Unit 3- Neurobiology and Immunology Flashcards
(124 cards)
1
Q
what does a reverberating neural pathway allow for?
A
repeated stimulation
2
Q
how could a weak stimuli pass on the signal?
A
if the the post synaptic neuron were to receive several smaller stimuli
Aka SUMMATION
3
Q
what does the CNS consist of?
A
the brain and the spinal cord
3
Q
what does the PNS consist of?
A
the somatic and the autonomic nervous systems
4
Q
what do peripheral nerves do?
A
allow information to be sent to and from the CNS
5
Q
what does the somatic nervous system do?
A
takes messages from the sense organs to the muscles and glands
6
Q
how does the somatic nervous system work?
A
it takes impulses along SENSORY NEURONES to the CNS and along MOTOR NEURONES to the muscles and glands
7
Q
what are the 2 systems that make up the autonomic nervous system?
A
sympathetic system and parasympathetic system
8
Q
what does the sympathetic system do?
A
prepare the body for action (fight or flight)
9
Q
describe what the sympathetic system does to the heart rate, breathing rate, peristalsis and intestinal secretions
A
increased heart rate
increased breathing rate (allowing bronchioles to take in more air)
decreased peristalsis
decreased intestinal secretions
10
Q
describe what the parasympathetic nervous system does to the heart rate, breathing rate, peristalsis and intestinal secretions
A
decreased heart rate
decreased breathing rate
increased peristalsis
increased intestinal secretions
11
Q
what does the parasympathetic nervous system do?
A
return the body back to normal (rest and digest)
12
Q
which gland is the only gland to be solely controlled by the sympathetic system?
A
the adrenal gland
13
Q
what are the 3 types of neural pathway?
A
converging
diverging
and reverberating
14
Q
what is a converging neural pathway?
A
many nerve impulses from several neurones travel to one
15
Q
what does a converging neural pathway cause?
A
the sensitivity to excitatory and inhibitory signals is increased
16
Q
what is an example of a converging neural pathway?
A
rods and cones in the eye
17
Q
what is a diverging neural pathway?
A
impulse from one neuron splits and travels to several neurones
20
Q
What is the axon?
A
A single nerve fibre that carries impulses away from the cell body
21
Q
what does a diverging neural pathway cause?
A
the impulse can affect more than one destination at a time
21
Q
what is an example of a reverberating neural pathway?
A
breathing
22
Q
what is an example of a diverging neural pathway?
A
temperature control
23
Q
what is a reverberating neural pathway?
A
neurones later in the pathway create synapses with neurones earlier in the pathway creating loops
25
Q
What are the three main parts of neurone structure?
A
Cell body
Axon
Dendrites
26
what is the PNS?
the peripheral nervous system
27
what is the cerbral cortex?
the outside layer of the brain which is split into two cerebral hemispheres
it is the centre for conscious thought where memories are recalled and what alters behaviour in light of experience
27
what are the 3 stages of memory?
encoding, storage and retrieval of information
28
what are the 3 types of memory?
sensory memory
short term memory
long term memory
28
what is retained in the sensory memory?
all visual and auditory input
30
what happens during drug addiction?
antagonists block specific receptors causing the nervous system to compensate by INCREASING THE NUMBER and SENSITIVITY of these receptors
leading to sensitisation
this leads to the individual craving more of the drug
32
what is the serial position effect?
that items at the start of a list and items at the end are remembered more than those in the middle
32
how are items lost in the short term memory?
by either displacement (pushed out by new information) or decay (breakdown of memory trace)
33
what is encoded from the sensory memory to the short term memory?
only selected images and sounds
34
what are the two ways to increase the capacity of short term memory?
chunking and rehearsal
37
What is a randomised clinical trial?
All relevant details are entered into the computer and the computer randomly sorts the members into two groups to reduce bias in the distribution of age and gender
38
how much information can the long term memory hold ?
unlimited
39
how is information transferred from STM to LTM?
rehersal, organisation and elaboration
40
what is the CNS?
the central nervous system
40
what does transfer between the two cerebral hemispheres occur through?
the corpus callosum
42
how is retrieval of items from the LTM aided?
the use of contextual cues related to the time and place that were present when information was encoded
43
describe the inflammatory response.
injury
mast cells become activated and release large quantities of histamine
histamine causes vasodilation and the capillaries to become more permeable
increased blood flow leads to accumulation of phagocytes and clotting factors
44
What are the 3 types of neuron?
Sensory neurones
Inter neurones
Motor neurones
46
What is the function of the cell body in a neurone?
