General features of the brain Flashcards
What is sagittal plane?
splits the hemispheres
what is horizontal/transverse/axial plane?
separates the top from the bottom (cerebellum and brain stem below, cortex above_
what is the coronal/frontal plane?
splits the front from the back (frontal cortex at front and occipital cortex at the back)
what makes up the hindbrain?
medulla, pons and cerebellum
what makes up the midbrain?
tectum (superior and inferior colliculi) and cerebral peduncle (tegmentum and crus cerebri)
what makes up the forebrain?
diencephalon (thalamus and hypothalamus) and telencephalon (cerebral cortex, basal ganglia)
what is a neuropil?
feltwork of intermingled an dinterconnected neuronal processes space between the neuronal cells bodies
whats the difference between nuclei and ganglia?
nuclei in the CNs, ganglia in the PNS
whats the role of the frontal lobe?
- higher intellectual functions
- voluntary movement
- expressive language
where is Brocas area found and what does it do?
frontal lobe
articulation of speech
whats the function of the temporal lobe?
- primary auditory cortex
- memory processing
where is wernickes area and where is it found?
temporal lobe
speech comprehension and formulation
what happens in wernickes aphasia?
-speak in jumbled ‘word salad’ and others cannot understand
what happens in brocas aphasia?
- limited language but people can understand
whats the role of the parietal lobe?
-primary somatosensation
- maths
- spatial sense and nagivation
whats the role of the occipital lobe?
- vision
whats the role of the cerebellum?
motor control of equlibirium, posture and muscle tone
whats the role of the thalamus?
filter and relay station
whats the role of the basal ganglia?
modulator, motor and cognitive patterns generator
whats the inferior brachium?
auditory information from the medial geniculate body to the inferior colliculi
whats the superior brachium?
visual information form th elateral geniculate body to the superior colliculi
what are the two layers of the dura?
outer endosteal layer and inner meningeal layer
whats the role of the falx cerebri?
keeps the two hemispheres seperate
whats the tentorium cerebelli?
sheet of dura between cerebellum and occipital ples
what are the small calcified bumps important for CSF reabsorbtion called?
arachnoid granulations
what is typically the cause of extradural haemorrhage?
traumatic head injury
what is the typical cause of subarachnoid haemorrhage?
- stroke and vascular incidents
what artery supplies the anterior circulation of the brain?
internal carotid arteries
what supplies posterior circulation?
- vertebral and basilar arteries
what two major branches come from the carotid artery?
- anterior cerebral artery
- middle cerebral artery
what does the anterior cerebral artery supply?
supplies the corpus callosum and the medial territories of hemispheres
what are the anterior cerebral arteries joined by?
anterior communicating artery
what does the middle cerebral artery supply?
lateral territories of hemispheres
where does the middle cerebral artery run through?
middle of lateral fissure
what does the posterior circulation supply blood to?
- hindbrain and inferior and posterior regions of cerebrum
whats the final branch of the basilar artery and what does it supply?
- posterior cerebral artery
- supplies inferior and medial surface of temporal lobes and occipital lobes
which arteries supply the cerebellum?
- posterior inferior cerebellar arteries
- anterior inferior cerebellar arteries
- superior cerebellar artery
what joins the basilar to the internal carotid artery?
posterior communicating artery
what vein runs along the lateral fissure?
superficial middle cerebral vein
how does the venous drainage system work?
internal cerebral veins -> external cerebral veins -> dural sinuses
how are dural venous sinuses formed?
- endosteal and meningeal layers of dura separate and the spaces formed between these layers are venous sinuses
which sinus runs along the superior surface of falx cerebri?
superior sagittal sinus
which sinus runs along the inferior sagittal sinus?
inferior sagittal sinus
which sinus runs along the middle of the tentorium cerebelli?
straight sinus
whats it called when the straight sinus meets the superior sagittal sinus?
confluence of sinuses
whats the flow of blood after the confluence of sinuses?
transverse sinus -> sigmoid sinus -> jugular vein
clinical relevance of sinuses?
potential root of infection is the cavernous sinus
- contains 5 cranial nerves (2,3,4 and V2 of 5) and internal carotid
where does the carotid arteries enter the skull?
carotid canal
where does the vertebral arteries enter the skull?
foramen magnum
where does the sigmoid sinus leave the skull and what does it become?
- jugular foramen and becomes internal jugular vein
where does opthalmic arteries leave the skull?
optic canal with optic nerve
where does the middle meningeal artery pass through the skull?
foramen spinosum
Explain the parts of the lateral ventricle?
- anterior horn (goes into frontal lobe)
- inferior horn (goes into temporal lobe)
- posterior horn (goes into occipital lobe)
how are the 3rd ventricle and lateral ventricle connected?
intraventricular foramen (foramen of Munroe)
how are the 3rd and 4th ventricles connected?
cerebral aqueduct
what are oligodendrocytes?
-myelinating cells of CNS
-provide metabolic support for axons
what are the myelinating cells of the PNS?
Schwann cells
Apart from location whats a difference between oligodendrocytes and Schwann cells?
- oligodendrocytes can myelinate multiple axons
- Schwann cells can only myelinate single or single bundles of axons
what is BBB sensitive to?
inflammation. hypertension, trauma and ischaemia
what is BBB formed from?
- endothelial cells, astrocytes and pericytes
features of BBB?
- endothelial tight junctions
- astrocyte end feet
- pericytes
- continuous basement membrane (lack of fenestrations)
- need specific transporters for glucose, water (AQP4), essential ions
what are circumventricular organs?
- lack normal BBB as they are important for homeostasis and endocrine function
