Biopsychology AO1 - up to fight or flight Flashcards
1
Q
What is the Nervous System?
A
A specialised network of cells in the human body that is our primary internal communication system
2
Q
What types of signals is the Nervous System made up of?
A
Chemical and Electrical
3
Q
What are the 2 main functions of the Nervous System?
A
1) To collect, process and respond to information in the environment
2) To co-ordinate different organs and cells in the body
4
Q
What are the 2 sub-systems of the Nervous System?
A
The Central Nervous System
The Peripheral Nervous System
5
Q
What does the CNS stand for?
A
Central Nervous System
6
Q
What does the PNS stand for?
A
Peripheral Nervous System
7
Q
What is the CNS made up of?
A
Brain and Spinal cord
8
Q
What is the function of the Brain in the CNS?
A
It is the centre of all conscious awareness
It is divided into 2 hemispheres (Left and Right)
9
Q
What is the function of the Spinal Cord in the CNS?
A
It is an extension of the brain
It passes messages to and from the brain
It connects to the PNS
It is responsible for reflex actions
10
Q
What does the CNS do?
A
Connects nerves to the PNS to pass messages
11
Q
What does the PNS do?
A
Transmits messages to and from the CNS via millions of neurons
12
Q
How many subdivisions does the PNS have?
A
2
13
Q
How many components are in the CNS?
A
2
14
Q
What are the 2 subdivisions of the PNS?
A
The Autonomic Nervous System
The Somatic Nervous System
15
Q
What does the Autonomic Nervous System do?
A
Governs vital functions in the body
e.g. breathing, heart rate, digestion, sexual arousal, stress responses
16
Q
What does the Somatic Nervous System do?
A
Governs muscle movement and receives information from Sensory Receptors
17
Q
How many states can the Autonomic Nervous System be in?
A
2
18
Q
What are the 2 states the ANS can be in?
A
Sympathetic
Parasympathetic
19
Q
What is the ANS’ resting state?
A
Parasympathetic
20
Q
When does the ANS change to a sympathetic state?
A
When adrenaline levels rise (fight or flight)
21
Q
Define Nucleus
A
The control centre of cells containing chromosomal data
22
Q
What does a Dendrite do?
A
Receives nerve impulses (signals) from adjacent neurons
23
Q
What is an Axon?
A
Where electrical signals pass along
24
Q
What does the Myelin Sheath do?
A
Insulates and protects the axon from external influences that might affect the transmission of the nerve impulse
25
What is the Myelin Sheath?
A fatty layer surrounding the Axon
26
What do the nodes of Ranvier do?
Speed up the transmission of the impulse by forcing it to 'jump' across the gaps
27
What do Terminal Buttons do?
Send signals to adjacent cells by communicating across the synaptic gap
28
Name all the parts of a neuron:
Nucleus
Dendrites
Axon
Myelin Sheath
Nodes of Ranvier
Terminal Buttons
29
*How many neurons are in the Human Nervous System?
Around 100Billion
30
*What percentage of neurons are in the brain?
80%
31
What is the purpose of neurons?
To provide the nervous system with a means of communication by transmitting chemical and electrical signals
32
How many types of neuron are there?
3
33
What are the 3 neurons called?
Sensory Neurons
Relay Neurons
Motor Neurons
34
What order do signals pass through the neurons in?
Sensory --> Relay --> Motor
35
What direction do Dendrites carry the signal?
Towards the cell body
36
What direction does the Axon carry the signal?
Away from the cell body
37
What are the segments of Myelin Sheath called?
The Nodes of Ranvier
38
How does Electrical Transmission work?
- When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second
- An action potential occurs
- This creates an electrical impulse that travels down the axon to the end of the neuron
39
Where are Sensory Neurons located?
They are found in clusters called Ganglia in the Peripheral Nervous System
40
Where are Relay Neurons located?
They are in the brain and visual system
41
Where are Motor Neurons located?
