T1L3 topography of the brain Flashcards
neurulation
- neuroectoderm receives signals from neurochord
- induces cells to thicken to form neural plate
- lateral edges of this fold in to make neural tube
neurochord location
within mesoderm
development of ns from:
- neural crest cells
- mantle layer
- ependymal layer
- lumen
neural crest cells:
- neurons and glia of sensory and autonomic ns
- cells of adrenal gland
- epidermis
- skeletal/connective tissue
mantle layer:
- becomes brain parenchyma
ependymal layer
- lines ventricles
lumen
- becomes ventricles and central canal
neural tube defects
- failure of anterior neuropore to close»_space; anencephaly (fatal)
- failure of posterior neuropore tube to close»_space; spina bifida (open vertebral canal)
development of the brain
expansion of cranial end of neural tube leads to 3 portions:
- prosencephalon > forebrain
- mesencephalon > midbrain
- rhombencephalon > hindbrain
these are primary vesicles
prosencephalon >
telencephalon > cerebral hemispheres
optic vesicles > eyes
diencephalon > thalamus/hypothalamus
these are secondary vesicles
mesencephalon >
eventually develops into midbrain
rhombencephalon >
metencephalon > pons/cerebellum
myelencephalon > medulla
these are secondary vesicles
see s6 x
forebrain and brainstem contents
forebrain:
- cerebral hemispheres
- diencephalon
brainstem:
- midbrain (mesencephalon)
- pons (metencephalon)
- cerebellum (metencephalon)
- medulla (myelencephalon)
grey vs white matter
grey- mainly neuronal cell bodies (eg cerebral cortex)white- mainly myelinated axons
telencephalon
- cerebral hemispheres (frontal, occipital, temporal, parietal)
- limbic system
- basal ganglia
80% of the cortex is involved with perception of the world and cognition
see s12 for functional areas
precentral vs postcentral sulcus
precentral = motor postcentral = sensory
corpus callosum
- white matter tract linking cerebral hemispheres
deep brain structures
limbic system (memory and emotion) basal ganglia (posture and voluntary movement)
limbic system
spans telencephalon and diencephalon includes: - cingulate cortex - fornix - hypothalamus - mammillary bodies - amygdala - hippocampus
fornix
- semi-circular white tract matter connecting hippocampus and mammillary bodies
hippocampus
looks like seahorse (hence the name)
- sits on floor of lateral ventricle
basal ganglia
series of interconnected nuclei at base of forebrain
corpus striatum > caudate nucleus
> lentiform nucleus > putamen
> globus pallidus
lentiform is lens shaped
caudate is c shaped and sits in lateral wall of ventricle
- lentiform nucleus sits lateral to caudate nucleus
worth looking at all these slides to learn to cross sections too
capsules
the internal capsule is major white matter tract
- connects cortex to brainstem
also an external capsule
diencephalon
thalamus and hypothalamus
- central location
thalamus:
- relays sensory information to cortex
- voluntary movement, personality, consciousness
hypothalamus: - inferior to thalamus homeostasis: - ANS and endocrine responses - involved in thermoregulation, feeding, drinking, circadian rhythms - receives input from limbic system - pineal and pituitary gland
brainstem contains
- cranial nerve nuclei
- respiratory and cardiovascular centres
- vomiting
- nuclei involved with motor control and sleep
- white matter tracts
midbrain
- cerebral peduncles (white matter tracts connecting pons with diencephalon)
- superior colliculus (eye movement)
- inferior colliculus (auditory)
- red nucleus (motor coordination between cortex and cerebellum)
- substantial nigra (part of basal ganglia- dopaminergic neurons)
pons
relays info to cerebellum
peduncle meanign
stalk like
