NEURO: Structure of the Nervous System Flashcards
What are the three orientations for brain scans?
- sagittal
- coronal
- transverse/horizontal
With afferent sensory fibres, what type of information is being carried where?
Sensory information is being carried from the periphery to the brain.
With efferent motor fibres, what type of information is being carried where?
Motor instructions are being carried from the brain to the periphery.
List the names of the 12 cranial nerves.
- Olfactory Nerve
- Optic Nerve
- Oculomotor Nerve
- Trochlear Nerve
- Trigeminal Nerve
- Abducens Nerve
- Facial Nerve
- Vestibulocochlear Nerve
- Glossopharyngeal Nerve
- Vagus Nerve
- Accessory Nerve
- Hypoglossal Nerve
Describe the olfactory nerve (CN I).
It is purely sensory - olfaction (smell).
In our noses, there is olfactory epithelium, which transmits information to the olfactory bulb.
The olfactory bulb then transmits the smell information to 3 different places:
1. olfactory cortex: where we have the conscious perception of the smell
2. hippocampus: where we have odour memory, and it decides if an action is to be induced because of the smell
3. hypothalamus amygdala: where we store the motivational
Describe the optic nerve (CN II).
It is purely sensory - vision.
It takes information from our rods and cones at the back of our retinas to the visual cortex in our occipital lobes (in the brain). It does this via retinal ganglion cells, with the information travelling through the lateral geniculate nucleus in the thalamus.
Describe the oculomotor nerve (CN III).
It is both motor and parasympathetic.
For the motor part, it controls some of our eyeball and eyelid movement (CN III + IV + VI).
For the parasympathetic part, it’s concerned with pupillary constriction and accommodation.
Describe the trochlear nerve (CN IV).
It conveys motor information.
It is involved in eyeball movement (CN III + IV + VI).
Describe the abducens nerve (CN VI).
It conveys motor information.
It is involved in eyeball movement (CN III + IV + VI).
What is the function of the palpebrae muscles?
They are controlled by CN II, and they’re used for eyelid opening.
Describe the trigeminal nerve (CN V).
It is involved in receiving signals from our facial skin regions. It has three divisions:
- opthalmic (sensory)
- maxillary (sensory)
- mandibular (sensory)
Describe the facial nerve (CN VII).
It conveys sensory, motor and parasympathetic information.
For the sensory part, it helps with taste on the anterior two-thirds of the tongue.
For the motor part, it controls the muscles of facial expression. It also controls the stapedius muscle, a muscle in our ear which blocks it when we need to dull down information that is either harmful or useless.
For the parasympathetic part, it controls the salivary glands, the lacrimal glands, the glands of the nose and palate.
Describe the vestibulocochlear nerve (CN VIII).
It conveys sensory information - hearing and balance.
With hearing, the cochlea cells project to the medial geniculate nucleus (in the thalamus), then to the auditory cortex (in the temporal lobe).
With balance, the vestibular hair cells project to the ventral posterolateral nucleus (in the thalamus), then to the vestibular cortex (in the temporal lobe).
Describe the glossopharyngeal nerve (CN IX).
It has sensory, motor and parasympathetic functions.
It has a variety of sensory functions. It plays a sensory role with the pharynx, the auditory tube, the middle ear, the posterior third of the tongue, and detects blood pressure changes in the aorta.
With its motor functions, it controls swallowing.
With its parasympathetic functions, it stimulates the salivary glands.
Describe the vagus nerve (CN X).
It has sensory, motor and parasympathetic functions.
With the sensory, its involved with the sensation of pain and associated viscera.
With the motor, it controls the muscles used for speech and swallowing.
With the parasympathetic, it controls the smooth muscle in the lungs, heart and abdominal organs.
