Topography of the brain Flashcards
Neuroectoderm cells
From ectoderm germ layer, found in embryonic neural cells.
Thickens day 20 to form neural plate.
Notochord
Cartilaginous tissue of the mesoderm layer.
Sends signals to neuroectoderm cells.
Neural tube
Form from the folding of the neural plate at day 20.
The lateral neural plate folds inwardly.
Layers:
- Neural crest
- Mantal
- Ependymal
- Lumen
Spina bifida
Neural tube defect caused by the failure of the posterior neural tube to close.
Leaves vertebral canal open.
Occulta= vertebral arch defect only
Cystica= projection of tissue, e.g meningocele.
Anencephaly
Neural crest defected caused by a failure of the anterior neuropore to close.
It is fatal.
Primary vesicles of the brain/
Formed by the expansion of the cranial end of the neural tube.
Prosenceophalon
- Forebrain
Mesencephalon
- Midbrain
Rhombacephalon
- Hindbrain
Forebrain/ Prosencephalon
Primary vesicle of the brain that gives rise to
- Telencephalon
- Optic vesicles
- Diencephalon
Mesencephalon/ midbrain
Primary vesicle of the brain, stays as mesencephalon.
Rhombencephalon/ hindbrain
Primary vesicle of the brain that gives rise to
- Metencephalon
- Myelencephalon
Secondary vesicles
Arises from primary vesicles.
- Forebrain: telencephalon, optic veiscles, diencephalon.
- Midbrain: mesencephalon
- Hindbrain: metencepbalon, myelencephalon.
Telencephalon
Secondary vesicle from the prosencephalon.
- Gives rise to the cerebral hemisphere
Optic vesicles
Secondary vesicles from the forebrain that form the eyes.
Diencephalon
Secondary vesicles from the forebrain that forms the thalamus and hypothalamus.
Metencephalon
Secondary vesicles from the hindbrain.
- Gives rise to the pons and cerebellum.
Myelencephalon
Secondary vesicles from the hindbrain.
- Gives rise to the medulla.
Forebrain
Composed of the cerebral hemispheres, thalamus and the hypothalamus.
Brainstem
Composed of the midbrain and hindbrain.
- Mesencephalon
- Pons
- Medulla
- Cerebellum
Thalamus
- Ventricle
- Structure
- Function
Part of the forebrain- diencephalon.
Structure
- Paired structure, connected by inter-thalamic adhesions
- Superior to hypothalamus
- Inferior to cerebral cortex, superior to midbrain
Function:
- Relays sensory information to the cortex
- Voluntary movements
- Personality, consciousness
- Part of the limbic system
Hypothalamus
- Ventricle
- Structure
- Function
Of the forebrain- diencephalon
Structure:
- Inferior to thalamus
- Anterior to pineal gland
- Superior to pituitary gland, connected by infundibulum.
Function:
- Functions of the ANS, endocrine
- Homeostasis: temperature, hunger, thirst, circadian rhythm
- Input from limbic system
Limbic system
Brain nuclei that includes part of the telencephalon and diencephalon.
Components: [Telencephalon] - Cingulate cortex - Fornix - Amygdala - Hippocampus
[Diencephalon]
- Hypothalamus+ Thalamus
- Mammillary bodies
Function:
Involved in motivation, emotion, learning and memory.
Fornix
White matter tract connecting the hippocampus to the mammillary bodies.
- Part of the telencephalon
Function:
- Component of limbic system
Basal ganglia
Group of cell bodies (nuclei) in at the base of the prosencephalon
Includes:
- Lentiform nucelus
- Caudate nucleus
Functions include:
- Voluntary motor movements, posture.
- Eye movements
- Emotion
Lentiform nucleus
Component of Basal ganglia
- Lens shaped
- Lateral to thalamus
- Lateral to internal capsule
Composed of:
- Putamen (larger)
- Globus pallidus
Caudate nucleus
Component of basal ganglia
- L-shape
- 3 parts: head, body, tail (links to amygdala)
- Located in the wall of lateral ventricle.
