neurobiology Flashcards
1
Q
What are the three regions of the brain
A
- hindbrain
- midbrain
- forebrain
2
Q
What are the two regions in the hind brain
A
- medulla oblongata
- cerebellum
3
Q
What are the six regions in the forebrain
A
- limbic system
- hypothalmus
- thalamus
- hyptoahlamus and thalamus
- cerebrum
- hippocampus
4
Q
What is the function of the medulla oblongata
A
involved with the control of heart rate, ventilation and blood pressure and contains many important centres of the autonomic nervous systems
5
Q
What is the function of the cerebellum
A
involved with the maintenance of posture and coordination of voluntary muscular movement
6
Q
What is the funciton of the midbrain
A
contains the nerve fibres that link the forebrain to the hindbrain
7
Q
What is the role of the limbic system
A
involved in emotion, learning and memory
8
Q
What is the role of the hypothalmus
A
involved in regulating body temperature, blood solute concentration, thirst, hunger and sleep, it is the main controlling region of the autonomic nervous system and provides a link between the brain and the endocrine system via the pituitary gland
9
Q
What is the role of the thalamus
A
important relay centre, sending and recieving information to and from the cerebral cortex
10
Q
what is the role of the hypothalmus and thalamus
A
interconnect with different areas of the brain including hippocampus
11
Q
What is the role of the cerebrum
A
controls the body’s voluntary behaviour , learning, reasoning , personality and memory
12
Q
what is the role of hippocampus
A
interacts with other areas of the cortex.is involved in learning, reasoning and personality and also consolidates memories into a permanent store
13
Q
What are the four structural regions of the cerebral hemisphere
A
- frontal lobe
- temporal lobe
- parietal lobe
- occipital lobe
14
Q
What is the function of the frontal lobe
A
reasoning, personality, planning, part of speech (Broca) and movement (the motor cortex), emotions and problem solving
15
Q
What is the function of the temporal lobe
A
language (Wernicke), auditory, learning, face processing and memory
16
Q
What is the function of the parietal lobe
A
somatosensory functions, visuo spatial processing and taste
17
Q
What is the function of the occipital lobe
A
visual cortex
18
Q
What are the subdivisions of the cerebral cortex
A
- sensory areas
- motor areas
- associaiton area
19
Q
What is the role of sensory areas
A
recieve nerve impulses from receptors in the body
20
Q
What are the functions of the motor areas
A
send nerve impulses to appropriate effectors via motor neurones
21
Q
What are the functions of association areas
A
makes up most of the cerebral cortex and recieve impulses from sensory areas and associates this information with previously stored informaition (from memory) which allows the information to be interpreted and given meaning, It is also responsible for intitiating appropriate responses which are passed to the relevant motor areas
22
Q
meninges
A
three membranes: pia mater, arachnoid mater, and dura mater that line the skull and the vertebral canal surrounding the brain and the spinal cord
23
Q
ventricles
A
- four connected cavities in the brain into which the cerebro spinal fluid is secreted
24
Q
What is the brain responsible for
A
- coordination responses to sensory stimuli
25
What is the brain surrounded by
* three membranes called the meninges
26
Describe the structure of the brain and spinal cord
* brain is continuous with the spinal cords
* contain four ventricles which are continuous witht he central canal of the spinal cord so contain cerebro spinal fluid
27
What does cerebro spinal fluid do
* supplies neurones in the brain with oxygen and nutrients eg glucose
28
What is the autonomic nervous system
* part of the nervous system which controls automatic processes including heart rate , ventilation rate, blood pressure, digestion and temperature regulation
29
What are the two parts of the autonomic nervous system
* sympathetic nervous system
* parasympathetic nervous system
30
What does the sympathetic nervous system do
* generally has excitatory effects on the body
* increasing heart and ventilation rates
* most synapses in the sympathetic nervous sytem release noradrenaline as the neurotransmitter
* which has similar effect on target cells as the hormone adrenaline
31
What doe the parasympathetic nervous system do
* generaly has inhibitory effects on the body
* decreasing the heart and ventilation rates.
