Physiology Flashcards
define the CNS
brain + spinal cord
what are the components of the PNS
12 CN
31 SN
+ branches
what percentage of cardiac output does the brain recieve
15%
what percentage of oxygen usage does the brain take?
20%
What are gyri, sulci and fissures?
gyrus = outward projection sulcus = inward projection fissure = deep sulcus
what is the other name for the Sylvian fissure
lateral fissure
what is the name of the fissure separating the 2 cortexes
cerebral interhemispheric
what is the function of the corpus callosum
communication between hemispheres
name the components of the brainstem in order from superior to inferior
midbrain, pons, medulla
what is the main function of the thalamus
relay centre
the LGN is part of what brain structure
thalamus
the thalamus, hypothalamus, subthalamus and epithalamus are collectively known as what?
diencephalon
what hormones does the hypothalamus synthesise
ADH, oxytocin
the hypothalamus has a role in hormone release from the _____
anterior pituitary
name the meninges from superficial to deep
dura mater
arachnoid
(subarachnoid space +CSF)
pia
what arteries does the anterior circulation arise from
internal carotid
what arteries does the posterior circulation arise from
vertebral arteries
the IC bifurcates into the ….
MCA and ACA
the ophthalmic artery is a branch of the ____
IC
the anterior choroidal artery is a branch of the ___
IC
what artery connects the right and left anterior cerebral arteries
anterior connecting artery
what artery supplies the medial cerebral hemispheres
anterior cerebral arteries
what artery supplies the lateral hemispheres, basal ganglia and the internal capsule?
middle cerebral artery
what artery runs in the sylvian lateral fissure
middle cerebral artery
the vertebral arteries are a branch of the _____
subclavian arteries
the vertebral arteries pass through the _____ of C_ to _
through transverse foramen of C6-C2
the vertebral arteries join to form the ____ at the _____
join forming basilar at pons
the posterior inferior cerebellar arteries are branches of the _____
vertebral arteries
what artery terminates at the interpeduncular cistern?
basilar artery
the superior and anterior inferior cerebellar arteries are branches of the _____
basilar artery
what artery supplies the thalamus and occipital lobe
posterior cerebral arteries
the pontine arteries are branches of the _____
basilar artery
what structure does the dural venous sinuses drain to
internal jugular vein
is the superior sagittal sinus is paired or unpaired?
unpaired
the superior sagittal sinus goes from the anterior falx cerebri to the _____
confluence of the sinuses
is the calcarine sulcus is on the anterior or posterior aspect of the brain?
posterior
the cingulate sulcus is in the midline or lateral brain surface?
midline
During foetus development, there are 3 primary vesicles which give rise to the brain, what are their names?
prosencephalon
mesencephalon
rhombencephalon
ROMan PRO MESsage
Name the lobes of the brain
parietal frontal occipital temporal insular limbic
What is the function of the insular lobe?
has a role in pain
the precentral gyrus of the frontal lobe contains the _____
motor cortex
the calcarine fissure of the occipital lobe contains the ____
visual cortex
the postcentral gyrus of the parietal lobe contains the _____
somatosensory cortex
the superior temporal gyrus of the temporal lobe contains the ____ and _____ on the dominant side
auditory cortex and wernicke’s area
what is the function of wernicke’s area
speech comprehesion
the inferior frontal gyrus of the frontal lobe on the dominant side contains _____
broca’s area
what is the function of broca’s area?
speech production
the micturition inhibition centre is part of which lobe?
frontal lobe
which lobe is responsible for executive function?
frontal lobe
which lobe contains the hippocampus
temporal lobe
what is the main function of the hippocampus
memory
which lobe contains the frontal eye feilds
frontal lobe
the amygdala is a part of the ____ system
limbic system
is the cerebellum directly above or below the tentorium cerebelli
below
does the cerebellum control ipsilaterally or contralaterally?
ipsilaterally
Name the structures that attach the cerebellum to the brainstem
superior, middle and inferior peduncles
Name the tree of white matter in the cerebellum
arbor vitae
Name the layers of the cerebellum from superficial to deep
outer molecular layer
middle Purkinje cell layer
inner granule cell layer
What is the name to the midline portion of the cerebellum?
vermis
What cell type sends efferents from the cerebellum
purkinje cells
Where to afferent inputs to the cerebellum arrive?
peduncles
What is the commonest cause of bilateral cerebellar disturbance?
Acute alcohol exposure
What type of information does the cerebellum receive and where doe sit send it?
receives sensory info for movement and sends it to thalamus
also sends intented motor
the cerebellum receives sensory info for movement, where does it send it?
thalamus
where does the cerebellum send intended motor information?
corticospinal tract
Is the basal ganglia a grey or white matter structure?
grey
Name the 5 components of the basal ganglia
caudate nucleus putamen globus pallidus subthalamic nucleus substantia nigra
Name the components of the striatum
caudate nucleus, putamen
Name the components of the corpus striatum
caudate nucleus, putamen, globus pallidus
Name the components of the lenticular nucleus
putamen, globus pallidus
Is the internal capsule a grey or white matter structure?
white
What is the function of the internal capsule?
Connects cerebellar hemispheres
What is the function of the direct pathway of the basal ganglia?
increases thalamus outflow to enhance movement
What is the function of the indirect pathway of the basal ganglia?
inhibits thalamus outflow to stop unwanted movement
Describe the main function and appearance of the substantia nigra?
dark streak in brainstem
produces dopamine
does the basal ganglia control ipsilaterally or contralaterally?
contralaterally
changed muscle tone, dyskinesia, tremor, chorea and myoclonus could all arise due to a lesion in the ______
basal ganglia
what structure produces CSF
choroid plexus of the ventricles
how much CSF is produced/absorbed a day
a pint
what structures does the cerebral aqueduct connect?
3rd and 4th ventricle
what structures does the interventricular foraminae of Monroe connect
3rd to lateral ventricles
dendrites convey graded electrical signals ____ to the neuron soma
passively
what part of a neuron contains the nucleus
body aka soma
neurons coma in different shapes; unipolar, pseudounipolar, bipolar and multipolar. what shape is a retinal neuron?
bipolar
neurons coma in different shapes; unipolar, pseudounipolar, bipolar and multipolar. what shape is a DRG?
pseudounipolar
neurons coma in different shapes; unipolar, pseudounipolar, bipolar and multipolar. what shape is a LMN?
multipolar
What is the most numerous cell type in the CNS?
glial cells
Name the 4 major types of glial cell
astrocytes
oligodendrocytes/Schwann cells
microglia
ependymal cells
There is no connective tissue in the CNS, what cell type instead takes on this role?
astrocytes
What is the shape of an astrocyte
a star
Name 3 of the roles of an astrocyte
blood brain barrier
homeostasis
support
Name the cells that produce myelin
oligodendrocyte in CNS
Schwann cell in PNS
Describe how the appearance of schwann cells and oligodendrocytes differs
oligodendrocytes have multiple branches attaching to multiple axons, whereas there is only 1 schwann cell for every segment of each axon
Name the gap in the myelin sheath of a nerve, between adjacent schwann cells
node of ranvier
What is the function of myelin sheaths and rodes of ranvier?
increase conduction velocity