Introduction to Neural Structures and The Nervous System Flashcards
What are the two types of cells that form brain tissues?
Neurons and glial cells (neuroglia)
What is the ratio of neurons to glial cells in the brain?
1:10
What are three features of a neuron?
they always have an axon, communicate via a synapse and have dendrites
What is the axon, where, in the cell, do they come from?
The output side of the cell. The protrude from a conical shaped thickening of the cell body called an axon hillock.
What are dendrites?
how do they interact with dendritic spines ?
they are the input side of the cell, usually thicker and shorter than an axon.
They have their area increased by dendritic spines that lie perpendicular on the dendrites.
What are dendritic spines?
3 points
Protuberances on dendrites, They receive most of the neuron’s excitatory output. They then increase the dendritic arbour.
they are made of a neck and head,, made up of actin filaments and b tubulins. As this emulates muscle tissue, they are able to change their shape.
What are the three ways that synapse can be classified/differentiate from each other?
By the number of processes (dendrites/axons) (i.e. if it is bipolar, multipolar)
By the length of the axon- i.e. Golgi type 1 neurons have a long and large axon to project information far away, while golgi type 2 have a short axon.
They can vary in shape
what are the three shapes of neurons (specifically the cell body)?
triangular, fusifoid (kind of conical) and ovoid (kind of oval shaped or circular
What are pyramidal cells?
4 features
They are the main neuron that makes up the most mass within your cerebral cortex,. They are present in every layer off the cortex (there are five) bar the superficial one (the top one).
They have many processes, with very spiny dendrites
They are projection neurons (Golgi type 1) as the axons are long and project into other cortexes.
They have a triangular cell body
What are spiny stellate cells?
What are 3 features of them
They occur in the cerebral cortex as well as pyramidal cells
They have ovoid cell bodies, they are multipolar, dendrites are radial, short/spiny and only in once area, meaning they are golgi type 2
What are dopaminergic neurons?
4 features
They have fusiform cell bodies
They have axons that emerge from dendrites as well as their cell body (usually the axon only comes from the cell body)
These axons project to many other areas, so are therefore golgi type 1
These cells often tend to degenerate in people with parkinson’s
What are Purkinje cells?
What are they like? what happens if they are damaged?
They are a type of neuron found in the cerebellum.
They are bipolar, have an ovoid cell body, are highly branched and spiny in their dendrites.
Damage of this type of cell can cause issues with motor movements
How many of the 5 main types of neurons are found in the cerebellum?
4
What are glial cells?
what are three types
the gLuE of the brain, they link together tissue and neurons.
Oligodendrocytes, astrocytes, microglia
What do oligodendrocytes form?
schwann cells (and therefore the myelin sheath)
What are astrocytes like?
- They are star shaped
They constitute 20-50% of the volume of most brain areas - They are connected by gap junctions
What are four functions of astrocytes (which, in case you forgot, are a type of glial cell)
They make the cuff around the nodes of ranvier,
they ensheath synapses and dendrites
They therefore maintain the blood/brain barrier- the glial cells wrap around the endothelial cells and the capillaries, therefore stopping the blood content from affecting the brain.
They contribute to the reuptake of neurotransmitters
They are also involved in neurovascular coupling
what is neurovascular recoupling?
The changing of blood supply to different areas in the brain based on the responses needed.
What are microglia?
They are a type of glial cell. As the immune system in the blood can’t access the brain, they act as the brain’s immune system. They have many processes and will carry out phagocytosis on antigens affecting the brain
What do these anatomical “directions” mean?
Dorsal/ventral?
Anterior/Posterior
Rostral/Caudal
Medial/Lateral
Towards the back/towards the belly (top and bottom)
Towards the front/back
Towards the beak (front)/ tail (back)
Towards the middle/towards the side
What do we call the ways we cut cross sections of the brain?
Planes of section
what are the three planes of section and what do these look like
Horizontal- sideways, like when you cut a victoria sponge in half
Coronal- side on slice from the top, like if you sliced a walnut in half but NOT down the seam
Sagittal- vertically down the middle, like a hot dog bun
What are the 5 subdivisions of the brain?
Myelencephalon, metencephalon, mesencephalon, diencephalon and telencephalon
What are the main features of the myelencephalon?
Clues- vagus nerve
It contains the medulla oblongata. It controls things like heart rate. It has nuclei that It has nuclei that control respiration, tongue musculature, blood pressure (hypoglossal nuclei) and heart rate via the nucleus ambiguus (which gives rise to the vagus nerve, part of the ANS)
What does the metencephalon contain?
the pons and the cerebellum.
What are pons?
They contain the nuclei involved in sleep and arousal, so are therefore involved in noradrenaline release.
What can alcohol do?
create a temporary leisure in your cerebellum.
What is the mescencephalon made up of?
The tectum and the tegmentum.
what is the tectum?
it is important in processing visual and auditory information. It consists of inferior and superior colliculi. Inferior colliculi are part of the auditory nervous system while the superior colliculi are part of the visual system and are involved in rapid eye movement ( and eye movement in general)
What are the three major structure within the tegmentum?
Periaqueductal grey, red nucleus and substantia nigra (part of the motor system)
What does the Periaqueductal grey do?
wraps around the duct carrying cerebrospinal fluid. Contains bits of tissue that control species-typical innate behaviours (such as courtship or hunting behaviours).
What does the red nucleus do?
controls the muscles of the shoulder and the upper arm
What part of the brain are the diencephalon and telencephalon?
the forebrain
What does the diencephalon contain?
The thalamus and hypothalamus
What are the four fs that the hypothalamus controls via glandular response?
Fighting, fleeing, feeding and fucking
What is the telencephalon?
info about area, location and subsections
The telencephalon has a lot of mass, it makes up most of the 2 cerebral hemispheres and is connected by the corpus callosum. It contains the limbic system- emotional processing, basal ganglia Motor behaviour , cerebral cortex
Which primary cortexes does the telencephalon contain?
the primary visual cortex (in the occipital lobe), the primary auditory cortex (in the temporal lobe), the primary somatosensory cortex (in the parietal lobe)
It has the primary motor cortex in the frontal lobe
What do we call cortexes that are not “primary”?
How do they interact with primary cortexes?
association cortices. These work with primary sensory and motor cortices to create a relationship between input/sensation and action, as well as coordinating perception, learning, memory etc.
What does the hippocampus consist of? (3 things)
Amygdala, cingulate cortex, medial septum
What does the basal ganglia consist of?
Caudate nucleus, Putamen, Globus Pallidus.
