Tired BIMS Student

Central nervous system

Glutamate 

GABA 

Glycine 

Dopamine 

Serotonin 

Noradrenaline 

Histamine 

Orexin 

Endorphins 

Peripheral nervous system 

Noradrenaline 

Acetylcholine 

Neurotransmitter synthesis/packaging 

Some neurotransmitters are readily available amino acids eg Glutamate, glycine 

Some are synthesised by the cells that secrete them eg GABA, noradrenaline, dopamine 

Noradrenaline synthesis:

Packaging

In the presynapse, neurotransmitter is contained in vesicles 

The neurotransmitter must be packaged into the vesicle ready for release 

Uses transporters and proton gradients to package 

[packaging and release - above]

Neurotransmitter release is quantal – Each vesicle contains the same amount of neurotransmitter 

Therefore it is the number of vesicles fusing which determines the post synaptic potentials 

membranes must fuse for release - membrane fusion is energetically unfavourable so must be catalysed by something

SNARE Hypothesis 

Proteins on the presynaptic membrane ‘grab’ proteins on the vesicle membrane 

These SNARE proteins pull the two membranes close together 

SNARE proteins provide most of the energy for membrane fusion

v-SNARE (VAMP2) – on vesicle membrane 

t-SNAREs (syntaxin1A, SNAP-25) on target membrane 

Bind together to make SNARE complex 

 SNARE ‘zippering’ forces the membranes close together 

Spontaneous, highly energetically favourable 

Once assembled, they require ATP hydrolysis to separate them 

 Ca2+ binding to synaptotagmin provides extra energy to fuse the membranes

Neurotransmitter release

synaptic vesicle release sites are highly organised and regulated

exocytose into synaptic cleft

presynaptic active zone:

Neurotransmitter detection

Ionotropic (ion channel coupled) – Glutamate, GABA, Glycine 

Metabotropic (G-protein coupled) – monoamines, histamine etc. 

Some have both kinds, e.g. glutamate, GABA 

Ionotropic responses are faster 

Metabotropic responses can have more diverse effects 

Glutamate receptors

Glutamate is the main excitatory neurotransmitter in the brain 

Three classes of ionotropic receptor – AMPA – NMDA – Kainate 

 Named after pharmacological agonists 

All let in positive ions when they bind glutamate 

Glutamate also has a family of metabotropic receptors – mGluRs – These modulate neurotransmission 

AMPA Receptors 

 Main fast excitatory receptor 

Strength of a synapse is largely determined by its complement of AMPARs

 More AMPAR in the post-synaptic membrane = stronger synaptic transmission 

NMDA Receptors 

Minor role in postsynaptic firing 

Major role is in synaptic plasticity 

NMDA receptors are calcium permeable 

Normal acid production in body 

VOLATILE ACIDS: 

Produced by oxidative metabolism of CHO, Fat, Protein 

Average 15000-20000 mmol of CO₂ per day 

Excreted through LUNGS as CO₂ gas 

FIXED ACIDS (1 mEq/kg/day)

 Acids that do not leave solution ,once produced they remain in body fluids until eliminated by kidneys

 Eg: Sulfuric acid, phosphoric acid

 Organic acids 

Are most important fixed acids in the body

generated during catabolism of: amino acids(oxidation of sulfhydryl gps of cystine,methionine) Phospholipids (hydrolysis) and nucleic acids 

Regulation

Buffers 

Moderate changes in pH 

Combine with or release H+, cellular proteins, phosphate ions, haemoglobin, or bicarbonate 

Lungs 

Ventilation = rapid response, corrects 75% of disturbances; can also cause them 

Renal regulation 

Receptor-mediated endocytosis 

Directly by excreting or reabsorbing H+ 

Indirectly by changing in the rate at which HCO3– buffer is reabsorbed or excreted 

Imbalances

Normal pH : 7.35-7.45 

Acidosis  = abnormally low plasma pH - Acidemia: plasma pH < 7.35

Alkalosis = abnormally high plasma pH - Alkalemia: plasma pH > 7.45 

Metabolic acidosis: dietary and metabolic input of H+ exceeds excretion 

Metabolic alkalosis: loss of H+ through excessive vomiting or excessive ingestion of bicarbonate-containing antacids

Repository:  hyperventilation or hypoventilation cause pH to shift when PCO2 changes

Hi Everyone! 

