Higher Human Bio > Unit 3 > Flashcards

Unit 3 Flashcards

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1
Q

What are the two main divisions of the nervous system?

A
  • Central Nervous System (CNS)
  • Peripheral Nervous System (PNS)

The CNS is composed of the brain and spinal cord, while the PNS includes the somatic and autonomic nervous systems.

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2
Q

What does the Central Nervous System (CNS) consist of?

A
  • Brain
  • Spinal Cord

The CNS is responsible for processing sensory information and coordinating responses.

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3
Q

What are the components of the Peripheral Nervous System (PNS)?

A
  • Somatic Nervous System (SNS)
  • Autonomic Nervous System (ANS)

The PNS connects the CNS to the rest of the body.

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4
Q

What is the role of sensory neurons in the somatic nervous system?

A

Carry impulses from sense organs to the CNS

Sensory neurons are crucial for transmitting information about external stimuli.

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5
Q

What is the function of motor neurons in the somatic nervous system?

A

Carry impulses from the CNS to muscles and glands

Motor neurons enable voluntary movements of skeletal muscles.

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6
Q

The somatic nervous system (SNS) controls functions under _______.

A

conscious control

Examples include walking and speaking.

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7
Q

What does the autonomic nervous system (ANS) control?

A

Body functions that happen automatically

Functions include heart rate, breathing rate, peristalsis, and intestinal secretions.

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8
Q

The autonomic nervous system can be divided into the sympathetic and parasympathetic systems. True or False?

A

TRUE

These systems have opposite effects on the same structures.

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9
Q

What is the role of the parasympathetic system?

A

Calms the body down (rest and digest)

It decreases heart rate and breathing rate, and speeds up peristalsis and intestinal secretions.

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10
Q

What is the role of the sympathetic system?

A

Prepares the body for action (fight or flight)

It increases heart and breathing rates, and slows down peristalsis and intestinal secretions.

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11
Q

What are the three types of neural pathways?

A
  • Converging
  • Diverging
  • Reverberating

Each type has distinct functions in processing neural impulses.

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12
Q

In a converging neural pathway, impulses from several neurons travel to _______.

A

one neuron

This increases sensitivity to excitatory or inhibitory signals.

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13
Q

In a diverging neural pathway, impulses from one neuron travel to _______.

A

several neurons

This allows affecting more than one destination simultaneously, such as in body temperature control.

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14
Q

In a reverberating pathway, neurons later in the pathway link with _______.

A

earlier neurons

This allows repeated stimulation of the pathway, such as in breathing.

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15
Q

The cerebral cortex is the outer layer of the _______.

A

cerebrum

It is the center of conscious thought and memory recall.

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16
Q

What are the three types of functional areas in the cerebral cortex?

A
  • Sensory areas
  • Association areas
  • Motor areas

Each area has specific roles in processing information.

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17
Q

The sensory areas of the cerebral cortex receive information as impulses from _______.

A

the body’s receptors

These receptors are located in the sense organs.

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18
Q

The association areas in the cerebral cortex are responsible for _______.

A

analyzing and interpreting impulses

They help ‘make sense’ of the information and ‘take decisions’.

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19
Q

The motor areas of the cerebral cortex carry out orders by sending impulses to _______.

A

the appropriate effectors

Effectors include muscles or glands.

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20
Q

The cerebrum is divided into two _______.

A

cerebral hemispheres

Each hemisphere processes information from the opposite side of the body.

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21
Q

The corpus callosum connects the two cerebral hemispheres and allows _______.

A

the transfer of information

This is crucial for coordinated brain function.

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22
Q

What are the three main processes involved in Memory?

A
  • Encoding
  • Storage
  • Retrieval

Memory involves encoding, storage, and retrieval of information.

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23
Q

Define Encoding in the context of memory.

A

Transferring information into memory

Encoding is the first step in the memory process.

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24
Q

What does Sensory memory do?

A
  • Retains visual and auditory input for a few seconds
  • Only selected images and sounds are encoded into short-term memory

Sensory memory captures all incoming sensory information briefly.

