Chapter 2 Structure & Function Flashcards
Myelin is produced by what kind of glial cell?
Oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system
What is the neuronal membrane?
A bilayer of fatty lipid molecules that separates the cytoplasm from the extra cellular milieu
What is the resting membrane potential?
The voltage difference across the neuronal membrane in the resting state (difference in voltage inside and outside the neuron) which is usually -70mV
What does “neutrons are excitable mean”?
They can change the permeability of their membrane
Neuronal membrane is more permeable to potassium or sodium ions?
K+ potassium
What is meant by electrical gradient?
When positive and negative charges are attracted to each other; in this case positive ions are attracted to a negatively charged space (inside the neuron)
What is meant by the concentration gradient?
The tendency for an ion to travel from a high concentration of the same ion into an area with a low concentration of that ion
What is electrochemical equilibrium?
When the force of the electrical gradient driving K+ in is equal to the force of the concentration gradient pushing K+ out
What is decremental conduction?
Also called electrotronic conduction or a passive current; When a single EPSP enters a neuron and diminishes with distance from its synapse, it is not strong enough to trigger the firing of its own cell
What is the Hodgkin-Huxley Cycle?
The first part of an action potential; When the threshold is met, voltage gated sodium channels open and sodium flows rapidly into the neuron causing it to become further depolarised
What does EPSP stand for?
Excitatory Post Synaptic Potential
What is the necessary excitation threshold needed for an action potential?
-55mV
What happens at a synapse?
Information is passed from the presynaptic neuron to the post synaptic neuron via neurotransmitters
What causes Ca+ channels to open?
An action potential travelling into the axon terminal and depolarising the terminal membrane
What is exocytosis in relation to the synapse?
When the neurotransmitter carrying vesicles travel through the membrane and release the transmitter into the synaptic cleft
Why didn’t the grey matter want to take the white matter to the ball?
Because he wanted cell body to dance with
Describe a presynaptic neuron versus a post synaptic neuron
Presynaptic neuron passes information from an axon terminal to a post synaptic neuron at a dendritic spine
What is a voltage gated ion channel?
An ion channel that opens when the voltage of the surrounding membrane depolarises
Which way is rostral or anterior when talking about the human brain?
Towards the front
What way is dorsal or superior when talking about the human spine or animal brain?
Towards the back
Which way is ventral or inferior when talking about the human brain?
Towards the bottom
Which way is caudal or posterior when talking about the human spine or animal brain?
Towards the bottom
Define grey matter
Grey matter makes up the outer layer of the cerebral cortex which is folded like a handkerchief into gyri and sulci
The grey matter if the cerebral cortex is made up if what!
Neuronal cell bodies
What is the name of the neurologist that mapped the brain into 52 different areas according to their cytoarchitectonic (histological) characteristics?
Korbinian Brodmann
Where is the frontal lobe?
The front part of the cerebral cortex
Where is the temporal lobe?
Under the frontal lobe of the cerebral cortex, near the temples at each side of the head
Where is the occipital lobe?
At the back of the brain, under the parietal lobe
Where is the parietal lobe?
The upper back section of the cerebral cortex
Where is the central sulcus?
The sulcus or chasm that divides the frontal and parietal lobes; posterior to the frontal and anterior to the parietal
Where is the sylvian fissure?
Between the frontal and temporal lobes; dorsal to the temporal and inferior to the frontal
Where is the superior frontal gyrus?
Superior (at the top) of the frontal lobe
Where is the middle frontal gyrus?
In the middle of the frontal lobe
Where is the inferior frontal gyrus?
Inferior (at the bottom) of the frontal lobe
Where is the pre-central gyrus?
Anterior to the central sulcus
Where is the post central gyrus?
Posterior to the central sulcus
Where is the supra marginal gyrus?
Superior (above) the sylvian fissure in the parietal lobe
Where is the angular gyrus?
Posterior (behind) the temporal lobe, anterior (in front) to the occipital lobe
Where is the lateral occipital gyri?
Towards the outside of the occipital lobe
What role does microglia play?
Devour and remove damaged cells
The somatosensory areas of the parietal lobe is where?
In the primary somatosensory cortex (s1) - Brodmanns areas 3, 1 and 2
And the secondary somatosensory cortex (s2)
The primary visual cortex is also known as what?
Striate cortex, v1 (visual area 1) and Brodmanns area 17
The primary visual cortex receives visual inputs from where?
From the outside world, through the optic nerve to the lateral geniculate nucleus of the thalamus
Where is the primary visual cortex?
Occipital lobe
What is the extrastriate cortex and what does it process?
Literally means “outside the striate”; Includes areas B18 and 19, lying outside the striate cortex. Considered the secondary visual area that receives input from PVC.
Describe the ‘what’ pathway. Origin, destination and purpose
Ventral stream is a visual pathway that traverses the occipital and
temporal lobes. Associated with object recognition and visual memory.
Describe the where pathway.
Dorsal stream is a processing pathway for visual stimuli specialized for
spatial perception, and analyzing spatial configuration between objects.
Where is the auditory cortex?
The primary auditory cortex is located in the superior temporal lobe.
Higher mental processes occur where?
Higher mental processes occur in the prefrontal cortex.
What are the functions of the lambic system?
The limbic system (emotional brain) is the emotional network.
The basal ganglia is associated with what?
Motor control and learning.
The three main subdivisions if the basal ganglia are?
Striatum (caudate nucleus and putamen), globus pallidus,
subthalamic nucleus, substantia nigra.
Is the amygdala part of the basal ganglia?
No, it’s part of the lambic system. But the amygdala is important for emotional memory.
What cognitive functions are the basal ganglia associated with?
Learning.
What role do the basal ganglia play in motor muscular activity?
Initiating movement
Where is the hippocampus and what does it do?
The hippocampus is a layered structure located in the medial temporal
lobe. Involved in learning and memory, and is especially critical for the
formation of long-term memory.
The brains diencephalon is composed of the thalamus and the hippocampus. True or false?
True The caudal (posterior) part of the forebrain, thalamus, hypothalamus, and ventral thalamus and the third ventricle
Why is the thalamus known as the gateway cortex?
Everything passes through the thalamus and gets directed to higher brain regions.
Why is the hypothalamus known as the hypothalamus? What does it do?
Hypo refers to “Below”, it is below the thalamus. Important for the autonomic NS and endocrine system, pituitary gland, hunger, thirst, temperature. Secretes hormones.
