Central Nervous System Flashcards
what is the CNS composed of?
brain and spinal cord
what is the PNS composed of?
nerves (cranial and spinal), and ganglia outside of the brain and spinal cord
what are the three main parts of the brain?
forebrain, midbrain and hindbrain
what is the forebrain composed of?
cerebral hemispheres and diencephalon
what is the hindbrain composed of?
pons, medulla and cerebellum
what does the diencephalon consist of?
thalamus and hypothalamus (underneath the thalamus)
where does the pituitary gland sit?
inferior to the hypothalamus (green)
what are the three parts of the brainstem in descending order?
midbrain, pons, medulla
what does the frontal lobe do?
regulate and initiate
- motor function,
- language,
- cognitive functions (executive function [planning] , attention and memory)
what doe the parietal lobe do?
sensation (touch and pain), sensory aspects of language, spatial orientation and self perception
what doe the temporal lobe do?
process auditory information
what does the occipital lobe do?
processesd visual information
where is the central sulcus?
between frontal and parietal lobes
where is the lateral fissure?
along temporal lobe, separating it from frontal and parietal
where is the parieto occipital sulcus?
runs along edge of occipital lobe separating it from parietal and temporal lobes
what does the limbic lobe contain?
what is it concerned with?
amygdala, hippocampus, mamillary body and cingulate gyrus
learning, memory, emotion, motivation and reward
which lobe lies deep to the lateral fissure?
insular cortex
what is the insular cortex concerned with?
visceral sensations, autonomic control, interoception, auditory processing, visual-vestibular integration
what are the three layers of the meninges?
dura, arachnoid, pia mater
which two layers is the dura composed of?
periosteal (layer of periosteum)
meningeal (durable, dense, fibrous membrane)
where is the cerebrospinal fluid in relation to the meninges?
sub arachnoid space
where is cerebrospinal fluid produced?
modified epithelial cells in choroid plexus of lateral, 3rd and 4th ventricles
where is cerebrospinal fluid located?
ventricles and sub arachnoid space
how many mls of cerebrospinal fluid produced per day?
125ml-500ml
where does CSF exit the ventricular system?
The ventricular system contains three small openings: the two lateral foramina of Luschka and the median foramen of Magendie. Through these openings the cerebrospinal fluid enters the subarachnoid space.
what are the bumps called that you find at the surface of the superior sagittal sinus?
arachnoid villi (granulations)
what do the arachnoid villi do?
reabsorb cerebrospinal fluid
where does the sub arachnoid space become continuous with the superior sagittal sinus?
arachnoid villi
describe the appearance of the arachnoid villi
cauliflower-like projections
how does CSF differ to blood plasma?
lower pH
less glucose
less protein
less potassium
from the spinal cord, does the dorsal root contain afferent or efferent nerves?
does the ventral root contain afferent or efferent nerves?
afferent/sensory
efferent/ motor
name these
- dorsal rootlets
- dorsal root
- dorsal root ganglion
- mixed spinal nerve
- dorsal horn
- grey matter
- ventral horn
- white matter
- ventral rootlets
- ventral root
posterior raymus contains what?
large anterior part - goes to most of muscles and skin
small posterior part - muscles down back of spine and skin of spine
many types of fibres but different in number
what is the spinal cord composed of?
segments which give each rise to a pair of mixed spinal nerves
how many nerves are…
cervical?
thoracic?
lumbar?
sacral?
coccygeal?
8
12
5
5
1
where do the nerves emerge?
intervertebral foramina
how do vertebral levels and spinal levels differ
the further down the spinal cord you get, the lower down the vertebrae get from the spinal cord
how does the relationship between nerves and foramina change between cervical and thoracic regions?
nerves C1-C7 emerge above vertebrae
nerves C8 to Co1 emerge below vertebrae
so above C7 vertebra lies C7 nerve and below it lies C8 - there are 8 nerves but only 7 vertebrae
what are the two spinal cord enlargements?
why are they larger?
C5 cervical enlargement (towards top, innervation of upper limbs)
L2 lumbar enlargement (towards bottom, innervation of lower limbs)
huge amount of innervation going in and out