Neuroanatomy, Asymmetry and Visual System Flashcards
What is the name for incoming sensory information coming INTO the CNS?
Afferent information
What is the name for outgoing motor information going OUT of the CNS?
Efferent information
What is the Dorsal/Superior view?
“above”; “towards the top”
What is the Ventral/Inferior view?
“below”; “towards the bottom”
What is the Medial view?
towards/at the middle
What is the Lateral view?
towards/at the side
What is the Anterior/Rostral view?
in front of
What is the Posterior/caudal view?
in back”; “behind
When talking about a a 4-legged creature, “dorsal” can also mean:
In the back of
When talking about a a 4-legged creature, “ventral” can also mean:
In the front of
Which brain slice would we expect to show a dorsal or ventral view?
Axial/Horizontal/Transverse Slice
Which brain slice would we expect to show a medial view?
Sagittal Slice
Which brain slice would we expect to show a frontal view?
Coronal Slice
The cerebellum is ______ to the cerebral cortex.
posterior
The frontal lobe is ______ to the occipital lobe.
anterior
Why is the nervous system thought to be bilaterally symmetrical?
It has a left and right side that roughly mirror one another.
When something is bilateral, this means that it is _______ ?
On both sides
When something is ipsilateral, this means that it is _______ ?
On the same side
eg. Connections between the thalamus and the cortex are generally regarded as ipsilateral
When something is contralateral, this means that it is _______ ?
On opposite sides
eg. the cerebrum has contralateral influence on behaviour
When something is proximal, this means that it is _______ ?
Close to something else
eg. The hypothalamus is proximal to the thalamus
When something is distal, this means that it is _______ ?
Far from something else
eg. The occipital lobe is distal from the frontal lobe
What is the name inclusive of the three layers of protective tissue that encase the brain and spinal cord?
The meninges
What is the purpose of the meninges?
Purpose is to protect the nervous system
What are the three layers of the meninges?
Dura mater, arachnoid layer, pia mater.
What is the name of the meningeal layer that is outer, tough and fibrous?
Dura mater
What is the name of the meningeal layer that is found in the middle of the meninges, and is a thin sheet of delicate connective tissue that follows the brain’s contours?
The arachnoid layer
Where is the arachnoid layer found?
In the subarachnoid space
What is the name for the meningeal layer that is made of moderately tough connective tissues that clings tightly to the brain?
Pia mater
What is the name of the fluid that fills the ventricles and circulates around the brain and spinal cord in the subarachnoid space, located between the arachnoid layer and the pia mater?
Cerebrospinal fluid
Give a brief definition of meningitis and its cause (remember, -itis = inflammation).
- Infection in the CSF
- Can be viral or bacterial –> caused by microorganisms entering the meninges and causing infections
- Symptoms: Cervical stiffness and headache
What is encephalitis?
Inflammation of the brain
Where is the cerebrum located?
Forebrain
[FACT CARD] The cerebrum is found BILATERALLY in the forebrain hemispheres.
n/a
[FACT CARD] The cerebrum is found BILATERALLY in the forebrain hemispheres.
n/a
What is one of the MAJOR structures of the forebrain, responsible for conscious behaviours?
Cerebrum
What is one of the MAJOR brainstem structures specialized for learning and coordinating movements/balance?
Cerebellum
True or false: The cerebellum works with the cerebrum in generating behaviours.
True
What is the name of the small protrusions/bumps/hills on the folded cortex?
Gyrus
What is the name for the grooves/valleys of the cortex?
Sulcus
What is the name of the thin sheet of nerve tissue folded multiple times to fit inside the skull, and forms the outer layer of the brain?
The cerebral cortex
The hemispheres of the brain are divided into how many lobes?
4
Name the 4 lobes of the brain hemispheres.
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Why is it important to know the location of brain regions and their responsibilities?
Because we can predict behavioural changes based on damage
What is the main function of the frontal lobe?
Executive functioning, planning.
What is the main function of the parietal lobe?
Somatosensory processing
What is the main function of the temporal lobe?
Integrating auditory information
What is the main function of the occipital lobe?
Integrating visual information and primary visual processing
What is the role of the lateral fissure?
It divides the frontal and parietal lobes from the temporal lobe.
What is the parieto-occipital sulcus?
A fissure that divides the parietal lobe from the occipital lobe
What is a major structure of the brain, responsible for basic physiological functions that sustain life?