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25
What is the capacity of **Short term memory (STM)**?
About 7 pieces of information for about 30 seconds ## Footnote STM has a limited capacity and holds information for a short time.
26
What happens to items in **STM** when new items enter?
* Displace previous items * Lost by decay ## Footnote STM can only hold a limited amount of information at once.
27
How can **Memory Span** be improved?
* Chunking * Rehearsal ## Footnote Chunking groups information together, while rehearsal involves repeating information.
28
What is the **Serial position effect**?
First and last items in a string of facts are remembered best ## Footnote The first items are rehearsed, and the last items are still in STM.
29
What is the role of **Working memory**?
An extension of STM that uses retrieved information to perform simple cognitive tasks ## Footnote Working memory allows for processing data as well as storing it.
30
What is the capacity of **Long term memory (LTM)**?
Unlimited capacity ## Footnote LTM holds information for a long time.
31
What promotes the transfer of information from **STM** to **LTM**?
* Organisation * Rehearsal * Elaboration (OREO) ## Footnote Successful encoding changes information into a storable form.
32
Define **Organisation** in memory.
Grouping related information together ## Footnote Organisation helps in the transfer of information to LTM.
33
What is **rehearsal** in the context of information encoding?
Repeating information to yourself several times ## Footnote Rehearsal is regarded as a shallow form of encoding information into long-term memory (LTM).
34
What is **elaboration** in information encoding?
Providing additional or meaningful information ## Footnote For example, remembering dehydrogenase as a key enzyme in glycolysis and the citric acid cycle.
35
What are **organisation** and **elaboration** regarded as in terms of encoding?
Deeper forms of encoding ## Footnote These lead to improved information retention.
36
What is **retrieval** in the context of memory?
Taking information out of long-term memory ## Footnote Retrieval is aided by the use of contextual cues.
37
What are **contextual cues**?
Relate to the time and place when information was initially encoded into LTM ## Footnote They help in the retrieval of information.
38
What is the structure and function of **neurons**?
Bundles of nerve fibres carrying electrical impulses ## Footnote Neurons consist of a nerve cell body and nerve fibres.
39
What does the **nerve cell body** contain?
* Nucleus * Cytoplasm containing organelles ## Footnote Organelles include ribosomes which make various proteins including enzymes needed for neurotransmitter synthesis.
40
What are **dendrites**?
Nerve fibres that receive nerve impulses ## Footnote They carry impulses towards the cell body.
41
What is the function of an **axon**?
Carries impulses away from the cell body ## Footnote The direction of impulse travel is always dendrite-cell body-axon (DCA).
42
What is the **myelin sheath**?
Insulates the axon and speeds up impulse conduction ## Footnote Long axon fibres are covered in a myelin sheath.
43
What is **myelination**?
Development of myelin around axon fibres of individual neurons ## Footnote Myelination continues from birth to adolescence.
44
How does **myelination** affect impulse conduction?
Increases the speed of impulse conduction ## Footnote Certain diseases can destroy the myelin sheath, causing a loss of coordination.
45
What are **glial cells**?
* Produce the myelin sheath * Support neurons ## Footnote They are associated with neurons.
46
What is a **synapse**?
A tiny gap between two neurons or between a neuron and a muscle fibre/gland ## Footnote Neurotransmitters relay impulses across the synaptic cleft.
47
What are **neurotransmitters**?
Chemicals that relay impulses across the synaptic cleft ## Footnote They are stored in vesicles in the axon endings of the presynaptic neuron.
48
What is needed for **neurotransmitter synthesis**?
ATP ## Footnote ATP is essential for the production of neurotransmitters.
49
What happens to neurotransmitters upon the arrival of an **impulse**?
They are released into the synaptic cleft ## Footnote Neurotransmitters diffuse across the cleft and bind to receptors on the postsynaptic neuron.
50
What occurs if sufficient neurotransmitter molecules reach the **postsynaptic neuron**?
The impulse continues ## Footnote Weak stimuli are filtered out if not enough transmitter molecules reach the next neuron.
51
How are neurotransmitters removed from the **synaptic cleft**?
* By enzymes * Reuptake ## Footnote This prevents continuous stimulation of postsynaptic neurons.
52
What happens to **acetylcholine** after it is released?
It is broken down by enzymes and reabsorbed by the presynaptic neuron ## Footnote Acetylcholine is then resynthesized.
53
How is **noradrenaline** handled after release?
It is reabsorbed directly into the presynaptic membrane and stored in vesicles ## Footnote This allows for reuse of noradrenaline.
54
What determines whether a signal is **excitatory or inhibitory**?
Receptors ## Footnote Different receptors have different effects on the postsynaptic neuron.
55
Give an example of an **excitatory** neurotransmitter.
