Week 1 - Exploring the Brain Flashcards by Emilia Anning

What does the brain do?

Input -> communication -> output

Sensing -> processing -> effect

How well did you know this?

Not at all

Perfectly

How is the nervous system organised?

Input and output -> Peripheral nervous system (PNS)

Communication -> Central nervous system (CNS)

How well did you know this?

Not at all

Perfectly

How is the PNS organised?

Autonomic Nervous System:

Internal environment -> sensory neurones -> CNS -> motor neurones

Somatic Nervous System:

External environment -> sensory neurones -> CNS -> motor neurones

How well did you know this?

Not at all

Perfectly

Input and Output

Input -> SENSORY

Output -> MOTOR

How well did you know this?

Not at all

Perfectly

What are dermatomes sensation?

The idea that different vertebrae correlate with different parts of the body for sensational experiences

How well did you know this?

Not at all

Perfectly

What is dermatomes movement?

Different vertebrae controlling movements of different body parts

How well did you know this?

Not at all

Perfectly

What are the two parts of the autonomic nervous system?

Sympathetic (fight or flight)
[if someone is in this state you feel sympathy for them]

Parasympathetic (rest and digest)
[if someone is paralysed they’re rested]

How well did you know this?

Not at all

Perfectly

What are some signs of the sympathetic division?

Stimulatory:
Dilated pupils, constricted blood vessels, inhibits salivation, relaxes airways, increases heart rate, inhibits digestion, stimulates glucose release, secretion of adrenaline, contracts bladder, stimulates ejaculation

How well did you know this?

Not at all

Perfectly

What are some signs of the parasympathetic division?

Inhibitory:
Contracts pupil, stimulates salivation, contracts airway, slows heartbeat, stimulates digestion, dilates blood vessels, stimulates bladder, stimulates erection

How well did you know this?

Not at all

Perfectly

What structures of the brain is the brain stem made up of?

Midbrain
Pons
Medulla

How well did you know this?

Not at all

Perfectly

What structures of the brain is the diencephalon made up of?

[sometimes considered part of brain stem]

Thalamus and hypothalamus

How well did you know this?

Not at all

Perfectly

What is the forebrain made up of?

Cerebral hemisphere

[Diencephalon]

How well did you know this?

Not at all

Perfectly

How does information flow through the brain?

Inputs from senses, outputs to muscles or organs

In each region inputs come from upstream and downstream regions

(What a region does depends on the nature of the inputs and outputs and how the information is integrated in that area)

How well did you know this?

Not at all

Perfectly

What is the cerebellum?

A layered structure of the brain.

Involved in refined movements (maybe even thoughts) such as balance and procedural memory.

How well did you know this?

Not at all

Perfectly

What is the thalamus?

The “information hub” that relays ascending and descending information from widespread areas of the brain

How well did you know this?

Not at all

Perfectly

What is the hypothalamus?

Regulates several homeostatic processes such as feeding and drinking.

Links brain to the endocrine system (hormones).

What is the cerebrum?

The cerebral cortex.

Subcritical structures such as the hippocampus, basal ganglia, amygdala and olfactory bulb.

What is the role of the cerebral cortex?

Computations such as sensation, movement, decision making.

What are the three types of Glia and what are their roles.

Astrocytes -

Oligodendrocytes -

Microglia -

What are the main structures of a neuron?

Soma (integration), dendritic tree, axon terminal(output), myelin sheath, axon, axon hillock.

How do we transmit information within a neuron?

ELECTRICAL transmission: action potentials and synaptic potentials.

How do we transmit information between neurones?

CHEMICAL transmission: at synapses

What is an ion? Give 2 examples and state whether they are positively or negatively charged.

Ions are electrically charged particles.

Sodium - Na+ (positive)
Calcium - Ca2+ (positive)
Potassium - K+ (positive)
Chlorine - Cl- (negative)

What is the resting membrane potential?

-70 mV

What are ion channels?

Holes in the membrane that allow ions to enter and leave the cell. They’re selective for different ions. Can be open all the time. Or opened by stimuli. Ions flow down electrical and chemical concentration gradients.

What is an action potential?

Conveys a fast signal from one place to another in the body. Generated by changes in the membrane permeability due to opening and closing of voltage gated ion channels. Self regenerating electrical wave. Transient change in membrane potential. Occurs only if a threshold membrane potential is reached.

List the action potential events.

1) threshold potential is reached 2) depolarisation due to opening of sodium channels 3) depolarisation due to inactivation of sodium channels and opening of voltage gated potassium channels 4) hyper polarisation as voltage gated potassium channels are still open

What is the all or nothing theory?

Positive feedback. | Action potentials either completely happen or they don’t.

What is action potential propagation?

Action potentials propagate along axons They are the same size all along The action potential depolarises adjacent bits of membrane and opens sodium channels there If enough sodium channels are opened a threshold potential is reached

What is a ligand gated channel?

A channel that opens when a molecule binds to it

What are excitatory/inhibitory?

Makes action potentials more/less likely to happen.

What happens at the post synaptic membrane? [excitation - glutamate]

Depolarisation of dendrites by ion flow through glutamate receptors and generates an excitatory post-synaptic potential (EPSP). This drives the membrane potential towards the threshold of action potential firing.

What is usually needed to get an action potential generated?

(Temporal) summation. Where lots of EPSPs summary over time to reach necessary threshold.

What other kind of summation can trigger an action potential?

SPATIAL summation. Where lots of synapses are active at the same time and trigger a response.

Why does a larger stimulus produce a higher rate of action potentials?

Codes for more information and so releases more neurotransmitter.

What is the main inhibitory neurotransmitter in the brain and how does it function?

GABA. It opens chloride channels allowing negative charge into the cell, generating and IPSP (inhibitory post-synaptic potential). This hyper polarises the membrane, driving it away from the threshold of action potential firing.

What is synaptic integration?

The summation of exciting and inhibitory inputs. ``` Inputs = synapses Computation = integration Outputs = action potential ```