Intro to CNS Flashcards
what 2 things protect the brain from external environment
- skull + veretbral column
*meninges (three layers of membranes that cover and protect your brain and spinal cord. The delicate inner layer is the pia mater. The middle layer is the arachnoid, a web-like structure filled with fluid that cushions the brain. The tough outer layer is called the dura mater.)
where does the venous blood drain in brain?
The superiodorsal veins drain to the superior sagittal sinus (aka venous sinus), the posterior veins, and veins of the cerebellum drain to the transverse sinus, and the anterior veins can drain to the superior sagittal sinus, cavernous sinus, or the superficial middle cerebral vein
what protects the brain against the internal environment (aka circulating toxins, pathogens, bacteria, amoeba, viruses)
- BBB (Blood brain barrier)
*BSCB (brain spinal cord barrier) - ventricels + CSF (cerebrospinal fluid)
Majority of CSF is produced in _____ ______, we have about 150ml of CSF at any one time
Majority of CSF is produced in LATERAL VENTRICLES, we have about 150ml of CSF at any one time
the lateral ventricles are lined with what glial cell
lateral ventricles are lined with ependymal cells (type of glial cell) which have cilia and waft the CSF around into subarachnoid space, as well as bathe the spinal cord
whichc cells of CNS are in healthy individuals usually quiescent (switched off) they only switch on when there’s an infection
Microglia:
○ CNS macrophages
○ Mediators of neuroinflammation
when there’s an infection they become amoeboid means active/moving. Most of the time the microglia are quiescent (switched off) they only switch on when there’s an infection
we have 2 types of neurotransmitters
excitatory + inhibitory
what is adrenaline/ epinephrine + its function
adrenaline/epinephrine= excitatory neurotransmitter for fight/flight; produced in stressful situations. Increases heart rate + blood flow, leading to physical boost + hightened awareness
what is noradrenaline/norepinephrine + its function
noradrenaline/norepinephrine= Excitatory neurotransmitter for concentration; affects attention + responding actions in the brain. Contract blood vessels, increasing blood flow
what is dopamine + its function
dopamine= both a excitatory and inhibitory neurotransmitter for pleasure; feelings of pleasure, also addiction, movement + motivation. People repeat behaviours that lead to dopamine release
what is serotonin + its function
serotonin= inhibitory neurotransmitter responsible for mood; contributes to well-being + happiness. Helps sleep cycle + digestive system regulation. Affected by exercise
what is GABA + its function
GABA= inhibitory neurotransmitter thats calming; calms firing nerves in the CNS. High levels improve focus, low levels cause anxiety. Also contributes to motor control + vision
what is acetylcholine + its function
acetylcholine= is an excitatory mediator neurotransmitter for learning; involved in thought, learning + memory. Activates muscle action in the body. Also associated with attention + awakening
what is glutamate + its function
glutamate= most common excitatory neurotransmitter and is for memory; involved in learning + memory, regulates development + creation of nerve contacts
what are endorphins + their function
endorphins= inhibitory neurotransmitters that bring euphoria! Released during excercise, excitement + sex. Producing a sense of well-being + pain reduction (as endorphins block/inhibit pain signals)
substantia nigra is a brain structure that is part of your basal ganglia, what is its function
substantia nigra essential for movement
where is the locus coeruleus found and what is its function
Locus coeruleus is found in brainstem. The locus coeruleus regulates amount of NA in forebrain, arousal and sleep-wake cycle, attention and memory
ventral tegmental area (VTA) is located in what region of the brain, and what is its function
ventral tegmental area (VTA) located in the midbrain controls reward processing, aversion, stress modulation, drug addiction, learning, and memory
what is the function of the tuberomammillary nucleus of hypothalamus
Tuberomammillary nucleus of hypothalamus = arousal, learning, memory and sleep
where is the raphe nuclei located and what is it responsible for?
Raphe nuclei is found in brainstem. The raphe nuclei is responsible for appetite, sleep-wake cycle, movement, sexual function, modifies pain perception
90% of the parasympathetic nervous system is innervated by WHICH nerve
VAGUS NERVE (CN X)
Just about everything else (~90% of parasympathetic nervous system)
in short, what is cerebellum responsible
cerebellum= coordination of movement
what spinal level does the spinal cord go down to
L1/L2 VERTEBRAE (just below ribcage) is where spinal cord ends