* most synapses in the parasympatheitc nervous system release acteylcholine as the neurotransmitter
32
cerebrum
* contains two hemispheres resoponsible for integrating senesory functions and intiitating voluntary motor function
* it is the source of intellectual function in humans where it is more developed than in other animals
33
cerebellum
* part of the hindbrain that coorinates the precision and timing in muscular activity
* contributing to equilibrium and posture and to learning motor skills
34
medulla oblongata
* part of the hindbrain that connects the brain to the spinal cord and controls involuntary autonomic functions
35
autotnomic nervous system
* the part of the peripheral nervous system that controls the automatic functions of the body by the antagonitic activity of the sympathetic and parasympathetic nervous system
36
How is heart rate regulated and controlled
* by changes in the blood pH which happen during excercise when carbon dioxide build up in the blood
* control is autonomic by the cardiovascualr centre in the medulla oblongata and requires no concious thought
37
Describe how heart rate is increased
* when chemoreceptors in the carotid artery detect falling blood pH and stimulate the cardio acceleratory centre
* this stimulates the sino atrial node via sympathetic nerve fibres to increase the rate od electrical excitation of the heart muscle
38
Describe how heart rate is decreased
* when chemoreceptors in the carotid artery detect rising blood pH and stimulate the cardio inhibitory centre
stimulates the sino artial node via parasympathetic nerve fibres to decrease the rate of electrical excitation of the heart muscle
39
What is the corpus callosum
a bundle of nerves which connects the two hemispheres of the brain
40
Describe feature of the cerebral cortex
* the outermot layer i the cerebral cortex and is highly folded which increases the area available for processing information and contains thousand of millions of neurones each with many synaptic connections
41
What is the function of the cerebral cortex
* the cerebral cortex is reponsible for concious thoughts and action
42
Describe the structure of the cerbral cortex
* cortexx consists of gry matter with many cell bodies but the inner cerebrum consists of white matter due to the prescence of myelin in the myelinated axons
43
homunculus
a drawing of the relationship between the complexity of innervation of different part of the body and the areas and positions in the cerbral cortex tha represents them
44
Describe how the size of sensory and motor areas are assciated with different parts of the body varies
* where there are large numbers o sensory neurones eg tongue, lip, and fingers a large part of the sensory area is dedicated to recieving impulses from these area
* shown by the sensory homonculus
* muscles of the face and hands require many motor neurones to control fine movements and so a large proportion of the motor area is involved
* shown by the motor homonculus
45
What is Wernickes area
* association area that interprets written and spoken area
46
What is Brocas area
* in the motor area which innervates (supplies nerves to) the muscles eg intercostal muscles and muscles in the mouth and larynx required to produced sound
*
47
Where does larnguage and speech occur
* wernickes and brocas area
48
Where are brocas and wernickes area located
* located in the left hemisphere of the brain and are linked by a bundle of nerve fibres called the arcuate fasciculus
49
What are the five non invasive imaging techniques to reveal brain structure and function
* electronencephalography
* computerised tomography
* magentic resonance imaging
* functional magnetic resonance imaging
* positron emission tomography
50
Describe EEG and what does it stand for
* electroencephalography involves the placing of electrodes on the scalp which record general changes in electrical activity of regions of the brain over time
51
Describe CT and what does it stand for
computerised tomography scans combine many x ray images taken from different angles using computers to produce multiple high resolution images of the brain in cross section
52
Describe MRI and what does it stand for
* magnetic resonance imahing uses a powerful magnetic field radio frequency that pulses and a computer to produce 3D images which are more detailed that CT scans showing clearly the difference between white and grey matter in the brain
53
Describe fMRI and what is stands for
* functional magentic resonance imaging is a technique for examining activity of the brain tissue in real time as opposed to structure
* it uses radio wave pulse (in addition to magnetic field) which interacts differently with haemoglobin and oxyhaemoglobin showing areas where there is greater oxygen demand suggesting greater brain activity
54
# D
Describe PET scans and what they stand for
* positron emission tomorgraphy is a neuroimaging technique which invlves the injection of a small amount of radioactive isotope fluorodeoxyglucose which is taken up into active cell and then emits a positron as it decays
* this is detected by the scanner and show areas where respiration is occurring more
* isotope used has a short half life so is quickly eliminated from the body
55
What does the brain being plastic mean
* it can change in adulthood
* making new neural connections in response to senspry information, development or damage
* following a stroke or other brain injury undamaged axons form new pathways wtih damaged neurones
56
What is synaptic plasticity
* is the ability of a synape to alter the amount of neurotransmitter released or the response initiated in the post synaptic neurone
* plays a significant role in learning and memory
57
What is non synaptic plasticity
