Unit Three Flashcards
(116 cards)
1
Q
What does the sensory neuroma carry
A
Carry impulses from the sense organs to the CNS
2
Q
What do motor neurons carry
A
Carry impulses from the CNS to the muscle and glands
3
Q
What does the somatic nervous system do
A
It controls voluntary movements of the skeletal muscles and reflex actions
4
Q
What does autonomic nervous system consist of
A
Consists of sympathetic and parasympathetic systems regulating the heart, blood vessels, bronchioles and digestive system
5
Q
What does antagonistic mean
A
Affect the same structure but exert opposition effect
6
Q
What does the converging neural pathway do
A
Several impulses from several neurons travel to one neurone. This increase the sensitivity to the signal
7
Q
What do rods to in the converging pathway
A
Allow several impulses to be transmitted simultaneously to reach the threshold and allows bison in almost total darkness
8
Q
What does the diverging neural pathway do
A
Impulses from one neurone travel to several neurones affecting more than one destination at the same time
9
Q
What is reverberating pathways
A
A sound that occurs repeatedly as in an echos
10
Q
What is the cerebral cortex
A
The centre of consciences thoughts
11
Q
What does the cerebral cortex do
A
Able to recall memories. Receives sensory information, coordinates voluntary moment’s and decisions in light of post experience
12
Q
What is the corpus callosum
A
Which allows a transfer of information from one hemisphere to another
13
Q
What are the brain connected by and what is it called
A
The two hemispheres are connected by a large bundle of nerve fibres called the corpus callosum
14
Q
What does association mean
A
Analysis and interpret information and take decisions in necessary
15
Q
Areas of cerebrum are responsible for
A
Intelligence
Imagination
Language processing
16
Q
What does memorise include
A
Past experience
Knowledge
Thoughts
17
Q
What does encoding do
A
Information that we see, hear, think and feel is changed into form the brain can process and store
18
Q
What does storage do
A
The retention of information over a period of time. 30 seconds or a lifetime
19
Q
What is retrieval
A
Recovery of stored material
20
Q
What’s shallow encoding
A
Information encoded by rehearsal
21
Q
What’s elaborative encoding
A
Attaching information or links to their meaning leads to improved information retention
22
Q
What is level one of memory
A
Retains all visual and auditory input briefly (0.5-3 seconds). Only selected images and sounds are encoded to STM
23
Q
What’s level two of memory
A
Limited capacity hold information up to 30 seconds. Rehearsal helps transfer of information to LTM
24
Q
What’s level three of memory
A
LTM has unlimited capacity and stores information for a long time
25
STM capacity is
Limited capacity of 7 +/- 2 items
26
How can you increase STM
Capacity can be increased by chunking
27
What can happen to LTM
Some can be displaced (pushed out by incoming information)
| Or decay
28
What is chunking
A chunk is meaningful unit of information made up of several units
29
What is rehearsal
Repeating a price of information over and over to memorise it. Helps extend the length of time it is maintained in STM
30
What is the serial position effect
First few items remembered
Last few items remembered
Middle items not well remembered as STM is crowded
31
How can information from STM to LTM be aided
Rehearsal
Organisation
Elaboration
32
What is organisation
Information organised into categories this easily transfers to LTM
33
What is elaboration
By analysing the meaning of the item to be memorised and taking note of its various features and properties it becomes more meaningful
34
What are contextual cues
A contextual cues relates to the time and place when the information was encoded and commutes to the LTM
35
What is the dendrite
Nerve fibres which receive impulses and pass them towards the cell body
36
Where are dendrites in the neuron
End of cell body
37
What does the cell body do
Control centre of cell metabolism and contains ribosomes (protein synthesis making neurone transmitters)
38
What is an axon
Carries impulses away from the cell body to the effectors - muscles
39
What is the myelin sheath
A layer of fatty material
Insulates an axon
Greatly increase the speed at which an impulse can be transmitted from node to node along the axon
40
What is a node
Grapes in the myelin sheath
41
What is myelination
Development of myelin sheath around the axon. This is not complete at birth and continues during development until adolescence
42
What diseases can the myelin sheath cause
It can cause MS if it is damaged/destroyed causing a loss of co-ordination
43
What is a glial cell
Supports neurones
| Produces the myelin sheath (lay down layers of plasma membranes around the axon)
44
What is the synaptic cleft do
Neurones connect with muscle and glands via synaptic clefts. Messages are passed across the velds by neurotransmitters
45
What is the synapse
Tiny space between the axon ending of one neurone and the dendrite of the next
46
What are the stages of transmission of a nerve impulse
Nerve impulse travels down the pre-synaptic neurone
Vesicles containing neurone transmitter are triggered to move to and fuse with pre-synaptic membrane
