Biologyv

Question 1

Label brain

Answer 1

Cerebellum
Temporal lobe - processes auditory information
Frontal lobe - Includes primary mitote cortex, higher brain functions such as decision making
Occipital lobe/Visual cortex - Processing visual information
Parietal lobe - orientation and movements

Question 2

Label brain stem

Answer 2

Spinal cord
Medulla oblongata - balance, coordinated movement as it is being carried out
Pons
Midbrain - Relays information to the cerebral hemispheres

Question 3

CT scans and MRI

Answer 3

CT -
Thousands of narrow x-Ray beams rotated around a patient
Each been is reduced in strength according to the density of tissue in its path
X-rats are detected and used to produce an image of a section of the brain
Limited resolution so they don’t show smaller structures
Provide a frozen image, show structure and bit functioning, used to monitor brain tissue over the course of an illness

MRI -
Magnetic field and radio waves to detect soft tissue
The nuclei of atoms line up with the direction of a magnetic field when placed in one
Two magnetic fields are superimposed on each other and combined they cause the axis and frequency of hydrogen nuclei to change (taking energy for radio waves to do so)
When the waves are turned off they return to their original alignment and release the absorbed energy
This energy is detected and a signal is sent to a computer which analysis it to generate an image

Question 4

fMRI

Answer 4

Makes it possible to study human activities such as memory and emotion
Radio waves aimed at brain, deoxyhemoglobin absorbs radio wave signals and oxyhemoglobin doesn’t
Increased neural activity leads to an increased demand for oxygen and an increased blood flow, meaning oxyhemoglobin levels increase and less signal is absorbed
Less signal absorbed equals higher level of activity in an area, and on an imagine different areas will light up where there are more activity

Question 5

Positron emission tomography

Answer 5

Used to help diagnose and monitor cancers, heart disease and brain disorders
Isotopes with short half lived (e.g. carbon-11) are incorporated into compounds such as glucose
These are radiotracers
A patient is injected with a radiotracer and as it decays it omits positrons
When a tissue or organ is active there is increased energy in that area and more glucose will be required, so blood flow there increases and more radiotracer will be present there, which will show on the PET image cos more positrons
It will show because when positions collide with an electron gamma rays are emitted and picked up but detector
Only fine twice s year for safety reasons and are very expensive

Question 6

Huber and Weisel

Answer 6

Monocular deprivation

Retinal cells responded to light input , but the visual cortex didn’t

Question 7

What happens during the critical period of development? (Eye context)

Answer 7

1. There is a lack of visual stimulation in one eye
2. Axons from this eye do not pass to cells in the visual cortex
3. Axons from the non-deprived eye do
4. The synapses made by active axons are strengthened
5. Inactive synapses are eliminated

Question 8

Chemical imbalances

Answer 8

Dopamine - Neurotransmitter used in the motor cortex, in Parkinson’s dopamine secreting neurone die

Serotonin - Neurotradmitter secreted in the brain stem, used in several sections it eh brain, not understood if lack of is a symptom or cause of depression (when someone is depressed fewer nerve impulses are transmitted)

Question 9

Treatments

Answer 9

Parkinson’s -
L-Dopa - Dopamine can’t be prescribed because it can’t cross into the brain from the bloodstream, but this can, and is converted to dopamine when in the brain
Dopamine agonists - active dopamine receptors directly and triggering action potentials

Question 10

MDMA

Answer 10

MDMA - Increases serotonin conc in synaptic cleft by binding to molecules in the presynaptic membrane responsible for transporting serotonin back into the cytoplasm, preventing its removal from the synaptic cleft

Is a drug in ecstasy