Human Brain Flashcards
What are the 4 main lobes of the brain?
Temporal, Occipital, Frontal and Parietal
What divides the brain into its hemispheres?
The longitudinal fissure
What are sulci/fissures/gyri?
Sucli are shallow grooves in the brain’s cerebral cortex.
Fissures are deep grooves in the brain’s cerebral cortex
Gyri are the ridges between them.
What divides the frontal and parietal lobes?
The central suclus
What divides the frontal and temporal lobes?
The lateral fissure
What divides the temporal/parietal and occipital lobes?
The Parieto-occipital sulcus
What divides the temporal and parietal lobes?
The lateral fissure
What is an identifying feature of the occipital lobe?
The gyri are smaller and more tightly packed
What is the area ventral to the central sulcus called and what is its function?
The precentral gyrus. It is also called the Primary motor cortex, responsible for generating impulses for motor neurons.
What is the area ventral to the precentral gyrus called?
It’s the ‘planning area’, responsible for conscious planning of movements
What is the area posterior to the central sulcus called and what is its function?
The postcentral gyrus- also called the primary somatosensory cortex. It’s responsible for integrating all sensory information from the body as well as proprio sensation- knowing where your body is.
What is a motor/sensory homunculus?
A kind of map illustrating where in the brain the nerves/neurons for each area are located. The size of their representation is determined by the number of nerves/neurons for that particular part, rather than size alone.
Where is brocas area and what does it do?
It is ventral to the precentral gyrus in the planning area of the frontal lobe, between the middle and inferior gyri. It is responsible for forming speech. It is positioned near the homuncular mouth area of the precentral gyrus
Where is Exener’s and the eye area and what do they do?
Exener’s= hand area. Both are located in the planning area ventral to the precentral gyrus. They are responsible for fine motor movements of the hand and eye. This makes them important for reading and writing
Where is the primary auditory cortex and what does it do?
It is in the superior temporal gyrus, and maps sounds we hear in a tonotopic fashion- ie it separates high from low noises. It doesn’t interpret the sound, sending it to Wernicke’s area for this
What and where is Wernicke’s area?
It is also in the superior temporal gyrus, surrounding and just posterior to the primary auditory cortex. It makes sense of the tones the primary auditory cortex sends to it, making it a secondary auditory cortex.
What are the supramarginal gyrus and the angular gyrus and where are they?
They are in the inferior parietal lobule, with SM ventral to A. SM is responsible for reading interpretation/planning while A is responsible for writing planning and interpretation.
There is a white matter bridge between these areas and the areas of the eye and hand in the planning area, allowing them to talk to the motor nerves which initiate reading and writing.
What is the arcuate fasciculus and what does it do?
It connects Wernicke’s area and broca’s area, allowing you to know what you want to say (from W) and to be able to mechanically say it (from B)
What and where is the primary visual cortex?
It is located at the occipital pole, the most posterior part of the brain. It extends within the brain, separated by the calcarine sulcus, with granule cells which allow the rudimentary visual information to come through. It then sends this to the supplementary visual cortex.
What and where is the supplementary visual area?
It is posterior to the parieto-occipital sulcus and runs all the way down the back of the brain. It interprets sight.
What are the 5 groups of vertebrae/nerves in the spinal cord and how many of each?
Cervical- 8 Thoracic- 12 Lumbar- 5 Sarcal- 5 Coccygeal- 1
Where does the spinal cord itself end?
Between L1-2
What is the basic setup of the spinal cord?
Two roots coming in either side: Dorsal (with a ganglion) and ventral.
Circular, with an anterior median fissure on the front and a posterior median sulcus on the back
Gray matter is ‘butterfly shaped’, and separated into 3 horns: anterior, posterior and lateral
Central canal is located in the middle of the gray commisure
The white on either side of the gray commisure are called the anterior and posterior white commisure.
Posteriorly, there are 2 pairs of white columns.
The outer pairs are the cuneate fasciculii (Present C1-T8)
The inner pairs are the gracile fasciculii
There are also two anterior spinothalamic tracts and two lateral corticospinal tracts
What is a dermatome?
An area of skin supplied by a single spinal nerve