Neuro Anatomy Flashcards
What structures are included in the frontal lobe
- Precentral gyrus: primary motor cortex for voluntary control
- Prefrontal cortex: controls emotions & judgements
- Broca’s area: controls motor aspects of speech
What structures are included in the parietal lobe
- Postcentral gyrus: primary sensory cortex for integration of sensation
- Receives fibers conveying touch, proprioception, pain, and temperature sensations from opposite side of body
What structures are included in the temporal lobe
- Primary auditory cortex: receives/processes auditory stimuli
- Associative auditory cortex: processes auditory stimuli
- Wernicke’s area: language comprehension
- Primary vestibular area: head position & movement, perception of vertical
What structures are included in the occipital lobe
- Primary visual cortex: receives/processes visual stimuli
- Visual association cortex: processes visual stimuli
Where is the insula lobe located
- Located deep within lateral sulcus, associated with visceral functions
Functions of the limbic system
- Oldest part of the brain
- Feeding, aggression, emotions, & endocrine aspects of sexual response
- Critical role in memory, motivation, & learning
Define white matter
- Myelinated nerve fibers located centrally
- Includes transverse, projection, and association fibers
Define grey matter
- Composed of gyri (crests) and sulci (fissures)
Define transverse (longitudinal) fibers
- Interconnect the 2 hemispheres including the corpus callosum, anterior commissure, and hippocampal commissure
Define projection fibers
- Connect cerebral hemispheres with other portions of the brain & spinal cord
Define association fibers
- Connect different portions of the cerebral hemispheres allowing cortex to function as an integrated whole
What are the parts of the basal ganglia (BG)
- Striatum: caudate nucleus, nucleus accumbens, putamen
- Globus pallidus: external and internal
- Subthalamic nucleus and substantia nigra: reticular part
- Lenticular nucleus: putamen and globus pallidus
Describe the oculomotor circuit (caudate loop) of BG
- Originates in frontal & supplementary motor eye fields
- Projects to caudate
- Functions with saccadic eye movements
Describe the motor loop (putamen loop) of BG
- Originates in pre central motor and postcentral somatosensory areas
- Projects to & excites putamen neurons
- Putamen cells inhibit globes pallidus neurons which in turn boosts activity in the ventral lateral nucleus & supplemental motor area
- Functions to scale amplitude & velocity of movements
- Reinforces selected pattern and suppresses conflicting patterns
- Preparatory for movement
Describe the limbic circuit of BG
- Originates in prefrontal & limbic areas of cortex
- Functions to organize behaviors & for procedural learning
What structures are part of telencephalon
- Cerebral hemispheres
- Basal ganglia (BG)
What structures are part of diencephalon
- Thalamus
- Subthalamus
- Hypothalamus
- Epithalamus
Function of thalamus
- Sensory: integrate & relay sensory info from body, face, retina, cochlea, & taste receptors to cerebral cortex & subcortical regions
- Motor: relay motor info from cerebellum & globus pallidus to precentral motor cortex
- Does NOT do smell (olfaction)
Function of subthalamus
- Involved in control of several functional pathways for sensory, motor, and reticular function
Function of hypothalamus
- Maintains body homeostasis
- Integrates & controls the functions of the autonomic nervous system (ANS) & the neuroendocrine system
Function of epithalamus
- Habenular nuclei: integrate olfactory, visceral, & somatic afferent pathways
- Pineal gland: secretes hormones that influence the pituitary gland & several other organs; influences circadian rhythm
What does the midbrain connect
- Connects pons to cerebrum
- Superior peduncle connects midbrain to cerebellum
What does the tegmentum (posterior peduncle) contain
- Contains all ascending tracts & some descending tracts
- Red nucleus receives fibers from cerebellum
- Origin of rubrospinal tract: important for coordination
- Contains cranial nerve nuclei: oculomotor & trochlear
What does the substantia nigra (anterior peduncle) connect
- Large motor nucleus connecting with the basal ganglia & cortex
- Important in motor control and muscle tone
Functions of the superior and inferior colliculus
- Superior: relay station for vision and visual reflexes
- Inferior: relay station for hearing & auditory reflexes
Function of the periaqueductal grey
- Contains endorphin producing cells and descending tracts that are important for pain & reflex modulation
What does the pons connect
- Connects the medulla oblongata to the midbrain allowing passage of important ascending & descending tracts
What cranial nerve nuclei does the tegmentum contain
- Abducens
- Trigeminal
- Facial
- Vestibulocochlear
The midline raphe nuclei is important for
- Modulating pain and controlling arousal
What does the medulla oblongata connect
- Connects spinal cord with pons
- Contains relay nuclei of dorsal columns; fibers cross to give rise to medial lemniscus
- Contains important centers for cardiac, respiratory, and vasomotor centers
What is the medial longitudinal fasciculus important for
- Important for control of head movements and gaze stabilization (vestibulo-ocular reflex)
What cranial nerve nuclei are in the medulla oblongata
- Hypoglossal
- Dorsal nucleus of vagus and vestibulocochlear
Function of the reticular activating system (RAS)
- Anterior most segment of brainstem
- Includes 4 nuclei that produce key neurotransmitters that assist with attention, arousal, & modulation of muscle tone
- Damage to RAS result in dysregulation of sleep-wake cycles, impaired arousal, and ability to focus
Parts of the cerebellum and their fucntions
- Archicerebellum (flocculonodular lobe): connects with vestibular system & concerned with equilibrium & regulation of muscle tone; helps coordinate vestibulo-ocular reflex
- Paleocerebrellum (spinocerebellum/anterior lobe): concerned with modifying muscle tone & synergistic actions of muscles; important in maintenance of posture & voluntary movement control
- Neocerebellum (cerebrocerebellum/posterior lobe): concerned with smooth coordination or voluntary movements; ensures accurate force/direction/extent of movement