In the CNS
Their axons are part of the PNS
42
Where is the Cell Body located on Sensory Neurons?
The Side of the Axon
43
What is the function of Sensory Neurons?
- They sense the activity from the Sensory Receptors in the Peripheral Nervous System
- They carry the nerve impulses from the PNS to the CNS to send their message to the brain
44
What are the features of Sensory Neurons?
Long Dendrites - so they can feel more
Short axons - to send messages quickly
Cell body sits on the side of the axon
45
Where is the Cell Body located on Relay Neurons?
In the Middle of the Neuron (the middle neuron)
46
What is the function of Relay Neurons?
They relay information from the Sensory Neurons to the Motor Neurons
They act as messengers
They also carry messages back from the brain to the Motor Neurons
47
What are the features of Relay Neurons?
Short Dendrites
Short or Long Axons
Cell body in the middle of neuron
48
Where is the Cell Body located on Motor Neurons?
The end of the Cell Body (around cell body)
49
What is the function of Motor Neurons?
They produce a response by transmitting messages to an effector
50
What is an effector?
A muscle or gland - moves or secretes/inhibits hormone to change body's functioning
51
What are the features of Motor Neurons?
Short Dendrites
Long Axons
Cell body at the end of the Axon
52
What is the Endocrine System?
A network of glands throughout the body that manufacture and secrete hormones.
It works with the Nervous System to regulate the physiological processes of the body.
It uses Blood Vessels to deliver hormones from their glands to their target sites.
53
What are hormones?
Chemical Messengers that circle the body in the bloodstream to effect target sites
54
How do hormones travel from their gland to the target site?
Blood Vessels
55
What are target sites?
The desired recipient of a hormone.
They have target cells with receptors for the hormone they want to receive.
56
Is the Endocrine System faster or slower than the Nervous System?
Slower
57
What does the Endocrine System control?
Vital functions in the body through producing and secreting hormones
58
What are the major glands in the Endocrine System?
The Pituitary Gland
The Adrenal Glands - Adrenal Medulla and Adrenal Cortex
Ovaries
Testes
59
Where is the Pituitary Gland situated?
In the Brain
60
What is the function of the Pituitary Gland?
It is the master gland
It controls the release of hormones from all other glands
61
Where are the Adrenal Glands located?
On top of the Kidneys
62
What are the 2 Adrenal Glands?
Adrenal Medulla
Adrenal Cortex
63
What is the outer Adrenal Gland called?
Adrenal Cortex
64
What is the inner Adrenal Gland called?
Adrenal Medulla
65
What is the function of the Adrenal Cortex?
To increase blood pressure and the ability to respond to stress
66
What hormone does the Adrenal Cortex secrete?
Cortisol
67
What hormone does the Adrenal Medulla secrete?
Adrenaline
68
What is the function of the Adrenal Medulla?
To increase heart rate and blood flow for fight or flight
69
Where are the Ovaries situated?
In the Female Reproductive System
70
What do the Ovaries produce?
Eggs
Oestrogen
Progesterone
71
What is the function of the Ovaries?
To secrete oestrogen to create a suitable environment for fertilisation and implantation
72
Where are the Testes situated?
In the Male Reproductive System
73
What do the Testes produce?
Testosterone
74
What are Neural Networks?
The neurons that communicate with each other within a group
75
What is a Synapse?
The gap separating each neuron from its adjacent neuron
76
How are signals transmitted between neurons?
Chemically
77
How are signals transmitted within neurons?
Electrically
78
What are Neurotransmitters?
Chemicals that diffuse across the synapse to the post-synaptic receptors in the next neuron
79
What happens when Neurotransmitters reach the post-synaptic receptor site in the dendrites of the next neuron?
They change from a chemical signal to an electrical impulse to continue their journey
80
Why can direction of synaptic transmission only be one way?