Acetylcholine ## Footnote It causes muscle fibres to contract when released into the cleft between a motor neuron and a skeletal muscle fibre.
56
Give an example of an **inhibitory** neurotransmitter.
Acetylcholine ## Footnote It reduces the rate and strength of contraction of cardiac muscle when released into the cleft between a motor neuron and a heart muscle fibre.
57
What is the **threshold** in neurotransmission?
The minimum number of neurotransmitter molecules that must attach to receptors on the postsynaptic membrane ## Footnote This is necessary to transmit the impulse.
58
What is **summation** in the context of neurotransmission?
The triggering of an impulse by a series of weak stimuli from many neurons at once ## Footnote This can release enough neurotransmitters to fire an impulse.
59
What are **convergent neural pathways**?
Pathways that can release enough neurotransmitter molecules to reach the threshold and trigger an impulse ## Footnote They integrate signals from multiple neurons.
60
What are **endorphins** and their primary function?
Neurotransmitters that stimulate neurons involved in reducing the intensity of pain ## Footnote Endorphins increase in response to severe injury, prolonged exercise, stress, and certain foods.
61
List the factors that increase **endorphin production**.
* Severe injury * Prolonged and continuous exercise * Stress * Certain foods ## Footnote Increased endorphins are linked to feelings of pleasure from activities like eating and sex.
62
What is the role of **dopamine** in the brain?
Induces feelings of pleasure and reinforces particular behaviour by activating the reward pathway ## Footnote Dopamine is produced in several regions of the brain.
63
What is the **reward pathway** in relation to dopamine?
Involves neurons that secrete or respond to dopamine ## Footnote Activated when engaging in beneficial behaviours, such as eating when hungry.
64
Define **agonists** in the context of neurotransmitter-related disorders.
Chemicals that bind to and stimulate specific receptors mimicking the action of a neurotransmitter ## Footnote Agonists act at a synapse.
65
Define **antagonists** in the context of neurotransmitter-related disorders.
Chemicals that bind to specific receptors blocking the action of a neurotransmitter ## Footnote Antagonists act at a synapse.
66
What is the effect of drugs that inhibit enzymes like **acetylcholinesterase**?
They degrade neurotransmitters, enhancing their effect ## Footnote Example: Inhibiting acetylcholine degradation.
67
How do recreational drugs affect neurotransmission?
They act as agonists or antagonists, altering mood, cognition, perception, and behaviour ## Footnote Many affect neurotransmission in the reward pathway of the brain.
68
What is **drug addiction** caused by?
Repeated use of drugs that act as antagonists ## Footnote Antagonists block specific receptors, leading to increased receptor number and sensitivity.
69
How does **sensitisation** lead to addiction?
It causes the individual to crave more of the drug ## Footnote This occurs due to the nervous system's response to antagonists.
70
What causes **drug tolerance**?
Repeated use of drugs that act as agonists ## Footnote Agonists stimulate specific receptors, leading to decreased receptor number and sensitivity.
71
How does **desensitisation** lead to drug tolerance?
The individual must take more of the drug to get an effect ## Footnote This is a result of the nervous system's adaptation to agonists.
72
What is **immunity**?
The ability of the body to resist infection by a pathogen ## Footnote It can also destroy the organism if it invades and infects the body.
73
Define **pathogen**.
A bacterium, virus, or other organism that can cause disease ## Footnote Pathogens are the targets of the immune response.
74
What are the **physical and chemical defences** of the body?
* Epithelial cells form a physical barrier * Chemical secretions (tears, saliva, mucus, stomach acid) ## Footnote These defences help protect against invading pathogens.
75
What role do **epithelial cells** play in the body's defence?
They form a physical barrier ## Footnote Found in skin and inner linings of digestive and respiratory systems.
76
What is the **inflammatory response**?
A localized response at the site of injury or infection ## Footnote It involves mast cells releasing histamine and increasing blood flow.
77
What does **histamine** cause during the inflammatory response?
* Vasodilation (arterioles dilate) * Increased blood flow * Increased capillary permeability ## Footnote These changes help accumulate phagocytes and clotting elements at the site of infection.
78
What is the purpose of increased blood flow during the inflammatory response?
To accumulate phagocytes and clotting elements at the site of infection ## Footnote This aids in coagulation, stopping blood loss, and preventing further infection.
79
What are **phagocytes** responsible for?
Recognising pathogens and destroying them by phagocytosis ## Footnote Phagocytosis involves engulfing pathogens and their destruction by digestive enzymes contained in lysosomes.
80
What do **phagocytes** release to attract more phagocytes to the site of infection?