Neurotransmitters secreted into synaptic cleft
Neurotransmitters bing to the receptors in the post synaptic membrane
Nerve impulse is passed on
47
How is Acetylcholine removed
It is broken down by enzymes
48
How is non-adrenaline removed
Reabsorbed and stored in vesicles for reuse
49
What do receptors do
They determine weather a signal generated is excitatory or inhibitory when a neurotransmitter binds
50
A nerve impulse is only transmitted if
It causes the release of a minimum number of neurotransmitter to bind to a sufficient number or receptor sites and reach the threshold
51
What is summation
The cumulative effect of series of weak stimuli bring about an impulse
52
What are endorphins
Are neurotransmitters acting as natural pain killers. They combine with receptors at synapse and block transmission of pain signal
53
What does endorphins increase
Stress
Sever injury
Vigorous exercise
Certain foods
54
What is dopamine
It is a neurotransmitter that induces feeling of pleasure and reinforces certain behaviours by activating the reward pathway
55
What does the reward pathway involve
Involves neurones which secrete or respond to dopamine. Activated when you engage in a beneficial behaviour
56
What is agonist
Mimics the action of neurotransmitters by binding to and stimulating specific receptors
57
What is antagonist
Binds to specific receptors and block receptor sites preventing neurotransmitters from acting in them
58
What does inhibitors do
Prevent removal of neurotransmitter from the synapse by inhabiting enzymes action or reabsorption
59
What does Alzheimer’s diseases do
Loss of neurones that make acetylcholine and nerve impulses cannot be transmitted
60
What is Parkinson’s disease
Caused by a loss of neurones which synthesise dopamine
61
What is a treatment for Parkinson’s
Can include synthetic dopamine or enzyme inhibitors any dopamine in the synapse has a longer lasting effect
62
What do recreational drugs change in you
Mood
Cognitive thinking
Perception
Behaviour
63
How do recreational drugs affect neurotransmitters
Stimulate release of neurotransmitter
Act as an agonist and mimic the action of a neurotransmitter
Act as antagonist bind with receptors and block neurotransmitter
Inhibit reabsorption of a neurotransmitter
Inhibit enzymes which breakdown neurotransmitter
64
Canabis mode of action
Contains substances that bind to receptors involved in the nerve transmission of muscular control and pain sensitivity
65
Cocaine mode of action
Inhibits dopamine re-uptake channels leading to higher level of dopamine in the reward circuit
66
Ecstasy mode of action
Inhibits re-uptake of a neurotransmitter which remains in synapse increasing a felling of well being
67
Alcohol mode of action
Mimics neurotransmitter that can act to reduce feeling of anxiety
68
Nicotine mode of action
Mimics effect of acetylcholine on certain neural receptors leading to increased dopamine in the reward circuit
69
What a drug addiction
Repeated use of a drug that acts as an antagonist (blocks receptors) nervous system compensates by increasing receptors in number and sensitivity so users crave more of drug
70
What does drug tolerance mean
Repeated use of a drug that acts as an agonist (mimics neurotransmitter) nervous system compensates by decreasing receptors in number and sensitivity and a larger does is now required to have the original effect
71
What does immunity mean
The ability of the body to resist infection by a pathogen
72
What does non-specific mean
Work against any type of disease-causing agent
73
What does specific mean
Work against a particular pathogen
74
What is the first line of defence
Skin - physical barrier
Secretion of stomach acid
Secretion of mucus
75
What is the second line of defence
Inflammatory response
| Phagocytosis
76
What is the third line of defence
Response of t-lymphocytes production of antibodies
77
What is a pathogen
Disease causing organism
78
What are the physical barriers in the first line
Mucous membranes of digestive and respiratory track
Closely packed epithelial cells found in skin, digestive and respiratory systems provides an impermeable barrier when intact
79
What are the chemical barriers in first line
Tears and saliva contain lysozyme which destroys bacteria
Mucus traps microorganisms
Sweat keeps skin at a low PH so microbes Connor survive
Stomach acid destroys microbes
80
What is the inflammatory response
A physical injury triggers the response
After injury mast cells realise histamine
Histamine causes:
- vasodilation
- increased capillary permeability
- this allows phagocytes to accumulate at the damaged tissue and allows clotting elements to begin tissue repair and clotting at the injured site
81
What is phagocytosis
A phagocyte recognises pathogens and destroys them by phagocytosis. It engulfs the pathogen and digests it using lysozyms stored in lysosomes. Dead bacteria and phagocytes accumulate at an effected site as pus
82
What is cytokines
Cytokines protein molecules released by phagocytes which act as a signal for other phagocytes to accumulate at the site of infection
83
What is an antigen
Protein on surface of a cell that triggers a specific immune response
84
What are B-lymphocytes
