Cranial Nerves Flashcards
Cranial nerves have four types of functions…
They are = ?
Cranial Nerves
- 1) Somatosensory information from the skin and muscles of the face and from the temporomandibular joint (TMJ).
- 2) Special sensory information related to visual, auditory, vestibular, olfactory, and visceral sensations.
- 3) Motor innervation to the muscles of the face, eyes, tongue, jaw, and two neck muscles.
- 4) Parasympathetic regulation of pupil size, curvature of the lens of the eye, heart rate, blood pressure, breathing, and digestion.
CN I = ?
Cranial Nerves
Cranial Nerve 1
- Olfactory nerve
- Sensory
- Sense of smell
CN II = ?
Cranial Nerves
Cranial Nerve 2
- Optic nerve
- Sensory
- Vision
CN III = ?
Cranial Nerves
Cranial Nerve 3
- Oculomotor nerve
- Motor
- Eye movements; papillary constriction and accommodation
CN IV = ?
Cranial Nerves
Cranial Nerve 4
- Trochlear nerve
- Motor
- Eye movements (intorsion, downward gaze)
CN V = ?
Cranial Nerves
Cranial Nerve 5
- Trigeminal nerve
- Sensory and motor
- Somatic sensation from face, mouth, cornea; muscles of mastication
CN VI = ?
Cranial Nerves
Cranial Nerve 6
- Abducens nerve
- Motor
- Eye movements (abduction or lateral movements)
CN VII = ?
Cranial Nerves
Cranial Nerve 7
- Facial nerve
- Sensory and motor
Controls:
- Muscles of facial expression
- Taste from anterior tongue
- Lacrimal & salivary glands
CN VIII = ?
Cranial Nerves
Cranial Nerve 8
- Vestibulocochlear nerve (auditory nerve)
- Sensory
- Hearing; sense of balance
CN IX = ?
Cranial Nerves
Cranial Nerve 9
- Glossopharyngeal nerve
- Sensory & motor
Sensation from:
- Posterior tongue & pharynx
- Taste from posterior tongue
- Carotid baroreceptors and chemoreceptors
CN X = ?
Cranial Nerves
Cranial Nerve 10
- Vagus nerve
- Sensory & motor
Major Functions:
- Autonomic functions of gut
- Sensation from larynx and pharynx
- Muscles of vocal cords & swallowing
CN XI = ?
Cranial Nerves
Cranial Nerve 11
- Spinal accessory nerve
- Motor
- Shoulder and neck muscles
CN XII = ?
Cranial Nerves
Cranial Nerve 12
- Hypoglossal nerve
- Motor
- Movements of tongue
What is the primary function of cranial nerve I, the olfactory nerve?
Cranial Nerves
The primary function of the olfactory nerve is sensory, transmitting information from nasal receptors to the olfactory bulb, and then to the olfactory cortex located in the insula.
How often do the cells of the olfactory nerve undergo replacement, and how does this process change with age?
Cranial Nerves
- The cells of the olfactory nerve undergo replacement approximately every 30-90 days, but this process declines with age.
What parts of the brain does the olfactory nerve transmit information to within the limbic system?
Cranial Nerves
- The olfactory nerve transmits information to the amygdala for emotional responses to odor and to the parahippocampal gyrus for perceiving the quality of aromas.
- Additionally, it sends information to the secondary olfactory area in the orbitofrontal cortex for making value judgments and decisions.
What are the components of the limbic system?
Cranial Nerves
- The components of the limbic system include:
- Cingulate gyrus
- Fornix
- Amygdala
- Hippocampus
What functions are associated with the limbic system?
Cranial Nerves
The limbic system is associated with learning, emotions, and processing special sensory information such as afferents for olfaction.
What are the three concentric layers that make up the wall of the eye?
Cranial Nerves
(1) Outer layer:
- Sclera = outermost tough connective tissue
- Cornea = transparent, allow light to enter
- Conjunctiva
(2) Middle layer (vascular):
- Ciliary body = ciliary muscles connected to lens by zonular fibers
- Lens = focus light on retina, visual information is transduced
- Iris = 2 layer of pigmented smooth muscle, pigment determines the eye color, regulates the diameter of pupil
- Pupil = hole in the center of iris that allow light to enter
(3) Inner layer (neural):
- Retina = photoreceptors that detect light waves, conversion of light energy to electric energy
- Fovea = greatest visual acuity
- Optic disk = optic nerve and blood vessels supplying the eye pass through the retina- blind spot
The eye
Outer layer = ?
(one part is not pictured )
Cranial Nerves
(1) Outer layer:
- Sclera = outermost tough connective tissue
- Cornea = transparent, allow light to enter
- Conjunctiva
The eye
Middle layer = ?
Cranial Nerves
(2) Middle layer (vascular):
- Ciliary body = ciliary muscles connected to lens by zonular fibers
- Lens = focus light on retina, visual information is transduced
- Iris = 2 layer of pigmented smooth muscle, pigment determines the eye color, regulates the diameter of pupil
- Pupil = hole in the center of iris that allow light to enter
The eye
Inner layer = ?
Cranial Nerves
(3) Inner layer (neural):
- Retina = photoreceptors that detect light waves, conversion of light energy to electric energy
- Fovea = greatest visual acuity
- Optic disk = optic nerve and blood vessels supplying the eye pass through the retina- blind spot
CN II: Optic
Optic nerve transmits visual information from the retina to the = ?
