Topography of the Brain Flashcards
What sends inductive signals to neuroectodermal cells to cause them to thicken?
The notochord
What do neuroectodermal cells thicken into?
Neural plate
What can neural crest cells differentiate into?
- Neurons and glia of the sensory and autonomic nervous system
- Cells of the adrenal gland
- Epidermis
- Skeletal / Connective tissue of the head
What is spina bifida?
Failure of the posterior end of the neural tube to close, leading to an open cerebral canal.
It is not fatal.
What is anencephaly?
A fatal condition which is caused by the failure of the anterior neural tube to close.
What proportion of pregnancies are affected by anencephaly?
1 in 1000
What proportion of pregnancies are affected by spina bifida?
1-2 in 1000
What are the primary brain vesicles?
- Prosencephalon = Forebrain
- Mesencephalon = Midbrain
- Rhombencephalon = Hindbrain
What do secondary vesicles arise from?
Primary vesicles
What are the secondary vesicles of the prosencephalon?
- Telencephalon (cerebral hemispheres)
- Optic Vesicles (eyes)
- Diencephalon (thalamus + hypothalamus)
What are the secondary vesicles of the hindbrain?
- Metencephalon (pons + cerebellum)
- Myelencephalon (medulla)
What type of matter makes up the inner and outer brain?
- Outer brain consists of gray matter
- Inner brain consists of white matter
What can the cerebral hemispheres be divided into?
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
What does the folding of the outer layer of the cerebral hemispheres form?
Gyri and sulci
What does the central sulcus divide?
Parietal and Frontal lobe
What does the lateral sulcus divide?
Parietal and Temporal lobe
Where are the precentral and postcentral gyri located with respect to the central sulcus?
- Precentral = Anterior
- Postcentral = Posterior
Are the precentral and postcentral gyri sensory or motor?
- Precentral = Motor
- Postcentral = Sensory
What is the corpus callosum?
A white matter tract that links the two cerebral hemispheres
What is the limbic system involved with?
Emotion and Memory
What are the basal ganglia involved with?
Control of of posture and voluntary movement
What are the main components of the limbic system?
- Cingulate cortex
- Fornix
- Hypothalamus
- Mammillary bodies
- Amygdala
- Hippocampus
What is the fornix?
A semi-circular white matter tract that connect the hippocampus with the mammillary bodies.
How is the hippocampus shaped and where does it sit?
Seahorse shaped
Sits in the floor of the lateral ventricles
Where are the basal ganglia located?
Forebrain
What is the corpus striatum made up of?
Caudate nucleus and Lentiform nucleus
How is the caudate nucleus and lentiform nucleus shaped?
Caudate = C-shaped
Lentiform = Lens shaped
What is the lentiform nucleus made up of?
- Putamen
- Globus Pallidus
What are the different parts of the caudate nucleus?
- Head
- Body
- Tail
How is the lentiform nucleus and caudate nucleus located with respect to each other?
The lentiform nucleus is lateral to the caudate nucleus
What is the internal capsule?
A white matter tract that connects the cortex to the brainstem.
It is internal to the lentiform nucleus
What is the thalamus and what is it involved with?
A paired structure that relays sensory information to the cortex.
It is involved with voluntary movement, personality and consciousness.
Where in the brain is the hypothalamus located?
Inferior to the thalamus and in between the optic chasm and mammillary bodies.
What are the functions of the hypothalamus?
- Coordinates the autonomic system and endocrine responses
- Involved in thermoregulation, feeding and drinking
- Receives inputs from the limbic system
What are the contents of the brainstem?
- Cranial nerve nuclei
- Vital respiratory and cardiovascular centres
- Vomiting centre
- Nuclei involved with motor control and sleep
- White matter tracts
What are the contents of the midbrain?
- Cerebral peduncles
- Superior colliculus
- Inferior colliculus
What are the cerebral peduncles?
Acts as the feet of the brain and has white matter tracts that connect the pons to the diencephalon
What does the superior colliculus allow for?
Eye movements
What is the inferior colliculus?
Contains relay nuclei which are involved in auditory function
What are the contents of the medulla oblongata?
- Pyramid which contains the corticospinal tract (main voluntary motor pathway)
- Olive (olivary nuclei) which relays motor information to the cerebellum
- Cuneate and Gracile nuclei (nuclei in ascending tract)
What are the three lobes of the cerebellum?
- Anterior
- Flocculonodular
- Posterior
What connects the cerebellum to the brainstem?
Cerebellar peduncles
Where is the vermis located?
Inbetween the two hemispheres of the cerebellum