Produce form stem cells in the bone marrow
85
What do B-lymphocytes produce
Antibodies
| memory cells
86
What is an antibody
Are y-shaped proteins and each arm has a receptor site specific to a particular antigen Ona pathogen. Bind to antigen in-activating the pathogen so it can be destroyed by phagocytosis
87
What is an allergy
B-lymphocytes can respond to antigen on substances that are harmless to the body e.g. pollen and dust. This hypersensitive response is an allergic reaction
88
What is anaphylactic shock
A life threatening reaction to an allergen that has been infected (bee sting) or consumed (peanuts)
89
What happens I anaphylactic shock
Person is so allergic that the mast cells secret large quantities of histamine amusing excessive vasodilation which causes a loss of circulatory fluid to the tissue and a drop in blood pressure and volume. Death can occur
90
What are t-lymphocytes
Destroy infected cells by recognising antigen of the pathogen on the cell membrane and induce apoptosis
Produce memory cells capable of recognising the same foreign antigen in the future
91
What is apoptosis
T lymphocytes attaches to infected cells and reales proteins
Proteins diffuse into the cell and trigger production is self destructive enzymes which cause cell death
Dead cell remains are engulfed and digested by phagocytosis
92
What is agglutination
Clumping is red blood cells and causes major blockage of small blood vessels
93
What is the autoimmune meaning
Failure of the T lymphocytes h responding to self antigens and attacking the bodies own cells
94
What is rheumatoid arthritis
Inflammation of synovial membranes causes the membrane to swell up cartilage and bone are gradually destroyed and replaced by fibrous tissue which joins the two bones together making a joint immovable
95
What does HIV do
It attacks the t-lymphocytes by binding to specific receptors on the cell and entering it
96
What does HIV contain
It contains RNA. it need DNA to transcribe mRNA so it introduces an enzyme to bring about the reverse of normal transcription to produce viral DNA from viral RNA
97
What is natural squired immunity
Person survives infection by a pathogen
2nd exposure to same antigen results in a secondary response
98
What is artificially acquired immunity
A vaccination
99
What is a vaccination
Uses antigen from infectious pathogens to initiate an immune response and create memory cells Memory cells initiate the secondary response is a person is exposed to the disease at a later date
100
Antigen used in vaccines can be
Inactivated pathogen toxins
Dead pathogens
Weakened pathogens
Parts of a pathogen
101
What does adjuvant mean
Antigen is mixed with this to make a vaccine more effective and enhances the immune response
102
What is herd immunity
Occurs when a large percentage of the population is immunised
This reduces the spread of diseases and the chances of coming into contact with and infected individual is low
To be infected only an minority of the population can be left unvaccinated
103
What is the the herd immunity threshold
The percentage of the immune individuals in a population above which a disease no longer manages to persist.
104
How does the threshold of herd immunity vary
Type of disease (capacity to cause disease)(e.g how easily its spread)
Effectiveness of vaccine
Population density
105
What are mass vaccination programs for
Establish herd immunity for commons disease
106
Difficulty arises when in mass vaccination
Widespread vaccination is not possible in developing countries where the majority are impoverished and malnourished
When vaccines are rejected by a percentage of the population in the developing world
107
What is antigenic variation
Antigenes on the surface different from original strain
108
What does double blind mean
Neither the subject or doctors know who is in witch group and receiving witch treatment. This eliminates biased groups
109
What dose placebo control mean
Exactly the same form as the drug without the activation the drug would do to the body this allows valid comparison between test and control group
110
What does randomised mean
Participants randomly placed in a group by a computer to reduce biased in the distribution of age, gender...etc
111
What is a vaccine clinical trial
Vaccines and drugs must be subjected to clinical trials to establish there safety and efficacy (produce the intended result) before they can be licensed for use
112
What happens in phase one of clinical trials
Small dose of treatment tested on a small number of volunteers (25-30) to check if safe
113
What happens in phase two of clinical trials
Treatment tested on a larger number (150-300) of people who have the illness to see if the treatment is starting and effective and find out what the optimum does may be
114
What happens in phase three is clinical trials
Treatment tested in a very large number (1000-2000) of people who have the illness using a randomised, placebo controlled, double blind protocol
115
What happens if phase three is successful in clinical trials
Results submitted and licence sought to manufacture the new treatment
116
In phase three what happens in clinical trials
Test group who receive treatment
A control group who do not receive treatment
