brain (major structures and functions) Flashcards
what does the CNS first start out as? (brain embryology)
the neural tube
what is the lumen of the neural tube?
what is it filled with?
what does it become?
- neurocoel
- fluid
- eventually forms the brains ventricles
what 3 regions form at 4 weeks?
- prosencephalon
- mesencephalon
- rhombencephalon
what does the prosencephalon form?
- telencephalon
- diencephalon
what does the telencephalon form?
the cerebrum and the lateral ventricle
what does the diencephalon form?
the hypothalamus, thalamus, and the epithalamus
also the third ventricle
what does the mesencephalon form?
it becomes the midbrain
what does the rhombencephalon form?
- metencephalon
- myelencephalon
what does the metencephalon form?
the pons and cerebellum
what does the myelencephalon form?
the medulla oblongata
what are the major regions of the brain? (6)
- medulla
- pons
- midbrain
- diencephalon
- cerebellum
- cerebrum
general functions of the medulla oblongata
- relays info to the thalamus and the brainstem
- HR, BP, and digestion regulation
general functions of the pons
- relays info to the cerebellum and the thalamus
- somatic and visceral motor center regulation
pons (professor’s notes)
contains higher respiratory control centers
- apneustic
- pneumotaxic
apneustic pons
inhibits exhalation for inhalation
pneumotaxic pons
inhibits inhalation for exhalation
medulla (prof’s notes)
the medulla relays communication between the midbrain and the cerebellum
ex… you can’t maintain balance if your eyes are closed
balance = comes from cerebellum
eyes closed = comes from superior colliculi
general functions of the mesencephalon (midbrain)
- processes visual and auditory data
- maintains consciousness
- helps with reflexive somatic motor responses
visual = superior colliculi
auditory = inferior colliculi
midbrain (prof’s notes)
the reticular formation of the midbrain helps with maintaining consciousness
ex… when we’re walking down a dark alley and we’re scared, we become very alert
this is also an example of reverberation
general functions of the diencephalon
contains…
1. thalamus
2. epithalamus
3. hypothalamus
thalamus functions
- relays info from the cerebrum
- center for sensory information relaying
the spinothalamic tract runs through here
epithalamus functions
- contains the pineal gland
the pineal gland secretes hormones like melatonin and controls the secretion of FSH and LH from the pituitary gland
hypothalamus functions
- involved in emotions, thirst, and habitual activity
- involved in temperature control
- involved in circadian rhythm control
circadian rhythm control (prof’s notes)
in the morning, melatonin decreases and cortisol increases
the opposite is true for when you go to sleep
hypothalamus (prof’s notes)
the hormones released by the hypothalamus often control the release of hormones of the anterior pituitary gland
ex… corticotropic releasing hormone from the hypothalamus controls the release of cortisol from the ant. pituitary gland
general functions of the cerebellum
- coordinates complex somatic motor patterns
- adjustment of somatic motor centers for smooth movement
cerebellum (prof’s notes)
this basically controls balance and coordination
ex… to test balance, have one walk in a straight line
recall that communication with the corpus quadrigemina is maintained by the medulla
this also contains the vasomotor center (VMC) for blood vessel diameter control
general functions of the cerebrum
- conscious SKM regulation
- conscious thought
- intellectual thinking
- memory
cerebrum (prof’s notes)
contains the cortex which is grey matter
the junction between the grey and white matter are the pyramidal cells
the hippocampal gyrus is responsible for memory
what is the function of the ventricular system of the brain?
to filter and move CSF which brings nutrients and removes waste from the CNS
the 4 brain ventricles
- lateral ventricles (2x)
- third ventricle
- fourth ventricle
septum pellucidum
separates the 2 lateral ventricles
lateral ventricle horns
- anterior horn
- posterior horn
- inferior horn
pathway of CSF through ventricles
- CSF is made by the choroid plexus
- CSF is in the lateral ventricles
- goes through interventricular foramen to the third ventricle
- goes through the cerebral aqueduct to the fourth ventricle