Brain Anatomy Flashcards
What is gastrulation?
The process in embryonic development through which the gut develops.
Give a brief explanation of how the CNS develops in an embryo.
Around week 3 in development part of the ectoderm thickens to form the neural plate.
The plate starts to fold upwards and towards itself creates a neural groove in the middle.
The sides of the grooves called the neural folds come together and meet at the top. This fusion creates the neural tube which will eventually become the brain and the spinal cord.
Encephilisation then occurs
What is encephilisation?
Occurs during embryogenesis
The neural tube reshapes and buldges to form three primary vesicles.
The prosencephalon (forebrain)
The mesencephalon (midbrain)
The rhombencephalon (hindbrain)
And the final section of the tube becomes the spinal cord.
What happes to the prosencephalon in the development of the forebrain?
Evaginates to produce two secondary brain vesices calles the telencephalic vesicles. These branch out of the ‘stem’ diencephalon which has optic vesicles.
What does the telencephalon develop into?
Cerebral cortex and basal ganglia
What does the diencephalon develop into?
The hypothalamus
The thalamus
The retina
What does the hindbrain develop into?
The cerebellum, pons and medulla.
How does CSF flow from the lateral ventricle into the spinal canal?
The lateral ventricle flows into the third ventricle.
Flows into the cerebral aqueduct into the fourth ventricle then into the spinal canal.
What areas of the human brain are significantly enlarged?
Mainly the cerebral cortex, lots of sulcus and gyrus allow more neural connections to fit into the skull.
The cerebellum is also well developed.
What are the brain flexures in embryology?
The cephalic flexure - in the mesencephalon bends allowing the cerebral cortex into the skull
The cervical flexure - in the rhombencephelon allows the spinal cord down the brack
The pontine flexure - fold between the metencephalon and the myelencephelon.
Why does the cerebellum and cerebral cortex grow rapidly to dominate the postnatal CNS?
Proliferation of neural progenitor cells.
What are the different cortical lobes in the brain?
Broadly speaking each lobe processes different types of information and has different functions.
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Insula.
What are the basal ganglia?
What is their function?
Nuclei located deep to the cerebral hemispheres
Main role is in motor processing, may also help in motor learning, emotional regulation, reward and reinforcement of ideas.
Consists of the caudate, putamen, ventral straitum, globus pallidus and the ventral pallidum.
What is the ventral straitum?
Layers of grey and white matter connecting the caudate and the putamen??
Containes the nucleus accumbens.
What is the dorsal striatum?
A combined name for the caudate and the putamen.
What structures are located inferior to the thalamus?
The subthalamic nucleus
The substantia nigra
What is important about the substantia nigra?
Is the first area of nerves to die in parkinsons disease.
Key area for the production of dopamine.
What is the ventral palladium?
Part of the basal ganglia
Located inferior to the nucleus accumbens and globus pallidus.
How does the structure of the globus pallidus split?
Splits into the external and internal nuclei.
What does the substantia nigra split into?
Pars compacta and the pars reticulata.
What makes up the brain stem?
The midbrain
The pons
The medulla
What section of the brain and the third and fourth ventricle in?
Third ventricle is in the diencephalon (forebrain).
Fourth ventricle sits in the hindrain
Connected by the cerebral aqueduct in the midbrain.
What is the function of the thalamus?
Controls the relay of information between the brain hemispheres and the spinal cord.
What is the function of the midbrain?
Involved in visual and auditory reflexes dorsally
Involved in motor functions ventrally.
What is the function of the pons?
The point of communication between the cerebellum and the rest of the CNS
What is the function of the medulla oblongata?
Co-ordinates subconscious sensorimotor integration.
What is the function of the cerebellum?
Is the motor control centre
Clinical test of function is the finger to nose
Role in proprioception and motor commands
Conditions of the cerebellum often struggle with balance and co-ordination.
Shown to be stimulated in finger tapping, verb generation, mental rotation of letters and emotional picture ranking.