Neuroanatomy Lecture 1 Flashcards
What is neurulation? When does it occur?
central ectoderm –> neural plate –> neural tube, occurs in week 4
What are two growth signalling factors involved in neurulation?
Shh and BMP
What are the two ways in which the neural tube forms?
primary and secondary (sacrum) neurulation
What tissues develop into the neural tube in primary neurulation? What is primary neurulation?
epithelium (invagination of epithelium)
What tissues develop into the neural tube in secondary neurulation? What is secondary neurulation?
mesenchyme (mesenchyme condenses into a tube, then transitions to epithelium)
When does the neural tube close (what days of development)?
19-21
What are the five waves of neural tube closure?
- thoracic region. 2. skull 3. face 4. back of the neck 5. sacral region
What needs to occur for complete CNS formation?
closure of rostral and caudal neuropores
What is anencephaly? What is it caused by?
lack of skull and cerebrum formation, no brain, caused by failure of the second wave closure over the head
What are three types of spina bifida?
Spina bifida occulta, meningocele, meningomyelocele
What causes spina bifida?
incomplete closure of the caudal neuropore, at the junction of waves 1 and 5 (junction of primary and secondary neurulation)
What is the rhombencephalon? What two structures does it form?
the hindbrain, forms the medulla (myelencephalon) and the pons (metencephalon)
What is the mesencephalon?
the midbrain
What is the prosencephalon? What 3 structures does it develop into?
the forebrain, develops into the telencephalon (cerebral hemispheres), the optic vesicle and the diencephalon (thalamus, hypothalamus and epithalamus)
What does the diencephalon develop into?
the thalamus, hypothalamus and the epithalamus
What are the two flexures of the brain during development?
the cephalic flexure and the pontine flexure
What structure develops into the cerebellum?
the Pons
What are the three areas of grey matter (Rexed’s Lamina)?
Dorsal (sensory), Intermediate (autonomic), and Ventral (motor)
Once sensory stimuli reach the dorsal horn of the spinal cord, where can second order neurons send information?
to local spinal areas and ascend to brainstem and thalamus
What kind of neurons are in the intermediate region of grey matter in the spinal cord?
preganglionic autonomic neurons (visceral motor neurons)
What kind of neurons are in the ventral horn of grey matter in the spinal cord?
efferent motor neurons to skeletal muscle (somatic motor neurons)
What are the three funiculi of white matter of the spinal cord?
dorsal, ventral, lateral
What are the two fasciculi of the dorsal funiculus? What do they do?
the cuneate and the gracile fasciculi; carry tactile information to the brain stem and the thalamus
What three areas are in the lateral funiculus? What do they do?
Lateral corticospinal tract (descending tract from the cortex); Spinocerebellar tracts (ascending tactile and proprioceptive info to the cerebellum); Anterolateral system (ascending pain and temperature to thalamus)
What are two areas of the ventral funiculus? What do they do?
Anterior (ventral) corticospinal: descending motor from cortex
vestibulospinal and reticulospinal: descending motor from the brainstem
What is the propriospinal tract?
surround the grey matter, interconnects spinal levels but does not go to the brain
What are the three parts of the brainstem?
medulla, pons, midbrain
What six regulatory centers are in the brainstem?
urinary bladder control; pneumotaxic center; cardiac acceleration and slowing; respiratory center; vomiting center; swallowing center
What are the cerebellar peduncles?
input and output tracts that connect the cerebellum to the pons
What are five functions of the cerebellum?
muscle coordination, motor planning, procedural memory, balance, eye movements
What are four structures within the medulla?
substantia nigra, periaqueductal grey, superior/inferior colliculi and the red nucleus
What do the superior and inferior colliculi do?
superior looks, inferior listens
What does the red nucleus do?
part of the descending motor pathway
What does the periaqueductal grey do?
regulates pain, stress responses and threat responses
What does the substantia nigra do?
dopamine modulator of motor control; addiction center
What are the cerebral pundicles? Where are they?
sensory and motor tracts connecting spinal cord, brain stem and cortex; in the midbrain
The diencephalon is technically a part of what part of the brian? (forebrain, midbrain or hindbrain)
forebrain
What does the thalamus do?
process and distribute sensory and motor information to and from the cortex. underlies consciousness and awareness
The hypothalamus communicates with what three structures?
spinal cord, cortex and the pituitary (endocrine pathway)
What tissue does the anterior pituitary derive from?
primordial ectoderm from gut tissue
What is the adenohypophysis?
anterior pituitary from gut tissue (ectoderm)
How does the adenohypophysis communicate with the hypothalamus?
via portal circulation
What tissue does the posterior pituitary derive from?
the neural tube
What is the neurohypophysis?
the posterior pituitary from the neural tube
How does the neurohypophysis communicate with the hypothalamus?
neuronal communication
What does the frontal lobe do?
motor cortex (primary, premotor, supplementary); Broca’s speech area; behavior, ideas, integration of memories/emotion into action
What does the parietal lobe do?
somatosensory cortex (primary, secondary, association); Wernicke’s language area, egocentric
What does the temporal lobe do?
auditory cortex (primary, secondary and association)
What does the occipital lobe do?
visual cortex (primary, secondary and association)
What does the Insula do?
gustatory, visceral, emotional cortex (gut feelings)
What separates the frontal from the parietal lobes?
central sulcus
What separates the frontal from the temporal lobes?
lateral fissure
What is the reticular formation? What is it associated with?
general sensory input sent to the cortex and limbic structures. associated with arousal, attention, motivation and wakefulness
What makes up the basal ganglia?
The striatum and globus pallidus; substantia nigra and subthalamus
What two structures make up the striatum?
caudate and the putamen
What does the basal ganglia do?
habits, learning, easily stimulate significant or frequently stimulated areas (muscle memory?)
What is the limbic system associated with?
personality, nature of behavior, sense of self
What structures are a part of the limbic system?
Limbic cortex, anterior and medial dorsal thalamic nuclei, hippocampus, amygdala, ventral striatum (of the basal ganglia)
What are three parts of the limbic cortex?
orbital and medial prefrontal cortex; cingulate gyrus; parahippocampus
What is the white matter of the cerebrum made up of?
axonal bundles that communicate cortical regions
What are arcuate fibers?
axonal bundles in white matter that interconnect local gyri