Cranial Nerves
CN II: Optic (sensory):
- Optic nerve transmits visual information from the retina to the lateral geniculate body of the thalamus, then to the visual cortex:
- Visual Information Flow: From the retina, to the midbrain, to the lateral geniculate, and then to the visual cortex, where conscious vision is provided.
CN II: Optic
Optic nerve transmits visual information from the retina to the lateral geniculate body of the thalamus, then to the visual cortex:
- Visual signals in this pathway are involved in = ?
Cranial Nerves
CN II: Optic (sensory):
- Optic nerve transmits visual information from the retina to the lateral geniculate body of the thalamus, then to the visual cortex:
- Visual signals in this pathway are involved in analysis and conscious awareness of visual information
CN II: Optic
Visual signals sent to the midbrain are involved in reflexive responses of the pupil.
Cranial Nerves
CN II: Optic (sensory):
- To nuclei in the midbrain: Visual signals sent to the midbrain are involved in reflexive responses of the pupil.
?
Cranial Nerves
Pupil:
?
Cranial Nerves
CN II: Optic Nerve:
?
Cranial Nerves
Optic Chiasm:
?
Cranial Nerves
Optic Tract:
?
Cranial Nerves
Lateral Geniculate body:
?
Cranial Nerves
Visual Cortex:
CN’s involved in speaking = ?
Cranial Nerves
- Speaking requires cortical control and coordinated action of CN’s 5, 7, 10, 12 for articulation and sound production.
- CN V - Trigeminal:
- CN VII - Facial:
- CN X - Vagus:
- CN XII - Hypoglossal:
CN Involved in Swallowing = ?
Cranial Nerves
Swallowing Process:
- Oral Stage: Involves lips, jaw, tongue movements
- CN V - Trigeminal
- CN VII - Facial
- CN XII - Hypoglossal
Pharyngeal Stage: Soft palate, pharynx, larynx movements
- CN IX - Glossopharyngeal
- CN X - Vagus
Esophageal Stage: Peristalsis moves food into the stomach.
- CN X - Vagus
Functions of Cranial Nerves
Sensory = ?
- A ) Transmit sensory information from specific regions.
- B ) Control voluntary and involuntary muscle movements.
- C ) Regulate visceral functions such as digestion, heart rate, and pupil constriction.
- D ) Mediate various reflex actions like blinking, gagging, and swallowing
Cranial Nerves
- Functions of Cranial Nerves:
- Sensory: Transmit sensory information from specific regions.
- Motor: Control voluntary and involuntary muscle movements.
- Autonomic: Regulate visceral functions such as digestion, heart rate, and pupil constriction.
- Reflexes: Mediate various reflex actions like blinking, gagging, and swallowing
Functions of Cranial Nerves
Motor = ?
- A ) Transmit sensory information from specific regions.
- B ) Control voluntary and involuntary muscle movements.
- C ) Regulate visceral functions such as digestion, heart rate, and pupil constriction.
- D ) Mediate various reflex actions like blinking, gagging, and swallowing
Cranial Nerves
- Functions of Cranial Nerves :
- Motor: Control voluntary and involuntary muscle movements.
- Sensory: Transmit sensory information from specific regions.
- Autonomic: Regulate visceral functions such as digestion, heart rate, and pupil constriction.
- Reflexes: Mediate various reflex actions like blinking, gagging, and swallowing
Autonomic = ?
- A ) Transmit sensory information from specific regions.
- B ) Control voluntary and involuntary muscle movements.
- C ) Regulate visceral functions such as digestion, heart rate, and pupil constriction.
- D ) Mediate various reflex actions like blinking, gagging, and swallowing
Cranial Nerves
- Functions of Cranial Nerves:
- Autonomic: Regulate visceral functions such as digestion, heart rate, and pupil constriction.
- Sensory: Transmit sensory information from specific regions.
- Motor: Control voluntary and involuntary muscle movements.
- Reflexes: Mediate various reflex actions like blinking, gagging, and swallowing
Functions of Cranial Nerves
Reflexes = ?
- A ) Transmit sensory information from specific regions.
- B ) Control voluntary and involuntary muscle movements.
- C ) Regulate visceral functions such as digestion, heart rate, and pupil constriction.
- D ) Mediate various reflex actions like blinking, gagging, and swallowing
Cranial Nerves
- Functions of Cranial Nerves:
- Reflexes: Mediate various reflex actions like blinking, gagging, and swallowing
- Sensory: Transmit sensory information from specific regions.
- Motor: Control voluntary and involuntary muscle movements.
- Autonomic: Regulate visceral functions such as digestion, heart rate, and pupil constriction.
Coordination between the two eyes is maintained by synergistic action of the eye muscles. For example, looking at a pen that moves toward you requires a coordination of right and left = ?
What muscles
Cranial Nerves
Coordination - Eye movements and Head & Hye (H&E) movements:
- Coordination between the two eyes is maintained by synergistic action of the eye muscles. For example, looking at a pen that moves toward you requires activation of
- Right & Left medial rectus
Are cranial nerves considered a part of the central nervous system?
Cranial Nerves
No, cranial nerves are considered a part of the peripheral nervous system.
Coordination of H&E movements
H&E movement coordination is controlled by signals in ? of brainstem ?
Cranial Nerves
Coordination - Eye movements and Head & Hye (H&E) movements:
- H&E movement coordination is controlled by signals in medial longitudinal fasciculus of brainstem that provides bilateral connections among vestibular, oculomotor & spinal accessory nerve, trochlear, abducencs nuclei.