Neuroanatomy Flashcards
What are the brain’s functions?
receives info about the world, integrates the info, and then produces behaviour
What is the difference between efferent and afferent nerves?
afferent carries signals to the CNS, and efferent carries signals away from the CNS
Are sensory pathways afferent or efferent? What about motor pathways?
sensory is afferent, motor is efferent
What is neural plasticity?
brain volume can change in response to experiences, and the connectivity between certain neurons can also change over time
What is the difference between dorsal and ventral?
dorsal is from the top and ventral is from the bottom
What is the difference between lateral and medial?
lateral is towards the sides, medial is closer to the middle
What is rostral vs caudal when talking about the brain mean?
rostral (means beak) is part of the brain near the front, caudal (means tail) is part of the brain near the back
What is anterior vs posterior?
anterior is at the front and posterior is the back
What do coronal sections of the brain look like?
vertical cuts of the brain, shows the front of structures in the brain
What do horizontal sections of the brain look like?
horizontal cuts of the brain, shows the dorsal view of structures in the brain
What do sagittal sections of the brain look like?
splitting the brain in half down the middle, shows medial view of the brain
What is the function of the meninges?
they protect the CNS
What are the layers of the meninges?
dura mater (hard outermost layer), arachnoid (middle layer, looks like spider web), pia mater (soft innermost layer)
What is meningitis?
bacteria reaches the dura mater and releases a toxin which causes nerve cells to release CGRP which disables immune cells, dangerous infection of meninges
What is the difference between the gyrus and sulcus?
gyri is the outer folds of brain, sulci is the inner folds of brain
What is sulcus vs fissure?
fissure is a big groove which separates parts of brain
What are the four lobes of the brain?
frontal, parietal, occipital, temporal
What does the frontal lobe do?
voluntary movement, expressive language and for managing higher level executive functions
What does parietal lobe do?
helps integrate and percept sensory information
What does occipital lobe do?
helps with vision
What does temporal lobe do?
deals with language and hearing
What is white matter vs grey matter?
white matter looks lighter than grey matter, white matter neurons axons have a myelin sheath, grey matter is mostly cell bodies, white matter is on the inside of grey matter
What is the corpus callosum?
bridge of neurons that connects the two hemispheres of the brain
What are ventricles in the brain? How many are there?
they are filled with cerebral spinal fluid and act like a cushion for the brain and they help keep the brain buoyant
there are four ventricles in the brain
What is the midline of the brain? What structures straddle it?
a fissure down the center of the brain that divides the two hemispheres
3rd and 4th ventricles and the pineal gland
What are the three major arteries of the brain? Where are they generally located?
anterior cerebral artery (at the top of the brain), middle cerebral artery (the middle lateral part of the brain), posterior cerebral artery (bottom of the brain)
Why are knowing the locations of the major arteries of the brain important in case of strokes?
lets us know which areas of the brain will be affected by a stroke
What are the two types of strokes?
ischemic strokes (narrowing of blood vessels by clot), hemorrhagic strokes (rupturing of blood vessel)
What is the blood brain barrier?
surrounds and protects the CNS, helps maintain a constant environment for your brain
What does the blood brain barrier allow to diffuse?
small hydrophobic molecules (O2, some hormones, CO2) and lipid soluble molecules (heroin, cannabis, anti-depressants, vitamins)
What is the blood brain barrier made up of?
endothelial cells, pericytes, capillary basement membrane, and astrocyte end feet which bring nutrients to cells
What are the parts of the central nervous system?
brain and spinal cord
What are the parts of the peripheral nervous system?
somatic nervous system, autonomic nervous system, enteric nervous system
What are the parts of the somatic nervous system?
cranial nerves, spinal nerves
What are the parts of the autonomic nervous system?
sympathetic nervous system and parasympathetic nervous system
What is the enteric nervous system?
regulates the gut
Can the spinal cord act independently of the brain? Examples?
yes, reflexes
What is the brainstem? What are the regions?
where the brain turns into the spinal cord
hindbrain, midbrain, diencephalon
What is the hindbrain?
oldest part of the brain that controls motor functions like breathing, balance, and fine motor movement
What are the parts of the hindbrain?
cerebellum, reticular formation, pons, medulla
What is the reticular formation for?
part of the brain that lets us fall asleep and wake up, and arousal
What is the pons for?
bridge that connects the forebrain to the cerebellum, some facial movements
What is the medulla for?
regulates breathing, heartrate, basic life functions
What are the regions of the midbrain?
tectum and tegmentum
What is the tectum?
the roof of the midbrain, handles visual and auditory processing (superior/inferior colliculi), and produces orienting movements (hearing someone call you and looking)
What is the tegmentum?
floor of the midbrain, eye and limb movements (red nucleus and substantia nigra), and perception of pain
What are the parts of the diencephalon?
epithalamus which includes the pineal gland, thalamus, hypothalamus, subthalamus
What is the thalamus for?
