Brain Flashcards
List the 3 parts of the brain
- Cerebrum + basal ganglia
- Cerebellum
- Brainstem
List the lobes of the brain (5)
frontal, parietal, occipital, temporal, limbic
List the functional areas of the frontal lobe.
Describe the areas of the frontal lobe in relation to each other.
Primary motor cortex (anterior to central sulcus): voluntary movement and muscle activity coordination
Premotor motor cortex (anterior to the primary motor cortex): planning/ coordination of movement
Prefrontal cortex (most anterior part of the frontal lobe): executive functions, behaviour, personality
Broca’s Area: most ventral portion - muscles of speech and production of speech
List the functional areas of the parietal lobe.
Describe the areas of the parietal lobe in relation to each other.
overall: sensory perception and integration
Primary somatosensory cortex (closest to central sulcus. anterior to it): receives somatosensory information
Somatosensory association cortex (posterior to primary somatosensory cortex): processing/analyzing/recognizing somatic sensations; memory of sensation
Posterior association cortex (most posterior portion of the parietal lobe): visual, auditory, spatial awareness of body
- Deficits can affect attention, perception of time, mathematical reasoning
- Difficulty with spatial awareness, body image, proprioception. Can affect coordination and balance
- Hemispatial neglect, reduced awareness of stimuli on one side
- Difficulty with tactile perception - recognizing objects by touch
List the functional areas of the occipital lobe.
Describe the areas of the occipital lobe in relation to each other.
Overall function: vision
Primary visual cortex: Straddles the calcarine sulcus
visual association cortex: above the calcarine sulcus; object recognition, spatial perception, formation of mental images
Deficits result in: partial or complete loss of vision; visual hallucinations, disturbances in visual perception, altered color perception, motion blindness; difficulties perceiving and recognizing objects or faces (visual agnosia)
List the functional areas of the temporal lobe.
Describe the areas of the temporal lobe in relation to each other.
Primary auditory cortex (ventral transverse slice): awareness of auditory stimuli
Auditory association cortex (lateral slice that is dorsal to primary auditory cortex) : process, analyze, understand, recognize, memory of sounds
Wernicke’s area: speech comprehension
Primary olfactory cortex
Deficits: fluent aphasia; difficulty understanding speech
Limbic lobe function and components
Emotional processing, memory formation, regulation of basic instinct and drives such as hunger, thirst, sexual behaviour
Includes hippocampus, cingulate gyrus, amygdala, parts of hypothalamus and thalamus
Longitudinal cerebral fissure
separate the hemispheres
Central sulcus
prominent sulcus that runs down the middle of the lateral surface of the brain, separating the frontal lobe from the parietal lobe. Separates the primary motor cortex and the primary somatosensory cortex
Lateral sulcus
separates the temporal lobe from the frontal and parietal lobes
Parieto-occipital sulcus
separates the occipital lobe from the parietal and temporal lobes
Basal ganglia
- function
- components
- what diseases arise from issues with the basal ganglia?
selection and sequencing of motor movement; suppresses unwanted movement.
Caudate and lentiform nuclei (lentiform is further divided into putamen and globus pallidus)
- Parkinson’s disease; Huntington’s disease; OCD
Internal capsule
partition between caudate and lentiform. White matter structure that couples the cerebral cortex to deeper structures of the brain.
where the corona radiata converge; key conduit for communication between the cortex and other parts of the CNS
Corona radiata is the fanlike structure of myelinated nerve fibers including both motor and sensory pathways
Thalamus
- function
- what can deficits to this area result in?
relay station for sensory information
damage causes loss of sensation, altered sensation, movement disorders
Amygdala
- function
- where can you find this?
- what can deficits to this area result in?
- processing and regulation of emotions and memories; response to fear and threat
- temporal lobe; component of limbic system
- Deficits can affect: recognition or response to emotion; increased propensity for fear, anxiety, or aggression
- Deficits can contribute to depression or anxiety disorders
Hippocampus
- function
- deficits can result in what?
- associated with what disease
memory formation, learning, spatial navigation
Deficits results in difficulties forming new memories (anterograde amnesia), difficulties with recalling past events or information (retrograde amnesia)
Associated with Alzheimer’s
Hypothalamus
- function
- deficits can result in what?
Governs autonomic nervous system, endocrine system, and various motivated behaviors
Dysfunction can result in disturbances to appetite, body weight, sleep disorders, hormonal imbalance, disruption to emotional and behavioural regulation
Cerebellum
- function
responsible for balance, coordination, and integration of movement
What are the components of the brainstem and their functions
midbrain: associated with CN III and CN IV; plays an important role in motor eye movement
- Also plays a role in arousal and wakefulness
pons: Sleep regulation, respiration, micturition; Relays information between cerebral cortex and cerebellum; contributing to coordination and modulation of motor movements
medulla: essential autonomic functions
- Essential autonomic functions, cardiovascular regulation, respiration, swallowing, coughing
Draw the somatosensory and motor homunculus
see photo album
List and describe the 3 categories of white matter tracts
- Commissural fibres
- cross midline transversely
- corpus callosum: bridge left and right cerebral hemispheres - Association fibres
- Link different regions of the same cerebral hemispheres. Don’t cross the midline.
- Example: Connects lateral geniculate nucleus of the thalamus (where visual information arrives) to primary visual cortex in the occipital lobe - Projection fibres
- Travel long distances, mostly superiorly and inferiorly
- Example: corticospinal tract (voluntary motor function)
- Example: corona radiata
Corticospinal tract
- function
- pathway
Function: control of the musculature of the body
Upper motor neurons coalesce in the internal capsule, descend ipsilaterally through brainstem until it decussates at the medullary pyramids (and becomes the lateral corticospinal tract)
Innervates lower motor neurons in the ventral horn of the spinal cord; these neurons extend axons via the ventral root and then innervate skeletal muscles
however: some axons peel out of this tract early. At the brainstem is where cranial nerves emerge from.
important notes:
- Motor control from the primary motor cortex is contralateral
- medial portions of the primary motor cortex govern the opposite lower limb
- Lateral portions of the primary cortex govern the opposite upper limb
- anterior tract: axial limb
- lateral tract: distal limb
Corticobulbar tract: governs volitional motor control of the head
Originates in primary motor cortex (precentral gyrus)
Pathway: primary motor cortex (precentral gyrus) → internal capsule → brain stem via the cerebral peduncles → synapses onto cranial nerve nuclei in the brainstem
What would damage to the primary motor cortex be called?
What about damage to the cranial nerve?
upper motor neuron lesion
lower motor neuron lesion
list the two somatosensory tracts
the dorsal column-medial lemniscus pathway and the spinothalamic pathway
Describe the function and pathway of the dorsal column medial lemniscal tract
Fine touch, two point discrimination, conscious proprioception, vibration
Information ascends, then decussates at the medullary pyramids to synapse on the contralateral thalamus and then synapse on the contralateral primary somatosensory cortex
If its information about fine touch and proprioception from the face, it joins at the medial lemniscus, synapses onto the contralateral thalamus, then travels to the contralateral primary somatosensory cortex
Describe the function and pathway of the spinothalamic tract
pain/ noxious stimuli, temperature, deep touch
Information immediately commissures at the spinal cord level once entering the dorsal horn. Then ascends upwards to synapse on the contralateral thalamus and contralateral primary somatosensory cortex
If it’s information about pain and temperature from the face, it crosses the midline at the brainstem, travels to contralateral thalamus and contralateral sensory cortex
