink.
133
What happens in a corneal reflex lesion?
Absent reflex if V1 (sensory) or CN VII (motor) is damaged.
134
What is Millard-Gubler Syndrome?
A syndrome caused by a vascular lesion affecting the pons, usually due to occlusion of basilar artery branches.
135
What are the Key features of Millard-Gubler Syndrome?
Ipsilateral medial squint: Damage to CN VI (Abducens nerve), causing inability to abduct the eye.
Ipsilateral facial palsy: Damage to CN VII (Facial nerve).
Contralateral hemiplegia: Damage to corticospinal tract.
136
What structures are damaged in Millard-Gubler Syndrome?
CN VI (Abducens nucleus or nerve).
CN VII (Facial nucleus or nerve).
Corticospinal tract.
137
What causes Pontocerebellar Syndrome?
Acoustic neuroma (a tumor at the cerebellopontine angle).
138
What are the key features of Pontocerebellar Syndrome?
Ipsilateral symptoms:
Ataxia.
Lower motor neuron type facial palsy.
Contralateral symptoms:
Loss of pain and temperature sensation (face).
Other symptoms:
Tinnitus, deafness, vertigo.
Loss of corneal reflex.
139
Why do these symptoms occur in Pontocerebellar Syndrome?
Pressure on cranial nerves and brainstem structures at the cerebellopontine angle.
140
What is an acoustic neuroma?
A benign tumor of the Schwann cells of CN VIII (Vestibulocochlear nerve).
141
Describe the Symptoms of acoustic neuroma
Early symptoms: Tinnitus, hearing loss, vertigo.
Advanced symptoms (compression of nearby structures):
Ipsilateral ataxia (cerebellar compression).
Ipsilateral CN VII palsy (facial muscles).
Contralateral sensory loss (pain and temperature).
142
Why does an acoustic neuroma cause loss of corneal reflex?
Compression of the ophthalmic division of CN V and motor component of CN VII, both involved in the corneal reflex arc.
143
What are the main parts of the midbrain?
- Tectum: Contains the colliculi (superior and inferior).
- Tegmentum: Central part with nuclei, fibers, and cranial nerve pathways.
- Substantia nigra: Involved in motor control and dopamine production.
- Crus cerebri: Contains descending motor fibers.
- Cerebral peduncles: Include the crus cerebri, substantia nigra, and tegmentum.
- Aqueduct: Connects the third and fourth ventricles; located centrally.
144
Describe the key structures of the Midbrain at the level of the Inferior Colliculus:
Inferior colliculus: Auditory pathway.
Trochlear nerve (CN IV): Exits dorsally to innervate the superior oblique muscle.
Substantia nigra: Motor control.
145
Describe the key structures of the Midbrain at the level of the Superior Colliculus
Superior colliculus: Visual reflexes.
Red nucleus: Motor coordination.
Substantia nigra: Dopaminergic control of movement.
Oculomotor nerve (CN III): Eye movement
146
What arteries supply the midbrain?
Posterior cerebral artery: Primary supply.
Superior cerebellar artery: Contributes to upper areas.
Posterior communicating artery: Supplies lateral areas.
Anterior choroidal artery: Supplies medial structures.
147
Congenital Hydrocephalus:
Definition: A condition where cerebrospinal fluid (CSF) builds up in the brain due to blockage of the cerebral aqueduct.
Effects: Enlarged head, increased intracranial pressure, and neurological deficits.
Mechanism: Blockage prevents CSF flow from the third to the fourth ventricle.
148
Weber’s Syndrome:
Cause: Occlusion of the posterior cerebral artery.
Structures affected:
Oculomotor nerve (CN III): Ipsilateral ophthalmoplegia (eye movement paralysis).
Crus cerebri: Contralateral hemiplegia (paralysis of one side of the body).
Symptoms:
Drooping eyelid (ptosis) and dilated pupil (mydriasis) on the affected side.
Weakness or paralysis on the opposite side of the body.
149
What is the pathway for the light reflex?
Stimulus: Light enters the eye and stimulates the retina.
Pathway:
Optic nerve (CN II): Carries light signal to the brain.
Lateral geniculate body (LGB): Relay point in the thalamus.
Pretectal nucleus: Located in the midbrain; processes the signal.
Edinger-Westphal nucleus: Parasympathetic nucleus in the midbrain.
Oculomotor nerve (CN III): Carries parasympathetic fibers to the eye.
Ciliary ganglion: Synapse point near the eye.
Sphincter pupillae muscle: Contracts to constrict the pupil.
150
What is the sequence of structures in the visual pathway?
Retina: Photoreceptor cells (rods and cones) detect light.
Optic nerve (CN II): Transmits signals from the retina.
Optic chiasm: Partial crossing of fibers (nasal fibers cross, temporal fibers do not).
Optic tract: Carries visual information to the brain.
Lateral geniculate body (LGB): Located in the thalamus; relays signals to the visual cortex.
Optic radiations: Fibers projecting from the LGB to the primary visual cortex in the occipital lobe.
Primary visual cortex (V1): Processes visual information (Brodmann area 17).
151
What is the role of the optic chiasm in the visual pathway?
Crossing fibers: Nasal retinal fibers cross to the opposite side.
Non-crossing fibers: Temporal retinal fibers remain on the same side.
Result: Each optic tract contains visual information from the contralateral visual field.
152
What are optic radiations, and how are they organized?
Meyer's loop: Fibers passing through the temporal lobe (carry information from the superior visual field).
Parietal pathway: Fibers passing through the parietal lobe (carry information from the inferior visual field).