Contains nucleus so is the control centre
47
What is the function of the dendrites?
To pass impulses to the cell body
48
What is the myelin sheath?
A layer of fatty material that insulates the axon
49
What is the function of the myelin sheath?
To greatly increase the speed of impulse conduction
49
what is the region of contact between the axon ending of the pre synaptic neuron and the dendrites of the post synaptic neuron called?
the synapse
50
What is myelination and when does it occur?
The development of myelin and it occurs from birth to adolescence
50
what is the gap between the pre synaptic neuron and the post synaptic neuron called?
the synaptic cleft
51
What is the result of myelination occurring until adolescence?
Response to stimuli in the first 2 years of life is not as rapid or coordinated
51
what are neurotransmitters stored in in synapses?
vesicles
52
What do certain diseases do to the myelin sheath?
Destroy it causing loss of coordination
53
Why is it important to use a large group size for a clinical trial?
To reduce experimental error and improve statistical significance
55
what is chunking?
breaking the information down into meaningful units to make it easier to remember
56
how does direct re absorption work when reuptaking neurotransmitter?
neurotransmitter are absorbed directly without being broken down
57
how do neurotransmitters work at synapses?
when an impulse passes through the PRESYNAPTIC NEURON the it stimulates several vesicles to move to the synapse and fuse with the membrane
the neurotransmitters are then released across the synaptic cleft by diffusion and bind with receptors on the POST SYNAPTIC NEURON
58
what are the areas of the cerebral cortex?
sensory areas
motor areas
association areas
59
what are the two ways neurotransmitters are reuptaken at synapses?
enzyme degradation
| direct re absorption
60
name 4 neurotransmitters
acetlycholine
noradrenaline
endorphins
dopamine
61
what are endorphins?
neurotransmitters that stimulate neurones involved in reducing the intensity of pain
62
why can the short term memory perform simple cognitive tasks?
the short term memory can process data to a limited extent, as well as store it, this is known as the working memory
62
what determines whether or not a signal is excitatory or inhibitory?
receptors on the post synaptic neuron
62
what must be acquired for a signal to be transmitted?
a certain threshold of neurotransmitter
66
how do endorphins reduce the intensity of pain?
By combining with receptors at synapses blocking the transmissions of the pain signal
67
where are endorphins produced?
the hypothalamus
68
what are increased levels of endorphins in response to?
severe injury
prolonged and continuous exercise
physical and emotional stress
certain foods such as chocolate
69
what are increased levels of endorphins linked to?
the feelings of pleasure obtained from:
eating
sex
prolonged exercise
70
what is dopamine?
neurotransmitters that induce feelings of pleasure by stimulating the reward pathway which reinforces certain behaviour to satisfy a need that is beneficial such as hunger or thirst
71
give 2 examples of neurotransmitter related disorders
alzheimers and schizophrenia and depression
72
how can neurotransmitter related disorders be treated?
by agonist or antagonist drugs
73
how do agonist drugs work?
they bind to and stimulate specific receptors on postsynaptic neurone, mimicking action of naturally occurring neurotransmitters triggering normal cellular response
74
how do antagonist drugs work?
they bind to specific receptors on postsynaptic neurone and block the action of the neurotransmitter, inhibiting normal cellular response
75
how do inhibitor drugs work?
act by preventing the removal of the normal transmitter causing an enhanced effect
76
how to recreational drugs act?
like both agonists and antagonists
76
how is drug tolerance caused?
the repeated use of drugs that act as agonists
77
in individuals what do recreational drugs affect and alter?
mood (happier, more confident, aggressive)
cognition (cant carry out complex mental tasks such as problem solving and decision making)
perception (misinterpretation of stimuli)
behaviour (stay awake for longer, talk endlessly about themselves)
77
what happens during drug tolerance?
agonists stimulate specific receptors causing the nervous system to compensate by DECREASING THE NUMBER and SENSITIVITY of these receptors
leading to desensitisation
this leads to the individual needing to take more of the drug to get an effect
78
what do recreational drugs do to the reward circuit?
affect them and cause them do be overstimulated
78
what are the 2 types of non-specific body defences?
physical and chemical defences
79
how is drug addiction caused?
the repeated of drugs that act as ANTAGONISTS
80
what is the physical non-specific body defence?
closely packed epithelial cells found on the surface of skin and lining the body's digestive system and respiratory systems
offer a physical barrier against bacteria and viruses
81
what is the chemical non-specific body defence?
secretions including tears, saliva, mucus and stomach acid are produced against invading pathogens
83
what is the name of the response to a cut or physical injury?
the inflammatory response
84
What is a placebo controlled clinical trial?
