Neurobiology

Question 1

what makes up the CNS?

Answer 1

brain and spinal cord

Question 2

what makes up the peripheral nervous system?

Answer 2

somatic (sensory info and signals from CNS to muscles) and autonomic (regulates internal environment)

Question 3

whats the difference between parasympathetic and sympathetic nervous system?

Answer 3

para - generally calming

sympathetic - generally arousing

Question 4

what makes up the forebrain?

Answer 4

basal ganglia, cerebral hemisphere, diencephalon

Question 5

what makes up the midbrain and hindbrain?

Answer 5

brain stem which is made up of midbrain, pons, medulla oblongata
hindbrain makes it all up and also includes the spinal cord and cerebellum

Question 6

what makes up a neuron?

Answer 6

cell body/soma, dendrites, axon, axon hillcock, axon terminal

Question 7

function of cell body and axon?

Answer 7

cell body - integrates input and converts to output

axon - conducts output signal and terminal transmits the output

Question 8

what are microglia?

Answer 8

small mesodermally derived, defensive function - immune cells of the CNS - can become macrophages

Question 9

what are astroglia?

Answer 9

star shaped, symmetrical, nutritive and support function
support neurons by physically separating cells
- regulating K conc
- remove neurotransmitters after they’ve been realised by neurons
- release growth factors

Question 10

what’s the potential of the inside of the cell?

Answer 10

-50 - 70mV (inside more negative than outside)

Question 11

whats the action potential graph like?

Answer 11

steady then curves up to overshoot (+40mV)
dips to the undershoot (-70mV)
raises again to resting potential (-65mV)

Question 12

what’s the action potential?

Answer 12

sodium/potassium pump action - it propagates down the axon

Question 13

why can’t the action potential go backwards?

Answer 13

due to the absolute refractory period - recovery time

Question 14

why is mylein important?

Answer 14

insulates to prevent leakage of ions - help action potentials travel faster

Question 15

what’s synaptic transmission?

Answer 15

action potentials depolarise the axon terminal causing the fusion of vesicles to the plasma membrane and release of neurotransmitters

Question 16

what are the two types of receptors?

Answer 16

ionotropic - ligand gated

metabotropic - g-protein receptors

Question 17

how do excitatory transmitters work?

Answer 17

activate receptors that allow sodium influx driving towards action potential

Question 18

how do inhibitory transmitters work?

Answer 18

activate receptors that allow chlorine influx which drives away from action potential threshold

Question 19

how does our brain make sense of the world?

Answer 19

detect physical stimulus to transduce it into a change in membrane potential to convert it into action potentials in sensory cell to transmit signal to sensory regions of brain to perception or conscious experience

Question 20

how does the eye work?

Answer 20

light focused by retina - where transduction of the light occurs
photoreceptors pass info on to ganglion cells which then have the axons that come together to make up the optic nerve
detection of light by rods and cones

Question 21

where does the information from your right eye go?

Answer 21

to the left hemisphere

Question 22

whats in the somatosensory system?

Answer 22

skin receptors 
free nerve endings - temp and pain
hair follices - touch moving hair 
meissners corpuscles - light touch 
merkels discs - pressure
ruffinis endings - pressure 
pacinian corpuscles - vibration

Question 23

why can we tell if there are two things touching our skin?

Answer 23

receptor density and number of sensory neurons touched

Question 24

where does sensory info come in?

Answer 24

dorsal root ganglion cell

Question 25

parts that make up the spinal cord?

Answer 25

cervical cord, thorasic cord, lumbar cord, sacral cord

Question 26

how is sensory info transmitted?

Answer 26

info travels up dorsal column into medulla, here the dorsal column nuclei recieve the info and pass it onto the brain, axons cross over to the other side and travel through the brain stem to the thalamus and another synapse here which will send it to the cortex

Question 27

where do we get most of our sensory info?

Answer 27

fingers, lips

Question 28

types of muscles?

Answer 28

smooth, cardiac, striated

Question 29

what helps us move?

Answer 29

motor neurons, unevenly distributed - more in legs

Question 30

how does reflex work?

Answer 30

simple motor action, evoked by a sensory stimulus

Question 31

types of reflex?

Answer 31

stretch - movement autogenic inhibition reflex - prevents over stretch flexor - withdrawl in response to harmful stimuli crossed extensor - distributes load evenly

Question 32

how does stretch reflex work?

Answer 32

action potentials flow through axon from muscle spindle into spinal cord to the motor neuron where glutamate is used to stimulate the sensory neuron and this causes the muscle to retract

Question 33

which neurones are involved with pain reflex?

Answer 33

flexor, excitatory neurons and motor neurons

Question 34

what is locomotion controlled by?

Answer 34

neural networks, central pattern generations

Question 35

what does the motor cortex do?

Answer 35

complex and precise movements - lateral pathway is fine movements

Question 36

what does the basal ganglia do?

Answer 36

voluntary movements

Question 37

what does the cerebellum do?

Answer 37

coordination of movements, error detection copy of commands sent to cerebellum, as is sensory feedback, the two then compared and if feedback differs from expected the error can be rectified

Question 38

what do the four lobes do?

Answer 38

temporal - auditory perception pariteal - somatic sensation occipital - visual perception frontal - motor control

Question 39

ways to study brain functions?

Answer 39

EEG, PET scan, fMRI

Question 40

what do split brain patients do?

Answer 40

if two objects, draw one but say the other

Question 41

what are the symptoms of parkinsons?

Answer 41

tremours, akineasia (difficulty initiating movement), bradykinesia (slow movements), shuffling gait

Question 42

what causes parkinsons and how is it treated?

Answer 42

loss of dopaminergic neurons of the substantia nigra | deep brain stimulation, pharmacological 2-DOPA

Question 43

what is alzheimers and what are the symptoms?

Answer 43

neurofibrillary tangles and amyloid plaques disrupted brain function and shrinkage of brain tissue memory loss, language difficulties, progressive dementia

Question 44

what is motor neuron disease and how is it managed?

Answer 44

progressive loss of motor neurons, death within 3/4 years no effective treatment managed through glutamate mediated excitotoxity, protein aggregates and mitochondria dysfunction