Neuroanatomy 1 Flashcards
how many pairs of cranial nerves?
12
how many pairs of spinal nerves and their branches?
31
name the 3 primary vesicles (initial swellings at 4 weeks)
prosencephalon
mesencephalon
rhombencephalon
what to the primary vesicles develop into?
prosencephalon - telencephalon - diencephalon mesencephalon - mesencephalon rhombencephalon - metencephalon - myelencephalon occurs at 6-8 weeks
what does the telencephalon become?
cerebral hemispheres
what does the diencephalon become?
thalamus
hypothalamus
what does the mesencephalon become?
midbrain
what does the metencephalon become?
pons
cerebellum
what does the myencephalon become?
medulla oblongata
what are the components of the brainstem?
midbrain
pons
medulla oblongata
what is the largest component of the brain?
cerebral hemispheres
what does the midbrain do?
connects larger cerebral hemispheres to everything else
everything (bar a few things) has to pass through it on way into brain
what are neurons?
communicators
receive info mainly via synapses
integrate the info then transmit electrical impulses to another neuron or effector cell
most are multipolar with may dendrites and one axon
what is the soma of a neuron?
cell body (including nucleus)
how is an axon defined?
carries info leaving the cell body
do all neurons have an axon?
no
neurons in retina don’t have axons
what are glial cells?
greek for “glue”
holds the brain together and gives structural integrity
more numerous than neurons in the CNS
what are the 4 types of glial cells?
astrocytes
oligodendrocytes
microglia cells
ependymal cells
what are astrocytes?
type of glial cell
many numerous processes (star-shaped)
involved in support, maintaining blood-brain barrier (induces blood brain barrier in capillaries of the brain to stop things from blood from accessing brain tissue), environmental homeostasis
no connective tissue in the CNS
what are oligodendrocytes?
produce myelin in CNS
(not in PNS)
have numerous branches which extend to wrap cell membrane (made of myelin) around axons of neurons
they have a round nucleus that is moderately stained
what does myelin do?
allows electrical impulse to skip between non-myelinated areas of the axons (nodes of ranvier)
hugely increases rate of conduction
what are microglia?
cells of similar lineage of macrophages (hemopoietic - from bone marrow)
immune monitoring and antigen presentation, but stay in the CNS and don’t move around the body
how do microglia change when activated by an antigen?
resting state = elongated nucleus with short, spiny cell processes
activated state = rounder, more like a macrophage
what are ependymal cells?
ciliated cuboidal/columnar epithelium that lines the ventricles in the CNS but generally do not form a barrier between the CSF and brain tissue
cilia wave in the CSF
fissure vs sulcus?
fissure is deeper
lateral fissures
great longitudinal fissure
gyrus vs sulcus?
gyrus = outward bumps sulcus = inward valleys
types of tissue in brain?
darker outer rind = grey matter (areas of grey matter also found in the core - thalamus etc)
paler inner core = white matter
what makes up grey matter?
huge number of neurons
where the cell bodies of neurons are found
cell processes, synapses and support cells
what make sup white matter?
axons and support cells
no nerve cell bodies in the white matter, just the axons projecting from the grey matter
grey vs white matter in the spinal cord?
grey matter forms “H” in the middle
white matter surrounds the grey matter
organisation of spinal cord?
anterior (ventral)horns = thicker ends of grey matter
anterior (ventral) colums = thicker columns of white matter
posterior (dorsal) horns = thinner ends of grey matter
posterior (dorsal) columns = thinner colums of white matter
lateral columns
important gyri and sulci?
central sulcus precentral gyrus (primary motor cortex) postcentral gyrus (primary sensory?)
what does the central sulcus do?
divides frontal and parietal lobes
divides primary motor and sensory cortexes
septum pellucidum?
divides the lateral ventricles
calcarine sulcus?
sits posteriorly
area for vision
what is the corpus callosum?
largest connection/communication between hemispheres
large band of white matter
sits above the fornix
what is the fornix involved in?
part of limbic system
involved in memory and emotion
where is the hypothalamus in relation to the thalamus?
infront and below
where is the 4th ventricle?
sticks out from behind pons/medulla
what gives the boundary between frontal and parietal lobe?
central sulcus
- extend line down to corpus callosum
location of parietal lobe?
posterior to central sulcus
superior to lateral sulcus (and a backward extension of it)
anterior to a line from the parieto-occipital sulcus to preoccipital notch
where is the occipital lobe?
posterior to the parieto-occipital sulcus
where is the temporal lobe?
inferior to the lateral sulcus
posterior border = line between parieto-occipital sulcus and pre-occipital notch
what is the 5th, hidden lobe?
insular lobe/insular cortex
hidden beneath the temporal lobe
what does the insular lobe do?
involved in experience of pain
what are the 3 layers of meninges?
dura mater > arachnoid mater > pia mater
from superficial to deep
what sits between the arachnoid and pia mater?
subarachnoid space containing CSF
describe dura mater?
periosteum of inner surface of the skull
very very tough membrane
describe arachnoid mater?
like a layer of cling film
describe pia mater?
1-2 cells thick covering of the brain
follows all bumps and indentations of the brain unlike the arachnoid mater, therefore a space forms between them
where is CSF found in the brain?
subarachnoid space
ventricles
some then flows down canal through spinal cord
describe path of CSF movement?
lateral ventricles > IV foramen > 3rd ventricle > cerebral aqueduct > 4th ventricle > out into subarachnoid space/down spinal cord
what is the 3rd division of the nervous system?
enteric
found in digestive system from oesophagus to rectum
neurons in 2 plexuses in the walls of gut (myenteric between outer layers of smooth muscle and submucosal in the submucosa)
controls motility in the digestive system
