Nervous System Part 2 - The Brain Flashcards
what do the brain and spinal cord develop from?
different sections of the neural tube
- and throughout fetal development, it is going to undergo more and more differentiation to get to the brain structure we have
what three sections does the brain begin to develop into?
- the forebrain
- the midbrain
- the hindbrain
- called the primary brain vesicles
the primary brain vesicles develop further until we get?
our brain structure as well as the spinal cord
what is the cerebrum of the forebrain?
- the big part of the brain that we picture
what are the two aspects of the cerebrum?
- grey matter
- white matter
what does white matter in the brain and spinal come from?
myelinated axons of neurons
- they are light in colour
why do we end up with areas where we have a lot of cell bodies clumped together in the cerebrum?
because of the grouping and organization of the neurons
- called grey matter
what is grey matter made up of?
mainly cell bodies as well as dendrites that are attached to them
what is deeper grey matter?
internal structures that develop from the forebrain
what is a fissure?
a division between two segments of the brain
what are the bumps on the brain called?
gyrus (single)
gyri (plural)
what are the valleys on the brain called? (deep to the bumps)
- sulcus (single)
- sulci (plural)
what does our sulcus and gyrus allow us to do?
cram a lot more brain into a small space
what is the outermost surface of the brain called? (grey matter)
the cortex
what is the inner surface of the brain?
white matter
what is the cerebellum?
a part of the hindbrain attached to the bottom of the cerebrum
what is each hemisphere of the brain divided into?
lobes
- the names match the names of the skull
what are the lobes of the brain?
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
- insula lobe
which lobe is deep to the rest of the lobes?
the insula lobe
- cannot been seen from a surface view
what are our deeper gray matter of the brain?
- thalamus
- hypothalamus
- basal nuclei
what is the MAIN function of the thalamuS?
passes sensory signals to the cerebrum from other areas of the brain and spinal cord
where is the hypothalamus located with respect to the thalamus?
inferiorly and a little anteriorly of the thalamus
what does the hypothalamus control?
the autonomic nervous system
- involuntary motor control of organs
also controls the endocrine system (the system that regulates hormones)
what is the basal nuclei?
a collection of cell bodies
what does a ganglia mean?
it is in the peripheral nervous system, while the brain is NOT. so this is why we call it a basal nuclei and not a basal ganglia
where can the basal nuclei be found?
on either side of the thalamus
what is the function of the basal nuclei?
to pass voluntary motor signals from the cerebrum down to other areas of the brain and the spinal cord (so signals can go to the skeletal muscles)
- quick the opposite of the thalamus
which aspect of the brain is affected during parkinsons disease?
the basal nuclei
- when they do not function properly, you end up with these additional voluntary motor signals being sent down to the skeletal muscles
- typically the basal nuclei filters the signals before sending them out because the cerebrum often sends off unnecessary motor signals
different areas of white matter in the brain are going to be grouped based on?
the direction that the axons are carrying information
- the groups are called tracts because they are all carrying information in the same direction
what are your commissural tracts?
the tracts that run horizontally in the brain
- myelinated axons that are connecting the left and right hemispheres of the brain
what are your projection tracts?
the tracts that run vertically in the brain
- axons carry sensory information from the cerebrum and other aspects of the brain (deeper grey matter) down towards the spinal cord and bringing motor signals back up to the cortex and the deeper grey matter
what are the association tracts?
the myelinated axons that stay within their hemisphere of the brain
what are our two types of association tracts?
- longitudinal fibres/tracts
2.arcuate fibres/tracts
what are the association longitudinal tracts?
tracts that are going to travel all the way through the hemisphere (cross lobes)
what are the association arcuate tracts?
tracts that stay within their same lobe
- pass information throughout their lobe
what is the only structure in the midbrain?
the midbrain
what is the midbrain responsible for?
- controlling eye movement
- visual and auditory reflexes (if there is a loud sound, you will turn to look at that sound)
how is the midbrain connected to the cerebellum?
through an area called the peduncle (cerebellar peduncles)
what do peduncles do?
going to attach structures in the brainstem area to the cerebellum in the back
what are cerebral peduncles?
peduncles that attach structures up to the cerebrum
what is the hindbrain composed of?
- cerebellum
- pons
- medulla oblongata
what is the pons most importantly responsible for?
regulates your breathing (with the medulla oblongata)
what is the pons connected through?
cerebellar peduncles to the cerebellum
what peduncle connects the midbrain to the cerebellum?
the superior cerebellar peduncle
what peduncle connects the pons to the cerebellum?
the middle cerebellar peduncle
what peduncle connects the medulla oblongata to the cerebellum?
the inferior cerebellar peduncle
what is the function of the medulla oblongata?
regulates many vital functions like:
- heart rate
- breathing (works with the pons)
- blood pressure
- works with the hypothalamus to regulate the ANS to control the vital functions
what are cranial nerves?
nerves of the PNS that come directly off of the brain
what is the vermis?
connects the left and right hemispheres of the cerebellum
what is the white matter of the cerebellum called?
arbor vitae
- means “tree of life” because it sort of looks like a tree
where is the cerebellum located?
posterior to the brainstem
what is the outer dark matter of the cerebellum called?
the cortex
what is the function of the cerebellum?
to coordinate motor actions
- works with many other components of the brain that are involved in motor actions in the body