Central sulcus
Fold that separates the frontal from parietal lobe.
Also separates the primary motor cortex from somatosensory cortex.
Somatosensory cortex
Functional area located in the post-central gyrus of the parietal lobe.
Sensory function
Primary motor cortex
Functional area in the pre-central gyrus, of the frontal lobe.
Motor function- controls movement
Visual cortex
Sensory functional area of the occipital lobe.
Auditory cortex
Sensory functional area of the temporal lobe.
- Processes sound
Olfactory cortex
Sensory functional area located in the lateral sulcus.
- Process smell
Gustatory cortex
Sensory functional are found in the inferior frontal gyrus of the frontal lobe.
- Processes taste
Insula cortex
Portion of cortex folded in the lateral sulcus.
- Cognitive function
Accessory motor cortexes
Supplementary motor cortex
- Of the frontal lobe
Premotor cortex
- frontal lobe
Motor speech of Broca
Prefrontal cortex
Region of the brain responsible for cognition and association.
Corpus callosum
White matter tract of the telencephalon
- Links the two cerebral hemisphere
Regions: Rostrum (head) Genu Body Splenium
Hippocampus
- Vesicle
- Structure
- Function
Grey matter tissue of the telencephalon
Structure
Linked to the mammillary bodies by the fornix.
- Seahorse shape
- Sits on the floor of the lateral ventricle
Function:
- Part of the limbic system
- Memory
Pineal gland
Structure posterior to the thalamus, tucked between where it is joined.
Produces melatonin
- Regulates sleep
Brain stem
Composed of:
- Mesencephalon
- Pons
- Medulla oblongata
Function:
- The location of where most of the cranial nerves are contained
- Contains respiratory and cardiovascular centres
- Contrains vomiting centr
- Motor and sleep control
Cerebral peduncles
White matter tract of the mesencephalon, connects the pons to the diencephalon.
Superior colliculus
Tissue of the mesencephalon that receives visual input.
- Controls eye movements
Inferior colliculus
Tissue of the mesencephalon that has auditory function.
- Receives inputs from the auditory pathway and cortex.
Red nucleus
Tissue of the mesencephalon that appears pinkish/red.
- Responsible for relaying information between cortex and cerebellum
- Motor co-ordination
Substantial nigra
Structure of the basal ganglia (mesencephalon)
- Posterior to cerebral peduncles.
Function:
- Contains dopaminergic neurones (looks black due to melanin production)
Pons
Tissue of the rhombencephalon- mylencephalon
Structure:
- Transverse fibres that continue to form cerebellar peduncles
Function:
- Relays information to and from the cerebellum
- Region where most of the axons descending in the midbrain synapses.
- Contains nuclear formation
Reticular formation
Brain nuclei in the Pons.
Runs from the mesencephalon to the medulla.
- Controls sleep
- Motor controls
Middle cerebellar peduncle
White matter tract that connects the cerebellum to the mesencephalon.
Medulla oblongata
- Vesicle
- Structure
- Function
Tissue of the myelencephalon
Structure:
- Inferior to the pons
- Pyramid: corticospinal tract involved in the main voluntary motor pathway
- Olive: olivary nuceli which relays motor info to the cerebellum
Tubercles: form part of the ascending tract
- Cuneate- lateral.
- Gracile- medial
Cerebellum
Tissue of the metencephalon
Structure
- Posterior to brainstem
- White + grey matter
- Two hemisphere
- 3 lobes
Functions:
- Posture
- Co-ordination of limbs
- Control eyes movements
Arbor vitae
White matter of the cerebellum
Connects sensory and motor tissues
Lobes of the cerebellum and their function
Anterior- Unconscious proprioception
Flocculonodular- eye movements
Posterior: motor co-ordination
