Chapter 1: External Anatomy Of The Brain Flashcards
Parietal lobe
spatial processing
language understanding
somatosensation
Parietal lobe
Superior parietal lobule
Lesions in this region cause people to forget to dress part of their body ( contralateral limb) “unilateral body neglect”. Can also get lost easily, can’t draw and exhibit the inability to carry out purposeful movements (apraxia)
Parietal lobe
Inferior lobule
Wernickes area is located here and is needed to understand language
Damage to this area affects the ability to read
Occipital lobe
Cuneus and lingual gyri make up the primary visual cortex
Conscious vision occurs here and is processed in other areas
Forebrain Lesion Symptoms
consciousness loss memory loss language understanding and production loss personality changes seizures thinking/cognition deficits vision deficits
Precentral gyrus
primary motor strip
well learned, voluntary movement
part of the frontal lobe
Postcentral gyrus
primary somatosensory cortex
conscious awareness of touch
part of the parietal lobe
Superior parietal lobule
perceptual processing
lesion here can result in “unilateral body neglect”
-person fails to dress contralateral side of the body
body awareness and orientation in space
Inferior parietal lobule
Wernicke’s area is located here
- understanding of language - damage to this area affects the ability to read
Cuneus and Lingual gyri
primary visual cortex
part of the occipital lobe
conscious vision occurs here BUT is processed in many other places
Cuneus gyrus
processes lower quadrant and opposite side of vision
Lingual gyrus
processes upper quadrant and opposite side of vision
Temporal lobe
primary auditory cortex= Heschl’s gyrus
most of visual perception and processing occurs here
contains the uncus, parahippocampal gyrus, insula, and cingulate gyrus
Uncus
holds the amygdala
part of the temporal lobe
Amygdala
produces behaviors related to sex, thirst and hunger
part of the temporal lobe
Parahippocampal
contains the hippocampus
responsible for forming new, explicit memories, remembering events and learning facts
part of the temporal lobe
Insula
part of the social brain ANS regulation vestibular processing interpretation of pain and quality of touch part of the temporal lobe
Limbic lobe
Memory Motivation Olfaction Visceral Function Emotions Social brain part of the temporal lobe found on the medial surface of hemisphere
borders of the limbic lobe
uncus, cinguate gyrus, parahippocampal gyrus and paraolfactory gyrus
Frontal lobe
planning/thinking voluntary movement impulse control personality language production
Cranial Nerves
I- olfactory nerve II- optic nerve III- oculomotor nerve IV- trochlear nerve V-trigeminal nerve VI-abducens nerve VII-facial nerve VIII-vestibular, auditory nerve IX-glossopharyngeal nerve X-vagus nerve XI-accesssory nerve XII-hypoglossal nerve
Corpus callosum
connects frontal, parietal and occipital lobes for communication
Forebrain
telencephalon + diencephalon
Telencephalon
cerebral cortex + subcortical matter + basal ganglia
Diencephalon
hypothalamus + thalamus
Mesencephalon
midbrain
Metencephalon
pons + cerebellum
Myencephalon
medulla
Hindbrain
pons + cerebellum + medulla
( metencephalon + myencephalon)
Brainstem
midbrain + pons +medulla
Cerebellum
balance and eye movements
posterior commisure
how the right and left midbrain communicate
Choroid plexus
secretes the cerebrospinal fluid
Cerebral peduncle
crus cerebri + tegmentum
Tectum
posterior part of the midbrain
made up of the superior and inferior colliculi
Superior colliculus
conscious vision pathway
inferior colliculus
auditory pathway
crus cerebri
takes info from all areas of the cerebral cortex and brings it everywhere else
major axonal highway
Voluntary motor cortex
precentral gyrus + premotor areas
found in the frontal lobe
Which nerves help move your eye?
CN III, IV and VI ( oculomotor, trochlear and abducens)
Infindibulum
connects the hypothalamus to the pituitary gland
CN II- optic nerve
conscious vision
CN V- trigeminal nerve
somatosensation of the face
mastication
CN VIII-vestibular, auditory nerve
vestibulocochlear
a tumor here can causing hearing loss and equilibrium problems or veritgo
located at the pons-medulla junction
CN IX- glossopharyngeal nerve
somatosensation of the tongue and throat
the exit of CN IX is close to the pons-medulla junction
a lesion here may result in loss of the gag reflex
CN X- vagus nerve
visceral motor and sensory
CN XII- hypoglossal nerve
allows you to stick your tongue out and speak clearly
a lesion of this root will result in a deviation of the tongue to the side of the root damage; medulla lesion can also cause this same deviation
Cuneate fasciculi
upper somatosensory pathway
graceal fasciculi
lower somatosensory pathway
Cerebellar peduncles
inferior, middle and superior
Inferior cerebellar peduncle
connects the medulla to the cerebellum
spinal cord —-> cerebellum
Middle cerebellar peduncle
connects the pons to the cerebellum
cortex——> cerebellum
Superior cerebellar peduncle
connects the midbrain to the cerebellum
sends info out of the cerebellum
Where do CN 9, 10, 11 and 12 originate?
the medulla
What does disrupted breathing or irregular heartbeats suggest?
a damaged medulla
What do CN 9, 10, 11 and 12 collectively do?
They control breathing and heart rate
Where do CN 5, 6 and 7 originate?
the pons
What symptoms indicate a pontine dysfunction?
loss of sensation in the face
a medially deviated eye
or weakness of the facial muscles
Where do CN 3 and 4 originate?
the midbrain
What symptoms indicate midbrain dysfunction?
dilated pupil or restricted eye movements
Where do CN 1 and 2 originate?
the forebrain
What symptoms indicate forebrain disease?
loss of smell
loss of vision
changes in mental functions, memory and language
What constitutes somatosensation?
pain, touch, temperature, kinesesthia, positioning
What makes up the dorsal surface of the midbrain?
the superior and inferior coniculli (tectum)
What makes up the dorsal surface of the medulla?
the cuneate and gracile fasciculi which carry somatosensation rostrally
What connects the hypothalmus to the pituitary gland?
the infundibulum
CN VI- abducens nerve
controls movement of the lateral rectus muscle of the eye
a patient with this lesion experiences a loss of voluntary lateral gaze in the eye on the side of the lesion (paralysis of lateral rectus muscle)
This is called diplopia; eye on lesioned side is medially deviated
superior gyrus of the temporal lobe
audition and makes up part of Wernicke’s area
middle and inferior gyri of the temporal lobe
visual memory and perception
superior and middle gyri of the frontal lobe
includes the “secondary motor” and premotor areas for organization of voluntary movements
prefrontal cortex of the frontal lobe
personality, planning and sequencing of complex tasks
inferior gyrus of the frontal lobe
contains Broca’s area for language production
Why is it that damage to Heschel’s gyrus on one hemisphere produces little defecit?
because auditory information is processed bilaterally in the brain
UMN signs
weakness spastic paralysis slow atrophy hyperreflexia eventually -Babinski -increased DTRs -clonus contralateral innervation
LMN signs
weakness flaccid paralysis fast atrophy fasiculations Hyporeflexia or areflexia ipsilateral innervation cell bodies sit in the ventral horn
What does the posterior limb of the internal capsule carry?
carries somatic sensory and motor info from each side of the central sulcus and visual info to the occipital lobes
Where does the medial geniculate give input?
to the inferior colliculus to target the auditory cortex
Where does the lateral geniculate give input?
to the optic tract to target the visual cortex