P2 - Brainstem, Diencephalon, Basal Ganglia Flashcards
Thalamus
- central hub
- relays and integrates motor + sensory impulses b/w higher centers of brain and the periphery
- where all motor + sensory signals (except olfaction) pass through
Pineal Body
- neuroendocrine gland
- secretes melatonin
- maintains body’s circadian rhythm + regulates sleep-wake cycle
- role in modulating onset of puberty and development of reproductive system
Superior Colliculus
- visual pathway
- receives signals from retina
- visual body reflexes (automatic + involuntary movements)
- ie. scanning during reading, covering eyes in bright areas, turning head towards sudden and unexpected sounds
Inferior Colliculus
- auditory pathway
- receives information from cochlear nuclei
- automatic + involuntary movements
- sound localization, frequency determination
- allow us to turn our head towards unexpected acoustic stimuli
Facial Colliculus
houses abducens nucleus and facial motor fibers
Lateral Geniculate (and Nucleus)
- thalamic relay station of visual pathway
- receives input from retina and relays it to visual cortex
- role in normal visual processing
Medial Geniculate (and Nucleus)
- thalamic relay station of auditory pathway
- direct auditory attention
- relays auditory sensory information from inferior colliculus to primary auditory cortex
- organization of sound and frequencies
Cerebral Peduncle
- connects midbrain w/ thalamic nuclei and cerebrum
- assists in refining motor movements, learning new motor skills, and converting proprioceptive information into balance and posture maintenance
Superior Cerebellar Peduncle
- connects midbrain to cerebellum
- almost entirely efferent
Middle Cerebellar Peduncle
- connects pons to cerebellum
- entirely afferent
Inferior Cerebellar Peduncle
- connects medulla to cerebellum
- both afferent + efferent
Fasciculus Cuneatus
transmits vibration, conscious proprioception, and fine touch sensations from upper body
Fasciculus Gracilis
transmits vibration, conscious proprioception, and fine touch sensations from lower body
CN IV
(trochlear)
- moves eye down + in
- efferent for vestibulo-ocular reflex
CN V
(trigeminal)
- somatosensation from face + TMJ
- afferent for corneal reflex
- chewing (muscles of mastication)
CN VII
(facial)
- facial expression
- closes eyelid
- efferent for corneal reflex
- taste
- salivation, tears
CN VIII
(vestibulocochlear)
- hearing
- proprioception
- afferent for vestibulo-cochlear reflex
CN IX
(glossopharyngeal)
- sensation from pharynx, posterior tongue, middle ear
- afferent for gag and swallowing reflex
- constricts pharynx
- salivation
- taste
CN X
(vagus)
- sensation from pharynx, larynx, skin in external ear canal
- regulates swallowing and speech
- efferent for gag and swallowing reflex
- afferent for viscera
CN XI
(accessory)
- elevates shoulders
- turns head
CN XII
(hypoglossal)
- tongue movement
Cerebral Aqueduct
connects 3rd and 4th ventricle to allow for CSF flow
Periaqueductal Gray Matter
- pain
- sympathetic responses
- learning and action of defensive and aversive behavior
Substantia Nigra
- produces dopamine
- affects mood, learning, judgement, decision-making
Ascending Tracts
DCML, spinothalamic, spinocerebellar
Descending Tracts
corticospinal, rubrospinal, reticulospinal, olivospinal, vestibulospinal
Medial Lemniscus
- part of dorsal column
- starts w/in brainstem and sends sensory input to thalamus + postcentral gyrus
Lateral Lemniscus
passes auditory information from cochlear nucleus to contralateral inferior colliculus
Red Nucleus
- in ventral midbrain tegmentum
- part of rubrospinal tract (distal UE extension)
4th Ventricle
- helps form central canal for CSF flow
- protects brain from trauma (cushioning effect)
Reticular Formation
- autonomic, motor, sensory, behavioral, cognitive, and mood-related functions
- modulatory and pre-motor
- cardiovascular control
- consciousness, sleep
Cuneate Nucleus
carries information from upper limb and body
Gracile Nucleus
carries information from lower limb and body
Pyramidal Decussation
where lateral corticospinal tract (motor) fibers cross
Inferior Olivary Nucleus
- coordinates signals from spinal cord to cerebellum to regulate motor coordination and learning
- learning and timing of movements
- comparing intended w/ achieved movements
Hypothalamus
- smart control coordinating center
- controls hormonal system by releasing hormones to pituitary gland
- HEAL = homeostasis, endocrine, autonomic, limbs
Amygdala
- integrative center for emotions, emotional behavior, and motivation
- process fearful and threatening stimuli
- activation of appropriate fear-related behaviors
Fornix
- white matter tract that transmits information from hippocampus to mammillary bodies + anterior nucleus of thalamus
- memory function
Infundibular Stalk
- tube-like structure that connects posterior pituitary to hypothalamus
- allows for hormones synthesized in hypothalamus to be sent to posterior pituitary for release into bloodstream
Cingulate Gyrus
- process emotion
- behavior regulation
- regulate autonomic motor function and pain
Septum Pellucidum
partition b/w lateral ventricles, forming walls of anterior lateral ventricles
Mammillary Bodies
recollective memory
Hippocampus
- regulates learning
- memory encoding + consolidation
- spatial navigation
3rd Ventricle
produce, secrete, and convey CSF
Corpus Callosum
connects two brain hemispheres, permitting communication b/w R + L sides
Anterior Commissure
collection of nerve fibers that cross midline of spinal cord and transmit information from/to contralateral brain
Posterior Commissure
collection of nerve fibers that connects language processing centers of both cerebral hemispheres
What regions are a part of the limbic system?
amygdala, hippocampus, hypothalamus, cingulate gyrus, mammillary bodies
Putamen
- regulate movements
- influence various types of learning
Globus Pallidus Internus (GPi)
- output nucleus
- controls conscious + proprioceptive movements
- cognition and motivation
- primarily sends inhibitory signals to motor thalamus
Globus Pallidus Externus (GPe)
- input nucleus
- controls conscious + proprioceptive movements
- cognition and motivation
- central hub for processing motor and non-motor information
Caudate Nucleus
planning execution of movements, learning, memory, reward, motivation, emotion, vision, romantic interactions
Subthalamic Nucleus
- movement regulation
- mostly excitatory neurons projecting to GPi (glutamate)
Anterior Limb of Internal Capsule
carries thalamic + brainstem fibers from prefrontal cortex to regions associated w/ emotion, motivation, cognition, and decision-making
Posterior Limb of Internal Capsule
- contains corticospinal fibers and sensory fibers from body
- LTAF = leg, trunk, arm, face