Update: I am now officially done with my second year! I know i’ve been MIA on here for a while now - but that’s only because I was drowning in textbooks and assignments! I will be writing a whole other post on what my second year in medical school was like - so watch out for that :)

I, for one, can not just rely on one method of learning. Meaning, I’ll jump from videos, to textbooks, to flashcards. In this post I’m going to list some of my holy grail youtube channels that have helped saved me. 

1) Handwritten Tutorials

https://www.youtube.com/user/harpinmartin

Every video in this channel is short, but not so much that you feel like you’re missing out on information. Definitely one to save as a favourite!

2) Armando Hasudungan

https://www.youtube.com/user/armandohasudungan

The best thing about this channel is the fact that there are over 300 videos, covering a wide range of core topics in endocrinology, neurology, physiology and pharmacology. Another pro is the presentation of topics (otherwise considered snooze-worthy) in an artistic manner!

3) Speed Pharmacology

https://www.youtube.com/channel/UC-i2EBYXH6-GAglvuDIaufQ

Raise your hand if you’ve ever fallen asleep trying to read about the mechanism of action of opioids, their side effects and contraindications. I know I have. Fret not, for this youtube channel will introduce you to a world where pharmacology is actually interesting.

4) Wendy Riggs 

https://www.youtube.com/user/wendogg1

Wendy Riggs is a very down-to-earth professor in Northern California, and she covers a wide range of  topics in Anatomy, Physiology and General Biology. 

5) Anatomy Zone

https://www.youtube.com/user/TheAnatomyZone

A better way to learn anatomy is to supplement your textbook information with videos from this channel. The explanations and visuals provided are absolute gold.

Requested by anonymous: Human Physiology, The Nervous System. Includes: Organization of the NS, Structure of a Neuron, Reflex Arc, Nerve Impulse, Synapse.

Central nervous system

Glutamate 

GABA 

Glycine 

Dopamine 

Serotonin 

Noradrenaline 

Histamine 

Orexin 

Endorphins 

Peripheral nervous system 

Noradrenaline 

Acetylcholine 

Neurotransmitter synthesis/packaging 

Some neurotransmitters are readily available amino acids eg Glutamate, glycine 

Some are synthesised by the cells that secrete them eg GABA, noradrenaline, dopamine 

Noradrenaline synthesis:

Packaging

In the presynapse, neurotransmitter is contained in vesicles 

The neurotransmitter must be packaged into the vesicle ready for release 

Uses transporters and proton gradients to package 

[packaging and release - above]

Neurotransmitter release is quantal – Each vesicle contains the same amount of neurotransmitter 

Therefore it is the number of vesicles fusing which determines the post synaptic potentials 

membranes must fuse for release - membrane fusion is energetically unfavourable so must be catalysed by something

SNARE Hypothesis 

Proteins on the presynaptic membrane ‘grab’ proteins on the vesicle membrane 

These SNARE proteins pull the two membranes close together 

SNARE proteins provide most of the energy for membrane fusion

v-SNARE (VAMP2) – on vesicle membrane 

t-SNAREs (syntaxin1A, SNAP-25) on target membrane 

Bind together to make SNARE complex 

 SNARE ‘zippering’ forces the membranes close together 

Spontaneous, highly energetically favourable 

Once assembled, they require ATP hydrolysis to separate them 

 Ca2+ binding to synaptotagmin provides extra energy to fuse the membranes

Neurotransmitter release

synaptic vesicle release sites are highly organised and regulated

exocytose into synaptic cleft

presynaptic active zone:

Neurotransmitter detection

Ionotropic (ion channel coupled) – Glutamate, GABA, Glycine 

Metabotropic (G-protein coupled) – monoamines, histamine etc. 

Some have both kinds, e.g. glutamate, GABA 

Ionotropic responses are faster 

Metabotropic responses can have more diverse effects 

Glutamate receptors

Glutamate is the main excitatory neurotransmitter in the brain 

Three classes of ionotropic receptor – AMPA – NMDA – Kainate 

 Named after pharmacological agonists 

All let in positive ions when they bind glutamate 

Glutamate also has a family of metabotropic receptors – mGluRs – These modulate neurotransmission 

AMPA Receptors 

 Main fast excitatory receptor 

Strength of a synapse is largely determined by its complement of AMPARs

 More AMPAR in the post-synaptic membrane = stronger synaptic transmission 

NMDA Receptors 

Minor role in postsynaptic firing 

Major role is in synaptic plasticity 

NMDA receptors are calcium permeable 

[10.26.16] chapter 5 anatomy notes! (Types of tissues) im so tired these days :( but i did pretty well on my anatomy test so im proud!