Neuroscience

Question 1

What are the two major divisions of the nervous system and what do they control?

Answer 1

Central nervous system - brain and spinal cord

Peripheral nervous system - motor nerves, autonomic nervous system, sensory nerves, enteric nervous system

Question 2

In the peripheral nervous system what is the input/output of the two parts?

Answer 2

Sensory - input to cns from sensory organs

Motor - output from CNS to muscles

Question 3

What is the function of the autonomic nervous system?

Answer 3

Controls many non-voluntary functions e.g. Digestion, heart rate sweating pupil size genitals

Question 4

What are the two branches of the autonomic nervous system?

Answer 4

Sympathetic - prepares for action

Parasympathetic - involved in rest and recuperation

Question 5

What is the enteric nervous system?

Answer 5

Controls digestive activity (peristalsis and secretion of enzymes) and sense physical and chemical conditions of the gut.

Question 6

What are the brain and spinal cord protected by?

Answer 6

Bone, meninges, blood brain barrier

Question 7

What is the meninges?

Answer 7

Flexible sheet made from 3 membranes, between bone and nervous tissue.

Question 8

What are the 3 membranes of the blood brain barrier?

Answer 8

Pure mater
Arachnid membrane
Pia mater

Question 9

What is the function of the blood brain barrier?

Answer 9

Protect brain and spinal cord –> particular blood vessels that have special walls restricting entry of many chemicals.

Question 10

What are the ventricles of the brain?

Answer 10

• cavities inside the brain, filled with cerebrospinal fluid

- sewage system of the CNS

Question 11

What are the 7 major subdivisions of the brain?

Answer 11

Brain stem
Cerebellum
Thalamus and hypothalamus
Limbic system
Basal ganglia
Neocortex
Corpus collosum

Question 12

What can happen if damage occurs to the brain stem?

Answer 12

Coma and death due to increase in intracranial pressure squashing brain stem.

Question 13

Where and what is the function of the cerebellum?

Answer 13

Top of brain stem - control of precision movements, densely packed with neurons.

Question 14

What is the function or the limbic system?

Answer 14

Control of emotion and memory

Question 15

What is the function of the basal ganglia?

Answer 15

Involved in action and thought - at any time variety of actions, basal ganglia determines what you do.

Question 16

Where is the basal ganglia and neocortex located?

Answer 16

Basal ganglia - wraps around thalamus

Neocortex. - convoluted sheet on top of brain

Question 17

Why is the neocortex convoluted?

Answer 17

• increased surface area

- thickness remains fixed.

Question 18

What are the four lobes of the neocortex and what are their functions?

Answer 18

1. Frontal lobe - support planning and many executive decisions
2. Parietal lobe. - understanding space and how to move in it
3. Temporal lobe - memory and language
4. Occipital lobe - vision

Question 19

What is the sophistication of our brain due to?

Answer 19

High speed of information AND complexity of connections between neurons.

Question 20

What is the function of myelin?

Answer 20

Prevents depolarisation

Speeds up propagation of action potential

Question 21

What have we learned from knowledge of neuronal function?

Answer 21

Certain Drugs work by interfering with action potentials e.g. Anaesthetics prevent opening of ion channels

Question 22

What two types of neurotransmitters are there?

Answer 22

Excitatory - promote action potential in 2nd neuron

Inhibitory - block action potential

Question 23

TMS (transcranial magnetic stimulation) studies the brain how?

Answer 23

• magnetic pulse to induce electrical current which depolarises neurons and provokes action potentials

Question 24

What is the function of an EEG?

Answer 24

Electrodes plates against skull record elective all fields by activity of many neurons –> good temporal resolution poor spatial resolution

Question 25

What does positron emission tomography measure?

Answer 25

Activity in Brain by measuring changes in Blood flow by using radioactive labelled glucose

Question 26

How does PET work?

Answer 26

Records amount of oxygen in areas of the brain --> bad areas will draw more blood as they require more oxygen.

Question 27

How does magnetic resonance imagine or MRI work?

Answer 27

Bombards head with high frequency radio waves measures orientation of protons - identifies different types of brain tissue.

Question 28

What does fMRI measure?

Answer 28

Changes in oxygen in blood

Question 29

What does magnetoencephalography (MEG)do and what does it measure?

Answer 29

Measures magnetic fields emitted from brain to create 3D visualisation of where electrical activity arises from --> creates functional map of brain response.

Question 30

What keeps us awake?

Answer 30

Noradrenaline neurons, in locus coeruleus, serotonin neurons, and acetylcholine neurons in pons.

Question 31

What is caused by destruction of the pre optic area?

Answer 31

Insomnia and stimulation can cause sleep.

Question 32

What is sleep characterised by?

Answer 32

Rhythmic patterns of electrical activity in the brain.

Question 33

What is rem sleep?

Answer 33

At multiple times through the night brain becomes desynchronised, rapid eye movement. If woken we typically report we are dreaming.

Question 34

What is rem sleep caused by?

Answer 34

Caused by neurons in pons that contain acetylcholine and stimulates neurons in the thalamus, which project to the visual cortex.

Question 35

What does the destruction of the lateral hypothalamus do in rats?

Answer 35

Stop eating dramatically. Weight drops until rat begins eating but only a fraction of what is previously ate and weight becomes stable but much lower than before.

Question 36

What is lateral hypothalamus feeding control by?

Answer 36

Controlling release of insulin Regulating attention Influencing taste

Question 37

What does the destruction of the hypothalamus cause?

Answer 37

Rats - over eaters, making them gain weight quickly | However each meal is normal size but they eat more often

Question 38

Are the two hemispheres mirror images of each other?

Answer 38

No - several higher functions are lateralised , one side is more important. Eg hand preference

Question 39

What is the evidence for the lateralisation of language?

Answer 39

Stokes in left cause aphasia (problems with speech) Brain imaging - left hem more active when person list be to speech Dichotic listening task - people understand word better if presented to right ear.

Question 40

What does damage to Broca's area cause?

Answer 40

Difficulties speaking and can understand speech.

Question 41

What does damage to wernickes area cause?

Answer 41

Problems with comprehension - produces fluent but meaningless speech.

Question 42

What is weird about split brain patients?

Answer 42

Still walk talk and suffer little impairments to intelligence or emotion but differences in what right and left hands do.

Question 43

What is the most commonly know function of the right hemisphere?

Answer 43

Memory structure

Question 44

What is hippocampal amnesia?

Answer 44

Damage to the hippocampus - remember old events but can't learn anything new.

Question 45

What is Wernickes-Karsakoff's syndrome caused by and does it lead to?

Answer 45

Severe deficiency in vitamin D in alcoholics Confusion, disordered gait and eye movements May lead to profound amnesia