Neuroanatomy Flashcards
what three structures make up the brain stem
midbrain pons and medulla
as the brain develops what parts make up the 3 vesicle structure
forebrain, midbrain, hindbrain
what structures make up the peripheral nervous system
Cranial Nerves
Spinal Nerves
Ganglia (Dorsal root ganglia and autonomic ganglia)
what makes up grey matter
neuronal cell bodies
what makes up the white matter
myelinated axons
what is the function of the brain stem
creates a junction between the spinal cord and brain acting as a conduit for ascending and descending tracts. contains important reflex centers associated with control of respiration, heart rate, blood pressure and consciousness
how does the brainstem regulate consciousness
via extensive forebrain projections of a portion of the brain stem core, the reticular formation
what is the limbic system
interconnected structure in the telencephalon and diencephalon (sit on/around the top of the brainstem) - relates to brain structure that deal with emotion memory and basic drives
what are the 3 major components of the limbic system
hypothalamus
amygdala
hippocampus
which brain structure is considered the feeling/ emotional brain
the limbic system
what is the fornix (in the brain)
a bundle of whit ematter fibres that arches around the thalamus
what is the primary output node of the limbic system (what other connections)
Hypothalamus - with connections to the frontal lobes and brainstem and interactions with the pituitary gland for hormone production/ release
what does the hypothalamus do
maintains homeostasis by influencing the autonomic nervous system and managing the endocrine system. also regulates sexual motivation and other emotional behaviors (primary output of limbic system)
what lobe is the amygdala located in
temporal lobe
what are the two major inputs of the limbic system
amygdala and hippocampus
what is considered the fear centre of the brain
the amygdala
responsible for arousal, fear, excitement, anxiety, violence
what is considered the memory centre of the brain
hippocampus
where is cerebral spinal fluid produced
the choroid plexus in the cerebral ventricles
what are the three layers of the meninges
Dura mater (outer, tough) Arachnoid (web-like) Pia mater (inner, delicate)
where is the cerebral spinal fluid contained
in the subarachnoid space
what is the dentate gyrus
Part of the hippocampal formation. the first region where all sensory modalities merge together to form unique representations and memories that bind stimuli together, and thus, it plays a critical role in learning and memory. also maintains neural stem cells (NCSs) and neurogenesis into adulthood.
anatomical changes to this structure cause alzheimers disease
hippocampus; atrophy and degeneration
what structures make up the hippocampal formation
Hippocampus (CA1 - CA4), Dentate gyrus, and Parahippocampal gyrus (subiculum & entorhinal cortex)
what parts make up the parahippocampal gyrus
- Entorhinal cortex (input) (gateway between hippocampus & cortex)
- Subiculum (main output)
what is the trisynaptic circuit
3 interconnected afferent pathways, taking information into the hippocampus for processing – memory retrieval. Consisting of 3 cell groups: Granule cells in DG, Pyramidal cells in CA3, Pyramidal cells in CA1.
what are the three excitatory/glutaminergic synapses in the trisynaptic circuit
(synapse 1) Entorinal Cortex → DG via the perforant path
(synapse 2) DG → CA3 via mossy fibres
(synapse 3) CA3 → CA1 via Schaffer collaterals
what is the simplest form of nervous system sound in invertebrates
Nerve nets: Neurons exist in a ‘loose network’ to allow for contraction and expansion of the body cavity. Lack distinct central or peripheral regions. No associative activity, just reflexes. Nerve signals travel in both directions.
what is the simplest centralisation of the nervous system
A ring of neurons is located in the center with simple bundles of neurons (radial nerves) extending from the ring to the tip of each arm.
Radial nerves form nerve nets permitting coordinated movement of each arm and the tube feet located on the surface of the arm. (sea star- echinoderms)
what is the simplest emergence of the central nervous system
Cephalisation and formation of the primitive brain: In animals with bilateral symmetry, a clustering of neurons into ‘ganglia’ near head of animal form more complex systems to integrate incoming/outgoing signals (seeing, hearing, tasting, etc.) (C.elegans)
Nerve cords and trunks: With bilateral symmetry (flatworms, etc), 2 nerve cords run down the length of the body allowing more complex control of muscles for movement.
what structures of the brain tend to be conserved in vertebrates
olfactory lobe, cerebrum, optic lobe, cerebellum, medulla oblongata, spinal cord
define sulci
Infoldings of the cerebral hemispheres that form ‘valleys’ between the gyri
define gyri
Ridges of the infolded cerebral cortex
