Intro to CNS

Question 1

what 2 things protect the brain from external environment

Answer 1

• 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.)

Question 2

where does the venous blood drain in brain?

Answer 2

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

Question 3

what protects the brain against the internal environment (aka circulating toxins, pathogens, bacteria, amoeba, viruses)

Answer 3

• BBB (Blood brain barrier)
  *BSCB (brain spinal cord barrier)
• ventricels + CSF (cerebrospinal fluid)

Question 4

Majority of CSF is produced in _____ ______, we have about 150ml of CSF at any one time

Answer 4

Majority of CSF is produced in LATERAL VENTRICLES, we have about 150ml of CSF at any one time

Question 5

the lateral ventricles are lined with what glial cell

Answer 5

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

Question 6

whichc cells of CNS are in healthy individuals usually quiescent (switched off) they only switch on when there’s an infection

Answer 6

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

Question 7

we have 2 types of neurotransmitters

Answer 7

excitatory + inhibitory

Question 8

what is adrenaline/ epinephrine + its function

Answer 8

adrenaline/epinephrine= excitatory neurotransmitter for fight/flight; produced in stressful situations. Increases heart rate + blood flow, leading to physical boost + hightened awareness

Question 9

what is noradrenaline/norepinephrine + its function

Answer 9

noradrenaline/norepinephrine= Excitatory neurotransmitter for concentration; affects attention + responding actions in the brain. Contract blood vessels, increasing blood flow

Question 10

what is dopamine + its function

Answer 10

dopamine= both a excitatory and inhibitory neurotransmitter for pleasure; feelings of pleasure, also addiction, movement + motivation. People repeat behaviours that lead to dopamine release

Question 11

what is serotonin + its function

Answer 11

serotonin= inhibitory neurotransmitter responsible for mood; contributes to well-being + happiness. Helps sleep cycle + digestive system regulation. Affected by exercise

Question 12

what is GABA + its function

Answer 12

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

Question 13

what is acetylcholine + its function

Answer 13

acetylcholine= is an excitatory mediator neurotransmitter for learning; involved in thought, learning + memory. Activates muscle action in the body. Also associated with attention + awakening

Question 14

what is glutamate + its function

Answer 14

glutamate= most common excitatory neurotransmitter and is for memory; involved in learning + memory, regulates development + creation of nerve contacts

Question 15

what are endorphins + their function

Answer 15

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)

Question 16

substantia nigra is a brain structure that is part of your basal ganglia, what is its function

Answer 16

substantia nigra essential for movement

Question 17

where is the locus coeruleus found and what is its function

Answer 17

Locus coeruleus is found in brainstem. The locus coeruleus regulates amount of NA in forebrain, arousal and sleep-wake cycle, attention and memory

Question 18

ventral tegmental area (VTA) is located in what region of the brain, and what is its function

Answer 18

ventral tegmental area (VTA) located in the midbrain controls reward processing, aversion, stress modulation, drug addiction, learning, and memory

Question 19

what is the function of the tuberomammillary nucleus of hypothalamus

Answer 19

Tuberomammillary nucleus of hypothalamus = arousal, learning, memory and sleep

Question 20

where is the raphe nuclei located and what is it responsible for?

Answer 20

Raphe nuclei is found in brainstem. The raphe nuclei is responsible for appetite, sleep-wake cycle, movement, sexual function, modifies pain perception

Question 21

90% of the parasympathetic nervous system is innervated by WHICH nerve

Answer 21

VAGUS NERVE (CN X)
Just about everything else (~90% of parasympathetic nervous system)

Question 22

in short, what is cerebellum responsible

Answer 22

cerebellum= coordination of movement

Question 23

what spinal level does the spinal cord go down to

Answer 23

L1/L2 VERTEBRAE (just below ribcage) is where spinal cord ends