helps bring info together, all sensory info except for smell passes through the thalamus, also helps transfer motor info
What is the hypothalamus for?
important for emotion, temperature, eating, drinking, sexual behaviour, homeostasis
What is the epithalamus for?
acts as a connection between the limbic system and other parts of the brain, pineal gland is part of this
What is the subthalamus for?
movement regulation
What does diencephalon mean?
between brain
What is the cerebellum for?
finely coordinated movements, might be used for cognitive things (doing a motion when seeing a certain thing)
What are some similarities between the cerebellum and cerebral cortex?
both have left/right hemispheres, folded cortex, subcortical nuclei
What is the densest part of the brain?
cerebellum
What are the parts of the forebrain?
neocortex (cerebral cortex), basal ganglia, allocortex
What is the function of the neocortex?
higher order behaviours (cravings, lust, words, images, perception)
What makes up the allocortex?
hippocampus, amygdala, cingulate cortex, limbic system, olfactory system
What are the parts of the olfactory system?
olfactory bulb, receptors, pyriform cortex, vomeronasal organ (VNO)
What is the function of the limbic system?
core part of emotional centre of brain
What is the function of the cingulate cortex?
emotion formation and processing, learning, memory, linking behaviour to emotion
What is the basal ganglia?
caudate, putamen, globus pallidus
controls voluntary and involuntary movement, associated w/tourettes and parkinsons
What are the 12 pairs of cranial nerves?
olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibular, glossopharyngeal, vagus, accesory, hypoglossal
What are the 5 categories of vertebrae?
cervical, thoracic, lumbar, sacral, coccygeal
What is the difference between posterior and anterior nerve fibers in the spine?
posterior fibres are afferent, sensory neurons (dorsal horn of spinal cord)
anterior fibres are efferent, motor neurons (ventral horn)
What does the sympathetic NS do? What about parasympathetic?
sympathetic: dilates pupil, stops digestion, increase heartrate, increase breathing, stops saliva
parasympathetic: constrict pupil, start digestion, slow heart/breathing, allows for slaiva
How are the brain and ENS connected?
ANS and vagus nerve
What are the two main types of cells in nervous system?
neurons and glial
What are axon bundles called inside and outside of the CNS?
inside called fibre tracts, outside called nerves
What are types of interneurons?
stellate cell (small w/many dendrites around cell body), pyramidal cell (long axon, pyramid cell body, two sets of dendrites), purkinje cell (very branched fan like dendrites)
What are the main parts of a neuron?
dendrites, axon, cell body
What are dendritic spines?
extend off dendrites, increase surface area, usually point of contact for axons
What are the parts of an axon? Describe them?
hillock (junction of cell body and axon, where action potential begins), collaterals (branches of axon), teleodendria (end branches of axon), terminal button (at tip of axon, conveys info to other neurons)
What do association neurons do?
integrate info from different places
What is excitatory vs inhibitory?
on vs off (active vs not active)
What are types of glial cells?
ependymal, astrocytes, microglial, oligodendroglial, schwann
What do ependymal cells do?
secrete CSF, help move it around
What do astrocytes do?
contributes to nutrition, support, and repair, also makes tight junctions in BBB
What do microglial cells do?
defensive function to remove dead tissue (macrophage)
What do oligodendroglial cells do?
form myelin around axons in the CNS
What do schwann cells do?
form myelin around nerves in PNS
What are the steps in neuronal repair?
- peripheral axon is cut and the axon dies
- schwann cells shrink and divide, forming glial cells along the former path off axon
- neuron sends out axon sprouts, which find schwann cell path and make new axon
- schwann cells then myelinate the new axon
What is the function of the cell membrane?
separates intra/extracellular fluid, regulates movements of substances in/out of cell
What is the cell membrane made up of?
phospholipids (hydrophilic head, hydrophobic fatty acid tails)
What is the nucleus?
contains 23 pairs of chromosomes, contains genes
What are the basic steps of protein synthesis?
- dna uncoils to expose gene tha encodes a protein
- one strand of gene is used as template for transcribing mRNA
- mrna leaves the nucleus and comes in contact with ribosomes in ER
- ribosome moves along mrna and translates codon into amino acids
What are the levels of protein structure?
primary (amino acid sequence), secondary (alpha helix, beta sheet), tertiary (fold upon itself), quaternary (multiple polypeptides)
What packages and what transports proteins in the cell?
golgi bodies, microtubules
What is the differences between a channel, gate, and pump?
channels use diffusion, gates can be switched from open to closed, pumps use active transport
Give an example of a recessive and dominant genetic disroder that affects the brain?
Tay-sachs (loss of gene for breaking down fatty substance)
huntingtons (increase in CAG repeats of 4th chromosome, makes protein that attacks brain cells)
What are some approaches to genetic engineering?
selective breeding, cloning, trasngenic techniques, knockouts
