Neuroanatomy Flashcards
What are the 5 lobes of the brain?
Frontal Parietal Temporal Occipital Limbic
What is the role of the frontal lobe?
Executive function - planning and decision making
Behavioural traits
Praxis - purposeful learned movement
Primary motor cortex - voluntary movements
Brocas area - speech (word formation and saying them)
What is the role of the parietal lobe?
Sensory cortex - integrates sensory inputs
Object recognition
post central gyrus - conscious feelings of touch
What is the role of the occipital lobe?
Vision, contains the visual cortex
What is the role of the temporal lobe?
Primary auditory cortex (hearing)
emotions
learning and memory
Where is the limbic lobe/ system located?
Deep to the temporal lobe
What is the role of the limbic system?
Emotions
behaviour
smell
Associated with PTSD
What is the role of the cerebellum?
Coordination and balance
Longitudinal fissure
Separates the left and right hemispheres, stops at the corpus callosum
What is a sensory homunculus
A pictorial representation of the primary somatosensory cortex
Broca’s area
Speech formation
Wernicke’s area
Speech understanding, located in the temporal lobe near the parietal lobe
Where are the speech areas normally located?
Left hemisphere, but in some people they are in the right .
What is dysphasia?
A deficiency in the formation / generation or comprehension of speech caused by a brain disease or damage. Receptive or expressive. Site of problem = speech centres - brocas or wernickes areas
Broca’s dysphasia
Motor. expressive aphasia
inability to produce the words
limited effect on comprehension
Wernicke’s dysphasia
Receptive/ sensory aphasia
speech is unaffected
speech is meaningless as they are unable to comprehend what they are being asked.
Dysarthria
problems with the mechanical creation of words. Occurs in the motor neural pathway - upper/ lower or NMJ or pharyngeal muscles
Dysphonia
Problems in production of sound for speech. Occurs in motor pathway or vocal cords .
What is found within the brainstem?
Respiratory, cardiovascular and vomiting centres
Nuclei involved in motor control, sleep, respiration and bladder control
What are the 3 parts of the brainstem?
Midbrain
Pons
Medulla
What is the cardiovascular centre?
Responsible for regulation of heart rate, found in the medulla oblongata
Respiratory centre
made up of 3 major groups - 2 in medulla and one in pons. Its main function is to control the rate of involuntary respiration
For voluntary respiration the motor cortex controls it. Voluntary respiration can be overridden by involuntary
Pons
Contains nerve tracts - ascending and descending. Nerves of different pathways cross over at the medulla .
Medullary pyramids
2 pyramid shaped swellings on the medulla oblongata, on either side of the ventral midline.
What are the 2 paired arteries that supply the brain?
Vertebral and Internal carotid
What do the vertebral and internal carotid arteries form?
Circle of Willis
What is the blood supply to the midbrain?
Basilar superior cerebellar
What is the blood supply to the pons?
Pontine
What is the blood supply to the medulla?
Anterior spinal artery
Regional blood supply
Anterior cerebral supplies the very front of the frontal cortex. The middle cerebral artery supplies the majority of the cerebral cortex. The posterior cerebral artery supplies the posterior of the parietal, occipital and inferior of the temporal lobes.
Anterior cerebral supplies all the centre of the brain up to corpus callosum and posterior cerebral supplies the posterior section.
Which artery is stroke most common in?
Middle cerebral - affects speech
Arteries supplying the spinal cord
3 - 1 anterior and 2 posterior.
Where does the anterior spinal artery originate?
Branches off the vertebral arteries
Where do the posterior spinal arteries originate?
Vertebral or posteroinferior cerebellar artery
Venous drainage of spinal cord
Anterior and posterior spinal veins drain into the internal and external vertebral plexuses
What are the 2 types of stroke?
Haemorrhagic and ischaemic
Ischaemic stroke
Obstruction within the blood vessel supplying the brain due to atherosclerosis
Haemorrhagic stroke
weakened blood vessel ruptures and bleeds into the brain. Blood accumulates and compresses the brain tissue
How to treat haemorrhagic stroke
Reverse existing anticoagulant treatment
Give clotting factors and vitamin K
How to treat ischaemic stroke
Thrombolytics e.g. altepase injection
How to differentiate between the 2 types of stroke?