The brainstem
What are the names of the 3 main cerebral arteries?
Anterior, middle and posterior arteries.
What are the two types of strokes?
Ischemic and haemorrhagic.
Symptoms of a stroke are often found _________?
Contralaterally
What is the central sulcus?
Horizontal central division in the brain which separates the frontal and parietal lobes.
What is the name of the fissure that divides the left and right brain hemispheres?
The longitudinal fissure.
What are the two main types of cells found in the brain?
Neurons and glial cells.
What is the role of neurons?
Communicating and carrying out the brain’s major functions.
What is the role of glial cells?
Aid and support the activities of neurons.
What is grey matter made up of?
Cell bodies and blood vessels
What is white matter made of?
Fatty tissues and neural axons.
What is the brain matter found on the most external part of the brain?
Grey matter
What is the role of grey matter?
Collecting information before passing it on
What is the role of white matter?
Making connections between brain regions to facilitate the passing of information.
What is the largest white matter tract in the brain?
Corpus callosum
What is the role of the corpus callosum?
To connect the two cerebral hemispheres
How can we treat epilepsy with the corpus callosum?
Cutting it.
What are the wing-shaped cavities in the brain that are filled with CSF?
Ventricles
How many ventricles are there in the brain?
4
What are the 4 ventricles in the brain?
2 lateral ventricles
Third ventricle
Fourth ventricle
What is the piece in the brain and spinal cord that connects the 4 ventricles?
Cerebral aqueduct
What is the role of CSF?
To remove waste, to allow compound flow, to cushion the brain from injury.
What is a nucleus/nuclei?
A group of cells forming a cluster of specific functional grouping
What is an axon?
Fiber of a neuron that carries messages to other neurons
What is the name for a large collection of axons coming together OUTSIDE the CNS?
Nerve
What is the name for a large collection of axons coming together IN the CNS?
Tract
What makes up the CNS?
Spinal cord, brainstem, forebrain
What is the spinal cord responsible for?
Executing body movements
What part of the CNS is able to act independently of the brain?
Spinal cord
What reflexes are very hard to prevent?
Spinal reflex/reflex arc.
Where does the brainstem begin?
Where the spinal cord enters the skull and extends up the forebrain.
The brainstem receives ______ information coming from the senses.
Afferent
The brainstem sends out ______ information coming from the brain to control movements.
Efferent
What are the 3 regions of the brainstem?
Hindbrain, midbrain, diencephalon
What is the motor region of the brainstem?
Hindbrain
What is the sensory region of the brainstem?
Midbrain
What is the integration region of the brain?
Diencephalon
What is the oldest part of the brain?
Hindbrain
What part of the brain controls both voluntary and involuntary movement?
Hindbrain
What are the 4 parts of the hindbrain?
Pons, medulla, cerebellum and reticular formation.
What is the role of the cerebellum?
Controlling complex movement and cognitive functions
True or false: The size of the cerebellum increases with dexterity and physical speed of a species.
True
What is the role of the reticular formation?
Plays a role in the sleep-wake cycle and stimulates the forebrain
What is the role of the pons?
Connects the cerebellum to the rest of the brain and controls movements of the body.
What is the role of the medulla?
Vital life functions (breathing and HR).
Where is the medulla?
On the anterior tip of the spinal cord.
What are the dorsal and ventral components of the midbrain?
Tectum (dorsal)
Tegmentum (ventral)
What is the sensory processing component of the midbrain?
Tectum
What is the motor component of the midbrain?
Tegmentum
What are the two components of the tectum?
Inferior and superior colliculi.
What are the two structures found in the tegmentum?
Substantia nigra (Basal ganglia) and the periaqueductal grey
What is the role of the substantia nigra?
Responsible for initiating movements
What are the two structures in the diencephalon?
Hypothalamus and the thalamus
What part of the brain receives and integrates sensory and motor information on its way to the cerebral cortex?
Diencephalon
What part of the diencephalon is responsible for hormonal interactions?
Hypothalamus
What brain organ is responsible for controlling feeding behaviours?
Hypothalamus
What are some of the roles of the hypothalamus?
Regulation of hormones, feeding, sexual behaviours, emotion, temperature regulation, movement, motivation.
Which brain area is the gateway for channeling sensory information?
