7. Nervous Systems + Neurons Flashcards
What is a neural unit?
Individual neurones that contain specialised features (dendrites, cel body, axon)
What are neuronal fibres?
The outgrowths of neurons e.g. axons and dendrites
What is Dale’s Law?
How can neurons be specialised according to function and location?
Change shape, size and structure
Describe the structure and possible functions of anaxonic neurones?
Describe the structure and possible functions of bipolar neurones?
Found often in sensory regions with very specific receptors instead of general dendrites. They have a cell body in the middle of the axon.
Describe the structure and possible functions of unipolar neurones?
They have the the cell body pinched off to one side in the middle of the axon.
Describe the structure and possible functions of multipolar neurones?
aka the alpha motor neuron. Cell body with dendrites extending from it and one long axon.
What are neuroglia?
What do ependymal cells do?
What do astrocytes and oligodendrocytes do?
What do microglia do?
Where might ependymal cells, microglia, astrocytes and oligodendrocytes be found?
CNS
What do satellite cells do?
What do Schwann cells do?
Where might Schwann cells and satellite cells be found?
PNS
What does an axon do?
Signal output, pass information to subsequent neuron
What do dendrites do?
Transmits information from sensory receptors and other neurones
What do cell bodies do?
Integrates information + has a nucleus
What is the axon hillock?
What is a phase response?
Stim
What is a tonic response?
Stimulus keeps firing
What is stress?
Anything that throughs your body out of homeostatic balance.
What is allostasis?
The maintenance of stability (homeostatic balance) through physiological / behavioural change. Process involves how an organism can prepare to
Describe the stress response
- Hypothalamus releases corticotropin-releasing hormone
- This acts on the pituitary gland to release adrenocorticotropic hormone
- This acts on the adrenal gland to release glucocorticoids from the adrenal cortex or hormones from the adrenal medulla (epinephrine and norepinephrine = adrenaline and noradrenaline).
What is the name given to daily biological cycles?
Circadian rhythms (process C)
How long is a daily biological cycle and what types of things are regulated?
around 24hrs
e.g. alertness, temp. , hormones
What is the suprachiasmatic nucleus?
The brain’s master circadian pacemaker (control centre for sleep-wake)
Specialised group of hypothalamic cells that receives info on light exposure from ganglion cells in the retina.
It activates melatonin secretion by pineal gland
How do we measure the circadian rythms?
Measure melatonin (sleep-promoting hormone) is measured via saliva or blood samples
Where is melatonin secreted?
Pineal gland (at night)
How does melatonin production differ throughout the day? Why does it do this?
Melatonin production increases in the evening, peaks in the middle of the night and decreases to normal daytime low by early morning.
This is because melatonin is suppressed by light exposure
What is the dim light melatonin onset?
Time that melatonin levels rise above threshold under dim light conditions in lab
Stat 4 consequences of insufficient sleep + circadian misalignment
Cognition + academic performance
Safety (road collisions)
Mental health
Physical health (obesity + long-term conditions)
SLIDE 23 OREXIN
TRANSPLANTATION PARADIGM
State 4 neurochemicals that phase shift in a pattern similar to light **
Glutamate
NMDA
GRP
HA
State 3 neurochemicals that phase shift in a pattern similar to behavioural stimuli *******
NPY
O5HT Agonist
GABA Agonist