* involves the excitability of an axon changing by altering the voltage gated channel often as a result of injury
58
neuorplasticity
* the ability of the brain to modify its own structure and function following changes within the body or in the external environment
59
synaptic pruning
the elimintation of synapses that happenns between early childhood and maturity
60
what is synaptic pruning and when does it occur
* occurs in adolescence reducing the number of synapses per neurone from around 15000 per neruorone by age 3 to 1000-10000 per neurone by adulthood in response t interactions with the environment
* the result is hard wired connections allowing quick and accurate transmission signals
61
Describe the development of language in humans and why learning it may be difficult and delayed
* the devlopment of language in humnas requires extenssive postnatal experience to produce and decode speech sounds that are the basis of language and so must occur in early life
* a language developmental delay can result if hearing is compromised
* as a result of repeated ear infections during the first few year and with deaf children unless they can express themselves by other means eg signing
62
What is an example of delayed development of language
a 'feral' girl deprives of language up to the age of 13 years meant that depsite intensive training she only ever manages basic commmunication
63
Describe how mental illnesses may be casued
* mental illnesses such as depression and schizophrenia are caused partly by genetic factors bu thte causes are complex and varies
* many conditions arre polygenic and epigenetics is thought to play a part as many brain functions are accompanied by changes in gene expression at a cellular level
64
How is cortisol production controlled and what are it's functions
* cortisol production is controlled by the hippocampus and is released from the adrenal glands into the blood
* function is to inrease blood glucose and uppress the immune system
* it production increases during periods of stress
65
Describe how cortisol production is increased during periods of stress
* hippocampus sends impulses to the hypothalamus which releases two hormones corticotrophin releasing hormone and arginine vasopressin
* these hormones stimulate the pitutitary gland to release the hormone adrenocorticotrophin into the blood resulting in cell of the adrenal glands releasing cotrisol
* cortisol binds to glucocorticoid receptors on the hippocampus which responds by sending nerve impuleses to the hypothalamus inhibiting further release of cortisol
66
what is the mechanism for increased cortisol production called
negative feedback
67
Describe the relationship between cortisol and adults that suffered traumatic childhoods
* constantly over stressed as they produce too much cortisol
* suggesting that the feedback loop is not functioning properly
68
What are behaviours
* they are innate (inborn) which is instinctive or learned
69
Describe innate behaviour
* more significant in animals with less complex neural systems as they are les able to modify their behaviour as a result of learning
70
What are the three types of innate behaviour
* reflexes
* kineses
* taxes
71
Describe reflexes
* are rapid and automatic and protect part of an organism from harm
72
Describe kineses
* more complex than reflexes involved the movement of the whole organism and are non directional resulting in a faster movement or the change in direction
73
Describe taxes and an example
* involve the whole organism moving in response to a stimulus where the direction of the movement is related to the direction of the stimulus either towards or away from it
* woodlie show negative phototaxis by moving away from light
74
What is learned behaviour
builds upon and modifies the existing knowledge resulting in a relativley permanenet change in behaviour or skills
75
What are the two types of learned behaviours
* habituation
* imprinting
76
What is habituation
involves learning to ignore stimuli because they are not followed by either reward or punishment
77
What is imprinting and who discovered it
* it occurs at a very early age in a critical period of brain development in birds and some mammals
* Konrad Lorenz notes the young of birds and some mammals respond to the first larger object they see,smell, touch or hear
* they attach to this object and the attatchment is reinforced by rewards eg food
78
what are asociative behaviours
* include operant and classical contiditoning
* in which animals associate one type of a stimulus with a particular response or action
79
What are the five types of associative learning
* imitation
* insight learning
* latent (explortary learning)
* operant conditioning
* classical conditioning
80
Describe classical conditioning and what pavlov did and concluded
* involves the association between a natural and artificial stimulus to bring about the same response
* pavlo conducted experiments with dogs in hcih he used a 'neutral stimulus' of a bell ringing in which dogs learnied to associate with good. the dog would salivate in response to the bell even in absence of food
81
Describe operant conditioning
* involves the association between a particular behaviour and reward or punishment
* BF Skinned conducted experiments with mice where they learned to press a lever to recieve a reward (food) or to stop a loud noise (punishment)
82
Describe latent (exploratory learning)
* not directed to satisfying a need or obtaining a reward
* many animals explore new surroundings and learn information which at a later stage can mean the difference between life and death
83
Describe insight learning
* does not result from immediate trial and error learning but may be based on information previously learned by other behavioural activities.
