Anatomy Test 3 - The Brain Part 2 Flashcards
Median Longitudinal Fissure
separates the left hemisphere from the right hemisphere
Note the numerous folds (elevations) and creases (depressions) in the cerebral cortex - known as
gyri(elevation) and sulci(depression), respectively
Purpose of sulci and gyri?
allow the brain to fit into the skull
Central sulcus
a vertical sulcus that runs pretty much from top of the cerebral cortex down to the bottom. Not interrupted by gyri
-Seperates frontal lobe from parietal lobe
Precentral sulcus
rostral to central sulcus and IS interrupted by gyri
postcentral sulcus
posterior to central sulcus, partially interrupted by gyri
lateral (Sylvian) fissure
depression on the lower side of the cerebral cortex. First structure on the brain to have a name
-separates the temporal lobe from the frontal and parietal lobes
How many lobes does the cerebral cortex have?
6 total
4 you can see from the side, 2 are primitive so you can’t really see them as they are covered up
frontal, occipital, parietal, temporal and the other 2
Precentral Gyrus location
and what lobe?
Part of the frontal lobe. It is located between the precentral sulcus and the central sulcus.
Discuss the importance of the Precentral Gyrus
It is also called the primary motor area (or cortex)
- Pyramidal tract fibers originate here
- These big fibers descend into the brainstem down as far as it will go, and control FINE DIGITAL AND VOLUNTARY MOVEMENT
Homonculus…. and what region of the body is it on
regions of the body represented on the primary motor area
-shows neuronal mass concentrations for each body part
-Notice inverse relationship. Lower body controlled by the upper portion of cerebral cortex, and upper body is controlled by the lower portion of cerebral cortex.
Note: top of the gyrus controls the lower body.
The cerebral cortex consists of an exterior layer of “___ ____ “ and a deep layer of “___ ___”
exterior layer = gray matter (cells)
deep layer = white matter (mylinated)
Location of Premotor Cortex and what is next to it?
It is infront of the precentral gyrus. Next to it is the supplementary area (abbreviated as SMA)
Premotor Cortex purpose
Controls gross motor movement as well as trunk movement
-follows a homoncular pattern- lower portion controls more upper portion of body and visa versa
Supplementary motor area is for:
-For motor planning
-Plans the performance of sequence of motions from memory (kind of muscle memory)… (as opposed to movements guided by a visual cue)
An example: putting on a coat. We’ve done it so many times, we can put it on without even looking at it
Below the supplementary motor area is the
Premotor cortex (PMC)
Premotor cortex (PMC) is mostly associated with
gross motor movement / trunk movement
The little area just rostral to the Supplementary Motor Area (SMA) and Premotor Cortex (PMC) is called
the frontal eye fields
Frontal Eye Fields purpose
Motor control of extraoccular movements.
Permits conjugate movement/ conjugate deviation of eyes- eyes move at the same speed and in the same direction
What does the frontal eye fields give rise to?
fiber pathways that descend down to brain down to cranial nerves that control eye movement
Prefrontal area or the prefrontal cortex
the rest of the area infront (rostral) of the premotor area and the frontal eye fields.
Functions of the prefrontal cortex
“CEO” of the Brain Executive Control Personality Emotions Problem Solving Reasoning Decision Making
Broadmanns area map
numbered areas of the cerebral cortex
Pars orbitalis
part of the basal portion of the prefrontal cortex
-language production
Pars triangularis
behind the pars orbitalis
working assembly for language assembly
Pars Opercularis
behind pars triangular
speech motor function
3 structures of the frontal lobe’s inferior frontal gyrus
Pars orbitalis, Pars triangular, Pars opercularis
Broca’s Motor Speech Area -
its on cerebral cortex and it drives ____
what side of body are most dominant for speech on?
a lesion to this =
o a portion of our cerebral cortex that drives motor speech
o most of us are dominant for speech on left side 80-95%
o lesions = Expressive Aphasia
What makes up Broca’s motor speech area?
Pars triangularis and pars opercularis
Expressive Aphasia
an injury to Broca’s motor speech area that results in the loss of ability to form words and speech. Interestingly enough, some of the only words these people can say is profanity
The area right behind the central gyrus is called the ____ and what lobe is it located in?
the post central gyrus and it is located in the parietal lobe
The post central gyrus is also called the
somesthetic sensory area
Post Central Gyrus / Somesthetic Sensory Area purpose?
The primary receiving area for general sensation
Receives projections from thalamic relay nuclei
Types of General Sensation
pain and temperature but also
- stereognosis
- 2 point discrimination
- kinesthetic sense
- vibration
stereognosis
the ability to hold something in your hand and tell the shape of it without looking at it
2 point discrimination
the ability to recognize the difference between two points touched on your skin that are close together
kinesthetic sense / joint proprioception
the ability to know where your limbs are in space without looking at them
vibration
the ability to detect a vibrating object that is touched to your skin
General Sensory Association area is found where?
the area is found behind the post central gyrus
General Sensory Association does what?
it processes and associates or defines general sensory information. It decides how intense a sensation was
2 primary gross areas within the general sensory association area and what separates them?
- The superior parietal lobule
- The inferior parietal lobule
These are separated by the interparietal sulcus
what makes up the inferior parietal lobule
- the supramarginal gyrus
2. the angular gyrus (behind the supramarginal gyrus)
What does the supramarginal gyrus do?
- it provides sensory feedback to help plan or guide motor tasks
- it provides texture feedback/discrimination input for motor -tasks.