CT scan
management of stroke
aspirin for life
What is a TIA
Transient Ischaemic attack - mini stroke
What are the signs of a stroke
Facial weakness
Arm weakness
speech problems
What are the cranial nerves?
olfactory optic oculomotor trochlear trigeminal abducens facial vestibulocochlear glossopharyngeal vagus accessory hypoglossal
How many branches does the trigeminal nerve have and what are they
3
Opthalmic
Maxillary
mandibular
What nerves do through the cribriform plate?
Olfactory
What nerves go through the optic canal
optic
What nerves go through the superior orbital fissure
Occulomotor
Trochlear
V1 - opthalmic
Abducens
What goes through the foramen rotundum?
V2 - maxillary
What goes through the foramen ovale?
V3 - mandibular
What goes through the foramen lacerum?
arteries, no nerves
What goes through the foramen spinosum?
Middle meningeal artery
What goes through the internal acoustic/ auditory meatus?
Vestibulocochlear and facial nerves
What does through the jugular foramen
Glossopharyngeal
vagus
accessory
nerves
Venous drainage of the brain
Drained by sinues that are hollow cavities in the skull where deoxygenated blood drains into. They are like veins but do not have valves
Main sinuses of the brain
Superior sagittal sinus Inferior sagittal sinus Straight sinus Transverse sinus Sigmoid sinus
What is found at the back of the head?
Confluence of the sinuses, where the sinuses all connect
Where do the sinuses drain into?
The internal jugular vein
What are the layers that cover the brain?
Dura mater
Arachnoid mater
Pia mater
what is the dural sinus
hollow spaces that collect pools of blood and drain into the internal jugular vein
Where are dural sinuses found?
Between the layers of the dura mater - periosteal and meningeal layers
How many sinuses are there?
11
Route through sinuses
Converge at confluence of sinuses > transverse sinus > sigmoid sinus > Internal jugular vein
Where are the straight, superior and inferior sagittal sinuses found?
Falx cerebri of dura mater
Straight sinus
A continuation of the great cerebral vein and inferior sagittal sinus
What does the cavernous sinus drain?
drains the ophthalmic veins and can be found either side of the sella turcica
What goes through the hypoglossal canal
Hypoglossal nerve
What is a cerebral venous sinus thrombosis
The presence of a thrombus within one of the dural venous sinuses. Venous return is occluded through the sinuses and causes an accumulation of deoxygenated blood and cerebrospinal fluid which can no longer drain .
How is cerebral venous sinus thrombosis treated?
Anticoagulation
What can accumulation of blood and cerebrospinal fluid cause?
Venous infarction
What are the symptoms of venous infarction?
Headache, nausea and vomiting
neurological defects
How is venous infarction diagnosed?
CT or MRI scan
What innervates the meningeal layers?
Middle meningeal artery and trigeminal nerve
If there was pain due to stretching of the meningeal layers as a result of a haemorrhage where would the pain be referred to?
Face and forehead
What innervates the dura mater below the tentorium
Cervical plexus, so pain is referred to the back of the head and neck
Arachnoid mater
No innervations
beneath the arachnoid is the subarachnoid space - where the CSF is contained. Arachnoid granulations reabsorb CSF from the dural sinuses
Dura mater
Has no innervations and is avascular
has 2 layers periosteal and meningeal
Pia mater
Underneath the subarachnoid space
tightly adhered to the surface of the brain - follows the gyri and fissures
Highly vascularised - vessels which supply the underlying neural tissue
Spinal meningeal layers
Dura mater - periosteal and meningeal layers join together
Arachnoid mater
Pia mater
What are the extensions of the dura mater that divide the brain?
Falx cerebri
Tentorium cerebelli
Falx cerebelli
Tentorial notch
Falx cerebri
In the longitudinal fissure between the cerebral hemispheres
Tentorium cerebelli
Separates the cerebellum from the occipital lobes
Falx cerebelli
Separates the 2 cerebellar hemispheres
Tentorial notch
An opening that is bounded by the anterior border of the tentorium cerebelli
Intracranial haemorrhage
Increases intracranial pressure
What are the types of Intracranial haemorrhage?
Epidural hematoma
Subdural hematoma
Subarachnoid hemorrhage
Intracerebral hemorrhage
Epidural hematoma
Blood accumulates between the skull and periosteal layer of the dura