T1 L3 Topography of the brain Flashcards
What is neurulation?
Formation of the embryonic neural plate & its transformation into the neural tube
What is the notochord?
Small flexible rod made from cells of the mesoderm
What do neural crest cells differentiate into?
Neurons & glia of sensory & autonomic nervous systems
Cells of adrenal gland
Epidermis
Skeletal / connective tissue of the head
What does the mantle layer become?
Brain parenchyma
What happens to the ependymal layer?
Lines ventricles
What is anencephaly?
Failure of anterior neuropore to close
Fatal
Entire forebrain is exposed
How common is anencephaly?
1 in 1000 pregnancies
What is spina bifida?
Failure of posterior neural tube to close
Causes open vertebral canal
Occulta - hidden, vertebral arch defect only
Cystic - meningocele - meninges projects out
How common is spina bifida?
1-2 in 1000 pregnancies
What does the prosencephalon vesicle form?
Forebrain
What does the mesencephalon vesicle form?
Midbrain
What does the rhombencephalon vesicle form?
Hindbrain
What primary vesicle forms the forebrain?
Prosencephalon
What primary vesicle forms the midbrain?
Mesencephalon
What primary vesicle forms the hindbrain?
Rhombencephalon
What does the telencephalon vesicle form?
Cerebral hemispheres
What does the optic vesicles form?
Eyes
What does the diencephalon vesicle form?
Thalamus / hypothalamus
What does the metencephalon vesicle form?
Pons / cerebellum
What does the myelencephalon vesicle form?
Medulla
What secondary vesicle forms the cerebral hemispheres?
Telencephalon
What secondary vesicles forms the eyes?
Optic vesicles
What secondary vesicles forms the thalamus / hypothalamus
Diencephalon
What secondary vesicles forms the pons / cerebellum
Metencephalon
What secondary vesicles forms the medulla
Myelencephalon
What is grey matter?
Mainly neuronal cell bodies
Includes cerebral cortex & brain nuclei
What is white matter?
Myelinated axons
What does the central sulcus divide?
The frontal and parietal lobes
What does the lateral sulcus divide?
The temporal and parietal lobes
Describe the properties of the cerebral cortex
Outer layer of cerebral hemispheres
Fairly thin at 2-5mm
Folded to form gyri & sulci
What is the corpus callosum?
White matter tract linking the cerebral hemispheres
What are the 3 parts of the corpus callosum?
Genu
Body
Splenium
What is the limbic system involved in?
Emotion
Memory
What is the basal ganglia involved in?
Control of posture
Voluntary movement
What does the limbic system span?
Telencephalon
Diencephalon
What are the main components of the limbic system?
Amygdala Hippocampus Cingulate cortex Fornix Hypothalamus Mammillary bodies
What is the fornix?
Semi-circular white matter connecting the hippocampus with mammillary bodies
What are basal ganglia?
Series of interconnectivle nuclei at base of forebrain
What does the corpus striatum divide into?
Caudate nucleus
Lentiform nucleus which divides into putamen & globes pallid us
What shape is the lentiform nucleus?
Lens shaped
What shape is the caudate nucleus?
C-shaped
Describe the thalamus
Paired structure
Relays sensory information to cortex
Involved with voluntary movement, personality & consciousness
Where is the hypothalamus located?
Inferior to thalamus
Sits below optic chasm & mammillary bodies
What does homeostasis do?
Coordinates ANS & endocrine responses
Involved in thermoregulation, feeding, drinking, circadian rhythms
Receives inputs from limbic system
What is the brainstem made up of?
Midbrain
Pons
Medulla
What is contained within the brainstem?
Cranial nerve nuclei
Vital respiratory & cardiovascular centres
Vomiting centre
Nuclei involved with motor control & sleep
White matter tracts
What is in the midbrain?
Superior colliculus Inferior colliculus Substantial nigra Red nucleus Cerebral peduncies
What does the superior colliculus do?
Vision
What does the inferior colliculus do?
Auditory
What does the red nucleus do?
Motor coordination - relay between cortex & cerebellum
What does the pons do?
Relays information to the cerebellum
Contains reticular formation - nuclei concerned with sleep, motor control
What does the medulla oblongata contain?
Nuclei important in controlling respiration & the cardiovascular system
Describe the cerebellum
Posterior to brainstem Outer grey matter Underlying white matter 2 cerebellar hemispheres 3 lobes Contains nuclei
What is the functions of the cerebellum?
Motor control
Control of posture
Coordination & planning limb movements
Control of eye movements
What are the 3 lobes in the cerebellum?
Anterior lobe
Flocculonodular lobe
Posterior lobe