Cytokines ## Footnote Cytokines are protein molecules that signal specific white blood cells to accumulate at the site of infection.
81
What are **lymphocytes** derived from?
Tissue stem cells in the bone marrow ## Footnote Lymphocytes are the white blood cells involved in the specific immune response.
82
Lymphocytes respond to specific **antigens** on invading pathogens. What are antigens?
Molecules, often proteins, located on the surface of cells that trigger a specific immune response ## Footnote Antigen binding leads to repeated lymphocyte division resulting in a clonal population of identical lymphocytes.
83
What are the two types of **lymphocytes**?
* B lymphocytes * T lymphocytes ## Footnote B lymphocytes produce antibodies, while T lymphocytes destroy infected body cells.
84
What do **B lymphocytes** produce against antigens?
Antibodies ## Footnote Antibodies are Y-shaped proteins that bind to specific antigens on pathogens, leading to their destruction.
85
What happens when antibodies bind to antigens?
They inactivate the pathogen ## Footnote The resulting antigen-antibody complex can then be destroyed by phagocytosis.
86
What is a **hypersensitive response** to harmless substances called?
Allergic reaction ## Footnote B lymphocytes can respond to antigens on substances like pollen, leading to this reaction.
87
What do **T lymphocytes** do to infected body cells?
Destroy them by inducing apoptosis ## Footnote Apoptosis is programmed cell death initiated by T lymphocytes recognizing antigens on infected cells.
88
What do T lymphocytes release to induce apoptosis in infected cells?
Proteins ## Footnote These proteins diffuse into infected cells causing the production of self-destructive enzymes leading to cell death.
89
What are **phagocytes** responsible for?
Recognising and destroying pathogens by phagocytosis ## Footnote Phagocytosis involves engulfing pathogens and destroying them with digestive enzymes in lysosomes.
90
What role do **cytokines** play in the immune response?
Attract more phagocytes to the site of infection ## Footnote Cytokines are protein molecules that signal specific white blood cells to accumulate at the infection site.
91
What are **lymphocytes** derived from?
Tissue stem cells in the bone marrow ## Footnote Lymphocytes are white blood cells involved in the specific immune response.
92
Lymphocytes respond to specific **antigens** on invading pathogens. What are antigens?
Molecules, often proteins, located on the surface of cells that trigger a specific immune response ## Footnote Antigens are crucial for the identification of pathogens.
93
What happens when a lymphocyte binds to an antigen?
Leads to repeated lymphocyte division and formation of a clonal population ## Footnote This process results in identical lymphocytes that target the same antigen.
94
Name the **two types of lymphocytes**.
* B lymphocytes * T lymphocytes ## Footnote Each type has distinct roles in the immune response.
95
What do **B lymphocytes** produce against antigens?
Antibodies ## Footnote Antibodies are Y-shaped proteins that bind to specific antigens on pathogens.
96
What is the function of **antibodies**?
Inactivate pathogens by binding to their antigens ## Footnote The antigen-antibody complex can be destroyed by phagocytosis.
97
What is an **allergic reaction**?
A hypersensitive response to antigens on harmless substances ## Footnote B lymphocytes can respond to non-harmful antigens, such as pollen.
98
What do **T lymphocytes** do?
Destroy infected body cells by inducing apoptosis ## Footnote Apoptosis is programmed cell death initiated by T lymphocytes.
99
What is **apoptosis**?
Programmed cell death ## Footnote T lymphocytes induce apoptosis in infected cells to eliminate them.
100
How do T lymphocytes cause cell death?
By releasing proteins that produce self-destructive enzymes in infected cells ## Footnote The remains of the cell are then removed by phagocytosis.
101
What are **phagocytes** responsible for?
Recognising and destroying pathogens by phagocytosis ## Footnote Phagocytosis involves engulfing pathogens and destroying them with digestive enzymes in lysosomes.
102
What role do **cytokines** play in the immune response?
Attract more phagocytes to the site of infection ## Footnote Cytokines are protein molecules that signal specific white blood cells to accumulate at the infection site.
103
What are **lymphocytes** derived from?
Tissue stem cells in the bone marrow ## Footnote Lymphocytes are white blood cells involved in the specific immune response.
104
Lymphocytes respond to specific **antigens** on invading pathogens. What are antigens?
Molecules, often proteins, located on the surface of cells that trigger a specific immune response ## Footnote Antigens are crucial for the identification of pathogens.
105
What happens when a lymphocyte binds to an antigen?
Leads to repeated lymphocyte division and formation of a clonal population ## Footnote This process results in identical lymphocytes that target the same antigen.
106
Name the **two types of lymphocytes**.
* B lymphocytes * T lymphocytes ## Footnote Each type has distinct roles in the immune response.
107
What do **B lymphocytes** produce against antigens?
Antibodies ## Footnote Antibodies are Y-shaped proteins that bind to specific antigens on pathogens.