The neurotransmitters are released from pre-synaptic neuron terminals and are received by post-synaptic neurons at matching receptor sites.
The neurotransmitters will fit into a receptor site with its matching molecular structure so they fit like a lock and key.
Each one is different as each neurotransmitter is coded with a specific function.
81
What is Inhibition?
The neurotransmitter will make the receiving neuron more negatively charged, meaning it is less likely to fire
82
What is Excitation?
The neurotransmitter will make the receiving neuron more positively charged, meaning it is more likely to fire
83
What is an example of an Inhibitory Neurotransmitter?
Serotonin
84
What is an example of an Excitatory Neurotransmitter?
Adrenaline
85
What is Summation?
The process that decides whether or not a postsynaptic neuron fires by summing the excitatory and inhibitory influences
86
What is the process of Summation?
Adds all the excitatory and inhibitory influences on the neuron together:
- If the net effect on the postsynaptic neuron is inhibitory, it is less likely to fire
- If the net effect on the postsynaptic neuron is excitatory, it is more likely to fire as the inside of the postsynaptic neuron becomes positively charged momentarily. This electrical impulse allows it to travel down the neuron.
87
At what point is the Action Potential triggered (on the post synaptic neuron)?
If the sum of the excitatory an inhibitory signals at any one time reaches the the threshold
88
What are Neurotransmitters released from?
Synaptic Vesicles
89
What is the process of Synaptic Transmission?
1) A neuron is activated by a stimulus, causing the inside to become positively charged for a split second
2) This causes an action potential to occur, creating an electrical impulse that travels down the axon towards the end of the neuron
3) When the electrical impulse reaches the end of the neuron (the presynaptic terminal), it triggers the release of neurotransmitters from synaptic vesicles
4) The neurotransmitters diffuse across the synaptic gap to its postsynaptic receptor site on the dendrites of the next neuron
5) The neurotransmitters will either have an excitatory or inhibitory effect on the neighbouring neuron
6) The postsynaptic neuron will decide whether it fires or not based on the process of Summation
90
Which 2 systems work together during Fight or Flight?
The Endocrine System and the Autonomic Nervous System
91
What is the process of Fight or Flight?
1) A stressor is perceived
2) The hypothalamus in the brain activates the pituitary gland, which triggers activity in the sympathetic branch of the Autonomic Nervous System
3) The ANS changes from its normal parasympathetic resting state, to the physiologically aroused sympathetic state
4) The Sympathetic Nervous System sends a message to the Adrenal Medulla
5) The adrenal medulla releases the hormone adrenaline
6) Adrenaline circulates through the blood stream and causes changes that allows someone to either fight or flight
7) The stressor passes
8) The parasympathetic branch of the ANS reverses the changes made to bring the body back to its normal resting state
92
How long does the process of fight or flight take?
It is immediate and automatic
93
Where is the Hypothalamus?
In the brain
94
What does the Hypothalamus activate in Fight or Flight?
The Pituitary Gland
95
What does the Pituitary Gland do in Fight or Flight?
It triggers activity in the Sympathetic branch of the ANS
96
Which nervous system is involved in fight or flight?
The Autonomic Nervous System
97
What gland does the sympathetic nervous system signal to?
The Adrenal Medulla
98
What hormone is secreted in Fight or Flight?
Adrenaline
99
What are some physiological changes that happen when the ANS goes from parasympathetic to sympathetic?
Increased heart rate - increase blood flow to organs and movement of adrenaline
Increased breathing rate - increase oxygen intake
Pupil Dilation - Increase light entry into the eye and enhance vision
Sweat production - Regulate temperature
Reduction of non-essential productions (salivation, digestion, urination) - to increase energy of other functions
100
What are some physiological changes that happen when the ANS goes from sympathetic to parasympathetic?
Decreased heart rate
Decreased breathing rate
Constricts Pupils
Stimulates Digestion
Stimulates Salivation
Relaxes rectum