* Kohler conducted experiments with chimpanzees in the 1920s where they were given food but it was out of reach
* chimpanzees were given sticks and boxes and eventually learned to use them to reach the food
84
Describe imitation
* advanced from of social learning that allows learned behaviour patterns to spread rapidly between individuals and to be passed down from generation to generation
* it involves the copying of the behavious of another animal
* can result in differences between social group
85
fixed action pattern
an innate behavious which is a complex sequence of events that run to completion once it has been intiated by a sign stimulus
86
Describe the benefits and how animals live in social groups and give an example
* many species form highly structured social groups called soceities where the behaviour of one can influence the other within the group
* relies on the ability of animals to communicate with each oterh by one animal using sign stimul (signals) which are detected by another triggering an innate response
87
What is a fixed action pattern and give an example
* FAPs are a form of sterotyped behavious where the sign stimulus activates nerve pathways bringing about coordinated movements without any concious thought
* the reponse of the individual is depended upon it's motivational state
* more complex than reflexes modified from experiences
* begging response of a gull chick triggered by hthe red spot on it's parents beak
88
What wa tinbergen experiment
* foragin honey beeds sjowing that they showed curiousity for yellow and purple model flowers nut only landed to feed if the proper odour was also present
* only then would the bees insert there mouthparts and feed
89
Describe the social structure of insects
* many insects are social and live in colonies based on a caste system
* the colonies involve brood care for offspring overlapping generations in the colony and a division of labour where individuals cannot perform tasks of indiviudals in other castes
* lead to higfh efficieny within the group
* members communicate through touch, visual orientation and phermones
90
Describe the structure of colonies of honey bee
* honey bee colony consists of one female (the queen) and a few hundred reproductive males (drones) and tens of thousands of sterile female workers
* worker find nectar, clean the hive, care for the young, build new wax combs and defend the colony
91
Who discovered how honeybees communicate distance of food and diretion
* karl von frisch discovered how honeybees communicate the distance and direction of the food source to other worker bees by the use of a dance performed at the hive entrance
* a round dance indicates the source is less than 70m from the hive
* waggle dance indicates the source is over 70m away and its direction relative to the hive and the sun
92
dominance heirarchy
ranking system in an animal soceity in which each animal is submissive to animals in higher ranks but dominant to those in lower ranks
93
What are dominance hierarchies in vertebrate social groups and when does it exist
* a dominant individual is dominant over others
* hierarchies tend to be linear so they have no members os equal rank
* this type of hierarchy only exists where animals are able to recognise each othet as individuals and are able to learn
94
What are advantages of dominance hierarchies
* decreases amount of individual agressions with: feeding, mate selection , breeding site selection and ensures that resources are shared
* . It also ensure that the fittest male has access to femals and so produces the fitter offspring in a male dominant hierarchy
95
Describe how dominance hierarchies keep a stable vertebrate social structure and give an example where it may go wrong
* relativley stable as fighting is a last resort
* eg in red deer prior to mating there is a series of ritualised actions during mating season stags roar and walk parallel with each toerh to assess their opponents strenfth
* if the weaker stag fails to withdraw they will butt out antlers
* it this is rolonged injuries can arise
96
What is territorial behaviour
* most animals occupy an area called a home range but only a few defend a terriotry against other member of the same species
* territorie are marked by scent, visual signposts ef faeces, sounds or calls
97
Describe courtship behaviour and give an example
* courtship is used to attract a mate and allows sexually receptive individuals of te same species to be recognised
* elaborate courtship routine have evolved and are innate ensuring intraspecific mating eg sticklbacks egg carrying female approaches the male starts to zig zag which entices her to swim closer which in turn stimulates him to swim to the nest and stick his snout inside
* this action stimulates the female to wriggle into the tunnel
* the male then nuzzles her tail which stimulates her to spawn after which she swims out the other end of the nest
* the male then enters and deposits sperm onto the eggs
98
What is sexual dimorphism and give an example
* where males look different from females
* the peacock tail is large encumbrance and makes the male more susceptible to predaction but it does indicate his genetic fittness to the female
99
What are the two main theorie behind the driving force of sexual selection
* intra sexual selection
* inter sexual election
100
What is intra sexual selection
* male to male combat
* some species have males which are much bigger than females
* males fight for access to the females and so sexual selection has favoured the evolution of larger more aggressive males
101
What is inter sexual selection
* female choice
* physical attractiveness and the male handicap model drive a males reproductive success