Thalamus
What is the role of the thalamus?
To organize and integrate sensory information and sending it to appropriate cortical areas.
What are the 3 nuclei of the thalamus?
Lateral geniculate nucleus
Medial geniculate nucleus
Dorsomedial nucleus
Does olfaction skip the thalamus?
Yes.
What is the primary role of the thalamus?
Sensory processing
What is the largest region of the human brain?
Forebrain
What are the three principle structures of the forebrain?
Cerebral cortex/neocortex
Basal ganglia
Limbic system/allocortex
What is the role of the cerebral cortex?
Regulating brain activities
What is the role of the basal ganglia?
Control of voluntary movement –> think lack of control in Parkinson’s due to basal ganglia buildup of lewy body proteins
What is the role of the limbic system?
Regulating emotions and behaviours in relation to memory
How many layers make up the neocortex/cerebral cortex?
6
What are the visible differences that allow mapping of the cerebral cortex?
Cortical layers
What is brodmann area 17?
Primary visual cortex. Responsible for discerning the intensity, shape, size, and location of objects in the visual field.
Where is the basal ganglia located?
Below the white matter of the cortex.
What are the 3 principle structures of the basal ganglia?
Caudate nucleus
Putamen
Globus pallidus
What are hypokinetic movements?
Parkinson’s-like movements. Cannot begin movement.
What are hyperkinetic movements?
Tourette’s-like movements. Cannot prevent movement.
What are the principle components of the limbic system?
Amygdala
Hippocampus
Cingulate cortex
What is the nervous system part of the PNS that is responsible for transmitting information to the rest of the body?
The somatic nervous system
What part of the nervous system controls the cranial nerves?
The brain
What part of the nervous system controls the spinal nerves?
The spinal cord segments
How many cranial nerves are there?
12 pairs (24 total)
What are the afferent functions of the cranial nerves?
Sensory input
What are the efferent functions of the cranial nerves?
Motor control of the facial muscles (tongue, eyes, grimace, etc)
Where are the spinal nerves found?
Between the vertebrae
How many anatomical regions are there in the spine?
5
What are the anatomical regions of the spine?
Cervical
Thoracic
Lumbar
Sacral
Coccygeal
What spinal nerve fibers are afferent and carry information from the body’s sensory receptors?
Dorsol/posterior root fibres.
What spinal nerve fibers are efferent and carry information from the body’s spinal cord to the muscles?
Ventral/anterior root fibres.
What is the law of Bell and Magendie?
The anterior spinal nerve roots contain only motor fibers and posterior roots only sensory fibers and that nerve impulses are conducted in only one direction in each case.
How is Bell-Magendie useful in treating patients with nerve damage?
Can help locate damage when comparing movement to sensation
What is the role of the autonomic nervous system?
Controlling the internal organs (visceral organs)
What is the sympathetic system in the autonomic nervous system?
Arouses body for action (fight or flight response)
What is the parasympathetic system in the autonomous nervous system?
Calms the body down (rest and digest)
What is the role of the enteric nervous system?
Controlling the gut
Where can neurons be found in the ENS?
In the lining of the GI tract.
How many principles of the nervous sytem are there?
10
What is principle 1 of the nervous system?
The nervous system produces behaviour within a perceptual world the brain constructs.
What is principle 2 of the nervous system?
Neuroplasticity is the hallmark of nervous system functioning.
What is principle 3 of the nervous system?
Many brain circuits are crossed.
What is principle 4 of the nervous system?
The CNS functions on multiple levels.
What is principle 5 of the nervous system?
The brain is both symmetrical and asymmetrical.
What is principle 6 of the nervous system?
Brain systems are organized hierarchically and in parallel.
What is principle 7 of the nervous system?
Sensory and motor divisions exist all throughout the nervous system.
What is principle 8 of the nervous system?
The brain divides sensory input for object recognition and motor control
What is principle 9 of the nervous system?
Brain functions are both localized and distributed.
What is principle 10 of the nervous system?
The nervous system works through both excitation and inhibition.
Damage to which area of the brain produces obvious deficits?
Primary receptive areas
Damage to which area of the brain produces complex deficits?
Non-specific association areas
Give an example of damage to a primary receptive area.
Lesions to the somatosensory cortex produce obvious contralateral loss of sensory reception.
Give an example of damage to a non-specific association area.
