Brain Basics Flashcards
Brain is composed of
neurons, glia, stem cells, blood vessels
Brain Cells are not
Replaced. No adult neurogenesis.
Humans have the highest brain
neuron density
The neuron is composed of
Dendrite -> soma -> axon -> terminals
Pyramidal shaped neuron
Has apical and basal long dendrites.
Stellate shaped neuron
Neuron with star like shape. Dendrites in all directions
Purkinje shaped neuron
Very thin dendrites in a dense configuration, like roots.
Projection neurons (Shape, function)
Long axon. Projects from one brain area to another brain area.
Example: Medium spiny projection neurons (MSNs) 96% of neurons
Interneurons (Shape, function)
Star shaped. Axons project locally. Modify the signals. Often inhibitory in nature. Can synchronize the activity of projection neurons. Can gate information.
Glial Cells - Microglia
It spots problems and “hunts it”, they engulf the problem. (Like the immune system of your brain.)
Glial Cells - Astrocytes
The most abundant.
Regulates the environment of synapses.
Mediates needs and how active the brain is
Glial Cells - Oligodendrocytes
Their function is to myelinate multiple axons at once in the central nervous system
Glial Cells - Schwann cells
Work in the Peripheral nervous system.
They wrap around axons of motor and sensory neurons to form the myelin sheath.
The Tripartite synapse
2 neurons and 1 glial cell wrapped around the synaptic site
Astrocyte in Tripartite synapse
Astrocytes release signals in synapse, shaping conditions. Helps with cleaning of NTs. They release D-serine.
D-serine
Astrocytes release this to the site to manipulate ???
glutamatergic contribution to central chemoreception
D-Serine activates glutamate receptors that are involved in the formation of new synapses, which are important for learning and memory
Gray matter
Cell bodies of the neurons and unmyelinated neurons (like interneurons)
White matter
Myelinated axons
Anatomical dimensions
Anterior and posterior
Front and back (brain) up and down (spine)
(in most animals it is just front and back)
Varies on a Z-axis
Anatomical dimensions
Left Lateral, Right lateral and Medial
Varies on a X-axis. from left to right
Anatomical dimensions
Dorsal and ventral
Dorsal = superior (top of the head)
Ventral = inferior (bottom surface)
Varies on a Y-Axis on the brain
Peripheral nervous system
Somatic and autonomic
Somatic system
Neurons we can control consciously.
Can be Afferent or efferent
Autonomic system
Neurons our brains control automatically
Can be Afferent or efferent
The autonomic efferent can be sympathetic or parasympathetic
Afferent nervous system
Nerve impulses from sensory stimuli towards the central nervous system
Efferent nervous system
motor neurons that carry neural impulses away from the central nervous system and towards muscles to cause movement.
Autonomic efferent nervous system
Can be sympathetic - mobilize - or parasympathetic - rest and digest.
Drugs often act the autonomic…
Efferent nervous system. on the sympathetic or parasympathetic
Major divisions of the brain
Forebrain
Midbrain
Hindbrand
Forebrain
Cerebral cortex, basal ganglia, thalamus, hypothalamus, pituitary gland, limbic system, and the olfactory bulb
Hindbrain (components and function)
cerebellum, pons, medulla. Governs most basic functions of body.
Convolutions
Gyrus
Sulcus/ fissures
Gyrus - outward fold
Sulcus/ fissures - Inward fold
Lobes of the brain
Named after the bones
Frontal Parietal Occipital Temporal Cerebellum
Brain Nuclei
Grey matter clusters under the cortex
Hypothalamus
In the forebrain, cluster of nuclei.
Each has very specific roles. (eating, aggression, sexual behaviors)
Evolutionarily interesting roles, no conscious control over
Limbic ‘system’
Nuclei below the cortex
Emotion and behaviour
Nucleus accumbens
Ventral striatum. Part of basal ganglia. Plays a critical role in addiction and motivation.
What parts of the brain controls voluntary movement?
Prefrontal cortex, premotor cortex, motor cortex, basal ganglia, pons, cerebellum, more
Long term memory
hippocampus (important in consolidation), basal ganglia very important for learning
Short term (working) memory
the frontal lobe of the cerebral cortex
Cerebral blood flow
no redundancy of supply
Left internal carotid
Right internal carotid
Vertebral - 2
Blood-brain barriers
Protects the brain - astrocytes. doesn’t let most things into the brain.
We need drugs that pass this barrier.
Active transport for large molecules
Skull and meninges - protection
Layers?
Dura mater
Arachnoid mater
fluid between arachnoid and pia
Pia mater
Polymorphisms
Genetic Differences between individuals
Epigenetics
Some drugs, activities and trauma can alter the way the DNA is stored. How tightly or loosely packed it is. Makes it harder or easier to transcript
Neurogenetics
All the genes that are related to the nervous system
Knockout animals
We block or decrease a gene in the animal so it doesn’t express a trait
Conditional Knockout animals
rats normal until they are adult, but something in environment will knockout a gene (and therefore protein)
Glial cells
Provide supporting functions to the nervous system. microglia astrocytes oligodendrocytes schwann cells
