Neuroanatomy Flashcards
Describe the general organization of the nervous system (CNS vs PNS).
Central nervous system (CNS): brain + spinal cord
Peripheral nervous system (PNS): cranial nerves + nerves from spinal cord to periphery (muscles, organs, etc.)
What is the mass of the human brain app. (in g)?
1300-1500 g
What is the volume of the human brain app. (in ml)?
1200-1500 ml
How many neurons are there app. in the human brain?
100 billions
What’s the difference between gray- and white matter?
Gray: nuclei/soma/cell bodies
White: tracts
Describe the overall structure of a neuron.
Soma/cell body/perikaryon with multiple dendrites receiving signals from other neurons/cells, and one axon ending in one or multiple synapses, passing the signal
What is the difference between the axon hillock and the initial segment?
Both located in the begining of the axon:
Axon hillock is the anatomical start of the axon
The initial segment is the physiological start of the action potential
What is a collection of somas called in the CNS vs the PNS?
CNS: nucleus/cortex/gray matter
PNS: ganglion
What is a collection of axons called in the CNS vs the PNS?
CNS: tract/white matter
PNS: nerve
What does a Weigert staining stain?
Myelin –> white matter
What does a Mulligan staining stain?
Gray matter
What are the different anatomical planes in the CNS?
Horizontal, coronal/frontal, and sagittal (dividing the two hemipheres)
What are the anatomical directions in the human CNS, and why does it differ from e.g., that of a mouse?
Rostal/caudal: nose/tail
Dorsal/ventral: back/belly or top/bottom (this plane bends, is also referred to as superior/inferior and posterior/anterior)
It differs because the CNS is bend in humans, as we are standing on two legs, not four.
Describe the subdivisions of the brain.
Forebrain, brainstem and cerebellum
What are the subdivisions of the forebrain?
Telencephalon and diencephalon
What are the subdivisions of the brainstem?
Mesencephalon, Pons and medulla oblongata
Where is the rhomboid fossa located?
On the dorsal surface of the brainstem and cerebellar peduncles.
Where is the pineal gland?
Right above the dorsal surface of the mesencephalon, on the diencephalon
Where is the tectum (aka superior/inferior colliculus) located, and what is it involved in?
On the dorsal surface of the mesencephalon, below the pineal gland. It’s involved in vision and hearing, and is the reflex centers for head movements.
How many cranial nerves are there?
12
What is the cerebellum part of?
The motor system
What are the subdivisions of the cerebellum?
The vermis, the cerebellar hemipheres, and the flocculonodular lobe.
What are the subdivisions of the diencephalon?
Thalamus, epithalamus (with the pineal gland) and hypothalamus
Describe the hypothalamus (structures) from a ventral view.
Optic nerve, optic chiasm, pituitary stalk and the mammillary bodies
Describe the internal capsule.
Fibers above –> internal capsule –> basal ganglia
What is the corpus callosum?
The connection between the two hemipheres
What are the subdivisions of the telencephalon?
The cerebral cortex and the basal ganglia.
What are the subdivisions of the two hemipheres?
Four lobes: the frontal, the parietal, the occipital and the temporal.
Describe the division of the four lobes.
The central sulcus divides the frontal (the most rostral) from the parietal. The lateral sulcus divides the from both the frontal and parietal. The occipital are the most caudal lobe.
What is the basal ganglia?
Large nuclei deep in the telencephalon: caudate nucleus, putaman and globus pallidus. The caudate nucleus and the putaman is called the striatum collectively.
How many ventricles are there?
Four
What are the ventricles called?
The lateral, the 3rd, the cerebral aqueduct and the 4th
What is the structure connecting the lateral ventricles and the 3rd ventricles called?
The interventricular forearm
What is the 4th ventrical ending in?
The central canal
What is the hippocampus?
A deep part of the cerebral cortex