Lesions to the parietal-temporal-occipital association area causes the inability to understand the value of numbers.
What is cerebral asymmetry?
The differentiation between structure and function of the brain between the right and left hemispheres.
What is the concept of laterality in cerebral hemispheres?
Idea that the two hemispheres have separate functions, and some are specialized to one side.
What are some functions of the left hemisphere?
Producing and understanding language
Reading, writing and speech
Controlling movement on the right side of the body
What are some functions of the right hemisphere?
Perceiving and processing non-verbal information
Spatial tasks
Understanding jokes and sarcasm
Controlling movement on the left side of the body
What is the difference between cerebral site and cerebral side?
Site = specific location
Side = Hemisphere
What are two factors that are known to affect laterality?
Genetics and environment
Laterality and asymmetry was originally thought to be an exclusive characteristic to what type of processing?
Language processing.
From bottom up, which brain hemisphere protrudes anteriorly from the frontal lobes?
The right hemisphere
From bottom up, which brain hemisphere protrudes posteriorly from the parietal and occipital lobes?
Left hemisphere
Which brain hemisphere contains more grey matter relative to white matter?
Left hemisphere
Why is the right hemisphere lateral fissure bigger than the left hemisphere?
Larger parietal and temporal lobes due to spatially oriented behaviours associated in this hemisphere.
What is the frontal operculum and its purpose?
Broca’s area. Speech production.
What is the planum temporale and its function?
Wernicke’s area. Language comprehension.
What is Heschl’s gyrus and its function?
Primary auditory cortex. Auditory processing.
How do we assess cerebral asymmetries in neurological patients?
Neuropsychological assessments that determine whether the functions that are affected are lateralized or distal.
What is a dissociative function?
Function that is non specific to a hemisphere or lobe. Integrated processes.
What is double dissociation in neuropsych assessments?
A technique in which two cortical areas are proven to be dissociated by two separate tests. Performance on the tests dissociates the lesion from the brain area.
What would damage to the temporal lobe look like?
Loss of verbal and non-verbal (spatial tasks) skills.
What would parietal lobe damage look like?
Diffculties with copying, naming, readings, etc.
What is a comissureotomy?
The surgical disconnetion between the right and left hemispheres by cutting the corpus callosum.
What is the split brain phenomenon?
Contralateral processing of visual information affects recognition of objects. They “can’t” see.
How can we prove laterality?
Carotid sodium amobarbital injection (CSAI)
Transcranial magnetic stimulation (tMS)
What is the carotid sodium amobarbital injection?
An injection of anaesthetic into the ipsilateral carotid artery in order to paralyze the location where language is produced.
How can we identify asymmetry in the auditory system?
Dichotic listening tasks
What are dichotic listening tasks?
Patients are asked to recall sounds presented in both ears. Patients typically respond best to right ear stimulation.
Why are there variations in cerebral asymmetry?
No two brains are alike.
What are some facts about lefthandedness and functional asymmetry?
These people can have either:
- no asymmetry
- reversed asymmetry.
True or false: Those with a
deeper left central sulcus tend to be right-handed.
True
What are the 3 theories of hand preference?
Genetic theory
Environmental theories
Anatomical theories
Explain the genetic theory of hand preference.
Dominant genes determine right handedness, recessive determine left handedness.
Explain the genetic theory of hand preference.
Adaptations: Mothers hold babies in left arms.
Reinforcement: Favours in the world.
Explain the anatomical theory of hand preference.
Left hemisphere shows greater maturation in most individuals, which prefers the right hand.
What are motor differences in men and women?
Men have better gross motor skills, women have better fine motor skills.
What are spatial differences in men and women?
Men are better at mental rotation, women are better at recognition of movement.
What are mathematical differences in men and women?
Men have better mathematical reasoning skills, women are better at computation.
What are some perception differences in men and women?
Women are more sensitive to sensory stimulation, men are more sensitive to mechanical objects.
What are some differences in verbal abilities between men and women?
Women are superior at verbal fluency.
True or false: Asymmetry (left larger than right) in the planum temporale (Wernicke’s area) is seen more often in men than in woman
True
Which gender has more neurons?
Men
Which gender has more interhemispheric connections?
Women
What is the term for electromagnetic energy that we can see?
Light.
What is the range of electomagnetic energy that humans have the ability to see?
400-700 nanometers.
