8B Ppqs Flashcards
Using info in graph and table and your own info, comment on MDMA induced brain swelling
From graph: -as MDMA concentration in blood increases, ADH concentration increases
From table: -after 9 hours of taking MDMA ADH levels remain high/3x that at 96 hours
- as ADH concentration increases, sodium ion concentration in blood decreases
- brain swelling associated with lower sodium ion concentration in blood
From own knowledge
-ADH increases water reuptake by kidney
(Don’t mention increased osmosis causing brain swelling)
Describe relationship between light intensity and pupil diameter with incandescent and led light
-as light intensity increases, pupil diameter decreases
-LED lights cause greater reduction in pupil diameter than incandescent light
Describe how light entering eye causes pupil to respond
1- light detected by rods and cones in retina
2- reflex arc formed from sensory neurons, relay neurons and motor neurons
3- transmits impulses to muscles in the iris
4- radial relax, circular contract constricting pupil
What is meant by pluripotent stem cell
Continuously dividing cell
That can give rise to many different cell types
The epithelial layer is checked out to ensure that there are no stem cells present before it is placed in the eye of the patient
Why is this carried out?
Stem cells can continue to divide
Stem cells can differentiate into other cell types
Note
L-dopa crosses blood brain barrier and then is converted into dopamine
Explain why the release of reduced quantities of dopamine by presynaptic neuron could result in motor symptoms
-fewer dopamine molecules bind to sodium channels/receptors
-on post synaptic membrane
-fewer action potentials in post synaptic neuron
-fewer impulses sent to parts of the brain controlling motor function/muscles
Medulla oblongata function
Non conscious control of body processes, cardiac control
Cerebellum function
Balance and coordinating movement
Describe how positron emission tomography (pet) could be used to identify what parts of the brain are involved in a seizure
1) isotope incorporated into glucose
2) more active neurons with increased respiration
3) will require increased supply of glucose
4) positrons emitted from glucose produce gamma rays that are detected and converted into an image
Some seizures result in increase of body temperature
1) impulses from neurons at site of seizure
2) arrive at thermoregulatory center in hypothalamus
3) impulses sent to reduce sweating, increase metabolic rate
Parkinson’s disease affects movement
Some neurons in brain die and symptoms are due to loss of neurons producing dopamine
Describe how q neurotra skitter transmits nerve impulse across a synapse
1- impulse at pre-synaptic knob opens Calcium ion channels
2- calcium ions diffuse in causing vesicles with neurotransmitter to fuse with pre-synaptic membrane
3- neurotransmitter released into synaptic cleft and binds to receptors on post synaptic membrane
4- opening sodium channels
5- depolarisiny membrane and initiating action potential
Scientists can use pluripotent stem cells to produce transcription factors involved in the synthesis of dopamine.
Explain how transcription factors are involved in the synthesis of dopamine
-Transcription factors bind to DNA involved in synthesis of dopamine
- Allowing mRNA synthesis
- that is translated to produce enzymes that synthesize dopamine
Comment on results of parkinson’s and lrrk2
-mean number and length of dendrites decrease in lrrk2 and Parkinsons compared with control neurons
- error bars do not overlap bw parkinson’s disease and lrrk2 neurons
- error bars overlap bw parkinson’s disease and lrrk2 neurons
- number of dendrites the same for both groups but length longer in lrrk2 group
The size of the pupil changes when moving from dim to bright light. Explain how this change occurs
1) pupil becomes smaller so less light enters eye
2) circular contract radial relax
3) circular muscles arrange in concentric rings around pupil and radial run radially
4) pupil reflex is a reflex contracting and relaxation of antagonistic muscles in iris