- INTERPRETS / HELPS TACTILE LEARNING AND MEMORY
Dyspraxia
injury to supramarginal gyrus. Results in inability to provide sensory feedback to plan and guide motor tasks
Two types: (think of guy trying to put shirt on)
-Ideational- a person really doesn’t know what to do. More challenging than ideomotor
Ideomotor- a person knows what to do but just can’t carry out the motor task. Makes it hard for single step processes
Function of the angular gyrus
Reading Association! Meaning you have to see the word and understand the word before you can read it.
Disorders associated with angular gyrus
- reading delay
- agraphia
- acalculia
- finger agnosia
What is a primary cortical area?
that portion of cerebral cortex that receives direct projections from sensory relay nuclei of the thalamus
What is association cortex-
receive direct projections from the ___ ____ ___ then project into the ___ _____ so that we can make decisions about the information so that we can decide in a ___ ____
receive direct projections from the primary cortical areas then project into the association area so that we can make decisions about the information so that we can decide in a motor fashion
What is aphasia? what areas… specifically
the inability to form words and thus communicate. Injury to Broca’s Motor speech area which consists of pars triangularis and pars opercularis
what is dyspraxia?
an individual cannot take tactile information and integrate the information to know what to do with it and so they can’t produce a motor response to it (put on clothes or use a tool)
the occipital lobe is separated from the parietal lobe by
the parietal occipital sulcus
2 main parts of the occipital lobe
primary visual cortex and visual association cortex
Oromotor dyspraxia
also called verbal apraxia or apraxia of speech: Makes it difficult to coordinate muscle movements needed to pronounce words. Kids with dyspraxia may have speech that is slurred and difficult to understand because they’re unable to enunciate
The occipital lobe is the area containing the primary visual cortex. It receives information from
Thalamic Visual Relay Nuclei (the lateral geniculate body)
The primary visual cortex (medial occipital cortex) has two parts:
and what separates them?
the gyrus cuneus and below it the lingual gyrus
the calcarine sulcus separates them
Lesion to primary visual cortex results in?
cortical blindness- loss of integration of visual
input, with resulting Visual Agnosia,
implying the ability to see objects and
the environment, but having difficulty
in properly identifying what’s being seen
Visual association (lateral occipital cortex) includes -hint its three types of gyri
Lateral Occipital Gyrus
Superior Occipital Gyrus
Inferior Occipital Gyrus
association visual cortex allows for
integration of visual information. So they won’t recognize what they see
visual agnosia is a lesion to? What does it cause?
lesion to visual association cortex.
It causes the person to not be able to recognize what they see.
the 3 temporal lobe gyri
Superior Temporal Gyrus
middle temporal gyrus
inferior temporal gyrus
what separates the superior temporal gyrus from the
middle temporal gyrus?
the superior temporal sulcus
what separates the middle temporal gyrus from the inferior temporal gyrus?
the inferior temporal sulcus
What is in the Superior Temporal Gyrus?
anterior transverse temporal gyri also known as Heschels
anterior transverse temporal gyri (AKA Heschels) is the
primary auditory cortex
The primary auditory cortex is where
we receive information from thalamic relay nuclei
Wernike’s Speech Association Area (pronounced Vernicke)
dominant on the left
where we have language comprehension
receptive aphasia
injury to wernike’s speech association area (stroke or dramatic injury to brain) causing a person to not be able to understand or comprehend speech
Note: Broca’s Area and Wernicke’s Area are connected by the ____ _____
Arcuate Fasciculus
Where is wernike’s area?
It is between the temporal lobe and the parietal lobe (supramarginal gyrus and Superior Temporal Gyrus)
What side of our brain is responsible for speech understanding and our production of speech?
the left side of our body
the primary olfactory area is located
at the rostral portion of the temporal lobe
the primary olfactory area communicates with
the olfactory association cortex (called the entorhinal cortex)
Primary Olfactory Area is the area that is responsible for
receiving area for smell.
incoming olfactory information does not pass through
the thalamus!
What are the two lobes that are not visible?
the limbic lobe - the emotional brain
the insular lobe- found deep within the sylvian fissure
a very important structure associated with the limbic lobe and what is it’s believed function
the hippocampus - associated with emotional behavior memory
what brain structure is associated with Alzheimers disease?
the hippocampus
the insular lobe
also known as the island of Riel - nobody is 100% sure what it does. It may have some sensory and motor visceral function or taste and olfactory function.
what do basal ganglia do?
they kind of direct our automatic movements that we make without much thought process
what does the basal ganglia consist of?
globus pallidus, putamen, caudate nucleus, subthalamic nucleus and substantia nigra
Lateral ventricle
- there is one of these in each cerebral hemisphere - note the caudate nucleus, which forms the lateral wall of the lateral ventricle; ends at Amygdala
what amygdala for?
emotional fear
Fornix
connects the hippocampus with the mammillary bodies
Corpus callosum
above the thalamus and consists of a large group of commissural fibers interconnecting the two cerebral hemispheres
Gyrus cinguli
above the thalamus and serves as a receiving/integrating cortex for the limbic system;
Mammillary bodies
underneath the hypothalamus and interconnect the limbic system with the olfactory system
the caudet nucleus
has a head, body and a tail. The tail ends in the amygdala. This is in the temporal lobe
agraphia
difficulty writing and spelling
acalculia
difficulty with simple math problems
finger agnosia
wouldn’t be able to answer how many fingers am I holding, and which fingers am I holding?
