Anatomy review Flashcards
Sagittal?
Plane that separates your eyes
Coronal?
Slicing the brain from front to back
Where does CSF go after circulating through brain?
subarachnoid space
What are convergence / divergence?
Convergence: Neurons receive input from a ton of other cellls
Divergence: Neurons send out the same input to a ton of other cells
What is an axon collateral?
Part of an axon that branches out
motor efferents
Also from mixed nerves.
Begin in ventral home of spinal cord, end on skeletal muscles. Send out motor commands.
choroid plexus
cells that produce CSF
What are sensory afferents composed of?
They come from mixed nerves (nerves with both motor neurons and sensory neurons)
Sensory (somatosensory) afferents go to the dorsal root ganglion from outside of cell. Neurons have somas in dorsal root ganglia, with dendrites receiving somatosensory info.
What does the autonomic nervous system control?
Internal environment (e.g. hearts, organs, etc)
What / where are the sympathetic ganglia?
Cluster of cell bodies, many of which are near the spinal cord
Have to do with acetylcholine/neuropenephrine innervating muscle fibers
What / where are the efferent parasympathetic neurons?
(parasympathetic: internal organs, relaxed state)
Located in the brain or the ventral horn of spinal cord
Where are the meninges?
Dura mater?
Arachnoid?
Pia mater?
Meninges: layers of tissue under the skull
Dura mater: Outermost layer, closest to skull
Arachnoid: weblike sublayer filled with CSF just below dura
Pia mater: Sits directly on nervous tissue
What is a hydrocephalic brain?
‘fluid brain’
too much CSF
What is a nucleus at the whole-brain level of anatomy?
Group of neurons with a common purpose
What happens as we go caudal to rostral?
Functions get more complex
What is the neuraxis?
Central nervous system in a single plane
What can the spinal cord - and only the spinal cord - do?
Reflexes
e.g. walking (mostly spinal cord!)
Circuitry in spinal cord act as pattern generators
Brain only starts running/walking etc!
If you were looking up at a cross section of spinal cord, what would you see?
Dorsal horns > SOMATOSENSORY (dorsal always somatosensory!) gray matter
Dorsal columns (convey touch info) white matter
Ventral horns > MOTOR
Ventral columns (motor info)
Dorsal root ganglia come out of dorsal horns (peripheral nervous system)
Gray matter on the inside surrounded by white matter
What brain part plays role in cardiorespiratory cycles,
Digesting, coughing, vomiting?
Medulla oblongata
Has medulary pyramids, which is where motor pathways split
What is the difference between pons and medula?
Pons has locus coruleus (neurepenephrine)
Gets input from dorsal column nuclei
Beginning of emotional control, sleep/wake cycle….
Medulla only gets ventral column nucleus input
You have two rats
One doesn’t have a neocortex
What’s the difference in behavior?
Novel behavior in the rats
Caudal/inferior areas still give the lesioned one ability to survive
What does ‘mesencephalon’ mean?
Midbrain
Why is the substantia nigra black?
Melanin accumulates as dopamine is metabolized!
What are the structures of the midbrain?
Tectum (roof)
Tegmentum (floor)
in tectum:
Superior colliculi: visual relay/blindsight
Inferior colliculi: auditory relay/auditory localization
in tegmentum:
Substantia nigra (habit learning, initiation of movement)
Ventral tegmental area (reward)
Periaqueductal grey (modulation of pain)
What structure distributes sensory information to cortex?
Thalamus. Gets input from caudal structures (e.g VTA, substantia nigra, etc)
What does the superior colliculus do?
Inferior colliculus?
Superior: Visual relay
Inferior: auditory relay
Where is the superior colliculus located?
Tectum (‘roof’) of midbrain - superior to the pons
What structure in the tegmentum helps with movement initiation and habit learning?
Substantia nigra
What structure in the tegmentum helps with reward?
VTA
Where is the midbrain pain modulator located?
periaquaductal grey
Located in tegmentum
What pathway originates in M1 and goes down?
What are the medullary pyramids?
Motor pathway.
M1 has descending corticospinal neurons.
Go down past medullary pyramid (where they cross, left/right hemisphere)
Down past spinal cord
Medullary pyramids are to motor system as optic chiasm is to visual system
What does the insula do?
Act as interface between old brain / new brain
Key role in many motivated behaviors
‘interface between body-state and brain-state’
What does the longitudinal fissure do?
What is the falx?
Separates hemispheres
Falx is some dura mater on the longitudinal fissure?
Saggital slice
Where is the central sulcus?
Separates frontal lobe and parietal lobe
Coronal slice
Where is the lateral fissure?
Separates frontal/parietal from temoral lobe
Horizontal slice
Parietal lobe functions
Somatosensation - sensory integration; appreciation of spatial representation
Take separate sensory components and unify them into one view of the world
Higher-order representations of similar stimuli
Temporal lobe function
Language, learning/memory, olfaction, audition
Frontal lobe function
everything leads here
What do VTA neurons do?
Where is nucleus accumbens / vta?
Denote rewarding properties of stimulus by releasing dopamine in the nucleus accumbens
VTA in midbrain
Nucleus accumbens much more forward - in forebrain
VTA connected to accumbens by a pathway (‘medial forebrain bundle’)
What proteins form gap junction between some neurons? Where?
Connexons can form gap junctions between two neurons
(happens earlier in the visual system)
Happens so that action potentials can propegate more quickly
What is a multipolar neuron?
Lots of dendrites, one axon
What is a bipolar neuron?
One dendrite, one axon
What is an apolar neuron?
No neurons or axons, only soma
What is a unipolar neuron?
Only one neuron leaving the cell body