Members of the control group are given a placebo which allows a valid comparison to be made
85
what are cytokines?
protein molecules released by phagocytes which attract more phagocytes to the site of infection.
86
describe phagocytosis
phagocytes recognise pathogens and engulf them
they then destroy them using digestive enzymes that are stored in lysosomes
87
what must happen after neurotransmitter bind with receptors on the post synaptic neuron?
re uptake of neurotransmitter to prevent continuous stimulation.
87
what are lymphocytes and how do they work?
white blood cells involved in the specific immune system
they work by responding to specific pathogens because they have a specific type of membrane receptor which is specific for one antigen
87
what are antigens?
molecules located on the surface of cells which trigger the immune response
88
how is a clonal population achieved?
the binding of the membrane receptor and the antigen leads to the lymphocyte repeatedly dividing resulting in a clonal population of identical lymphocytes
89
what are the 2 types of lymphocytes?
b lymphocytes and t lymphocytes
90
how do b lymphocytes work?
they produce antibodies which bind to antigens inactivating the pathogen.
this antibody-antigen complex can then be destroyed by phagocytosis
91
how do b lymphocytes result in allergies?
b cells respond to antigens on substances that are harmless to the body resulting in an allergic reaction.
92
how do t lymphocytes work?
t lymphocytes destroy infected cells by recognising antigens and inducing apoptosis
94
What is the role of glial cells?
To produce myelin and support the neurones
97
what are antibodies?
y shaped proteins that have receptor binding sites which are specific to a particular antigen
98
what is apoptosis?
programmed cell death
99
how does apoptosis work?
t lymphocytes attach to infected cells and release a protein which diffuses into the cell causing production of self-destructive enzymes
the remains are removed by phagocytosis
100
what allows t lymphocytes to distinguish between self and non-self?
specific surface proteins
101
in terms of t lymphocytes what does immune system regulation failure lead to?
t cell immune response to self-antigens meaning they attack the body's own cells resulting in an autoimmune disease
102
what are 2 examples of autoimmune diseases?
rheumatoid arthritis and type 1 diabetes
103
What is the primary response?
When a person is infected by a pathogen or toxin and their body produced antibodies for the first time
104
How are memory cells formed?
Some t and b lymphocytes produced in the primary response survive long term as memory cells
105
What is the role of memory cells?
To allow for a secondary response
Meaning that they give rise to a new clone of lymphocytes producing a rapid and greater antibody production so the invading pathogen is destroyed before the individual develops symptoms
105
What does AIDS stand for?
Acquired immune deficiency disease
106
What does HIV stand for?
Human immunodeficiency virus
107
How does HIV work?
By attacking and destroying t lymphocytes by hiding in them causing a depletion of their numbers
108
how does enzyme degradation work when reuptaking neurotransmitters?
enzymes break down neurotransmitter which is the reabsorbed and turned back into new neurotransmitters
109
What is meant by immunisation?
The process by which a person develops immunity to a disease causing organism
110
what do mast cells produce?
histamine
112
How can immunity be acquired?
By vaccination using antigens from an infectious pathogen to create memory cells
113
What are antigens from infectious pathogens mixed with to create a vaccine?
An adjuvant
114
What is an adjuvant?
A chemical mixed with the antigen to increase the immune response
115
What are the forms of pathogen used in vaccines?
Inactivated pathogen
Dead pathogen
Parts of pathogen
Weakened pathogen
116
What is herd immunity?
When a large percentage of the population are immunised which helps reduce the spread of diseases
Protecting non immune people as there is less chance they will come into contact with an infected individual
117
What is the herd immunity threshold?
The percentage of the population that must be vaccinated to reach herd immunity status
118
What does the herd immunity threshold depend on?
The type of disease
Effectiveness of the vaccine and
Density of the population
119
When do difficulties arise in vaccine programmes?
When widespread vaccination isn’t possible due to poverty in the developing world and
A percentage of the developed world rejecting vaccines
120
What is antigenic variation?
When some pathogens can change their antigens meaning memory cells are not as effective against them
121
What does HIV become if left untreated?
AIDS
121
What must vaccines and drugs go through before being licensed for use in the public?
A clinical trial on humans
122
What are the 3 different types of clinical trial?
Placebo controlled
Double blind
Randomised
123
What is a double blind trial?
Neither members non doctors know whether they are receiving the active ingredient or the placebo to prevent bias
124
What does AIDS do to an individual?
Weakens their immune system making the person more vulnerable to infections
