Brain And The Body Flashcards
How much the does human brain weight
1.4kg
Does brain mass effect intelligence
It does not as humans have a greater brain weight to body weight
How has the brain size changed over the years
It has increased however the size is restricted but the size of the birth canal
How is the brain divided
It is divided into 2 hemispheres connected by the corpus collosum which has 200 neurons cross between
Where does connections between neurons take place
Grey matter
Where does the execution of motor action take place
Cerebellum
What is the Pons involved
Sleep and arousal
what is medulla involved in
reflexive actions
what are the 3 sensory regions in the lobe
motor cortex
sensory cortx
olfactory cortex
where does language take place in the brain
parietal and temporal lobes
what is a neuron
electrically excitable cells that communicate with other cells through synapse
what are the components of a neuron
soma - holds organelles
dendrites
axon
axon termina;
how is electrical activity conducted in neuron
outside of cell is sodium and inside is potassium, potassium-sodium takes in 2 K for 3 NA making cell negative creating -65mv resting potential. when NT bind to receptors ion channels convert chemical to electrical signals. sodium channels open causing flood of NA changing the resting potential when it hits threshold of -55mv it triggers action potential called depolarization. if there is a positive charge influx causes EPSP but if chloride flood it makes it harder as it causes IPSP. when action potential is triggered sodium channels open leading to rapid depolarization and when cell his 40mv the NA channels become inactive and K channels open leading to hyperpolarization
What happens at the synapse
synaptic transmission
what are the 2 kinds of NT
Excitatory NT - allow soidum to flow into post neuron
Inhibitory NT - allow for chloride to flow into post neuron
examples of E-NT
Glutamte and DA
examples of I-NT
GABA and SA
What are Agonits
increase effect of NT
what are antagonists
decrease effect of NT
What is Benzodiazepine an example of
indirect GABA agonist
what is curare an example of
direct acetylcholine antagonist
how was the brain studied historically
Post-mortem examinations e.g Tans PME found a big lesion in his broca’s area causing his expressive aphasia
How does MRI work
Magnetic fields and radio waves producing image based on hydrogen ions in body
how does a structural mri work
measure the amount of hyrdrogen are in structures of the brain being used and form an image the darker the image the more hydrogen
how does function MRI work
measures blood-flow changes in task changes
measures the protons released when hemoglobin in oxygenated blood releases oxygen
what is a strength of MRI
high spatial resolution
what is a weakness of MRI
low temporal resolution
how does an EEG work
non-invasive scan using up to 100 electrodes which has high temporal resolution but low spatial resolution
how does an MEG work
brain electrical current are associated with magnetic fields MEG records mag fields from outside the head / Better spatial resolution
what is a hormone
chemical messenger that travels in the bloodstream and targets other organs
why are hormones slower
because they travel in the bloodstream
what are some examples of hormones
testosterone/ Oestrogen/ insulin/ Ghrelin/ Adrenaline
what is the endocrine system
a network of glands that produce hormones to regulate bodily function
how does the adrenal glands work
it had 2 parts the medulla and the cortex
the adrenal medulla secretes adrenaline under the sympathetic control and maintaining fight or flight by increasing heart rates and breathing and it stays in the system for a while
how does the release of cortisol happen
hypothalamus releases CRH which triggers the pituitary glands to release ACTH which flows in the blood to the adrenal gland which releases cortisol
what are the pros and cons of cortisol
s: makes energy available by breaking down proteins into energy/ breaking down fats and affecting glucose metabolism
w: long term stress can have significant effects on the body as all parts have cortisol receptors which effect hormonal balance
