Gross Brain Flashcards
Cerebellum
little brain separate part that attaches to the brain
Lobes of the Cerebrum
Frontal - Higher order thinking area and make decisions, think abstractly, have personality, preform movements
Temporal- memory, auditory functions
Parietal - somatic sensation and integration sensation
Occipital - vision
Cerebral Cortex
the outer layer of cerebrum Cortex refers to tree brake Some parts of the cortex appear gray in color, and others appear white Consists more of grey matter Gray matter/white matter
What do you think underlies these differences in color?
Mylenations fatty covering/wrapping
White color - all the axons are due to the myline wrapping around the axons. All the whites are leaving the cell soma and coming down to the grey matter regions
Grey matter - neuron cell bodies and dendrites & somas
Features of the Cerebral Cortex
Fissures - deep grooves that divide large regions of the brain
Longitude fissure Running in sagittal plane separates left and right hemisphere
Separate frontal and temporal lobe
-Sylvian fissure or Lateral fissure
Gyri - look like the ridges around the brain
Sulcus/Sucli - valleys where the folds curl down in the grooves
Why do we have these folds?
-increasing surface area without changing the amount of space the cell takes up
How do we know the functions of different brain areas?
Classically, based of different type of injures
FMRI - Able to look at blood flow patterns in the brain and create a heatmap. If area has increase blood flow that means it’s more active
Most region have different functions and not easy and difficult to make large studies and basing results off a small amounts of ppl
Gyri
Central Sulcus divide frontal lobe and parietal lobe
Arise from the longitude fissue and straight down the lateral fissure
-Precentral gyrus - it’s functions primary motor cortex and initial our movements
-Post central gyrus - nuerons sensation and interpreting here
The homunculus
-Post central gyrus/Sensory Homunculus (Superior lateral)
-Amount of area number of neurons within our motor cortex and within somastic senory cortex dedicated to parts of the body
Why?
-This is how we interact with the environment and have better sensory or perception of those areas
Motor cortex is organized simillary is based on motions and joint movements
Why is knowing the organization of the homunculus important clinically?
Underlies the deficit we see in the patients and what parts of the cortex are damaged
Feet and genitals are located within the Longitude fissure
Hands - Superior Lateral portion where the sensory motor region will be
Inferior Lateral - face/mouth is represented
Patient suffered superior lateral of the brain what functions may they not be able to do -typing on a keyboard
Patients had a stroke and killed all neurons on the motor cortex along the longitudinal fissue what might not they be able to do? - Walk, dance
to know
Motor cortex is in the precentral gyrus
At the brain stem these axons will cross over to the other side of the body and descend down to the spinal cord .
Here we have neurons in the left precentral gyrus (left motor cortex) they’re sending their axons down through the brain stem and before right before the spinal cord and go to the right side of the spinal cord and control muscles on the left side of the body.
Motor neurons in the motor cortex control muscles on the contralateral side of the body
Deccusation = when axons cross from one side of the body to other
Gyri of the Frontal Lobe
Run horizontally across the lobe
Superior frontal gyrus - it’s job is short term working memory, five mins or so
Middle frontal gyrus - Memory recall librarian specific saved memory
Inferior frontal gyrus - generating speech, picking words to say and how that word sounds (located in the left hemisphere)
Speech and language are located on the left hemisphere for most ppl.
Clinical Correlate: Expressive/Broca’s Aphasia
Damaged to the Inferior Frontal Gyrus
- Halting, effortful speech, often less than 4 words
- Can understand spoken language and can read but often have difficult with writing, or sign language
- Due to damaged of the inferior front gyrus
Temporal lobe
Runs horizontal
Superior temporal gyrus - auditory processing, many neurons processing sound coming in
Middle temporal gyrus - does a little of both auditory and visual spatial processes
Inferior temporal gyrus - visual processing and spatial processing
Clinical Correalate: Receptive/Wernickle Aphasia
- Damaged to Superior Temporal Gyrus due to stroke or traumatic brain injury
- Difficulty processing and interpreting language incoming language (auditory or written)
- Fluent speech but is mostly meaningless
- Reading and writing severely impaired
Medial Occipital Lobe - cut in half right hemisphere of brain
Parieto-occipital sulcus - bc it separates parietal lobe from occipital lobe
Right above Calcarine sulcus from the LOWER half of visual field
Calcarine sulcus - Separates occiptal lobe to top and bottom interprets from visual information
Cuneus - Cuneiform bc it’s triangle form
Lingual gyrus - doesn’t have to do with speaking right below the calcarine sulcus neurons will interprets information from UPPER half our visual field
Cuneus and lingual gryus - primary visual cortex and involved with processing visual information
