anatomical and functional division of the brain Flashcards
what is rostral/anterior
toward the front
what is caudal/posterior
toward the back
what is dorsal/superior
toward the top
what is ventral/inferior
toward the bottom
what is the neural axes
an imaginary line drawn through spinal cord toward front of brain
what is lateral
toward the side
what is medial
toward the midline
what is ipsilateral
same side of the midline
what is contralateral
opposite side of the midline
what is the corpus callosum
large bundle of axons that connect two hemispheres
what are the contralateral parts of the corpus callosum
homotopic and heterotopic
what is homotopic
connects complementary region of other hemisphere
what is heterotopic
communicates to a different brain regions
what is a callostomy
procedure to cut the corpus callosum to stop severe epileptic seizures and prevents communication between hemispheres
what are the three subdivisions of the brain
forebrain, midbrain, hindbrain
what are the subdivisions of the forebrain
telencephalon and diencephalon
what is the subdivision of the midbrain
mesencephalon
what are the subdivisions of the hindbrain
metencephalon and myelencephalon
what are subdivisions of the telencephalon
cerebral cortex, basal ganglia, limbic system
what are the subdivisions of the diencephalon
thalamus and hypothalamus
what is the subdivision of the mesencephalon
tectum/tegmentum
what are the subdivisions of the metencephalon
cerebellum, pons
what is the subdivision of the myelencephalon
medulla oblongata
what is the cerebral cortex and what does it do
- largest structure of the human brain
- divided into two hemispheres
- inner ‘white matter’ is pale because it has a high proportion of axon fibres covered in fatty myelin layer
- outer ‘grey matter’ where the neurons synapse and connect together
what is the basal ganglia and what does it do
- responsible for controlling involuntary movement, particular aspects that are highly automatised or involuntary
- Parkinson’s disease is an example of when this is dysfunctional
what is the limbic system and what does it do
- Papez proposed an emotion circuit in the brain
- McLean included hypothalamus, thalamus, cingulate gyrus, fornix, hippocampus, amygdala and orbitofrontal cortex and some nuclei of the basal ganglia
- limbic system describes emtional circuit in the brain but has shortcomings
- amygdala plays crucial role in emotion but the hippocampus and parts of the surrounding cortex are involved in learning and memory
what is the thalamus and what does it do
- major relay station for sensory inputs to cerebral cortex
- divided into several nuclei
what is the hypothalamus and what does it do
- controls autonomic nervous system and endocrine (hormone) system
- regulates survival behaviours (fighting, feeding, fleeing, mating)
what does the midbrain part of the mesencephalon do
- located in the brain stem
- at very top of brainstem and sits directly above hindbrain
- connects the pons and cerebellum with forebrain
- plays important role in motor movement particularly movement of the eye and auditory and visual processing
what is the cerebellum in metencephalon and what does it do
- includes cerebellum - receives info from visual, auditory, somatosensory and vestibular systems helps coordination of movement
- damage to cerebellum - causes problems with jerky, poorly coordinated movements and problems maintaining balance
what is the pons in the metencephalon and what does it do
- lies on the ventral surface of the brainstem
- contains several nuclei important for regulating sleep and arousal
- relays information from cerebral cortex to the cerebellum
what is the myelencephalon and what do it do
- AKA medulla oblongata (medulla)
- links hindbrain to the spinal cord and contains neurons important for autonomic functions like respirations and heart rate
what are the seven lobes of the cerebral cortex
- frontal lobe
- central sulcus
- parietal lobe
- parieto-occipital sulcus
- occipital lobe
- pre-occipital notch
- temporal lobe
where is the primary visual cortex
- medial and lateral parts of the occipital cortex/lobe at posterior of the brain
what does the primary visual cortext do
- receives sensory info from retina
- the left and right visual fields are each projected to the contralateral hemisphere
- light stimulus stimulate the corresponding area of the retina within each eye
how are the different regions of the retina represented
- represented by different areas within the primary visual cortex
- areas further out in peripheral vision are processed by areas of the visual cortex that extend into the calcarine fissure
what do primary visual cortex neurons show
orientation selectivity
- Hubel and Wiesel won the nobel prize in 1981 for this
what does the parietal lobe do
- involved in attention and spatial awareness
- sits on the dorsal surface of cortex and referred to as part of the dorsal stream and ‘where’ pathway
what is the other nickname for the parietal lobe and why
where pathway - because it deals with spatial localisation
what is the role of temporal lobe
- auditory processing
- involved in more complex visual processing
what is the nickname for temporal lobe and why
what pathway - named for its role in complex object recognition
what is the primary auditory cortex and where
- superior part of the temporal cortex as well as a patch in Sylvian fissure
- receives auditory sensory information from the cochlea
- different frequencies are represented by different areas within the primary auditory cortex, forming a tonotopic map
what is the primary somatosensory cortex and where
- located immediately posterior to central sulcus
- reveives sensory information from skin (temp, touch and pain)
- different regions of skin surface represented by different areas along the strip of cortex
- forms a somatotopic map (face and hands are overrepresented - looks like a charicature)
what is the primary somatosensory cortex and where
- located immediately posterior to central sulcus
- reveives sensory information from skin (temp, touch and pain)
- different regions of skin surface represented by different areas along the strip of cortex
- forms a somatotopic map (face and hands are overrepresented - looks like a caricature)
what is the primary motor cortex amd wjere
- located in precentral gyrus immediately anterior to central sulcus
- different parts send signals that control different groups of voluntary muscles
- controls muscles on opposite (contralateral) sides of the body
what is different about human frontal lobe?
- relatively larger than nonprimates
- higher level of connectivity with rest of the brain
what is the frontal lobe’s higher order of functions
- voluntary, controlled behaviour
- impulse control and emotional regulation
- abstract reasoning and planning
- social cognition
- language
what happened to Phineas Gage - frontal lobe damage
- railway foreman in Virginia had an accident involving tamping iron
- survived profound damage to frontal lobe behavioural changes
- personality change, angry, impatient,
obstinate, capricious, unable to plan for the
future, unable to make decisions