108
What is the function of **antibodies**?
Inactivate pathogens by binding to their antigens ## Footnote The antigen-antibody complex can be destroyed by phagocytosis.
109
What is an **allergic reaction**?
A hypersensitive response to antigens on harmless substances ## Footnote B lymphocytes can respond to non-harmful antigens, such as pollen.
110
What do **T lymphocytes** do?
Destroy infected body cells by inducing apoptosis ## Footnote Apoptosis is programmed cell death initiated by T lymphocytes.
111
What is **apoptosis**?
Programmed cell death ## Footnote T lymphocytes induce apoptosis in infected cells to eliminate them.
112
How do T lymphocytes cause cell death?
By releasing proteins that produce self-destructive enzymes in infected cells ## Footnote The remains of the cell are then removed by phagocytosis.
113
114
What do **T lymphocytes** normally distinguish between?
* Self-antigens * Non-self-antigens ## Footnote T lymphocytes can identify the body's own cells versus infected cells.
115
Failure of the regulation of the immune system leads to T lymphocytes responding to _______.
self-antigens ## Footnote This response can cause autoimmune diseases.
116
Some of the cloned B and T lymphocytes survive long-term as _______.
memory cells ## Footnote These memory cells are crucial for a faster immune response upon secondary exposure to the same antigen.
117
During the **secondary response**, what happens to antibody production?
* Antibodies are produced faster * More antibodies are produced than during the primary response * Antibody concentration remains high for longer ## Footnote This rapid response helps destroy invading pathogens before symptoms appear.
118
What virus attacks and destroys **T lymphocytes**?
Human immunodeficiency virus (HIV) ## Footnote HIV reduces T lymphocyte numbers, leading to AIDS.
119
Individuals with **AIDS** have a weakened immune system and are more vulnerable to _______.
opportunistic infections ## Footnote This vulnerability is due to the reduced number of T lymphocytes.
120
What is **immunisation**?
The process by which a person develops immunity to a pathogen ## Footnote Immunity can be developed through vaccination using antigens from infectious pathogens.
121
Antigens used in vaccines can be: (list them)
* Inactivated pathogen toxins * Dead pathogens * Parts of pathogens * Weakened pathogens ## Footnote These antigens help create memory cells for future immunity.
122
What is an **adjuvant** in vaccine production?
A substance that makes the vaccine more effective ## Footnote Adjuvants enhance the immune response to the vaccine.
123
What is **Herd Immunity**?
Occurs when a large percentage of a population are immunised ## Footnote Establishing herd immunity is important in reducing the spread of diseases.
124
How do **non-immune individuals** benefit from herd immunity?
They are protected due to a lower probability of contact with infected individuals ## Footnote This occurs when a significant portion of the population is immunised.
125
What is the **herd immunity threshold**?
The percentage of immune individuals in a population above which a disease no longer persists ## Footnote It depends on the type of disease, effectiveness of the vaccine, and density of the population.
126
What are **mass vaccination programmes** designed to achieve?
Establish herd immunity to a disease ## Footnote They aim to immunise a large portion of the population.
127
What difficulties can arise in establishing herd immunity?
* Poverty in the developing world * Vaccine rejection in the developed world ## Footnote These factors can hinder widespread vaccination efforts.
128
What is **Antigenic Variation**?
Some pathogens can change their antigens ## Footnote This means that memory cells are not effective against them.
129
In which virus does **antigenic variation** occur?
Influenza virus ## Footnote Influenza remains a major public health problem requiring annual vaccinations for at-risk individuals.
130
What is the purpose of **clinical trials** for vaccines and drugs?
To establish their safety and effectiveness before licensing ## Footnote Clinical trials follow rigorous protocols to ensure valid results.
131
What are the key components of the **design of clinical trials**?
* Randomised * Double-blind * Placebo-controlled ## Footnote These protocols help reduce bias and ensure valid comparisons.
132
What does a **double-blind trial** entail?
Neither the subjects nor the researchers know which group subjects are in ## Footnote This prevents biased interpretation of results.
133
What is the role of the **placebo-control group** in clinical trials?
To ensure valid comparisons with the group receiving the vaccine or drug ## Footnote One group receives the actual treatment while the other receives a placebo.
134
Why is **group size** important in clinical trials?
To reduce experimental error and establish statistical significance ## Footnote A large sample size is needed for reliable results.
135
What is compared at the end of a clinical trial?
Results from the two groups ## Footnote The comparison determines statistically significant differences between the groups.
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